View Full Version : Aluminum Casting experience anyone have any?

05-05-2003, 08:43 AM
I read all the books available and I have built myself a casting furnace. Problem is I built it a year ago and just now getting to using it. I made it for charcoal and a blower, but now am going to use propane w/out blower. I have a PID controller I got for the powercoat oven, a thermocouple and a solonoid. I have a gas valve w.pilot but the flow is not high enough btu, so it has to be manned and monitored.
I made the furnace with a 5 gallon bucket for form, and a hot water heater outside, 2200 degree refractory in the middle, outside that is a 55 gallon barrel with cer-wool
inside and around the water heater. (double insulated for long term heats)
I will have to lift the pot out real high. Has anyone ever put a plug valve in the bottom of a iron pot? I am thinking of it.
How should I do it? will it swell and stick? should it be tapered to drop farther into the hole to seal when expanded? weighted?
I am scared lifting and pouring the aluminum by myself. Standing behind a piece of tin, pulling a rod plug does not worry me as much. I read the post on aluminum blowing up on contact with water, and have built a tin-steel framed building to put it all in now. (thanks HSM)
The thing I am wanting to do is cast metal in dies, pop them out into a bucket and cast some more.

My real QUESTION is..
IS THERE ANY DIE MAKERS here? What kind of metal do I need to make dies? the thickness? do they have to be preheated? cooled? can they be automated with a sprue cutter? The books don't touch any of this.

05-05-2003, 10:44 AM
The Tool Engineer's Handbook specifies a hardened steel (416 - 460 bhn) with a "composition of 5% chrome, .9% silicon, 1%molybdenum, and .35% carbon with tungsten and vandium as optional constituents". They state that too soft a steel will allow the aluminum being cast to solder itself to the die. I did a small amount of work for a die cast company about 10 years ago, seems to me the dies had galleys in them for coolant.

05-05-2003, 11:11 AM
Casting aluminum with die requires high pressure while the aluminum is still molten. I think this is beyond the means of most HSM.


05-05-2003, 12:57 PM
X.. Thrud said my D2 steel was used for dies. I have about a 6 foot bar.. Problem is my portaband just squeals on it and barely will scratch it. I know my mill ain't gonna like it either.

Rotate.. check out the die casting site on "A lot of Brass" they have a die casting pump made from turned fitted steel. (piston and cylinder) You got me thinking.. maybe the valve in the plug can be fitted too? a pump-valve with tapered top to seal off. I have not made the pot yet. I do have a piece of 8 inch pipe for it. Lift the plug fill the cylinder, allow the die to partially fill, then press the plug-piston and compress the molten aluminum?

We built a resin casting setup at Dupont to make the pnenolic pcb used in satellite pcbs. Every time they used the system it would harden in the dowtherm heated pipes. Dissassemble the whole system to unstop.. kinda scary, with aluminum? I bet them pcb's cost a bunch thou..

05-05-2003, 01:07 PM
There are spin cast machines that are not expensive out there.. Might look at how it is being done by them. Basically using the rotation of the table to get the pressure. I have seen it used for pot metal. Don't know about AL and how you would do it. Might be worth some thought.


05-05-2003, 01:10 PM
<font face="Verdana, Arial" size="2">Originally posted by ibewgypsie:
[B]X.. Thrud said my D2 steel was used for dies. I have about a 6 foot bar.. Problem is my portaband just squeals on it and barely will scratch it. I know my mill ain't gonna like it either.

I machined quite a bit of D-2 when I had a gig for about ten years making extrusion dies for the wire and cable industry. Also used a lot of Inconel 718.
Anyway, D-2 has a tendency to work harden in front of a dull cutter, this is compounded by the fact that it tends to gall on it's own chips. With sharp tooling and good chip evacuation, It's really not that bad to work with. I had pretty good luck using the old trichlorothane based "Tapfree" on it, but that's next to impossible to get any more (I've got a gallon stashed, I use it sparingly). Are you using a bi-metal blade in your saw?

05-05-2003, 03:05 PM
Well the weed burner tip, PID controller, opto-22 relay, asco solonoid and two hydraulic needle valves (one for burner, one for pilot) work great together. If it ever gets below zero in my shop again I know how I can heat it.
Man.. I moved the controller down to 80 degrees and zoom the metal building was that hot. My casting furnace is outside and wet at the moment (still working on the tin casting building), so redhot furnace is out of the question.
I had my cutting regulator on it,It runs best at 15 pounds, has about a 18" blue flame. Throttle down (as low as it can go) is about a 8-10 inch flame with 3-4 inch yellow tips. I tried moving the pressure up and down but it needs a smaller orifice I think. #57 drill currently.
I can post pictures as soon as the weather co-operates.

X.. glad to hear about the D2.. I think this piece has been tempered. Maybe first thing to do is heat it up red and let it cool with the furnace slow. I have to temper the refractory anyways.

05-05-2003, 03:06 PM

Looks like a molten aluminum squirt gun. Be very careful.


05-05-2003, 03:27 PM
yeah.. I want to stand behind something. The plug-piston will be inside at the bottom of the pot, no one around the discharge. I am still scratching my head and drawing that part. large mideval shield with eye hole? You know I got to metalflake it if I do.. ha ha.
I see something (in my head) dripping like a bad faucet.. drip drip drip.. molten aluminum. Ain't that a bad thought.. get ready to pour and its all gone.
I may build a couple of smaller crucibles to pour too..
I just think the 8dia x 16hi pot will be too much (too dangerous) for me by myself.
these guys in the books paint a pretty concept picture, but.. a guy could really get hurt. Yeah. I still got all my fingers too.
That's Why I like to ask questions.

(there are people already bringing me parts to reproduce and I ain't got a clue yet) I got the casting sand mixed thou.

05-05-2003, 04:18 PM
Hi gypsie.As for the valve,lead pots for bullet and sinker molding have a pintle valve on the bottom so I don't see any reason you couldn't make one work for aluminum.The one on my pot has a taper and the wieght of the rod holds it closed with an ocasional drip or two.If you made the pot tall and skinny it would increase "head pressure" to give more pressure at the nozzle.Production bullet casters use a spin mould of some sort but I haven't seen one to tell you if it is a rotating mould that drops the cast bullet and resets for the next pour or if it is to increase pressure while pouring(probably the former).Good luck and be careful.i've had a lead pot erupt from dampness before and it aint pretty.We were really lucky we didn't get burned.I still don't remember how we didn't.

05-05-2003, 07:12 PM
Hi Ibewgypsy,
I understand your trepidation, but before you go much further with new designs you really should melt some small amounts of metal to get a feel for it and learn the peculiarities about working with the molten aluminum. Sounds like you've put a lot of work in already and should be about there. I'm no die casting expert but I have poured ingots into metal molds. I think your success with this would depend entirely on the shapes you are casting. I think the shrinkage of the aluminum is about 7% so if your die has the appropriate draft angles it will pop itself out of the mold. If the mold is cool when you pour the metal, I think there will be little adhesion to the die but your surface finish will probably be more crystalline or mat flash finish. The difference in the coefficient of expansion and contraction will help unless your design "traps" your part in the mold. Still if you are new to it probably sand casting and lost foam casting would be good practice.
A couple of thoughts for you. You really should have the ability to adjust an air blower as well as the amount of gas you are burning. You can produce a lot of heat but you don't want to see any yellow flames and you don't want to see any flames coming out of the vent hole because you want it all burned inside. I'm not sure the bottom-pour method is going to be satisfactory because the dross is both on the top where you can skim it off, and the bottom because it sinks. Also once you unplug your crucible, can you stop the pour or does it all go down the drain? I've seen some steel pipe crucibles that look pretty good for aluminum. I use cast iron pots and I've done pours up to about a quart of metal. I should have used one of the available ceramic coatings because the wear and tear on cast iron is surprising. I wear both goggles and face shield and smock and welding gloves. I'm thinking of fashioning some sheet metal shoe covers. The thought of unlacing a molten boot isn't appealing. Your forge is probably cool to the touch in operation with your design, but having to lift the crucible very high seems like a problem. If you could hoist and trolley the crucible it might work. Otherwise it is nice to have it at a low work height. You may want to partially bury your forge to fix that. Having a comfortable and secure tool to handle the crucible is "crucial." I wouldn’t want to lift the crucible myself if it were very heavy and I don’t want it over waist high. Actually the closer you keep it to the ground the safer and less chance of splashing everywhere if you spill. I want the mold within a few steps so there isn’t much chance of tripping. I saw a good pipe crucible with simple “J” slots cut in the rim where a simple wire handle is inserted. Another wire tool is used to tip it for pouring. Here is a picture of a way that I don’t like, although I did like the design of his electric forge his methods are dangerous: http://www.dansworkshop.com/Aluminum%20Foundry.shtml

[This message has been edited by SJorgensen (edited 05-05-2003).]

05-05-2003, 07:29 PM
I have only cast in sand using a crucible. Always had two people to pour. It is not a good idea to be alone when casting.

Have never seen or heard of a tap hole being plugged on the inside of a furnace for molten aluminum. The plugs that we used in the furnaces were on the outside of the furnace. They were tappered and counterweighted to keep them closed. They were made of a casting and a soft refractory cone was placed over the tappered cone producing a good seal in the tap hole.

Aluminum shrinks a good bit when it cools. The molds will have to be preheated. Don't know what you are going to cast but getting any kind of great detail on an aluminum casting without pressure or vacuum is going to be tough to do.

Good luck and don't get burned.


05-05-2003, 07:38 PM
SJ.. thanks.. I have done silver casting via electromelt, lost wax casting and sand with purchased casting sand. I had about a 50 percent success rate with silver. Not real good but the successes were great.

I made my own sand this time, I hunted high and low for bentonite. I found it in kitty litter, the cheap kind. And it smells good.

I am engineering a valve for the bottom of the pot, one you can turn on and off. A fitted cylinder you can force down to push molten aluminum out under pressure. I am still in the thinking mode on this.

"a submerged casting die?"

I made a full length apron out of leather also. I hope I never need it's protection, but plan on wearing it. Also.. a green welding jacket. Also.. the shield is a ideal I have not gave up on.

Working (electrician) at wheland foundry was educational. YOU DON'T want molten metal around concrete, it'll jump 20 feet into the air and come back down in a shower. (guy on website was pouring on concrete)

Thanks for the help. It's all new to me.

05-05-2003, 07:44 PM
<font face="Verdana, Arial" size="2">Originally posted by ibewgypsie:
[B] YOU DON'T want molten metal around concrete, it'll jump 20 feet into the air and come back down in a shower(B]</font>
That kind of sounds like fun actually. Jeez, I think I need more excitement in my life or something! http://bbs.homeshopmachinist.net//wink.gif

[This message has been edited by x39 (edited 05-05-2003).]

Dave Opincarne
05-05-2003, 07:51 PM
Not a die maker but I am a patternmaker (not journey level yet though. I'd be more concerned about a plug failure than spilling a large crucible as long as proper hoisting or lifting is used. As others have said I don't think you'll get acceptible results pouring into an open die. You need risers to get decent pressure and metal reserve. Since it sounds like you're relativly new to this I STRONGLY recomend experimenting with sand molds first. It's a lot easier to change the rigging on a pattern than on a die and I can tell you that everything doesn't go as planed the first time a pattern is cast even for people with years of experience. Patternmakers don't even try to figure it out, we depend on the foundry men to tell us how they want the pattern rigged and every foundry has his own opinion. For the sake of your own sanity cast smaller patterns in sand first. Also consider a hoist rather than a plug.


05-05-2003, 10:46 PM
A little knowledge is a dangerous thing and in the case of foundry work it can be deadly. I recommend that you go to a foundry that is making aluminum castings and tell them you want to have them cast the parts and then ask them a lot of questions about how they do it. You can very likely get a tour of the operation. You should read up on foundry operations safety. Pouring sand castings of any size is pretty dangerous and you will see that the experienced people work in pairs and have a third party watching them. Splash some liquid metal on you and you will change the rest of your life if you have one. Great fun to make castings, fascinating but it is a lot more dangerous than working in a machine shop. Die casting is very capital intensive and doesn't make sense unless you are making a very large quantity of the same part. The rough break even point for choosing a casting over a machined hog out is about 20 parts. Definitely start with a small sand casting to get some experience. Press your finger onto a red hot stove burner to get an idea of what a relatively cool splash might feel like.

05-05-2003, 11:01 PM
Unless you want those tattoos to be damaged, wleding gear WILL NOT PROTECT YOU WHILE CASTING!

Get the proper heat and flameproof gear - you do not need to make your litle girl an orphan! Dead serious bro!

Casting lead is dangerous, but as you go up in melting point (*C) things get hairy fast. Make sure your casting area has several inches of dry sand covering the floor and have a spotter with a phone nearby (20-30' away).

05-05-2003, 11:48 PM
Been there done that,I can tell you that I made the same expensive mistakes on furnace building,you don't need anything special for aluminum,I built my new furnace out of a big truck brake drum and some fibrofrax wool,I stood it up one end and positioned the burner straight up the pilot hole in the drum,put some s/s peggs up from the bottom to support the s/s pipe crucible about three inches off the bottom and about five inches off the burner,I supply wind to mine with a nozzle hooked up to my shop air line with the reg turned down to 15psi.The top of the furnace is a piece of s/s plate cut out in a ring about an inch larger in dia. than the melting pot.When I get ready to pour I lift off the lid with a pair of tongs and am free to lift the pot out.The pot I use is about4gallons in capacity and is .315"thick it has a lifting ring right in the center welded stationary,it is heavy so I built a counter balance to hook it out and have a square peg to slip a t-handle over to pour,I also have my moulds set up on a section of roller table so I only have to move the pot a total of a few feet.Some things to thing about when casting aluminum is #1don't go straight from scrap to a casting you will be disapointed,go to the extra trouble of making ingots first,then re-melt for your castings#2make sure you wieght the topps of large moulds down with wieghts,molten aluminum will float the tops of some moulds and spill the pour on the floor#2green sand sucks!use oil bonded sand much easier,doesn't soakup humidity#3moulds that are too wet are dangerous tend to spit metal back at you(Thrud's right you DO NEED PROTECTION)Once saw a black floor hand go to the hospital with a brass plate on his back from a mould that gizered,if he had had a leather jacket on his back he might have got burnt but not near as bad#4heat radiation is just as bad as metal#5Take your time and don't be tempted to pour before you are setup for the task,and take your time during the pour it won't cool as fast as you think#6don't even try anything less than1500f for a casting just won't work#7don't mistake mag. for aluminum!#8visit Ray-Vin's website really cool lots of good ideas.#8don't skim dross,use a bottom pour laddle you will get much cleaner castings,as for the moulds I cast some buffer flanges in a steel mould I made out of pipe and hot rolled plate I made it tapered at about 6* and sandblasted and beaded it smooth,I do pre heat the mould first bout 800f by holding over furnace vent.

05-06-2003, 06:47 AM
Relax guys.. I am the largest worry wart on this site. I plan on using remotes for everything.

Hard to get burned several feet away, except for geysers or splashes or explosions. That is the reason I was suggesting a full length tin shield to hide behind to watch from. Kinda like a oil rig firefighter.

Sand is a good ideal thrud, I planned on that. Along with other saftey devices. I am amazed to see people doing the things they are on the metal pouring web sites. I am more nervous than that.

What I am looking for is a money making scheme of parts reproduction. One-offs is killing me.

I have thought of making a press, pressing sand and setting up the gantry table to carve it into a 3d form (I got one in pieces). Imagine that, no tool wear hardly. Just a triangle rotary with vacuum.
What a way to prototype, and once the part-ie the software, is the way I want it, a santa claus machine via permenant die.

Weird, lots of good info there. I tried casting aluminum at higher temps, it looked like air-rated cool whip. I must have boiled it. At that time I decided I wanted temperature control via pid. One friend of mine used to cast brass off a old blacksmith forge, pretty much the same. I want control over all the lil details. I plan on a valving arrangement on my iron pot to remote pour.
I just ordered the crucible book from OHOJIM on ebay.. That man has made about 1200 off me I think..

Don Warner
05-06-2003, 09:51 AM
If you can't afford die costs for die casting
and the runs a are small, there is a simple commercial process of using CFS or cast iron
as cast for molds and gravity feed to make Al or zinc castings in a simple air cylinder closed press. Three important things to remember use plenty of draft, preheat the mold 400/500 deg F and use a die casting mold release agent each time.


Alistair Hosie
05-06-2003, 11:04 AM
Ibewgypsy I have done many many castings using the lost wax process mostly gold and silver etc, but never used sand as a mould material. If you are making a one of item there is no need for a two part mould such as normally used for casting with sand as the investment material can be simply broken away when the casting is cold.I have also seen aluminum being cast with a one part mould using polystyrene and casting it into a cold mould,at room temperature. The polystyrene disappears from view when cast but in a one part mould.when it comes to investment material use something much finer than sand for better detail why not either try some plaster of paris mixed with some pumice powder , this if done correctly should not crack when heated greatly .it will be trial and error till you get it right.Or I would recommend contacting your local dental suppliers company they will keep you right when casting as to which materials for a mould are best.The secret with all castings are never to attempt to cast uphill, as metal when poured does not like to run back against gravity even when centrifugally cast , avoid this , try and make sure in other words that you always have a sprue at the highest point feeding any areas from top to bottom of the mould.And if possible make a small piece a little from the bottom of the sprue a little thicker just above the point of contact ( a small ball shape thicker than the sprue itself) this acts as a small reservoir so as to avoid a short casting.This usually happens when the metal hits the mould's coldest parts and even if it casts perfectly will tend to pull back a bit as it shrinks this little reserviour takes care of this for you by allowing a little more metal just to flow back as it tries to shrink. If you want I could give you more info also why not make a casting frame from tubular metal and sit the crucible into it when molten and stand well back lifting a lever to cast for you that way you are well out of harms way when it is being cast in case of accidental spillage. Try a few dummy runs when cold to get the hang of it taking the cold crucible from the furnace and so on , a man of your skill and intelligence should be able to knock up such a device quite easily.And as said before never work alone. If I can help you further let me know regards your pal . Alistair

05-06-2003, 11:26 AM
Alistair. yeah good advice thanks.
Got a lil tornado action here in the south.

I am raising the pot-furnace up, putting a platform ladder up around the top level to load scrap with tongs into cold pot, putting a table under it for the valve to exit directly over my sandbox, mold frames, and future die automation. The problem pouring before was to get a consistient pour directly into sprue and tilting the pot. This will come straight down into sprue, no juggling or major aiming.
Since I won't be directly in contact, mold monitoring and valve control is via truck mirror mounted on frame.
I feel that to be pretty safe. gonna put a sheet metal wall around 3 sides, so any major problems of splash or geysering (wet sand) will be contained.
All this is overkill I am sure, but why put hands on when you don't have to? Loading sand frames will still be manual at the moment. Welding gloves and flame retardant saftey gear still required to move and load sand molds.
If I just had a automated conveyor. I could drink beer and cast.
Looking around, I found the easiest sand frames are made out of metal wall stud materiel. Turn the channel in to help hold the sand. Locking pins to align I am still looking at.

05-06-2003, 01:33 PM
Sounds like you've done a lot of research, thinking and building. And that you have a high regard for safety. You also have some experience so what you end up with will probably be workable. Don't be surprised though when you learn alot in the first prototype that you'll wish you didn't do; and I hope you share this with all of us. Don't end up getting burned when trying to free up a stuck plug or clogged passageway as could happen as you get more comfortable with your equipment. All the gizmos, and elaborate devices intended for safety can often end up being dangerous if they get in the way or don't work as expected. Ladders or step stools around it sounds like trouble to me. The KISS principle should apply to your first forges. A nice clear work area out on dry dirt has a lot to be desired. What about making some plaster molds for making dozens of wax models. The models are then put together in a tree formation with wax sprues and then the whole thing is dipped repeatedly in the slip plaster until built up. I know you've read of this. I like the ability to touch up the little wax models and the great detail possible. It's not quite the Willy Wonka type factory that you'de like but just another approach. Can you give a little hint on what you are making? Are they clutch levers or foot pegs?

05-06-2003, 09:20 PM
&lt;br http://www.alltel.net/~decofer/301.jpg

Someone tell me why the Red Dantes inferno is green in the digital cam please.

First firing.. It runs better on 3-4 pounds gas then 20, it never did warm up at 20 psi, but at 3-4 it got about a degree a second till 1000 then barely clicked along. I ran the lil tank out of fuel. Looks like it will cost about 10-15 dollars per heat (two quarts aluminum) tomorrow I am working on the pot valve. I built the pot today during the tornados.


[This message has been edited by ibewgypsie (edited 05-06-2003).]

05-06-2003, 11:22 PM
David: ALL the below is from memory- so check my figures. I suspect you are putting too much air into the system. You are heating too much air and blowing it out the exhaust system.

A gallon of propane provides about 2,500 BTU. at room temp the propane gives 36 plus cubic feet of gas. Check a set of tables and I think you will see that aluminum will reach melting temp with a few btu per pound (less than 1000) the heat of transformation from solid to liquid will take most of your btu. I am shakey on this but i think radiated heat loss varies as the 4th power, so you at least need a reflector to keep the radiated heat in. The conducted heat (to air) is linear but if the air can move it will conduct your heat away quickly. I guess this should be called convection heat transfer rather than conducted. Even a little insulation will reduce the heat losses a lot and it sounds like you have insulated well so i suspect excess air flow even if you have no blower.

And I have no idea why the green glow . Maybe a digital camera is useful as a non touching pyrometer? try taking pic at differnt temps and patent it!. We ain't gonna admit that you just put it in public domain.
Its looking good- hope you work the bugs out.

05-07-2003, 02:01 AM
That forge looks pretty good but I agree with Doc, your forge should be a lot more economical once you get the fuel to air ratio adjusted. I have a regular sized propane can and I can melt a quart in about 10 or 15 minutes and I think it uses about as much gas as cooking 6 hamburgers (just a guess) If the volume of gas you are talking about was burned efficiently it would sound like a rocket engine wouldn't it? I use a hair dryer with a dimmer switch to adjust the air blowing into the same tube that the gas orifice probe is inserted. Actually I used a weed burner from Harbor Freight and kept the flame shield on the end too. It has worked very well and the adjustment knob for the volume of gas has worked very well. I am nowhere near the gas rate that pulling the lever gives you, but I can get a pretty good roar when I do. Why did the pictures appear green? Good question. Is it overloaded like pointing it at the sun? No permanent damage like would happen with vidicon tubes?
Once in a while I want to add a picture to my post. How is it done? My screen say's "HTML is OFF" how to turn it on?
Did you get a lot of steam out of your refractory? That first firing should have been low and slow and long, to dry and cure that refractory and hope it doesn't crack (but it always does.)

05-07-2003, 08:02 AM
Doc, SJ..
I was foolishly blowing my gas into the furnace thinking it would burn. I have a Weed burner as a burner,(23.99)(since my burner didn't work) tacked into the lower port. I was running 28-30 pounds pressure and it did sound like a jet. The air intakes are designed for 3-4 psi (I think normal) and I had no way of enlarging them.
Also, I have a lot of mass and accellerating it to 1250 is like drag racing a diesel with trailer. So smaller is better for smaller jobs.
I also have one made with a stock pot and electric elements (somewhere)
I had the 55 gallon drum off with the cerwool. Actually it did get a lil bit too hot to touch on the case, barely. So the extra insulation is overkill and not needed.
MY lid sucks, I could see such a crack in the seal I had to block the exhaust port.
Doing things over, I would put the thermocouple in the lid, put the exhaust in the lid and a throttle, put the burner in a pipe and bore concentric holes, bend a sheet metal throttle and bore similar holes and rotate it to throttle air to match propane to a blue flame, then throttle top port as small as flame stays blue.

Please let me help you post pictures.. You first have to ftp them to your webspace with a program such as FTP voyager.
Then This site requires a delimiter.. it took me 30 minutes to figure it out. minus quotation marks. ""http://www.yourserver.com/yourpicture.jpg""
there is a help file at the top of these pages called faq.. it saved my butt.. I post pictures all the time for ebay so I have a decent ftp program. everything must be exactly as needed, capital letters are not the same as small one.. stinking html..
perhaps this pays for your excellent advice a little..
Thanks guys.

05-07-2003, 12:22 PM
Casting frames made via internet ideal, first pic is a standard metal wall stud, cut at measurements, second is same stud bent at cuts ready to mig. I love them wall studs, a nibbler makes short work of them.
Thunderstorm moving in, I had to desert my metal shop for the nice dry house. Some kind of weather moving through the south, I didn't plan on it. If I get to the valve I will post it later, I got the pot made, not the plug valve.

[This message has been edited by ibewgypsie (edited 05-07-2003).]

05-07-2003, 02:08 PM
Heck with your crummy furnace!!!! Tell us about the car! http://bbs.homeshopmachinist.net//smile.gif

05-07-2003, 02:47 PM
doc.. you talking about the 54 ford w/5.0 AOD or the studebaker champion w/mustang suspension? They both didn't sell on ebay. I am going to cast some 59 cadillac lens adapters for the 54. cars are another hobby.

Crummy furnace? I got about 10 hours in that furnace now. Carrol says it looks like granny clampet's still. I need to hide it back in the 55 gal barrel. (no it is not pretty)

A friend in Lousiana has a factory one, with real fire stick and a Sand mueller, I am trying to get together with him. My poor engineered model may get replaced.

SJ, I got several things in mind, from forward controls to handlebar sets, something to make the cnc earn it's keep. I want a shaper-power hammer also and it might be a good place to start learning how to make it work like I want. They say aluminum wheels are the best alloy. (356) I been reading you can not get high quality castings with out removing the gas and blending the alloys. more confusion.
I really appreciate all the help and experience.

[This message has been edited by ibewgypsie (edited 05-07-2003).]

05-07-2003, 03:02 PM
I wouldn't give up on it yet. Get your air blower set up and retry. You'll get to high temperatures pretty quick. Even if you redesign your next one you'll know more after you solve this problem on this one.

Dave Opincarne
05-07-2003, 07:55 PM
I suspect the green glow is probably due to the extream overexposure of that area of the image. Since the green is probably the lowest frequency in that area of the image or the green "layer" of the CCD is the least sensative to overexposure it is still represented in the image.


05-07-2003, 11:10 PM
What kind of scrap are you using?I got lots of micro bubbles on some I had that was just the slightest bit oily.I had terrible results with with the first batch I tried to cast,I went right from scrap to a pour and what a disaster!You can I found out make a good alloy of 92-8 with measured amounts of scrap alum. and copper,I got my aluminum ready and and melted and the preheated and carfully droped in the copper,it was neat the copper disoved and flowed into the aluminum,one thing to remember is don't stir anything!ever!On alum. all it does is add bubbles and make dross.I like the bottom pour laddles I made I don't even skim once I just melt ,doctor the alloy and pour,as soon as the laddle is empty I flip it over and knock it on a sand filled drum top to clean out the dross while its hot.I first got enterrested in alum. casting because I like to use aluminum in my homw projects ,but always need a big chunck that I cant seem to find.The only other piece of advice I can give you is be selective with your scrap,I use pistons,bell housings,and big truck suspension parts.I especially like diesil pistons.I stay away from beer cans unless I need pure aluminum for alloy purposes,plus it takes a truck load for a three pound ingot.

05-08-2003, 12:17 AM
I plan on using cracked aluminum car wheels. That is what I heard was the best. Cutting them up to fit into the pot I have not figured out yet. I got a buddy with a scrapyard. I was told the same thing.. don't stir.. My pot don't empty directly from the bottom, so the crap hopefully will accumulate on top and the bottom. I do plan on probing it with a steel rod.
I am talking about going to Iowa? to get a real smelter and sand mueller. Probably this weekend. A college sold one at auction to my friend there.
Mine is not done, I got too much work in it already to scrap it. I do plan on adding a gasket around the lid. If the new one is that much better I will ebay it later. as I did the first powdercoat ovens.
Too much rain here to do anything outside.
Too much talking here and not enough melting, with the rain and all. It never fails, start a house addition, the monsoons come.

[This message has been edited by ibewgypsie (edited 05-08-2003).]

05-08-2003, 02:00 PM
I have my doubts about your "throttle" air control. Throttles work only where your intake is below atmospheric pressure. Your forge has no "intake" stroke to get air into it. Also I don't know what you meant about the intake ports being designed to work at 3-4 psi. You really don't need to worry about pressures on this, just volume and you don't need much of that either. You just need something to get a nice little breeze going into that tube. The exhaust hole will have about this volume coming out and it shouldn't blow any hats off or singed any hair!) I think you'll find you quickly get the temperatures you need to melt whatever you want up to the refractory limitations. My forge is just an old Webber BBQ on it's original stand it had a tube going into the center of the bottom and so I lined the BBQ with 3" of refractory and I cut about a 4" hole in the top and bottom and put the weed burner in the tube coming into the bottom (using a 90 elbow so that the weed burner handle and valve is out the side of the tube. I taped up any extra holes on the tube and rigged up a blower to the bottom (just used dryer flex tube and hair dryer.) I cast the refractory so that it only contacts the outer case at points so the shell never gets very hot. It still looks pretty much like a BBQ and the duct tape hasn’t even burned or turned brown. Sometimes when you lift the lid its like looking into the sun. The infrared radiation is pretty high. You have to let it come down a notch before you skim. I like it and it is pretty fun. It should compliment your mill and let you cast some good billets for your projects. I’m going to have to recast my refractory soon and I think I’ll cast in a special overlapping brick style so cracks won’t happen, and if it does I’ll just cast a brick.
Did you take pictures of the innards of your CNC before you gutted it? I’m going to take a look at that BP mill tomorrow. Might borrow a camera.

05-08-2003, 03:02 PM

yeah.. simple, My burner has no blower yet. I have one put back, but I will have to build a duct. Throttle the air, I have worked under houses on gas heat, they have a mixture plate to control air intake into the burner. You can throttle the air, till you get a pretty blue flame. That is what I was hoping for. The holes in my weed burner is set up for 3-4 psi at normal air intake, adding a blower could increase the gas able to be burned in the tube.
Going to be a day of two before I get back to this project. I am going on a road trip to get a sand mueller and a real furnace with blower. A real adventure since I am taking the girlfriend and she wants to sight see.

I got pictures of all the parts I didn't need in the mill, I sold them all on ebay to recoup my upgrade. Basically I kept the capacitors on the drives, the terminal strips, the motor overloads, the end limits, all the wiring outside the boxes to the motors and pulled the rest. I removed over a thousand pounds of electrical parts. I put in a new intel computer and it all works great. To do it over, I would sell the parts individually, not as a group. It would bring more money that way. Sell even the power transistors, they are 35 dollars each. I didn't.. they are in a box somewhere here. Just them alone might pay for the gecko drives.

[This message has been edited by ibewgypsie (edited 05-08-2003).]

05-09-2003, 02:42 AM
As far as reducing those wheels to a size that will fit in your furnace, you can build a good sized campfire and put a wheel in. Let it heat up till it's hot short and yank it out with channellocks and bash it with a hammer. It'll crumble pretty easily.
You wouldn't live up in Blairsville, would you? I sure am glad I don't live in Newnan, after the pounding they got last night. We got a whole helluva lotta rain but nothing more serious than a buncha rumbling thunder. The yard's soggy as hell now. "Soft like sh*t on a hot summer night." (Sorry, Dice) Darned spiders seem to have found a way into my shop. Li'l bastages, always want in out of the weather. Guess I need to do some more caulking and bug-bombing(pesticide fogger, not an explosive device.) I don't go anywhere near explosives, damned things are too dangerous. Darn shop equipment is more dangerous than I'd like, sometimes.


05-11-2003, 10:03 PM
I just got home from Iowa with a furnace capable of melting iron, two two-man pouring shanks, a sand mueller and some red eyes from driving too many miles. I am tickled to death.
Gary, thanks, I plan on taking the home-made items out of the equations.

05-12-2003, 08:44 PM
When you get it going I'd love to see how the Pro's do it. Sounds a lot less risky but still plenty fun. Will it still burn green like your last one?

05-12-2003, 09:55 PM
Pro? who you talking about? HUH? ha ha.. yeah. okay.. give me fifteen or twenty years.. I moved the propane over to the new furnace, it keeps blowing out. Looks like some tinker time.

05-13-2003, 03:35 AM
That ratio of gas to air is the same, so once you get that worked out the thing will fire up. If you pump more gas and air you are going to get those high temperatures pretty quickly. You are close to a breakthrough.

05-13-2003, 04:09 AM
Spence, I was a engineer at a carpet mill for a while. (4 years)

During my time there I was over some PLC related robotics and automated equipment.
A small company was installing a gas air make up heater there to correct negative pressure and heat inside the building.
I was working on a machine, and they were gassing up and powering up the unit. One small wiring mistake and the 1 1/2 line was filling the roof of the building up, then the fool hit the ignitor which was also misswired direct to the button.
A forty foot ball of flame came out of the heater, I got my tools and went home for the day. I had a serious talk with the engineer over the job and the company owner on my way out. I explained the first thing I learned about gas trains and honeywell flamepaks was phone the wires before hook up.

It was not that drastic today with the new furnace, but I am paying attention. ha ha.. POOF has a new meaning. I still have the hair on my face, but cause I am careful and I am a worry wart.
I think I might look over the gas valve requiring a flame sensing thermocouple I have.
My current problem is too much air from fan. It has a gate type valve on the discharge side. I think I will make a shutter type valve for the intake. Too mucho, all I needed was a hair drier and I got a turbo-prop plane.. ha ha..

I am still tinkering with the dies. I have two items I need lots of reproduction on. I read and reread the plastic injector post. INteresting.

05-13-2003, 04:34 AM
I will read and re-read what you said. but ultimately it will come down to the basic fundimentals about things like fuel and air and BTU's. I don't think that I have steared you wrong and I think you that you will get the temperatures you are after.

05-13-2003, 12:30 PM
Yep, Spence it is tinker time. Adjustment of air and gas pressure. that is all.. One thing I noticed with the professional smelter.. the flame goes around and around and around like a whirlpool. I hope it keeps doing that when I reduce the air.

05-14-2003, 01:29 PM
Yea, I don't think you need a lot of air. Remember that in the past they used billows.
When you get a chance I'd love to see what you've got. Did you get some crucibles too?

05-14-2003, 02:35 PM
Spence.. I just got a book from OHOJIM on making cruicibles. Author Vince Gingery. Not got to read much but it looks interesting. It says it is not hard to do it..
I am still trying to figure out how to get around the two man pouring shanks.. I can melt the aluminum, but can I pour the aluminum? I only have one friend I trust that much. It is a two way street also doing that.
There is a hole in the bottom of the smelter with a cast iron round plate on it? perhaps? My iron pot can be cut down..

I am still working on the house, except now it is raining again.. Climbing a extension ladder last night with a full sheets of 3/4 plywood (end gables), and nail gun trailing a hose.. Made me feel ALIVE.. ha ha..

05-14-2003, 02:42 PM
How do you know when the molten aluminum is hot enought to pour? Most thermocouples are not rated for foundry work. I guess the pros use optical pyrometer, but that can be expensive.


05-14-2003, 03:23 PM
the 1400 degrees is within a type J thermocouple range, (upper), Type K is much better, I don't have the information in front of me tho. I used to write linearzation subroutines for my software.
Any 0-50 mv meter can be used with thermocouples, but the read out will not be consistient through the range. ON the plastic injector post, he found a magic IC chip to cold junction compensate and amplify signal.
I am reading air temp inside the furnace, not the metal directly. Still have to let it saturate the heat and check the fluidity of the melt.

The more I learn the more I recognize I don't know.

Dave Opincarne
05-14-2003, 08:18 PM
You can make an optical pyromiter. Check out the r.c.m archives. It involves comparing the color temp of an incandecent bulb to the sample via a beam spliter or mirror. Should be easy enough for the electrical whizes on the board to figure out the circutry (I'm no help there) and I can help with the optics. I've may still have some front surface mirror around here too.


05-14-2003, 08:35 PM
I am using the thermocouple for temperature control. Keeping the temperature in range with a pid controller. Hopefully this will prevent some of the gassing that occurs when you boil aluminum.
We will see.. I used the Mueller I brought from Iowa. Great, like making pizza dough. I got a lot to learn tho.
If it rains I can get back on my projects in the shop.
I want a sandbox too before I heat and pour.
My casting frames turned out like crap, all warped up. Not happy with them. THEY would work, but don't fit my plans. I poured silver right through the sides of a small frame.

05-14-2003, 08:53 PM
When I bought my casting sand I was looking at some of the optical pyrometers. The salesman told me that there are some complications in using it on aluminum because of the high reflectivity of the molten aluminum. I wonder if the rate of nitrogen absorption increases with the temperature and also the time at temperature. I know the oxidizing keeps building up. I think my best pours were when I melted skimmed and poured without going very hot or waiting very long. When my cast iron crucible is just above a dull red heat seems right.

Dave Opincarne
05-14-2003, 08:53 PM
Makes sense if you're using it for control. Would be difficult with an optical device. Good for forge work though.

What happened with the flasks? Ours are pretty heavy but they could be scaled down. It would require more cutting and welding though. Wood flasks are possibly a better way to go initialy. The flask needs to be ridgid to prevent a mismatch at the parting line and to keep the mold cavity from growing. You also need a good way to index the two halves together. There are a couple of ways but a kingpin works well and is versitile. You should also have a way to clamp the cope and drag together to keep the metal from floating the cope. This will help reduce flash. You can also mold in an indexing lip if you're using a mounted pattern. This will help with the flash as well but you'll still need to clamp. The lip requires some skill though on the patternmaking end to get things to line up right though. A third means of reducing flash is to use a gasket material around the mold cavity before closing the two halves. This is what we use.


Dave Opincarne
05-14-2003, 08:57 PM
Spence, you'd need to use the pyrometer on the crucible not the aluminum. Reflected light will screw it up. An optical pyromiter is measuring radiated energy based on the idea of a black body generator. The aluminum won't radiate before it boils.

05-14-2003, 10:58 PM
Well.. I had someone who looks at sand a lot see mine. He says it is too damp. Sticks to his hands. It makes good impressions thou. He laughed about the kitty litter and suggested I go somewhere and get some foundry sand.


Here is a picture of the Speedy Melt smelter I went to Iowa and got, The Mueller I have already used.
I do not have the pictures of Gary with the custom Frame I traded downloaded yet. He is someone I met on the internet that has been a friend. He gave me the casting outfit outright, but good friendship would not let me take it without leaving him something. (a shiny pebble?)
It is raining here. I am working in the shop tomorrow.

site for speedy melt

[This message has been edited by ibewgypsie (edited 05-14-2003).]

05-15-2003, 02:03 AM
Was this before or after the tornado? Ha ..Just a little joke. I envy you the space and not having assholes tell you how to shape your backyard. I really think your first forge has as much capasity at the one you bought. But the size and shape might be a little better. Either one is going to consume the gas and air you put into it. That is the bottom line as far as the efficiency goes. If one is closer to the ground and easier to move the crucible out of it, it was probably worth it. Still I don't know how much you spent on the new forge, but you would have learned what you needed to learn if you had gotten the same fuel to air ratio burning in the forge of your own design.
I'm only sayin....

05-15-2003, 02:05 AM
Was this before or after the tornado? Ha ..Just a little joke. I envy you the space and not having assholes tell you how to shape your backyard. I really think your first forge has as much capasity at the one you bought. But the size and shape might be a little better. Either one is going to consume the gas and air you put into it. That is the bottom line as far as the efficiency goes. If one is closer to the ground and easier to move the crucible out of it, it was probably worth it. Still I don't know how much you spent on the new forge, but you would have learned what you needed to learn if you had gotten the same fuel to air ratio burning in the forge of your own design.
I'm only sayin....

05-15-2003, 10:05 AM
Picture was in Iowa. Yes they had been having some wind issues.

I spent less than a hour at his house I think. Lots of interesting things there too. They had more horse buggies than I have ever saw in my life in one place. Peacocks walking around. A bear skin on barnwall. A NICE studebaker car, weathered a little but nice. Country people.

Totally different from here, I had county people driving by to take pictures. I put up a Oak privacy fence to keep my hot rods. I have a 71 camaro in the drive that needs paint, a 54 ford, 50 studebaker bullet nose, a school bus (storage), a blue metal workshop, metal storage rack outside. And they don't appreciate it. Yes I live in the county, across from a working auto scrap yard, not a fine expensive neighborhood. I planned that.

They want you just to live inside your house, mow the grass, watch the stupid tele and pay your taxes. You know? be normal.. ha ha. I had one zoning woman tell me I can't have a workshop. Especially if you are large , scary and have tattoos.
I put up the fence, not seen her since. She interperts the law her way, I do the way I read it. All you have to do to keep a old car is show you have been working on it, or put it under a tarp or car port. She does not want to be embarrassed in court. But harrassment, yes they can do anything they want, just can't get a conviction.
I have wanted a real workshop since I was 10, Planned on it all my life. Just now at this point in my life I can have one.

How do you keep your workshop?
I hope I have not hurt your feelings, I just wanted to express a little.

05-15-2003, 11:24 AM
ibewgypsie: The "enforcers" can sure make life miserable for a man. I gave Kids and acre of landfor a house. Son-in-Law wanted 400 amp service. I suggested 200 for home and shop. He wanted 400, so I went to pull permit for him. Local enforcer refused, said S-I-L was going to put in some welding business or some thing that weas not code approved. I protested, enforcer agreed to issue 400 amp permit, but stated "they" would be watching me from now on. So county manager and I had a talk. Up shot was I had to tell the "enforcer" to inspect the work S-I -L did casue the "enforcer" was going to approve what ever was done (within reason) because I had filed a complint that the county was taking a personal interst in my business, legal or illegal. Man things have gone to hell here since 1971 (when I came here).

05-15-2003, 04:02 PM
I just now piled up the 2x4 ends, the plywood scraps and had me a nice lil fire. No fire department showed up.. shucks.. But, I put the shop fan (patton 16") up next to the fire, throwed some aluminum cans into the mix and they were gone in a matter of seconds.. Poof.. I think I burned my face too..
It'll melt a beer bottle in about 3-5 minutes.
I can always go back to charcoal in my original furnace. Plenty of heat there, let the pid-fan control the main heat. I am still waiting on sand for the pour floor.
I love fire, it cleans things. No more piled up mess. I only found one copperhead snake. and it was a small one. He is roasted now.
Junk to riches, here I come..

05-15-2003, 10:12 PM
I feel your pain,we have been having hell here with the city idiots,boss has been in business for 29 years,had some surplus steel a forklift and three old but running and driving trucks in his back lot.City came around and said we would have to move it or put up a fence or they would do it and fine us.So after much profanity we knucled under and blew $8,000 on a chain link fence.We are the only machine shop in the city limits,so we informed them that next time the city needed something we might not be interested in helping.As luck would have it about two weeks later we got a panic call from the sewage treatment plant saying that they had lost an obsolete F.P.circut breaker(1200amp)and desperately needed a new one because sewage was backing up in peoples houses!I said well we got three of those,and I wish I could help you but see you guys screwed us over on the fence deal and as far as we are concerned you guys can rot in hell!Then I hung the phone up,seconds later the mayor called up and asked what had happened that we were pissed off,I told him and he apoligized and said he would take care of it,if we would please sell them a breaker,I said sure and they came over and got it.The next day the zoning commissoner and the ordinace inspector were both fired http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gifWe got word from the new guy in charge that the city council and the mayor said we where not to be touched,this feels really good,its kind of like being the God father http://bbs.homeshopmachinist.net//biggrin.gif

05-15-2003, 10:20 PM
Wierdscience,That warms my heart to know that the boss actually got back at them so soon.I'm waiting for the other shoe to fall now about the city annexing me.I'll probably have to put up a privacy fence soon here because of a housing development going in behind me.I may never get a chance like your boss did though.Go look at Gypsies thread about the county for more on this knid of junk.Robert.

05-16-2003, 01:39 AM
My shop is an old single car garage with a dumpster in front of it and lots of storage in it. I have two 1969 J3000 Jeep trucks. One runs and is needing new paint but it has new 33" tires and the other is a parts doner. I also have a Triumph TR-7 and a 96 Ford Taurus and two truck-bed trailers so we have a lot in common. If I can get that Bridgeport we will have even more in common. I don't have any "airs." Who knows what your casting and milling will result in. Someday you might have a shop big enough to keep all those toys inside! That's what I'd like to do also.

Once I lived on a property with about a half acre. I cleaned up all the branches and debris and was going to have a nice fire. I knew the fire warden because he worked at the IFA where I bought horse tack, so I asked him for a fire permit. He wouldn't let me have one and said he'd have to give me a ticket if I burned my pile, even though it was in the middle of a tilled field. I said "but I see farmers burning their fence lines and stuff like that all the time." He said "Yea, but they are farmers and their burning is permitted but you aren't a farmer you're a home gardener and there isn't a provision for that." I was getting pretty upset that I was going to have to load all that crap on a trailer and haul it 10 miles to a dump. I had talked myself blue in the face but wasn't making any headway with the guy. I said look, I just wanted to get rid of this stuff and maybe cook a hotdog. He said "Hotdog? Now why didn't you say so! That would be a RECREATIONAL fire and those are PERMITTED!"

05-17-2003, 11:13 AM
OKAY new question, How do you know when your casting sand is too wet. I was told it would not stick to your fingers. Any help?

05-17-2003, 10:28 PM
I'd like to help you if I knew, but I bought some of that red commercially produced sand that uses an oil based binder. Water or even moisture, and molten metal generally don't mix. So I am surprised that water is used at all in casting sand. Then again I was surprised by the kitty litter too.

05-17-2003, 10:42 PM

The kitty litter was in cast pellets.. I had to throw rocks into the cement mixer to break them up. Impossible to do by hand.
and it went thump thump thump for about a hour.

05-17-2003, 10:44 PM
I always have been told that it should wad up in a ball and stay pretty hard with no drop outs or crumbs left over.I gave up on green sand around here the humidity is to high and it soaks up waterPITA.I had found a recipe for homemade oil bonded sand I think on Ray-vin's webpage,it used two-cvcle engine oil and works great.

05-17-2003, 11:02 PM
The humidity is high here too. I added the pounds recomended by the formula on the mix. it is now too wet. I have it spread out.
I am looking for the bentone locally, never heard of it before.
thanks.. I went right to the ray vin site.
Posted is the recipe.
100 lbs. sand - 100 mesh or finer - US Silica F110
6 lbs. Organo-bentone - Bentone 34 or VG-69
3 lbs. Polybutane (2 US Quarts) Indopol L-100 BP Petroleum or Chevron OLOA
0.2 lbs. (3.2oz or 91grams) Isopropyl alcohol - any pharmacy
- or -
0.2 lbs. (3.2oz or 91grams) Methanol (dry gas) - Auto Parts Store
- or -
0.2 lbs. (3.2oz or 91grams) Propylene Carbonate - Lab-Pro, Inc.
Mix the sand and bentone first, then blend in the oil thoroughly. I have done 10 lb. batches by hand with good results. The bentone is very dusty and the sand contains silica so wear a dust mask!

Add in the alcohol and mix thoroughly. Done!

The sand won't seem like much until the alcohol takes effect and then it will become like stiff cookie dough. How stiff? It boggs down my muller!
It will be much easier to handle when it is a day old and will get easier to use with time and use.
The sand gets powdery after it sits and it is best to mull it or warm it before use.
When green strength starts to fade, add in some alcohol.