My adventures in casting

[Dan Dubeau]

I ordered this guy about a couple weeks ago, and it arrived last Friday. I think this is the longest I've left a new toy in the box. One of the reasons for the big garage makeover today was to find a spot to play with it. Took about 35-40 minutes to heat up to ~720*, and I gotta say I'm pretty impressed with it so far, and pretty hooked with the process of casting now. (I moved the bucket of kitty litter after taking the pic). My only gripe was the opening needed to be filed larger to fit the crucible all the way in. I'll need to file it some more as when hot the crucible expanded a bit and made it tricky to get out.... The lid does feel a bit cheesy too, but it does the job required of it.....The tongs are a bit iffy also, but they are better than the welded style that sometimes come with these things. The bottom line though, it melts metal .


I welded up a little ingot mold from bed frame, and a slag scraper while it was heating up. First go round was just some scrap 6061 parts, and some cast pistons from an air compressor to try it out. I have a bunch more aluminum under my porch steps to haul out and melt down. A bunch of scrap copper too and I want to try some aluminum bronze as well.


First charge

First pour ready to go after scraping the slag off.

And the result. I stopped to adjust my grip on the second ingot and it froze up so I just moved to another.

My first "castings" after a quench in a bucket of water.


I was originally going to make one, along with a bigger propane fired foundry but just never had the time to get around to it. I have projects I want to make and get tired of the "make a tool, to make a tool, to make a part" process so I decided to just buy some time and ordered one instead. I'd already ordered a couple pids, and another 3kg crucible back in the winter, so I may still build one eventually. I put the other stuff to build my bigger one on hold after getting laid off last week until work picks back up. I've been following the home foundry boards on and off for years, so it's nice to finally be able to DO it. Even if it's just casting ingots.

Now to get the 3dprinted pattern--->cast aluminum part process down. I've been consuming seemingly every you tube and forum post on it all winter long, and have also come up with some of my own ideas, so now I just have to get to it and see if they work.

A full "3kg" crucible will get me 3 full ingots probably (if I don't stop pouring to adjust my grip.....), and when cold I can fit 2 of them in the crucible. I made the mold that size so eventually I can bulk cast ingots with the bigger one for use in this little one.

[outlawspeeder]

If you are going to do casting I found that silica sand and Sodium Silicate works the best. Green sand is great if you are going to do a lot of casting. I make some replacement parts and have plans on a taper attachment some day... Yup I making tools to make tools too.

[Mcgyver]

haha....you broke down and bought one! I'm thinking of doing the same, the project list is too long. What size is it and where did you find the best deal? With the printer, are we to see some investment casting in the near future?

[Dan Dubeau]

If you are going to do casting I found that silica sand and Sodium Silicate works the best. Green sand is great if you are going to do a lot of casting. I make some replacement parts and have plans on a taper attachment some day... Yup I making tools to make tools too.

I'll probably start with making some green sand, but want to get some sodium silicate for sure. Some of the things I want to make will have some tricky cores. Nice parts. I can't wait to actually make some parts, instead of just ingots.

haha....you broke down and bought one! I'm thinking of doing the same, the project list is too long. What size is it and where did you find the best deal? With the printer, are we to see some investment casting in the near future?

It was tough to get off my wallet.... but I saw this one (110v, 3kg) get down to $399 and figured what the hell. $20 shipping, and $35 duty though.....The quality is exactly how one would imagine it.......
https://www.amazon.ca/gp/product/B08...?ie=UTF8&psc=1

Lost resin investment is the goal. How far down the road that is remains to be seen, but that's where I'm headed. I still have to make a burnout over first though and now there's a few hurdles on that road....

I think I'm still going to make a small electric furnace like this at some point, as the convenience of plug and play in the garage is pretty nice, but I'd make it a bit bigger. The 3kg is the biggest import I found in this form factor and the volume is right on the borderline of being useful for what I want to do with it the most. Still a good value for capacity though IMO.

Really looking forward to playing with it more today, but have to run home school with the kids. Might have to work a foundry class into the afternoon lol.

[mattthemuppet]

you are DANGEROUS Dan, now I have another thing I want

There are also propane fired ones that are a bit larger for similar money, but it would be hard to beat these electric ones for convenience. I wonder if you could use one as a poor mans heat treat oven?

[Baz]

Had a look at the amazon ad - hope you made sure your armor was full. Yesterday by chance I was looking at this forum entry on lost PLA which he had also videoed - https://www.youtube.com/watch?v=ba8T-AgilCM As it is temperature controlled would it work for annealing? What dimension is the inside of the crucible?

[Dan Dubeau]

Had a look at the amazon ad - hope you made sure your armor was full. Yesterday by chance I was looking at this forum entry on lost PLA which he had also videoed - https://www.youtube.com/watch?v=ba8T-AgilCM As it is temperature controlled would it work for annealing? What dimension is the inside of the crucible?

The id is about 2" by 6" deep so if your part fit it might work. But with the thermocouple down at the bottom of the furnace you might have too much of a temp gradient to the top depending on your part.


The lost PLA looks interesting to me too, but you still need a burnout oven. It will probably be greensand for me until my cash flow situation starts to pick up and I can build the burnout oven. And buy investment, and buy castable resin......It's an expensive endeavor for a non income generating hobby.....I'm not really looking to make it pay for itself either as that takes the fun out of it for me, so it's a balancing act. Just chipping away at stuff hoping I live forever...Life's a journey.

Matt, dive in the water is warm.....

[mattthemuppet]

[chipmaker4130]

When I was researching this process a few years ago, it seemed the consensus was that one should only use aluminum castings for the melt. Adding typical extrusions like 6061 tended to result in poor pours.

[gellfex]

Look into 'lost foam' casting, saves a step over lost wax. The hot metal vaporizes the foam as you pour. Good for rough stuff. Also, you'd be amazed at how effective a little house of firebricks and a propane torch or 2 are. That's what I used to temper knives when my son was on a knifemaking binge.

[Rich Carlstedt]

Many Aluminum Alloys are poor at casting . You want a casting alloy and the best for home shops is A-356.
This is the Aluminum that auto companies use for transmissions where they need good fluid passageways and accuracy . Fluidity , Detail and Strength are all there.
Find a tranny repair shop and have your fill.

So according to your measurements, you have about 15 cubic inches of volume for metal , which if i figure right
is about 3-1/2 Pounds of steel, 4-1/2 pounds of brass or 1-1/2 (-) pounds of Aluminum ( eye ball estimates)
Rich

Edit
Also suggest you get separate flasks if you are pouring different metals so you do not contaminate a pour.
Common practice in foundry work

[garyhlucas]

Lost foam is really the easiest and the finish is better than sand castings. I got a beautiful casting from 6061 scrap by adding 7% silicon I got off ebay. If you look at the A356 alloy compared to 6061 you’ll see the major difference is the silicon.

I was fortunate to get some Mercedes metal. On a Sunday a Mercedes took down a traffic light pole and I got 50 lbs of nice clean junks of A356.

[Dan Dubeau]

Lost foam is on the list to try as well, but you still have to shape the foam. Cutting and shaping foam might not be at the bottom of my favourite things to do, but it's certainly down there with fiberglass insulation. Almost impossible to clean, and static clings to everything. I have an idea for lost foam and 3d printing that I haven't seen anybody do yet. Which means it's either dumb and wont work, or I invented something . I'm betting It's probably the first option though. lol. This guy's results and process for lost foam is incredible. His results speak for themselves and his all electric furnace is making me rethink my propane idea. https://www.youtube.com/channel/UCST..._ZarxhA/videos. I still find it incredible how much information is freely shared on the internet these days. Such an amazing learning tool.

I've been stock piling cast aluminum (a356) for a few years. Rims, bike cases, automotive castings etc because I knew I'd get into this eventually. I just threw in whatever was small and close by last night because I didn't want to break anything down into smaller pieces to fit the small 2" bore crucible. Path of least resistance, and I just wanted to melt something. I may try some straight up 6061 in a round permanent mold to see how it would be for machining stock. But for any castings that matter it's best to stick with stock that was previously cast.

I do have 2 crucibles for this and was planning on using one for aluminum and one for copper alloys.

Tonight I sifted a box of kitty litter and a 3gal pail of sand from the backyard to make some green sand. Sand is a bit too wet, and kitty litter was still too coarse, so I ground some in our seldom used blender, and am baking the sand dry in the oven right now . Wife is working a night shift so as long as you guys don't tell on me......... I did get a small bowl to what my amateur experience would tell me is "good", but had to dry the sand out with a torch on the welding table too much so I just decided to throw the whole lot in the oven to dry it out. That small bowl of green sand still feels too wet, but it's clumping and breaking cleanly. I figure it's easier to add the water I need, than to remove the water I don't, so I'm just going to dry all the sand out in the oven first. Going to shoot for a 70/30 sand to clay ratio

Also cut some wood today to make some small flasks tomorrow. If all goes according to plan I should have my first green sand "casting" tomorrow night. Maybe a lost foam one too. Doing the cad work now for a small pattern I'm going to print overnight.

New cat wondering why I'm sifting the stuff he poops in lol.



still think that's a bit too wet. But it's close.

[Dan Dubeau]

Did some more reading this morning and it seems 30% clay is way too much. Not sure where I picked up that number from, but I pretty much re read all the pages I'd already read, and they all say %10-15.....

[CountZero]

I used 4% clay in the sand i just mixed up, might be better at 6 perhaps. Make a small batch first and try out, easier to adjust if not good. I used way to much water at first. Also mixing the sand and clay before adding water is the way to go.