Todays casting adventure.

[Dan Dubeau]

I posted the start of this saga in the "what did you do today" thread,

I Started off today by printing new modified patterns of my tool rack brackets, Power went out about an hour in, and when It came back on It wouldn't restart. Bummer. Started again and had a bit of pullup on the buildplate in one of the corners. Bummer 2. Rest looked fine so I just let it finish, and figured I try and fix it with some casting resin.

You can see the pullup in the lower rh corner, as well as the failed prints in the background.


Some popsicle sticks, a glass platten, and hotmelt had me a quick and dirty dam to pour some alumilite casting resin into to try and rebuild that corner.







Did a bit of carving while it was still a bit green, and will sand and reshape it a bit better after dinner. While this was going on I was printing another set of patterns, that just finished actually. They came out good with no issues.



While the resin was hardening I had the foundry fired up, and was melting down some more small chunks of scrap.

I rammed up another pattern I printed last weekend, for a hub to make a rotating compost bin out of hdpe barrels. Not a project that "needed" a casting, but I wanted to. Took a few attempts with various different failures before I finally got one right. The last attempt fell apart as I was putting the cope on for the last time....argh. I need to make some better flasks. The cope is too thin to properly hold the sand on these ones.



With the crucible ready to go, I quickly rammed up another attempt, and honestly think it was my best mold yet.





I was getting really nervous while pouring wondering if I had my math right. I designed these parts this way to make sure I had enough volume in a crucible to pour. When the aluminum start coming up the riser I breathed a sigh of relief lol. Still had enough for a small ingot too.



Success, a good casting. Even the dimples for bolt holes came through. A bit of shrinkage near the riser, as It's WAY too small for that big section (flasks too thin). I might have to use a myfordboy type can in the future for stuff like this, but for this particular part it doesn't matter the center gets bored out anyway. Good learning experience though.





Riding high, I decided to ram up another and charge another crucible. This is the first back to back casting I've ever done, and was really surprised at how quickly another crucible melted. About 45 minutes for the first pour, and about 10 for the second. I need more flasks and more sand, and then I can get into some good back to back action.



2nd mold wasn't as good as the first, but still produced some useable castings, albeit requiring a bit more cleanup. I need 2 more of these to finished the 2 barrels I'm building.



Taking a break for dinner, then I will cleanup the bracket patterns, and maybe have a go at casting some of those tonight. I really want to get those racks done this week sometime.

[olf20]

Nice job!!
olf20 / Bob

[Joel]

Yeah, nice.
Thanks for going through all the trouble of taking the pictures and posting them.

[rubes]

can I ask your opinion of the electric furnace?
looking for something entry level to get started with.

[Dan Dubeau]

can I ask your opinion of the electric furnace?
looking for something entry level to get started with.

I'm entirely self taught through forums and you tube and still as beginner and entry level as they come. Go for it!.

I've got about 15-20 melts about split between castings and ingot pours out of this one over the past couple years so far, and love it. They are sold in a few different styles, under different "brands" but they're all pretty much the same. I think I paid about $450 cdn for this one. I can't recommend one over the other but I can say it just works, and works well. Takes about 45 minutes to load up a crucible to aluminum pouring temp from cold, running on 120v. Not sure it the 220v ones would do it quicker.

I still want to build a larger propane one eventually, Maybe a waste oil burner too. I have all the bits and pieces here ready to go it's just not a high priority project right now. For quick little pours like this one, flipping a switch and getting to it is really handy.

[rubes]

Thanx for your input Dan...yeah, Im just looking for something quick and easy to recover alot of the scrap I make and cast some blanks. been back and forth on electric and propane and just couldn't makeup my mind.

[SLK001]

I see that you're using a pouring cup to keep the metal flowing throughout the pour. That's fine for the top-side, but you need proper gate design in the mold to maintain laminar flow (and thus minimize porosity in you final result). This guy, swdweeb on Youtube has a lot of videos on casting gates and the like. Also, Andrew Martin has done some amazing experiments on casting that are fun to watch (the ones with the exploding glass window holding back molten aluminum).

[Dan Dubeau]

I see that you're using a pouring cup to keep the metal flowing throughout the pour. That's fine for the top-side, but you need proper gate design in the mold to maintain laminar flow (and thus minimize porosity in you final result). This guy, swdweeb on Youtube has a lot of videos on casting gates and the like. Also, Andrew Martin has done some amazing experiments on casting that are fun to watch (the ones with the exploding glass window holding back molten aluminum).

Thanks for the suggestions. I've watched quite a few videos from both of those guys, but will obviously go back and seek out some more information on proper gate design, as it's obvious I need some help there. This was the first time I'd used the pouring basin like the olfoundryman, and I really like it. I need to make a tapered sprue like him, as well as a few other molding tools that will help me get better results. There is a lot to learn. It's pretty apparent after todays adventures that my homemade green sand is not doing me any favours either. I had a problem tonight after dinner ramming up a mold for some brackets, and after a few failures I finally got one that still sucked, but not as much as the 3 previous ones. So I decided to pour it anyway.

Pattern repair and came out pretty good. I didn't know how it would turn out, but I'll put this method in the quiver for later. Even though I'm going to reprint this part tomorrow anyway.

I did lose an alignment hole by making that repair though. That will reveal itself later....

Nothing is safe from the crucible, not even BX armour lol. I try to stick to cast alloys, but a little "other" wont hurt for a project like this.

A little concerned while pouring when the riser didn't fill and froze up on me. I've never had that problem before, but after shake out the cavities filled ok


I think the gating on this pour was pretty poor, as well as the blowout I was having while pulling the patterns. I did sand these quite smooth, but perhaps some primer and paint might make them a bit slicker to draw. I'm going to reprint the repaired one tomorrow as the pattern shifted and the part on the right is complete scrap. The left one is pretty poor, but still useable for what I need it for.

Here you see the pattern shift and all the blowout

But there were some positives. This part, while not great, is pretty useable. Honestly every pour is a learning experience at this stage, so that's why I poured it knowing that one cavity was pretty crap. The good thing about casting it you can remelt your mistakes.


While I had the crucible hot I did another melt for ingots. Almost done my little bucket of "scrap" which consisted of a couple motor end bells, some lawnmower towers, and various other cast aluminum parts.


Pretty fun day.

[Dan Dubeau]

Thanx for your input Dan...yeah, Im just looking for something quick and easy to recover alot of the scrap I make and cast some blanks. been back and forth on electric and propane and just couldn't makeup my mind.

The electric is pretty handy and convenient for small stuff like this. But I kind of wish I had a bigger one, with more flasks and sand to get it all done in one shot. Something to work up to for the future. This one is great to get started with.

[Dan Dubeau]

Good morning


Cat work me up at 5am to go outside (he apparently only speaks in a tone that my ears hear......), so I got up, put a pot of coffee on, and went to class at youtube university, while watching the sun come up behind a haze of clouds. It's actually snowing again here. About 2.5 hours of videos now. Most I've already watched before, but need to watch again to reinforce and remember some good details, and other important stuff. I hadn't realized that Oldfoundryman was having some health issues. Very sad, as his videos really are amazing, and he's a wealth of knowledge. I've watched all of his videos over the years, but hadn't really noticed his series on molding boxes were his last. That was about the time I got really busy with work stuff and my casting interest and involvement at home dropped off.

I had quite a few ah ha moments where I realized I was doing things wrong. Things I'd clearly remembered from all the research and learning I did 2-3 years ago leading up to buying the foundry, but missed some important details on execution. Gating, runners, and feeders etc, how and why, where and when, etc.

My father inlaw (retired patternmaker) gave me a bunch of his books on pattern design and casting to read through too, so I'm going to start reading those too as I get back into this more.

Armed with a bit more knowledge this morning I think I'm pointed in a better direction to try some more castings today. Coffee is all gone, It's 9am now, and I'm still the only one awake in the house. Was a nice quiet morning to myself, a rare occurrence.

[mickeyf]

Wondering if you've tried any pours strictly with not-casting-alloy aluminum. I have been saving all my scraps of whatever type aluminum against the day that I finally build the rest of the needed equipment. Figured that even melting with stuff that was not designed for casting would provide lessons.

[Dan Dubeau]

Wondering if you've tried any pours strictly with not-casting-alloy aluminum. I have been saving all my scraps of whatever type aluminum against the day that I finally build the rest of the needed equipment. Figured that even melting with stuff that was not designed for casting would provide lessons.

yes, the first couple of parts and ingots I made were from regular 6061 bar scraps. They were useable, but my results drastically improved when I started to remelt previous cast parts, that were most likely a356. Which is basically 6061 but with added silicon for fluidity? Someone correct me if I'm wrong as I'm going 100% form memory here. They were brighter and much nicer, compared to the 6061 which was more of a dark grey after being cast.

Edited to add a picture. Cast scraps on top, extruded 6061 barstock scraps on bottom. Big difference.


I've tried melting down chips too, but I spent more time scraping dross out of the crucible than it was worth. Not to mention wasting electricity. I'd like to revist the chips when I get a chance to made a mold to press them into pucks, but again, probably not worth the effort. I have quite a lot of casting scrap to get through before I need to waste time going down that road. We build fixtures for production cast autoparts every once in a while and they usually send us a few parts for trial and setup, or gauge r&r. Those are fair game, and I've stock piled a couple few dozen. Not to mention the car rims, and other engine parts I've been squirreling away for the past decade in preparation for this "someday" adventure.

[Dan Dubeau]

Time was a bit harder to find today, as I had other stuff to do, but it's amazing how fast you can get stuff done when it's standing in the way of things you WANT to do .

after my morning education session, I turned up a tapered sprue, a larger tapered riser, and made a pipe cutter to cut a pouring basin.

I reprinted the damaged pattern half, and managed to pry Jr away form his tablet long enough to help me ram up another mold. My phone died when I went to take some pictures, turns out batteries run out if you don't plug them in once in a while. Figures, I manage to get him away from coding video games, and minecraft stuff long enough to do some hands on shop stuff (he actually loves it) and I can't even capture it lol. I had some corners fall off lifting the cope, but they are on machined surfaces and should dissapear. If my efforts in better sprue design, runners, gating and risers pay off, I should have 2 better castings in a little bit. My phone will be charged to and I might even take a picture of them .

[SLK001]

Your sand looks to be really light on the clay. What mix do you use? Do you have a muller?

[Dan Dubeau]

Your sand looks to be really light on the clay. What mix do you use? Do you have a muller?

No muller, just really working it and kneading it by hand. I can't remember exactly what ratio I used. 8-10% if I had to guess? It was homemade green sand with ground up kitty litter and home depot play sand. You know, the same mistakes that every broke beginner caster makes? . I actually added a bunch more clay to it last night after casting yesterday, but have come to the conclusion you can't polish a turd, and I'm going to break down and buy some commercial sand to go any further. I do not have a muller, just really working it by hand. It IS getting incrementally better the more I use it, but I doubt it will ever be "good". If I want better results I need better materials.

Back when I made this sand 2 years ago, I'd ordered the foundry, and then promptly lost my job due to covid before it even got here. The fun money tap got shut off real fast, so I tried to get by the cheap route for a few months till I got working again with what I had on hand. Then got back to work and have been super busy the past 2 years at work and with other pursuits and casting got put on the back burner. Just now getting caught up, paid up, and back into it. Trying to remember what I'd learned to start with, but seems like I need to make some mistakes twice. I'm going to buy some commercial sand shortly I can. Not sure about petrobond, or sticking with green sand. More research to do.

And yeah, I think I'm going to need to build a muller too (been scrounging some parts for a while). The kids are really getting tired of helping dad knead the sand. The shine wore off of that really quick lol.

Thanks for the input BTW, I appreciate every comment and suggestion.