[banctecbobn]

After months of talking I finally got my foundry built. Today was my first melts and it was a blast. Just made aluminum ingots in an old muffin pan.

Questions
1) Do you need to degass when just making ingots or can you just wait till you remelt for the final casting pour?

2) When removing the dross, how do you know when it is all removed? The first I removed was obvious but it got to the point of looking like I was pulling the skin off of warm pudding. Is this dross or just good aluminum starting to cool on top of the melt and the spoon I used to remove?

3) How much room do you need around the crucible inside the foundry? The bore/center of the foundry is 4 1/2 inches and the crucible is 2 1/4 inches. This leaves a bit more than an inch all around. Could I get a 3 inch crucible to work okay?

The home brew of refractory seems to work fine for now. Already thinking of building a bigger foundry and using real refractory and kaowool.

Have a great day,
Bob

p.s. It was fun today, anyone thinking of building a home foundry should do it, do it right now. lol

[metalworkz]

Hello Bob,
I'm glad to hear your first experience with your foundry was a good one. I only melt aluminum as a hobby but have used Dave Gingery's books to build the metal lathe, metal shaper, and horizontal miller. From my experience melting aluminum scrap in my homemade foundry:
1) I don't think degassing will be necessary for the ingots.
2) The dross will accumulate at the top of the melt but even after removing the bulk of it there will be a thin skin of it over the surface of the metal. I would not be concerned with that as when you pour the metal it normally runs out of the crucible/pot from under that skin and it has not caused me any perceptible problems with my castings. There always is a small amount of dross and aluminum that clings to the pot and the molten metal that pours usually is good in my experience.
3) you may find more definite information regarding the flow around the crucible but I would think that as long as there is a good air flow you will be OK, and probably the less air flow will allow you to retain more heat in the furnace.

What are you using to fire your furnace? I have only used charcoal so far with very good results, but a larger furnace with perhaps a propane heat source would be more functional.
Thanks for posting your thread and keep the information coming along with some pictures when you get time.
Regards,

[banctecbobn]

Use a propane burner. Heats things up real quick. I first built a charcoal fire to dry out the new foundry. I could tell from the mess I didn't want to deal with charcoal.

Bob

[Kipper]

I agree with all that's been said previously...Regarding the Propane suggestion....Using charcoal/coke etc "solid fuels" you won't have room for a 3" crucible......With Propane you will be OK with 1/2" or so around the sides....Try and cover the top to reflect some of the heat into the top of the crucible too...

Have fun and build a CNC router for the pattern making.

:cheers: