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Your work is so nice it is almost disheartening because I never feel like I will reach the level you are at! Unbelievable range of skills John. I'll be happy if my finished build is half as nicely designed and executed as yours (which will still be a lofty goal to reach)!

You are very creative. I like seeing your solutions and then the fabrication skills you have to construct them.

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My Haynes/Miata build: http://locostusa.com/forums/viewtopic.php?f=35&t=3774

Niko - here's some pics of my home-brew casting furnace and burner.

I found these burners online and liked the idea of a venturi burner (instead of forced air - I can cast anywhere and don't need power, just a propane bottle). http://www.hybridburners.com/

I just scaled the picture on his website and played around a bit with the nozzle size and fuel pressure once I got it running. I used a .035 MIG tip for a fuel nozzle and it seems to work well enough.

I made the furnace from an old air tank that the previous owner left in my barn when I bought my house. I had to compromise to fit the #6 crucible by only having one layer of 1" fiber blanket covered in a thin layer of castable refractory. It works fine for melting aluminum, but I think it would take a lot longer to melt bronze. Someday I'd like to make another furnace with 3" of fiber blanket and a thin layer of refractory - that would be super efficient. As it is, I think the whole setup cost me less than $150 for the Propane pressure regulator, hose, fiber blanker and castable refractory, and I have enough left over materials to make two more furnaces.

Here's some pics of the burner, and the furnace during burn-in.

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- John

Thanks Randy - looking forward to meeting you in person soon - crazy that we live so close!

Your build looks nice so far - it's amazing what you can do with minimal equipment, determination, and patience.

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- John

Really neat looking setup !

What refractory did you use? Did you add anything to the aluminum when melting?

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

My local supplier had some Insulcast 260 on hand. I forget what the temp rating was, but it's good enough for Bronze casting temps, I just used a thin layer troweled on by hand.

I didn't add anything to the aluminum when I cast it. Just melted it down and poured into my mold. My ingots had little or no porosity, but when re-melting ingots for casting I did see more porosity - I would want to de-gas in the future, but it seems to work fine as is.

The machineability of the cast 6061 is pretty poor (gummy), but you can artificially age it by soaking in an oven (I use my kiln). The data I found online was: one hour @ 400F; five hours @ 350F, or eight hours at 325F - all work. It made a bid difference in how well it machined. I did not do a full heat treat because it meant quenching in water after soaking at 900F - I was concerned with the parts warping too much. The manifold seems plenty strong as-cast.

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- John