Casting material to use for aluminum parts that end up being welded.

[KyleH2]

I was thinking I could cast aluminum into some thick walled tubing and then machine the ID and OD and make my parts rather than buying stock. (After baking at 300*F first). The parts are weld on aluminum flanges so finish and temper are not important. Nor are the tolerances real tight.

How much should I leave on the ID and OD for clean up turning? I was planning on making my pattern with a piece of steel pipe turned to the size I need for the pattern.

This would be done in my back yard and the parts are turned on a manual lathe in my garage.

[youngjim]

If you're going to make a pattern, allow 6% for shrinkage of the material itself; if you're going to be casting it at home, I'd leave a lot more because aluminum is pretty touchy to cast. Expect a lot of porosity too. Type 214 and 355 come up as good casting alloys, both with good machinability.

[KyleH2]

I believe the material I have access to is 356. The reason I am using it is it works out to be about .50-$1 per pound not counting preparation. (Paint removal and cutting into melt-able strips) And I can easily get it in about 22 pound blocks 7 days a week. Will probably use a plasma cutter to cut it and a sand blaster for paint removal.

[Kipper]

I made this a few weeks ago, It's around the 6" 150mm mark and I allowed 1.5% on the pattern and a 1° draft all over...I cast it in oil bonded sand.

It came out less than 0.005mm oversize=Acceptable

Printed by a Zcorp printer and I gave it a good bashing and it held together!

Oh the material was the same as you mention 356...AKA Scrap Soon to be cast in LM25 from bought in ingots.

Just a sample part for a customer.

Might be time for a new rug!