Awesome use of a cheap laser cutter

[vpt]

Are you being sarcastic Andy? That's just standard lost-foam aluminum casting.

Yes, it's a bitch to weld, but the strength is as good as any aluminum casting?

I notice on protruding tabs, bolt holes, and smaller "things" that there will be more porosity and it seams I see more broken off stuff with these castings than others. I know the styrofoam "look" doesn't go very deep but it goes plenty deep enough to be impossible to get perfectly clean for a TIG weld. These castings will have more voids and cavities than other "normal?" castings.

The last thing I saw with this kind of casting is OMC outboard motors. The head I used on my 60hp rebuild had visible voids, craters, and weird spots even right in the combustion chamber. There were places in the water jackets that had holes where they shouldn't be and casting where there should have been holes.

I don't know what this guy did to this head but you can see the porosity of this OMC head.

[wierdscience]

Absolutely no reason it won't work,he could also fill the steps with polyester filler and sand off smooth.If he has the % oversize right,the draft angles will all be the same.Some filling,some sanding followed by some lacquer and he will have patterns.

[wierdscience]

I notice on protruding tabs, bolt holes, and smaller "things" that there will be more porosity and it seams I see more broken off stuff with these castings than others. I know the styrofoam "look" doesn't go very deep but it goes plenty deep enough to be impossible to get perfectly clean for a TIG weld. These castings will have more voids and cavities than other "normal?" castings.

Your right,lost foam has it's trade offs,mainly the combustion products of the foam ending up in the alloy.

IIRC this was first developed by Mercruiser and later adopted by GM Central foundry to produce Corvette blocks.

[TRX]

The first mass production use of lost foam casting was (at least according to Ford's propaganda department) the cylinder head on the Ford Escort CVH engine.

[Weston Bye]

From Wikipedia:

http://en.wikipedia.org/wiki/Lost-foam_casting

Lost-foam casting was invented in 1964 by M.C. Flemmings. Public recognition of the benefits of LFC was made by General Motors in the mid 1980s when it announced its new car line, Saturn, would utilize LFC for production of all engine blocks, cylinder heads, crankshafts, differential carriers, and transmission cases.

Not to say that the two preceeding posts are incorrect, as everything from Wikipedia must be considered suspect until corroborated.

[michigan doug]

I have experimented a few times with lost foam casting. One advantage is that you use plain sand, not green sand, not petrobond, but plain sand. Use it over and over.

I cast a 9" pulley with cast lightning holes. Then I cast a separate bushing to mount it on my generator. I machined in grooves to accept a 6 rib serpentine belt.

Turned out great.

Make sure your aluminum is properly hot, I had two incomplete fills before I got a good casting. And pour as fast as you SAFELY can.

Pretty stinky.

I used the high density foam, not that stuff made of low density bead stuck together to make a sheet.


Finest regards,

doug