Lost wax vs lost foam

Hi folks, I'm undergraduating in materials engineering and I have some questions. I hope someone can help ;-)

What are the advantages of lost foam when compared to lost wax?

Can the lost foam process be used with low-carbon steel? Is it used commercially today?

Thanks! Fred

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The 'net is a legitimate source for research, but you'll get more out of it if you find the answers by actually searching rather than having somebody here tell you. Google will give you a zillion hits on "lost foam" & "lost wax", but you'll learn more sorting through them.


Reply to
Bob Engelhardt


I think lost foam is significantly cheaper, but as for whether it'll work with any particular metal I can't say. If it doesn't work today, someone is trying to make it do so -- you can count on that.

Reply to
Tim Wescott

[Lost wax requires an investment medium (usually plaster and silica) that has to be mixed and de-aired, then de-aired on the part to eliminate clinging bubbles that become positive attachments to the metal part. The investment molds then have to be heated in a kiln to 1200F or so to eliminate all traces of wax before introducing metal.

Lost foam uses expanded styrene foam as a master, which can be fabricated or cast (although the latter process is not simple). There's no investment to mix, although some variations on the method use a surface coat for better detail. Sand is used instead of the liquid investment. There's no need to burn it out, since the hot metal vaporizes the foam by proximity and the sand vents the fumes. And it can be a lot simpler to cast a complex part in one piece, as this method facilitates, than trying to piece it together using multiple conventional sand molds.]

[I'm not sure about the steel, although it seems like it should work. I have heard of the lost foam technique being used commercially for casting engine blocks in an aluminum alloy - see
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Andrew Werby

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Andrew Werby

I'll bet they covered this in your class. Randy

Reply to
Randy Replogle

Okay, so I'm late and catching up, but Fred wrote on 29 Apr 2007 10:20:35 -0700 in rec.crafts.metalworking :

Cost of materials (Styrofoam is cheaper), details of the resulting cast (Styrofoam is, in my experience, not up to the "holding fine details" as is lost wax. which may be as much a function of the material to make the mold as anything else.

Thirdly, what are you trying to cast, size and shape wise?

No idea. I just know what I've seen done with bronze.

-- pyotr filipivich "Quemadmoeum gladuis neminem occidit, occidentis telum est. " Lucius Annaeus Seneca, circa 45 AD (A sword is never a killer, it is a tool in the killer's hands.)

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pyotr filipivich

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