what every boy needs - yeah seriously

On Jan 10, 10:27*am, "Maxwell" #$$9#@%%%.^^^ wrote:
wrote in message


How can you mold or sculpt invest foam articles with a simple hobby process,
and then get something as detailed as air cooled fins on a foam or wax
investment to withstand even the most careful ramming process for green
sand, oil sand or air set casting?

Your're thinking WAY too much inside the box. Making the molds for
the wax/foam cores is simple and there are many references to the
process(s) on the internet.

Ramming up sand directly on a foam or wax mold - isn't - practical.
Maybe if you resorted to vibration to pack core sand and then gas the
whole thing with CO2 ? But there is a way around that limitation as
well. Again, a search on the net should turn up some clues. I'd find
a link or 2 for you to start but I have to head out for the weekend
shopping with the Wife .............. maybe this evening.


Also, if you use oil sand and wax investments, how can you possibly remove
enough wax from the mold to allow the introduction of molten aluminum and
yield a usable casting, when you have detail as fine as a cooling fin?

I may have been unclear in my earlier post. I did not intend to imply
using oil based sands with investment casting. Sounds kind of messy!
I meant that oil based sand allows one to make better detail and
thinner parts than you can get with bentonite based sands. Should
have been a separate paragraph...............

Investment casting of the quality needed is very doable by the hobby
caster.
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Leon McAtee