Talk Composites - The Forum for Advanced Composites

casting project

http://www.talkcomposites.com/Topic2739.aspx

By MattN34 - 9/3/2012 7:56:42 PM

hi 
i have taken on an aluminium casting project for my engineering college project and possibly make a bit of money from it.

my plan is to produce cast aluminium car fuel caps. (like the classic aston ones)

my plan was to use RTV silicone to produce a resin copy of an existing cap i have borrowed and then use that to form sand moulds to cast with.

my reason for making a resin copy is that it will need alteration (hole filling in etc.) before i can make the sand mould.

what i would like to know is 

is rtv silicone and casting resin the best way to achieve this

is there anything cheaper than RTV i can use as I'm on a tight budget and have calculated i will need 5 L of RTV to achieve this

any info or advice would be much appreciated 

thanks Smile
By brasco - 1/11/2013 2:54:08 AM

well epoxy is perfect for casting. it can be drilled and tapped and machined.  make SURE you get an epoxy made for this application tho.
casting
and silicone rubber is good for a mold, but you need a way to vac out the air bubbles in it(degassing).
make a mold
i am lucky this company has an outlet and warehouse near me. i love hanging out and talking with teh manager, he is a mountain of good information.
but most all this applies with any product line..
i have a hockey puck sized piece of epoxy and it is solid. no cracks and no softness. they say theirs can be drilled and tapped. and machined.

i think their tutorials are good as well. and a large variety of materials, from hobby to special effects and concrete casting even.

scott