Clear Casting Questions

John Katt

John Katt

Joined
Mar 19, 2012
Messages
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So a while back I got the idea I would like to make a knife with a clear handle using carbon fiber as the base material and a celtic design and this is what i came up with, I'm super happy with the transparent design and the 3D effect, but not so much with the casting resin, I looked around and found a few different brands and decided to practise with alumilite because it was readily available at the local hobby shop.

The issues i'm having with the casting resin is it seems a little soft even after curing for over a week at room temperature, it can be marred with your finger nail, second issue even after wet sanding to 2000 grit and a quick buff with fin grit red buffing compound, there is still a haze on the piece, Is there a buffing compound that is better for plastic?

Third problem this casting resin seems to have a very low melting point, after buffing for a minute the piece warms up and can be dented with you finger nail, also it is still a tiny bit flexible at room temperature.

So I,m hoping someone could recommend a better resin, and a better buffing compound

Thanks for any Info







 
I would recommend trying West Systems 105 epoxy resin combined with it's 207 Special Clear Coating Hardener. This creates a crystal clear uncolored coating - which can be used for tabletops and the like. This is quite a bit harder and more durable than typical casting resins.

West Systems Epoxy

TedP
 
Leave the piece in a warm area for at least a week. I use oil filled radiators in my shop, and sitting it on one of those would work well. A light bulb could work.
Let the piece cool to room temperature. Wet sand it to 1000 grit, then buff with tripoli or green rouge on a 1750 buffer. Keep the piece moving and keep the wheel loaded. Super fine grit compounds don't work well on plastic at all. Tripoli is the standard for buffing watch crystals.
 
Thanks for the tips guys

I'll order up some of the west system epoxy and the tripoli buffing compound and a new buffing wheel and give it another shot ;0)
 
White buffing compound is the stuff I use for plastic and CA. Not sure how well it would work on clear casting resin but it's cheap enough to try.

Those look fantastic and I'm impressed by your effort to make something different. Kudos.
 
It sounds like you didn't get enough hardener in the casting resin. Phillipsted's suggestion to use West System epoxy is the best way to do the job.

Tim
 
tim37a said:
It sounds like you didn't get enough hardener in the casting resin. Phillipsted's suggestion to use West System epoxy is the best way to do the job.

Tim
Click to expand...

I bought a fancy set of graduated measuring cups and the resin is 50/50 so I got that right, but the one thing I have been thinking is, what's the shelf life of that product, lord only knows how long that box was setting on the shelf before I came along,
 
Some casting resin doesn't fully cure for quite some time. Try buffing with tripoli on a soft mop-type buff, then paste wax it.
 
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