Casting wood question

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Dario

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Apr 14, 2005
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Austin, TX, USA.
I had the pleasure of trying different casted "worthless" wood from different sources and noticed that some tend to separate (between wood and PR/alumilite).

If memory serves me right...none from the master (Curtis) ever failed.

My question is...how do you properly prep your wood so the PR/Alumilite will stick/adhere to it properly and won't separate.

I am assuming moisture is a possible culprit and maybe wood surface cleaning (or lack thereof). Not sure if Alumilite sticks to wood better than PR.

The answer to this might help me decide on which product to use if I ever decide on doing some casting.

Thank you,
 
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You might try micro waving the blank to ensure it is dry before casting the resin in it. I've been saving lots of wormy wood to start doing this myself. I even have some with carpenter ants stuck in the holes.
 
I assume that you are ensuring that no wax is remaining on the wood.

I wonder if a quick DNA soak will help clean off any oils that might be causing a problem.
 
I have done some of Curtis' also and they are nice. I made a Agarita/Black PR shaving brush that came out ok. Everything seemed to "stick". All I can say is that I warmed my agarita before I poured......
 
I don't think you'll find any defects in Eugene's (El Mostro) either, but he uses Alumilite too. I do wonder also if Alumilite sticks any better than PR, because I'm in full casting mode right now. Nothing, and I mean nothing, is safe in or around my house right now.

I'd like to know, from those that know.

Dale
 
I've done quite a bit of worthless wood casting and had some problems with some not adhering in the beginning until I started preheating the blanks in my toaster oven, I can't remember where I heard to do this but it has worked fairly well for me.
 
I will offer one hint on this from personal experience. You want the resin (whatever type) to bond to SOLID WOOD when you cast it. No matter how cool you think that bark layer/black line/misc. stuff will look when cast, odds are, it will not stick. You want to have the plastic in direct contact with solid wood. Now the trick is figuring out how to get that wonderfully contorted, gnarly blank cleaned off without removing the best part of the figure right there at the edge. Good luck with that.

IMHO, the higher viscosity of PR makes it more difficult to achieve a good bond between wood and resin than the thinner, faster penetrating Alumalite. However this would theoretically be offset by the fact the the PR remains liquid much longer, allowing it to penetrate more deeply while under pressure. I have yet to resolve this conundrum to my satisfaction. I have however decided that PR will take a higher final polish by itself than Alumalite. This has led me to use pr for pure resin blanks that will be finished without a coat of CA, and alumalite when mixed with wood that needs to be sealed with CA before polishing.
 
Dario, mt 2 cents. (all this is when using alumilite, I do not use PR)

If using alumilite moister IS a problem, make sure blanks are really dry (how many times have you heard this? ;)

Oily woods are a problem so wipe down with DNA and then stick blanks in toaster oven (this is Curtis' idea and it works).

Some woods like ebony, Desert Ironwood and cocobolo tend to "weep" (weeping = pinhead size wet resin droplets forming on the surface of the cut blank). I did a casting once with DIW and it was under pressure for 24 hours. When I pulled the cast out it was set but after I cut it into blanks it started weeping.. I put it in the toaster oven thinking that the alumilite had not cured correctly but the weeping increased and the resin started separating from the DIW. At first I thought it was insufficiend mixing but several others I have made reacted the same. I solved the broblem by keeping the blanks under pressure for up to a week...so needless to say I do casy alot of DIW.

If the wood surface is really smooth or has really smooth areas rough it up with some 60-80 grit paper.
 
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