Using PR in a Pressure Pot

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vtgaryw

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I've been casting for quite a long time now. I use different resins for different things. I like using PR when I can because it's a lot easier and more forgiving. One thing I've never tried is using PR in a pressure pot. I'm wondering if for castings like pine cones and "worthless wood" and the like would PR work well in a pressure pot for forcing the resin into the voids?

Gary
 
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MRDucks2

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I have it tried, though still in the "trial" process. What I have found is that the PR will shrink away from the mold a bit, as well as the surface. It seems to bond to to the wood just fine. If you think about it, I do not believe it would be likely to shrink in all directions at once as much as it will "contract" away from the outer surfaces.

So far, the only issue I have had with bonding to wood has been with some pieces using Liquid Diamonds. There are other things LD bonds to very well, but so far not consistently with wood like Alumilite or PR.
 

vmsherp

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I've dove a lot of pine cones and worthless wood using polyester resins under pressure. Seems to work. I've never done them without pressure, so I can't completely answer your question. Like you, I guessed the pressure would help and simply started doing it right off the bat.


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I’ve used PR for both pine cones and sweet gum pods in a pressure pot and it’s worked just fine, although I always stabilized them in Cactus juice first. Stabilizing may make a difference but I’m inclined to think it wouldn’t. You can expect some voids but CA takes care of those. I find dipping the cone and mixing it around in the cup of resin first helps get most of the voids filled, then I put them in the mold, add the resin (usually a couple different colors) and swirl as needed.
 

MRDucks2

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I like the dipping idea. How do you keep things from floating around? Big pieces I can wedge but for end pieces, for instance, are tough. I hate damaging silicon molds with CA to hold them down but have found nothing else that works, yet.


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vtgaryw

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For those who have used PR in a pressure pot, have you found it affected the cure time at all?

-gary
 
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I like the dipping idea. How do you keep things from floating around? Big pieces I can wedge but for end pieces, for instance, are tough. I hate damaging silicon molds with CA to hold them down but have found nothing else that works, yet.


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I use a long pair of tweezers for dipping and just pack the pieces into the mold tight enough that they won’t float. I’ve never done just a single pinecone but if I did, I’d use one big enough for a jam fit into the mold. I use pvc and a block mold, but I also make my own for custom jobs which would be the case here.

For those who have used PR in a pressure pot, have you found it affected the cure time at all?

-gary
Faster for me but as Eric said, it sits in the sun. I also live in the desert which helps.
 
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