[Johanna]

 Hi, I have tried using polyester resin with rtv silicone molds for rings and bangles and I had a couple of problems. (This is the only type of resin available in my location that is affordable in large amounts and useable for jewelry making)

1.) Castings ended up being sticky even after a weeks have passed. Is there a way to avoid or fix this? (note: I have carefully followed the amount of resin, catalyst ratio.)

2.) Ive read somewhere that the mold breathes (?) during the curing process so my castings are left with wrinkles or creases if you would call it. How do I avoid or get rid of these? Theres one solution that said that I should sand it, but wouldnt that leave the casting with a frosted look and not clear?

Also, do you have any more tips and suggestions on handling polyester resin? I cant seem to find much tutorials or help about this specific type. It would be wonderful to get a few to guides on how to handle this resin.

Thank you!

P.S.

Do you know which types of flowers are best for casting? 

[Katherine Swift]

It’s very normal for the surface exposed to air to remain tacky on polyester castings.  I have castings that are years old that are still sticky to the touch.  The good news is that you can either sand the surface off, or you can coat it with a layer of our resin gloss sealer spray to take away the tackiness.  You can find the spray here:  https://shop.resinobsession.com/collections/tools-and-supplies/products/castin-craft-gloss-resin-sealer-spray

Is the surface of your mold smooth?  I wouldn’t expect any breathing to cause creases on your castings.  The good news is that polyester resin does quite well with a polishing compound and buffing wheel.  You can see what I’m talking about in this video on the resinobsession youtube channel:  http://www.youtube.com/watch?v=iszf4VO459U  Sand first, starting with a coarse grit paper, then work down to a fine (1000 or more) paper.  Using the buffing wheel after that will make it very shiny.

As flowers, I don’t know if there are ones that are any better or worse, but the key is that they have to be dry AND sealed.  You can use the gloss sealer spray I mentioned above.  You can see how flowers turned out in this tutorial on our blog:  https://www.resinobsession.com/resin-tutorials/how-to-resin-flowers/

I’m happy to help with other questions.

[Author]

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