[Faye]

Hello I’m wondering if any one can help, I use a lot of different molfds to casty resin in, a lot of them being for soap, sweets or plaster.
They all work well my only problem is they don’t come out see through or shiny so I have to add a clear coat of resin which can sometimes be very time consuming and sometimes wastes some resin.

I’m wondering if there is another way I can do it to make it look see through/clear or if I should make my own molds from previous items I have cast and then painted with resin to make them clear, will this give the mold the “shine” to make them come out clear/see through if I make the mold out of silicone? Y pieces go any where from 60ml or resin up to 500ml.

I hope this makes sense and some one can help, thanks in advance.

[Katherine Swift]

Hi Faye,

In order for a mold to make castings with a shiny finish, the template used to make the mold must be shiny as well. Before casting in the mold, check to see if the surface is shiny. If it isn’t, then it’s unlikely to make shiny castings. It has been my experience that molds for baking and soap making do not make castings with a shiny exterior.

If you want to try making your own, this article will help: https://resinobsession.com/resin-frequently-asked-questions/tips-for-selecting-a-model-for-your-next-mold

[Faye]

Thank you so much for your reply, yes I thought that would be the case, I think I will cast some of the pieces I have painted to make them shiney and see if it works. Thanks so much for your help.

[Martha Humphrey]

Hi Faye,

I’ve run into many of the same problems as you recently using silicone molds and found this helpful article and video explaining the difference between Shine vs. matte silicone molds: https://www.artresin.com/blogs/artresin/shiny-vs-matte-silicone-molds

It explains really well how the interior of the mold makes a big impact on whether or not your piece will come out with a matte or a glossy finish. Hope it can be helpful to you too!

[Faye]

Also when painting my pieces to give them a shiney/see through coat do I have to use the same type of resin or could I use an epoxy resin over a polystyrene resin, in general nothing to do with molding. I’ve always used the same but wasn’t sure if it would work with a different one.

[Katherine Swift]

I haven’t tried using an epoxy resin over polystyrene resin and don’t know if that would work. I have used one brand’s epoxy over another brand’s epoxy or polyester and been happy with the results.

[Faye]

Hello I’m wondering if any one can help, I’ve been casting with polyester resin and once it was out the mold I sanded it and then used another cost of polyester resin to give it a clear shine finish and after letting it dry for over 24-48 hours it is still tacky. I know my resin was mixed correctly as the other things I cast with the remaining resin all cured no problem. Is there anything I can do as I have already scraped it all off and sanded it once thinking my resin wasn’t mixed properly and don’t want to do it again as the pieces weighs 500g is about 8cm tall and takes a while to get into all the grooves.

[Katherine Swift]

Unfortunately, this is the nature of polyester resin. The surface exposed to air during curing will remain tacky, even after a full cure. When this happens to me, I finish it with a couple of light coats of resin gloss sealer spray. You can find it in our store here: https://shop.resinobsession.com/collections/tools-and-supplies/products/castin-craft-gloss-resin-sealer-spray

[Arlene Sherman]

I was pouring a new mold and didn’t realize my surface was uneven. Can I pour new silicone rubber compound on top of the cured mold to level it. Basically does the new silicone bond with the set silicone?

[Katherine Swift]

Yes, it should. If you used a mold release when making the first mold, you will want to wash it well first (and let dry) before pouring the second batch of silicone. Otherwise, the second layer may not adhere.

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