Problems with Mold-Making Putty

Karen,

I dont have as much experience with this product as Meredith of Cosmic Designs.  Ive asked her to comment.  🙂

Hey there, Ill do my best to weigh in on this, as I do use the amazing mold putty quite a bit. However, I use the molds I make mostly for polymer clay pieces and hardly at all for epoxy resin.

I do know I have similar problems when trying to use silicone bake ware for resin.  I got one of those "Brownie Bites" silicone pans at the craft store, because they were the perfect size cavities for some pendants I wanted to make.  I had what sounds like the same problem with the silicone bake ware as it sounds like you are having with the molds (pieces would come out rougher than expected given the smoothness of the mold and the images I embedded looked "frosty").  Now that I think about, I think I had trouble getting those pieces to cure completely, but chalked it up to bad measuring of the two compounds on my part.

I have used paint-on silicone molds for cameos (where the silicone for the mold is liquid and applied in layers to create a mold) and then used the molds for resin, and I think I had the same problem.

My "solution" to this was to add a fresh top coat of resin to make it shiny.  It worked as far as the tops being shiny, but it was very hard to control what it did on the sides, even taping down the flat bottom of the pieces to duct tape so it wouldnt leak under.  Maybe you coat the pieces with something a little easier to work with, like a nice gloss paint or even clear nail polish?

I also remember getting a cool "bubble" ring mold from the previous owner of resinobsession.com that was light blue in color and (I assumed) made from silicone.  I dont think that mold had the same issues as far as roughness/frosty appearance. I believe the surface was not quite as smooth as the plastic molds I use, but much better than other silicone molds I have used.

Katherine-Do you know which mold-making material Cindy used for those cool 2-part ring molds she used to sell?  Maybe that would be a good product to try?
Good luck, wish I could be of more help!

That was actually very helpful – thank you! Our situation sounds pretty
exact – I too had trouble getting the resin in the molds to fully
harden and I just blamed it on improper measuring on my part. Your post gave me some ideas and I will try putting a fresh coat on top either by "painting" or by doming.  And hopefully that will not only clear the top but give it some stability. 

Thanks again!!

I just had this issue the other day, with the yellow, pink and purple two part epoxy mold. 

my solution was to coat the areas with a sculpy top coat made for polymer clay, 

it worked great, also worked for areas you need to sand down on the resin.

i also tried using the resin with a paintbrush but it kept running an making more of a mess, plus it took forever to dry. 

the sculpey gloss dried in 15 minutes and you can put on two coats if needed.

hope this helps

christy

So basically you made the mold with your mold-making putty, then once it was set, you glossed it with a layer of sculpey liquid clay?  I just want to make sure I understand as I still havent had success with what Ive tried.  Thanks!

i glossed the resin, but now that you said that, i wonder if that would work.

i found a product called oomoo 25 a silicone rubber two part liquid 1:1 ratio.

it copies exact and things come out shiny too.

I am having issues on curing also, the top shiny part of the cast is sticky.
sometimes just a little and dries in a day or two, other times it doesnt dry at all.  put on a gloss coat of sculpey and that works to end tackiness, but sometimes i want it to be less glossy as in cameos.

going to try another brand and see if it works better.

i bought a few molds from mold muse on etsy and these are pink in color where mine were blue, her molds dont have this issue, i asked her what she uses and all she would tell me was that it was a 10:1 ratio product.

i dont mind buying her molds, but i want to cast my custom pieces, so i need to make my own.

 Greetings Ladies!

Jamie,

When I doubt, always use a mold release.  It doesnt hurt and can save you from the aggravation of the resin sticking to the mold.

As for bails, I think a two part mold putty would do you just fine.  The kind we sell is https://www.resinobsession.com/ItemPage/5323/Alumilite-Amazing-Silicone-Putty-Kit.html  There is also a video link on that page to show you how to use it.

You can also see Merediths way of using this mold putty on our blog:  https://www.resinobsession.com/Silicone-articles/111/How-to-make-a-silicone-mold-for-resin-or-polymer-clay.html

 I have experimented wit several different clay compounds that take an impression, and found that its not worth it for the money. Next I tried pourable "Oomoo," a tin-cure pourable two-part silicon rubber by a company named Smooth-On out of PA. Made nice molds that lasted longer, took better impressions, wore longer than kneadable putties. Then I noticed that they started to eventually wear out, discolor, lose surface detail. If you want a quick result & will only use the mold a dozen times, maybe the kneadable clay is fine. I needed molds that would last a long time. So I called Smooth-On (awesome, down-to-earth techies) for help. They turned me on to their line of platinum-cure silicon rubbers, which have superior tear strength and wearability. From their website videos, I even made two-part molds for casting big resin "statement" rings. I pour a mold at night, use it 1st thing in the am. If you want your moneys worth. look up the Smooth-On website and give their tech support a call. Tell them what youre doing and they can point you in the right direction.

Thank You Traci!
Your Info. Is so helpful!

Why is my mold putty still sticky ?