Pitted look in bookmarks?

[Erik]

I’m fairly new to resin casting and I feel like this is definitely a newbie question. I have poured a ton of resin on bartops and to fill cracks in wood so I’m not a complete neophyte, but I recently decided to use some leftover resin I had from filling in knots and cracks in woods to make some items. I’m a librarian so I thought making bookmarks would be fun. I bought some silicone molds from Amazon and poured, but the bookmarks came out with tiny little holes on the bottom side (the side that was in contact with the mold). I knew my epoxy wasn’t really made for this particular application, so I got a casting epoxy (Amazing Cast, the kind from Hobby Lobby). Although the bookmarks came out better in many other ways, there was still the odd pitting effect. I carefully washed the molds, and I even purchased an entirely new set which I also washed and applied a mold release to (more on that later). However, no matter what I seem to do, there is always a few of these spots that look like tiny little holes on the underside of the bookmark.

I have tried heating the epoxy once it was poured using a heat gun, a torch, and even one of those little candle lighters. They definitely all get rid of the surface bubbles, but I haven’t seemed to make much difference in the underside. What am I doing wrong?

Also, the mold release left a bunch of marks on that batch of bookmarks. Is there a way I can get rid of them? It’s kind of a sort of milky smudge. I definitely allowed all of the mold release to completely dry to the touch so I’m super confused as to how that happened.

[Katherine Swift]

Hi Erik

I’m sorry to hear this is happening to you. How frustrating!

Unfortunately, Amazing Clear Cast resin doesn’t do well in molds. It mixes thick, making it harder for bubbles to release.

Instead, a casting resin works better in molds. It mixes in a thin formula, allowing bubbles to easily escape.

Since you are making bookmarks, I’m guessing you are pouring less than 3 ounces of resin at once? If so, the Resin Obsession super clear resin is a great choice for a project like this. You can buy it in our store here: https://shop.resinobsession.com/collections/resin/resin-obsession-super-clear-resin

This article will also give you some other ideas on how to handle bubbles in your resin: https://www.resinobsession.com/resin-frequently-asked-questions/resin-bubbles/

[Author]

Posts