Why do bubbles trap around petals in epoxy resin coasters, and how can i fix it?

[JacobEM]

I’ve been trying to make a set of matching coasters using a simple resin pour, but I keep getting tiny bubbles trapped around the dried flower petals I’m embedding. I’m using a basic two-part epoxy and a heat gun, but it seems like the petals themselves are holding air no matter how carefully I place them.

[Timothy_H]

I chased this too last month. tiny bubbles stuck around the dried petals after the set, and the heat gun only rearranged them. the petals seemed to hold air no matter how careful I was. I blamed moisture in the blooms and the surface tension of the clear mix. I let one batch cure longer and tried a slower pour, but the specks stayed stubborn.

[Samuel_A]

I think I kept hoping a little pre-press would fix it, but the bubbles showed up anyway and it felt like a small battle I never won.

[VioletYB]

Honestly, I started wondering if my room’s humidity was playing tricks on the air in the cup. One sunny day the edges looked different, like the air moved and trapped tiny pockets near the petals. I drifted from that thought and kept going, but it didn’t help the bubbles.

[Dennis_L]

Do you think the problem is moisture in the petals, or is there something about the glue you used that traps air?