Does epoxy shrink as it cures, and can a solid epoxy casting warp?

Shrinkage is minimal. UltraClear Epoxy is 100% solids, so there is virtually no measurable weight loss from wet to fully cured. On properly sealed wood, UltraClear Deep Pour Epoxy should not show shrinkage. A river pour shrinks slightly as it cures, which is why you only slightly overfill the river and keep excess epoxy off the slabs.

Distortion is a bigger factor in thick castings with no wood substrate, such as a full-epoxy charcuterie board. Deep Pour Epoxy generates heat while curing. In a warm room (78°F, for example) it cures hotter and faster, exaggerating internal stress. Thick areas hold more heat while thin sections like a handle cure and shrink faster and pull upward. An unsupported mold section or a single pour deeper than 1" adds to the risk. For these projects, work at around 65-70°F. Deep Pour still cures up to 85°F, but warmer rooms raise the chance of warping, shrinkage and clarity problems on larger or deeper pours.

Epoxy is also not structural. Bar & Table Top Epoxy is a top coat for flat, level surfaces; a 1/8" layer cannot support its own weight, so a cast shelf will bend. Thick epoxy is heavy and cannot be drilled or screwed without risking cracks, so legs cannot be mounted to a pure epoxy slab. Our products are not designed for standalone slabs; if you want to try, test first with Bar & Table Top built up in 1/8" layers to 1.5" total or Deep Pour cast 1-2" thick.