The physics of resin cells
Why heat opens lacing, why silicone oil is cheating, and how to get cells that hold their shape through cure.
A cell is a Marangoni effect: two liquids of different surface tension meeting, with the lower-tension one spreading across the higher-tension one and pushing it into a rim. Everything else is detail.
Why heat works
Heat lowers surface tension. Passing a torch over a boundary between white paste and tinted resin drops the tension on the surface layer, and the paste spreads outward into lacing until it cools and locks. That's it — no additive required.
Why silicone oil is a trap
A drop of silicone oil creates cells instantly and dramatically, and it is genuinely useful for petri work. But silicone migrates. Any subsequent layer poured over it will fish-eye, and any piece that needs a second coat becomes a fight.
- Use oil only in a piece you will never re-coat.
- If you must re-coat, wash with IPA and scuff with 400 grit first.
- Never let an oil bottle near your clear-coat station.
Holding the shape through cure
Cells drift while the resin is still liquid. If you torch at ten minutes and the resin doesn't gel until forty, your beautiful lacing has half an hour to soften. Torch later — closer to the gel point — and the structure locks almost immediately.
Torch early for spread, torch late for structure. Most good boards get both, in that order.
Put it into practice
Everything in this article, on one bench.
Our starter benches ship with enough material for two attempts and a printed pour card — so the technique above has somewhere to land.