Builders' Forum Archives
Re: fast epoxy
Posted by LeeG on Mar 10, 2005
When I was suggesting getting a pint of fast it was with the idea of mixing the fast/slow together for clamped joints and short times. A 50/50 fast/slow mix makes for a workable pot life but shortens up the long cure time with MAS slowcure. For example four pumps of resin with two pumps of fast and two pumps of slow. So instead of relying on lamps providing even heat over a complex area without raising bubbles that complicate finishing you get the extra margin of error with faster curing epoxy. Putting lamps on does work,,slow cure will cure up well at 80degrees but for some joints like the hatch ribs the edge grain will outgas. So if you're making nice neat fillets or spent some effort making the outside edges of the coaming stack smooth it's a bother to have a few bubbles show up and harden. It'll be cured but there will be a little extra work removing them and it's one more spot that requires re-sealing. For a short stretch I was making the deck beams in the CLC shop, the molded ply never came off the molds in less than two days or the "spring back" kept springing back until the epoxy was cured and that was with some fast in the mix. A friend who was building a Ch16 had the coaming pop up when the clamps were removed after 36hrs,,,but the temps were cool. For folks familiar with West Systems and haven't used the very slow cure no-blush epoxies it can be a surprise to discover how slow is slow.
In Response to: Re: fast epoxy by LeeG on Mar 10, 2005