I’m using about 2 cups per side shot with about 8 cc. +/- depending on temp. More than enough. Setup seems like about 15 minutes. I’m getting saggy areas near the rails. (no, not me!..the board) Any advice?
You could either try spreading the resin a little thinner, or add a little more catalyst.
Fifteen minute setup seems a little slow, allowing the excess to sag.
On the final strokes you can always wring the brush a bit and give the rails a few extra passes.
Generally, cure for saggin hots is more brushing!
I normally used to apply resin, cross brush middle out both sides, lengthwise full board, cross again, then final lengthwise, usually taking a little over 7 minutes.
Keep an eye on rails, and if they just START to sag, brush rails again lengthwise.
thanks for the replies- does that long brush time pretty much take you right up to when it starts to gel? Also, do you think a hotter mix would hurt anything…I was reading a recent copy of Surfing Mag that kept referring to “steaming hot” hot coats. Also referred to a “cheater coat” of lam resin under the hot coat with out any explanation.
I’m not familiar with the steamy hot lam resin coat.
Most of my hot running problems were on hot days. Cool daze, no problems.
Don’t run too hot a hotcoat, as it tends to shatter easily and become brittle. Instead, wait around for 5 minutes after mixing to begin pouring the resin on.
Mixing well takes 2 minutes itself, wait 5, and you’ve eaten up half your working time.
Work quick for initial hot brushing and the cross stroke, then take your time, and youc an actually feel the resin get more tacky as it starts to go off.
Could be that you’re laying it on too thick?
Could be a sign you should start using UV cure, where within a minute of putting it in the sun, it gels?
Do you add too much surfacing agent, thus thinning out the resin?
Meantime, as previously stated, brush 'em out.
I use UV cure lam resin, home-made SA, and don’t have a problem with sags, working in Honolulu in low-to-mid-80-degree weather.
just throw a bra on it.
Mitchell, I used to have that problem too. With me it was trying to leave too much resin on the rails. Now, the last thing I do, is do one long pass on each rail, while pressing moderately hard to get the excess off. No problems after that.
I agree that making the hotcoat too hot is not a good idea. Not only will the glass be more brittle, but it will tend to yellow quickly. My board #007 is a classic three stringer pintail that went yellow after about 6 months. Also…work as fast as you can comfortably, then walk away from it. Too much fiddling will disturb the wax on the surface, and you’ll get sticky areas after it gels. Doug
Don’t stay in it until it starts to gel or the wax won’t have a chance to come to the surface and you’ll have a tacky mess…
A cheater coat is simply brushing on a thin layer of lam resin onto the layup prior to hotcoating.
I do this on the rails and to fill in the space where the laps meet. (doa search on basting) Prevents burnthrough’s on the rails when sanding.
My buddies brother works in a glass shop and he says that they coat the entire bottom side with a thin cheater coat.
Drew