Hi, I’ve made about 30 boards in my life with alot of trial and error problems. I thought I had it down pat but the last couple of boards I’ve done, the hot coat has dried incorrectly and I can’t work out why. Using polyester resin, it’s like the wax and the resin aren’t mixing properly, some of the board is perfect and fine to sand while others are streaky and no good. It also changed alot again doing another side has come up not flat at all and too gummy to sand. Anyone offer any advice?
The number one reason for gummy spots in a hot coat is brushing too much. Once the wax rises you don’t want to disturb it. If the resin has begun to kick and you keep brushing the wax won’t come back to the top,
Second pic looks like “orange peel”. Caused by too much catalyst or contaminated area.
those streaks are no big deal. They will sand right out.
That last pic to me looks more like you got too much resin on it. Quite possibly moved it while it was kicking??
Are you using uv cure??
If you were messing with it after it started to kick it’s like what Sammy said.
Put some wax paper on the gummy spots. use a finger or a spreader to stick the wax paper down good to the gummy areas. Let it sit for a day or 2 inside a warm area if your glassing spot is not warm. This should get those gummy spots to harden up so they can be sanded.
All good advice…
It is possible for the resin and wax solution to separate so keep it warm and mixed before each pour. Mix in catalyst thoroughly, spread the resin out and don’t fuss with it too much or for too long.
I’d agree that the middle photo looks to have been over brushed or had a resin mixture that ended up shy on wax solution… or both.