Postby kwik_wurk » Wed Apr 20, 2016 1:03 pm
Yes I have used is successfully, and the blemish you have is within reason. Few comments below:
1.) In addition to your Spectrum patch kit, also buy a black pigment (for gel coat obviously), you may need white. (I typically need black, and occasionally have used Spectrum white gel coat paste as an adder.) --- Due to your hull aging/etc the patch paste will be slightly off, and you need to add a little pigment. (The hull in interior of my whalers are slightly different colors is another example.) --- To color match: Mix the pigment into the paste before the hardener, with TOOTHPICK amounts of pigment until ONE shade too light. Then pull a bit (teaspoon) out and mixed it with hardener and put it on cardboard, and let it set. (Can't remember if it cures darker or lighter, but that is the point of the test.) --- Once cured, compare color match, and adjusted accordingly on final batch. (I would buy two kits...)
2.) Grind down the patch a little (very little), I prefer abnormal shaped perimeter vs a perfect circle or square. (I find it makes fading a little easier and the imperfect edge is harder to pick up with the naked eye.)
3.) Tape of the area, typically I put a very tight tape perimeter around the patch, allowing the gel coat to be over lightly applied. It is then easier (in my opinion) to sand it down, and remove the tape, than worry about over sanding the good gel coat perimeter whilst trying to flatten/polish the applied gel coat.
4.) When mixing and applying be very careful not to add bubbles. Specifically, don't mix in an under over manner like beating eggs with a fork. (The same goes for epoxy resins, I add fillers the night before (without hardener) and let them sit so the bubbles rise/pop.) And when you apply, again try your best to not add bubbles. (Use the small color test batch for practice so you know texture, etc..)
5.) You may want to get a PVA mold release to speed up curing of the gel coat surface. I cut it with a little water to use spray bottle, or one can dab it carefully with a brush (after it has set a bit). -- If it doesn't cure properly (within a day or so depending on temp), just set up a lamp and get some heat on it...it has happened to me, part of the learning curve...
6.) Get ready to sand a lot for such a small spot... go up to 4000 grit. (Have to look for it online, or an auto parts occasionally have it.) It will polish better than heavy rubbing compound.
Good luck
