A portion of my gloss coat slabbed off. Deck side of an 8’8" longboard, hot-coat was sanded to 100Grit. For the gloss I used Reichold Gloss resin: 12 oz with about .25 oz catalyst. It was cooler than normal in the room (about 60F, normally it’s 70F), so I think I didn’t use enough catalyst and perhaps the gloss coat was too thick. Took WAY to long to cure. Like overnight and only after I put a portable heater in the room to get it to 75F.
Anyway, the slabby area left a crater-like surface, and I know I need to re-gloss. I’ve re-sanded the entire deck with 100 grit, though it’s tough to get that cratery area smooth, especially because the resin there is kind of gummy. Question is how smooth do I need to get those cratery trouble spots before re-glossing? Will the gloss resin fill in the craters and sit flat, or should I keep working on the crater with low grits area to get it smooth before glossing?
Any help greatly appreciated. Normally I’m an epoxy guy, so this poly stuff is new to me.
You are correct. The low temp caused the resin to kick much too slowly. Gloss coats are one that you a want a fast cure time on. I’d also guess you went heavy on the resin. Gloss coats should be as thin as possible. After all, they’re only for the shine and using extra is just wasted resin.
Any additional coats you put on now will show, or rather follow, the preceding coat. If the current one has a crater, the next one will. You might get it to show less if you use a ton of resin with a real fast gel time, but that would be another waste of resin, not be very effective, and on top of all that it will be brittle.
Oh, if you want to eliminate that gummy spot in the crater, stick a sheet of wax paper on it and leave it there over night. It might help. No guarantees.
Scuff the craters with red scotchbright and acetone. tape off around the craters and shoot a hot hotcoat over the mess. Sand the whole board and regloss. Works for me. if you are carful you should be able to sand the old gloss resin off so it wont be heavy. I use 80 grit then 120 but 100 should be ok.
Thanks cleanlines! I was hoping you would reply, since you seem to be the Gloss King on here. I’ll give it a shot. There are a few weird spots that didn’t cure right so I’ll tape off and hot-coat all the trouble spots, then sand flush, then re-gloss.
Glossing is just spreading the resin. Two cross stroke passes. Two front to back passes with maybe one last stroked down the rails. if you use the brush right the thickness will be right on. I can’t explain it very well. I love glossing.
But even after thousands of boards over the last 50 years I still keep my fingers crossed. The trick to making boards is not so much how perfect you can do it but more how can I fix this fock up quick and easy.
I have glossed rooms full of boards in temperatures as low as 28 degrees successfully. It is all about even resin coverage. Cross-stroking is essential and even finish strokes with frequent draining the brush on the side of the bucket at any sign of a resin wave in front of the brush when finishing. Start with clean dry brushes- not right out of the acetone, mix the resin super well when catalyzing and go. and thin is better than thick.
I only use Reichold gloss resin. Sometimes I thin it with a bit of styrene. I always run it through a medium cone shaped strainer before adding the hardner. (That may or may not be necessary but I do it out of habit.) Hard to teach an old dog new tricks.
I have always had temp contolled glossing rooms. I try for 70 degrees or so.
I could write 30 pages on glossing and you still may fock up. If you were in my shop I could show you the whole deal in 15 minutes.
I agree with warm resin on a cold board comment. Heat the resin all you want but when it hits a cold board, the brush comes to an immediate halt…thick cold resin in an instant. You gotta push harder and it does not flow. Now I’m talkin’ Canada cold I try to heat my room up to 20 degrees Celsius … Heater blasting at 24 when it’s -20 Celsius outside takes a while. Haha
Was out of town for a week and now I’m back ready to take this on. All the gummy areas are now dry, so I’m going to sand everything flat with 100 and take another crack at glossing. I think my primary mistake last time was not using enough catalyst. Gloss sat wet for too long on the board. Thanks everyone for the tips. Wish me luck. Apparently I still need it, even if I do everything right :).
I try to heat my room up to 20 degrees Celsius … Heater blasting at 24 when it’s -20 Celsius outside takes a while. Haha