Made an epoxy longboard for a friend a few months ago. Finished it with a polyester gloss coat. As far as I recall I did the right prep. Board was sanded to 80 grit I think and I cleaned it. Now the board got banged on some rocks and the gloss coat has chipped off in about 4 places. Areas of about 4 square inches. Only one is a ding that has gone through the cloth but when I started cleaning up the edges the gloss just chips away more. It does not seem to have bonded very well at all. It was something I was aware could happen but did not think it would be me.
What to do?
There is moisture under the ding edges so I will need to dry the board out.
Do I:
Sand the exposed areas and reapply more poly gloss knowing that the rest is not sticking that well and further knocks will loosen it.
or
Will I have to chip the gloss off the entire board and refinish the epoxy with epoxy? Or with poly again following some foolproof prep?
I have only coated boards for 2 other people because they wanted the gloss look. My own boards I prefer a 400grit sanded finish which avoids all this stress.
Oh man, this is never a fun situation. If you just want to repair the board, then sand the areas, and re-apply the gloss coat. The gloss coat doesn’t add any strength to the board, it’s purely aesthetic, so if it chips again, then fix it again…and it will. You could try polishing out an epoxy gloss coat. It’s a bit more work but it still looks really good and it’s less temperamental to work with than gloss resin. I have never agreed with mixing an epoxy lam/hotcoat with a poly gloss coat unless it’s a wall hanger. We also carry a few different epoxy resins that have a great finish, and lay flat similar to a poly gloss resin. Good Luck!
ilovesabrina, You said you cleaned it after sanding. How did you clean it? Also I have been told to that you get better adhesion with the poly if you gloss not long after sanding. At least the same day. Definitely not as durable as an epoxy gloss but shouldn’t just peel up. The thing I hate about glossing with epoxy is if you have sand thrus it takes much longer to fix. The epoxy will shine pretty good if you sand up to 1500 grit. By the time you get to 1500 the board is so slick it’s hard to handle. regards Dave
If you hit rocks and get dings with some gloss coat chipping the solution next time is to miss the rocks. This is a repair. A poly board would have had worse dings.
After some thought I think it will be easier to just repair the damaged areas of gloss coat. I expect my friend will not expect me to go to all the trouble of chipping off all the gloss and doing a quality epoxy gloss finish especially if he is going to scratch it on rocks. I have had not had too much success getting a good finish on epoxy (my much preferred resin) but then I probably have not persevered enough. This has encouraged me to have a go on my next board. I have just finished a mini simmons that was epoxy on xps. I gave it a spray paint finish that I was not happy with. I was tempted to give a poly gloss coat but am glad now that I didn’t. An epoxy gloss coat would be great but I live in the UK and am not sure what is available here. I use Resin Research for my boards and I am happy with the sanded finish I get. I’m sure some would say that you can get a good gloss finish with RR alone. If it takes longer and thats what people want then they will have to pay accordingly.
I cant remember now how I cleaned it. I think I brushed it off, and cleaned it with either acetone or denatured alcohol. My workshop is pretty dusty so its possible it got on the board again. I considered washing the board with soap and water but was concerned that after a day or so it might not be moisture free. I think I did the gloss coat the day after sanding. I recall doing 3 epoxy boards last year with poly gloss. The others have not had this problem. I repaired a ding on one and it showed no sign of chipping but maybe my preparation was not the same. All my boards have been RR epoxy with Seabase Taupo gloss resin. All 3 guys wanted a shiny gloss finish even though I told them my personal preference was pure epoxy with a 400g sanded finish to keep labour coats down. Also the first gloss epoxy job I did on a board I was not happy with. All this is a good learning curve. I’ve also had the problem of sanding away the gloss leaving duller epoxy patches below. I am a garage board builder and make it clear to guys I make boards for that I cannot compete with factory quality but at the same time I like my boards to be relatively well finished. Practise will surely make perfect.
Sound advice thanks Greg. A poly board is no comparison. I was taking photos the other day of my recently completed Resin Research epoxy mini simmons. It was standing up against a bush, the wind caught it and it pitched forward, nose full force onto the concrete patio. Only a slight scratch to the paintwork. Nose completely intact. If it had been polyester it would have been been surely smashed. If it had a poly gloss coat it would have surely chipped. Perhaps best to avoid rocks and poly gloss.
Poly resin doesn’t really make a chemical bond to the epoxy. If you sand the epoxy to 60 or 80 grit, you’ll get a mechanical bond, but it will still come off if dinged hard enough. Feather it in as best you can with 80 grit, and then feather only the gloss back even further using 220 for a good overlap. Regloss, sand, polish, etc. Once you damage the poly “shell” and water gets under it, it’ll start coming off in sheets again.
I took off a poly gloss coat with a razor, chipping away, pain in the butt…but, after adding another 4 oz. epoxy, then sanding to 1500 (1000 looks good) it glows.
This is what worries me. The board was in the water for several hours after dinging so moisture could have travelled fairly far and I cant see how it will really dry out properly.
The crack to the cloth was a straight line of about half an inch but the gloss chipped off around in about a 2 inch radius.
Don’t worry, sand all poly gloss that peel with 80grit then recoat with poly. I do all my finish with poly on epoxy because it’s easier, cheaper and better against UV. I found that poly ISO is far better for gloss but cost near the same as epoxy in small package.
I lam with epoxy and fill coat with epoxy then i post cure in hot box. Sand flat, grit 40 with orbital high orbit, vaccum and finish coat thin with poly.
the series of wood boards I built for a movie got banged on the rocks at Malibu, I lam’d them epoxy and glossed poly, they chipped around the impact, but feathered in when repaired, leave them hand sanded with # 6o grit before gloss
I’ve seen a number of epoxy finishes that are not sanded and have a good shine. Sand the hotcoat smooth, wipe with a tack cloth and apply another coat with additive F (maybe thinned with xylene). The only sanding / polishing needed is at the tape lines.
I have tried this several times with Resin Research but never seem to get a good result. Its always seems uneven and needs sanding again. Would adding LOTS of Additive F help?. A friend of mine gets a good result with Surf Clear or Glass One Epoxy Resin but I have not used it because its much more expensive. I have made some fins using West Epoxy Resin which is more viscous and you get a beautiful smooth finish that requires no sanding but I have not used it to make boards because it does not have a uv retardant.
Have not got around to doing the repair in question yet. Had the day off yesterday but went surfing instead.
