Sun damaged hot coat

I picked up an epoxy SUP for cheap from a buddy awhile back. At the time, I didn’t have a spot in the garage for it, so it lived on my surf rack for about a month (or more).

In that time the bottom got pretty sun damaged.

Fast forward to now, I’m fixing a bunch of dings and cracks on the board, and figured it’d be a good time to sand down the bottom and reapply a hot coat.

There is a bunch of tiny white “blisters” and of course the edge of the peeling resin.

How much do I need to sand so those don’t show on the new hot coat?

I already hit a good portion with some 500 grit (second picture), but do I need to be more aggressive and get rid of the entire original hot/gloss coat? 


Does that look ring a bell to anybody else? To me it looks like maybe UV or something else was applied to an epoxy surface? But then you can see weave under some flaking. Maybe the lam was epoxy and hotcoat poly? On one of the 1st boards I made, not knowing any better, I hotcoated poly over epoxy and it peeled in spots in a way that looks a lot like what’s in the pic. If you put poly on epoxy, it will eventually peel off. Not sure if sun would make that work the other way around, too, but I’ve done several with epoxy hotcoats over poly lams and nothing untoward happened.

Looks like a cheap poly wipe on floor finish/sealer used to hide burn throughs.  

Or a bad automotive clear. 

Anything you put over that your gonna see where the old stuff peeled. 

I would sand it with 150 grit and take it all off. Whatever is on there now is likely to come off later if you leave it. This may be poly hotcoat over epoxy laminate. I had that happen to me about 25 years ago on an early epoxy I built. Real PITA when it happens. You can peel a lot of it off using a scraper, but it sands off pretty easily, just take it easy and don’t burn through the glass.

not a good idea to let a dark skin board in sun long time, even more if there is foam core. Sand of the peel skin with 40 to 80 grit with orbital sander then cover with a new finish coat. you can use epoxy resin or easier with polyester resin , not as durable in time but no problems on good prep surface (ie chemically stable=well cured and clean, well keyed=sanded with coarse grit).

It’s a Factory Polyurethane clear coat sprayed on at the factory.  As stated above;  sand it all off and recoat with cheap floor sealer.  Without seeing a logo I can tell you that the board most likely came out of the Cobra Factory in Thailand.  That is there standard finish.  They vac-bag the wood veneer on with cloth under the veneer and then spray with a clear coat.  No cloth and resin over the veneer.  They yellow quickly and don’t stand up to direct sunlight.  You don’t usually notice the yellowing on a wood grain veneer, but it’s pretty obvious on white pigmented boards that they produce.  Really cheap low grade Poly spray.   “Secret Sauce” (ie “cheap floor Sealer”). Would never peel that way.

Wipe on floor sealer like the Behr Floor and Tile Seal(ie Secret Sauce) is not Poly.  It is a 100% Acrylic.

Not a hot or gloss coat.

Thanks for the suggestion. And as others have suggested, I’ve sanded it down. Still have a bit to go, but you can see in the photos how that coat is pretty “smeary.”

I like the idea of the floor sealer, and have been reading up on some of the posts that you recomend that for. 2 coats with a sand between? How long do you wait to sand?

Now I have to figure out how to unfuck the deck (my fault, and possibly a whole different thread for that).

Poly or acrylic it’s cheap stuff. 

We know you like it. 

I still maintain it’s cheap and probably more often than not used to hide something. 

About $30 a gal.   Goes a long way.  I’ve used it on front doors, cabinets and too many sanded finish boards to think about.  Ten years of use on a front door and it looks the same as the day I did it.  Yeah we all know your the Gloss & polish boy.  Different finishes for different boards etc.  Don’t belittle the things you know nada about.

If you strain and wipe your sanded board down with a tac rag, you don’t have to sand between coats.  Some do and in that case fine grit like 320 or 600.  Just to knock down the tits or fine specks.  Burnish it with a maroon or grey 3M pad and a random orbital.  There’s no time frame in mind.  Just make sure it is good and dry.  You could also just rattle can it with Rustolem Poly Clear satin or gloss.  Then Wet n Dry sand and hit with a little polish.  The rattle can Poly is essentially the same finish you just sanded off.

All hail King Ding in his infinite knowledge! Come one come all and he will reveal to you the things you understand and the things you don’t! 

All hail! 

All hail! 




for acrylic sealer you need a finer sand than what is at last pictures, acrylic sealer isn’t thick as lam resin. at which grit you sand McDing ?

Most of the time I just go over everything with a maroon or grey pad under a random orbital.  I will wet & dry though if My sealer is dirty or I got dust on it somehow.  In that case I lightly sand with water using a worn out piece of 600.  Doing my best to not scratch it.  If I do I then hit it with Maguire’s “Perfect It”.   I only do these steps if I somehow screwed up and contaminated my wipe on.  Otherwise the pad and orbital do a good job.  The more wet and dry and polishing you do though the better it looks to a point.  Which is the point of sanding it off.  I use the Satin.  They also make a “Wet Look” Gloss.  

The key to hiding burn thus is to learn how to sand properly so that you don’t have them in the first place.  A Gloss hides them too.