Gloss coat or not

Another question. I have always gloss coated my boards, but am asking who doesn’t or skipped it once with bad results etc…

 

I just finished a board I’m not sure needs a top gloss coat. The fill coat went on so well and even that it looks great. The board is already a little heavy due to using left over cloth and getting glassed heavier than normal (6/4 top and 4/4 bottom). 

 

Does anyone think skipping the gloss coat on top will have negative results to strength? I glossed the bottom cause it needed it. 

 

thanks

If the board is just for yourself;  I would say a gloss is not necessary.  The question should be;  Is the hotcoat/fillercoat so good that I do not need to sand it?  Top and bottom?  

Thanks Mcding. I was just concerned about strength. 

 

the bottom did require sanding so I did gloss coat the bottom. 

 

the top is perfect from what I can tell. So unevenness or blemishes etc… I plan to polish it so there will be very minimal sanding with the finer grits. 

 

just making sure I’m not messing it up structurally as I’ve never not gloss coated the top

I’m sure it’s hard to tell from these pics but let me know from a pros eye if this clearly needs sanding and a gloss coat. Thanks much!


Nice job. I wouldn’t gloss it, probably wouldn’t sand it, maybe polish it lightly or just pat yourself on the back and call it a day. I’ve seen more than a few big-name boards where the finished gloss didn’t look that good. 

Consider what a slip of the sander or a moment’s inattention with the polisher might do. 

Right. As the cliche’ goes; perfection is the enemy of good enough.

hope that’s of use

doc…

It is Doc. Thanks much to all. I am happy with the result, but wanted confirmation the gloss coat wasn’t needed for structural reasons…

 

sweet!! Now I need some surf!!!

Gloss coat is only for cover exposed fiber after main sanding. You don’t want exposed fiber because it don’t look good, even more if you polish, it’s not fully watertight. Most mat finish are varnish spray on sanded hot coat. It do the job so if you don’t have exposed wave after finish no need to had something over. 

Funny you should say “Sweet”  -

A pretty fair analogy to what gloss does is what frosting on a cake does. It’s a coating that makes it look a better and maybe seals it a little from air, or in the case of a gloss, water, from going through any defects in the layer under it. Say, spots missing in the crust on a cake or light spots or sand-throughs in the hotcoat. 

Not really structural at all. 

Yeah, I could have said it’s like the clearcoat that you put over car or motorcycle paint, but that wouldn’t have been nearly as much fun. And now I’m hungry, dammit. Cake!

Hope that’s of use

doc…

Well awesome!

I like bone white so I dont gloss. On my first few boards though I had cosmetic flaws to fix so the gloss coat was really just another fill coat. Ive worked out a lot of the kinks in my process now, so I only need lam and fill coat. If the fill coat is full and the sanding prudent, I end up with a visually uniform and strong glass job. But Ive worked on about 12 boards, so there may be better ways

I like bone white so I dont gloss. On my first few boards though I had cosmetic flaws to fix so the gloss coat was really just another fill coat. Ive worked out a lot of the kinks in my process now, so I only need lam and fill coat. If the fill coat is full and the sanding prudent, I end up with a visually uniform and strong glass job. But Ive worked on about 12 boards, so there may be better ways

Gloss coats also serve to better seal the glass job.   “Sanded gloss” is a good option.   If you don’t want to use gloss then at least consider putting a sealer on it.   

That looks great.  I’d leave it.  It only becomes an issue if you sand it.  It’s gonna get waxed anyway.

Wouldn’t I see discoloration if water was seeping through the cloth and down into the foam?

I assume you’re using PE resin.  If so, that resin continues to harden and become less hydrostatic as it ages.    Microcracks and such.  Gloss coats, whether sanded or polished, will help slow that process down and keep the lamination in operating conditon longer.  

I stopped using PE resin almost 20 years ago because for a home builder there are better alternatives.   As a home builder whose volumes are super low and whose processes are super slow I don’t need fast/cheap as much as I need durability and resilience.     In my opinion, if you aren’t going to glass in epoxy, then at least use vinylester instead of polyester.  VE resins have markedly superior flex and strength metrics, are more hydrostatic, and they handle the same way as PE resins. VE resins are also a closer match to the strengths of E-cloth fiberglass so you’ll get fewer failures, dings, deck cracks, and board snaps.    And if you’ll stick with VE for a fill coat then you can finish with PE sanding and gloss coats to get the same finish as a PE lamination.  

The only reason I can think of for using either PE or VE resin these days is if you’re doing resin tints and opaques.  Other than that the costs of using Epoxy are getting so close to PE costs that it just doesn’t make sense for a home builder to use PE.   We don’t need to turn 8-10 boards a day through our racks and we don’t need boards to wear out in 6 months in order to keep those customers coming back so often.   We definitely don’t need to be adding so much more VOCs into the atmosphere or be using acetone in our work spaces.   

That isn’t a criticism of those pros who have to run an efficient manufacturing operation or control their costs.  Their businesses are already eing subjected to pressures from all directions just to keep their doors open - so they gotta do what they gotta do in order to make a living. 

But home builders don’t have those consideratons.    It’s not going to kill us to spend another $20 (if that) on our glassing or to spend 3x as long on the glassing/finishing process.  The one consideration we do have is that floating VOCs through our neighborhoods on the noticeable scale will piss off the neighbors.   

Thanks for explaining. Ok so you’re saying the fill-coat would benefit me over say 10+ years? The boards Ive made over the past two years had no gloss coat and exhibit no water stains in the foam. Surprised to hear epoxy resin is a poor choice, seeing how popular it is here. Im using RR Kwikick and their TDS sheet lists it as “modified cycloaliphatic amine”. Now Im not a chemist so Im not sure if that falls under the polyethelyne family? When I research vinylester I see that the uncured odor is really really strong. I shape and glass in my living, part of a 600sq ft condo unit. I wear a real respirator and have an air scrubber that cleans things up well, but i still leave the house for an hour after pouring. Either way, more odor is not what Im looking for…unless there’s a low-odor version somewhere

Not immediately. 

Typically, the discoloration (brown foam) happens when light, probably UV light hits foam. You see that in older boards, t’suntan’ look, especially those of highway surfers who ride around with their boards on the racks 24/7, that are exposed to bright sunlight all the time. The foam breaks down, shrinks in serious cases and when the foam is kinda crap to begin with, say old popouts. But it takes a while.Polyurethane isn’t the weakest molecule. 

However, water is interesting stuff, salt water even more so. Oxygen, in a polar molecule, and salts making it even more so. that breaks the foam down faster. If your glassing is flawed, well, when the board gets warm in the air and light the foam outgasses a little, the gas that makes it a foam rather than a solid resin expands, that escapes through pinholes. If your glassing is light, it may permeate through. 

Okay, neat, but what happens when you go in the water? Well, that’s cooler. The board cools and the gases in the foam cool and by the Ideal Gas Laws, they take up less volume, creating a vaccum. And if your board has pinhoes, well, it sucks in water. Repeat it, plus sun exposure to turn it brown, you eventually get ‘freckles’ in the foam. Though it’s too late by then to do anything about it.

This is pretty much cosmetic, no biggie. But it can, in my experience, lead to delamination over time, which is a biggie. Again, the foam is breaking down right where the glass bonds to it.

Now, surfboards are ephemeral things. They don’t last forever unless they don’t get used. They bang into things, doorways, parking lots, rocks, you. You can build them to last, I rented out boards that were made as rentals, multiple layers of 10 oz cloth top and bottom. Surprising number of them are still around, But they’re heavy. Now, the premium is on light weight, which means light construction. And shorter lifespan. Including light glass, hotcoats and glosses thinner than they were. 

And yes, those are more permeable. They break more easily. And they ding more easily. The manufacturers like that fine, a board that’s cheaper to make with a more limited lifespan, well, that is something you use up and replace more often. 

Caveat emptor

doc…

Read the 1st line of my comment.  My (incorrect) assumption was that you were using PE because that’s what most noobs start out with.    Since you’re already using epoxy (which is a good choice) then the rest of my comment is moot.  Not applicable to your situation.    

I still use sealer on my epoxy builds, though.   Water intrusion is a relentless force.  

ah ok, thanks for clarifying!

In depth, thank you. Totally makes sense, and I’ll be sure to consider gloss coats if my boards ever become good enough to keep around for that long! They’re getting better and better and Im happy with the quiver I’ve built,  the guys who buy the boards I dont want to keep are happy…so I think Im headed in the right direction