Don’t forget that a glossy board is slower than a sanded board. 
Idan; The gloss resin is more liquid (thinner) than sanding resin and will tend to run off the board. There are other things that can go wrong as well. In production, it would also take too long to sand down and use more sandpaper. Instead of 400 grit on a sanding coat most shops use a scotch-brite pad and a random orbit sander to give a mat finish. Gloss resin sanded and then polished correctly gives shine. If you want to make a shiny board, there are no cheater steps. It does not take that long anyway! Just my 2c…
Idan,
I have to commend you for your initiative. You’re asking good questions; most have been answered. Here are a couple more things:
Gloss resin is much thinner than regular laminating/hotcoat resin, and it is more expensive.
Unless you are a very skilled laminator, there are going to be lots of resin bumps and glass threads that need to be smoothed out, as well as the edge of the final lap, which you don’t want to sand into excessively. So it’s helpful for the filler coat (or hotcoat) to be fairly thick. This allows you to sand it all smooth without sanding into and exposing the weave of the fiberglass, which would weaken the board structurally. That is the theory. Now, in the real world, things don’t always end up as smooth as we’d like, and it’s not uncommon to expose some of the weave in the course of sanding. And, in the real world, there will often be micro-bubbles of air that get into the glass job. Maybe there’s a spot thet didn’t get 100% saturated. Maybe you’ve worked the same puddle of resin back and forth over the board too much, causing it to get foamy. Whatever the case, it’s almost gauranteed that there will be a few microscopic pin-holes or voids in the final sanded glass job. And, any exposed fiberglass creates a potential path for water to wick into the board by capillary action.
So, the question is: what do you do about it? Many people do nothing, especially with high-performance type shortboards. They are going to be surfed hard, destroyed in a matter of months, and replaced. The next easiest thing is what McDing mentioned. Here in the USA, there are all kinds of water-based clear acrylic products sold for protecting floors from wear. Wiped on with a cloth or applicator pad, they provide a simple way to seal those pin-holes and make the board shiny. The next easiest thing for you, in your situation, is probably to do a second hot-coat, and sand and polish that. It’ll add a few ounces of weight. Or, if it’s somehow available to you, you use the good Reichold gloss resin. Yet another option is to spray it with a clear coat, but this can give inconsistent results if you don’t know what you’re doing.
Some non-surfing friends of mine spent a few weeks in Israel not too long ago. They did show me some beautiful beach pictures from Caesarea. I hope to visit one day myself. Hope all goes well.
Regards,
Andrew
newschoolblue thank you now i understand the all thing and also thanks to every body that comment here. BTW newoceanblue, if you come to israel let me know.
antoher question pop up, is the clear acrlyic seal exposed weave?
what will give me lighter coat, is it the speed finish or the gloss?
im guesing that gloss coat will be more stronger, is it gonna be heavier?
now that im going to do finish coat…im a bit worry about heavy board, because after all its gonna be high preformence board.
last thing, do you recommend about finish coat to ding repair?
I’m in the same boat as idan1500. I am just finishing sanding #'s 5 and 6. I wanted to gloss them. I now get the feeling glossing should be left for when you are good at glassing/laminating, or its just going to highlight the mistakes? Same to be said with coloured resin?
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Yes the acrylic will seal the weave, you can use clear spray paint too. This will seal the weave too.
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Yes it will be light, it will be so light that you won’t notice the difference.
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Gloss coats do not any strength. all the strength in the board comes from the fiberglass, resin is brittle and weak.
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yes resin or gloss will add weight
When in doubt use you common sense in surfboard building. When you add more resin, glass, fins etc. The board is going to be heavier. When you use the lightest materials, and make sure only the minimun of epoxy or resin is being used…then presto, you get a lighter board.
Too many new builders make heavy boards. The main culprit is too much resin in the lam and hotcoat. The hotcoat should be tight, but not puddled with resin, the hotcoat should barely fill the weave. and then the sander should remove all the hotcoat, just to the very tip top of the weave. Really all you want is a glassed surfboard, and not fiberglass that has a thick layer of resin over it.
Also, Didn’t we have this discussion before in another post? Why don’t you just spray it with an automotive 2 part finish? It’s very durable, its very shiney, and it sticks to epoxy. Just sand the board to 220, spray it on, let dry, and buff out with a 600 wet sponge, then buff out with a car polish. Just look at any car repair Youtube for instructions on auto finishing.
it is a stupid question but if the clear paint spray seal the weave why it cant be use instead hot coat?
so if i get it right the bulding process is that:
shaping then lam then hot coat/filler coat then sand it to about 100 grit to get all the shiny spot out and take down any bumps then spray clear paint/acrylic sealer or gloss coat then sanding as need, right?
if i choose clear paint finish should i wet sanding it with 400 grit?
Not quite Lowel,
What I said was to play with it first.
So you have a question about gloss coat? Go buy a quart of gloss resin. Go take an old beater board that you bought off craigs list/ Garage sale for $15.00
Pour an ounce of resin into some dixicups. Check the temperature. Add 1%, 1.5%, 2%, 2.5% cayalyst into different cups. Mix it up, Paint it onto different areas of your beat up board. Check the time. How long until each one gels? TAKE NOTES!
Come back the next day. Try sanding the different areas with different grits. What works best? What sanding pattern works best? Start all over again. Try different stuff. Try to polish it. What works best for you?
So you’ve spent $15 on resin and tried some stuff on an old beater.
Next, break the fins off the old beater. Try glassing them back on.
So Lowel,
The beginner gets to try out stuff before he makes mistakes mistakes on a real board.
Lowel,
Didn’t you ever take woodshop in school?
Here Lowel,
Maybe this will make you feel better.
well…hummm?! I guess paint could be used to seal the weave, but the board would look like crap. You know there is a bit of pride in making a surfboard look good. And paint …if you packed it on would never be able to be sanded down like resin. Paint would get hot and burn, melt and make all sorts of problem.
So, shape, lam, hotcoat, sand with 80-100 to get flat as a pancake, then move to 150-220, or better 320 to remove big scratches,… Then spray with auto clear coat, wet sand with 500-600, buff out with auto polish.
This is amazing, i love this forum, especially the puppy at the end!!! amazing. Id say with glosscoats, don’t try to re-invent the wheel!!! Forget trying to shine your hotcoat up first go. For whatever it’s worth, i sand my hotcoat with 120, hard pad on the deck and bottom, soft pad on the rails (less rpms). Stop there, no need to go any further, as long as its flat. Then Gloss with normal poly resin with wax in styrene, just paint it on with a brush. Then Dry sand with 400. Then wet sand (bit of washing up liquid works wonders) with 600, 800, 1000, 1200. Then G3 and crystal glo with the polishing mop. Lovely!!
LOL ! Been a little busy. So late for the party. But you’re right on cue Mark. Name calling too. Ha Ha. I’ve gotta nice dog. When I need a laugh I read your posts. That’s quite a detailed experiment. Enough time and money tied up in it to pay for a blank. Good advice by some on this site though saves money and time.
Just ran into this …from my experience on prep sanding for gloss… We start with 100 grit flats and rails… Then move to 150, 220 on flats . Gloss goes on like glass. The prep sand is the key and is ok to burn since the gloss will correct any burns and board will be super flat. Sanded finishes in my opinion are only sufficient on boards laminated with 4 oz cloth. The hotcoat goes on really nice. 6 oz leaves a bit more bumps. Then a sanded gloss or a polish is your choice
thats nice. but why sand to 220? I stick with 80 or 100 and then gloss since I will be sanding after the gloss anyway…
whats the reason?
from my exprience with sand with high grits, somtimes it can make the surface a bit bummpy
For a sanded gloss you can stop at 150. We go the extra step to 220 and feel the end result leaves a better surface for the gloss resin to lay super flat and polishes out amazing. Just the way we do it… I never had any problem with the surface being bumpy after higher grits… Only thing I can think of is that your paper is getting clogged leaving blemishes