Epoxy problems first (wooden) surfboard


I just finished putting on a 4th layer of epoxy on the deck (since I had a lot of ugly drippers on previous layer, my bad…) and hand sanded it. In attachment you find the result: glossy spots remain everywhere. Similar to the bottom (with which I had no dripping problems) but much worse.


1. How can I avoid this? It’s a nice and warm temperature in the room and, at least with this last layer, I was very careful to remove all dust in the room and not touching it with my bear hands. 

  1. How can I make a layer that is thicker: For example, last layer I used a little less than 400 grs of epoxy but only about 1/2 ended up on the board (6’4’’ wooden board) and I already sanded the equivalent of it completely off the board. I can see the fiberglass in some places (after 4 layers?!).

  2. What do you recommend next? I’m not giving up on this time consuming and expensive board :-).


I have no way to know if you’ve tried this or not, but block sanding with a fairly rigid block should eliminate a good deal of your problem.

Hey Dobber. I am definately not a pro and still very green, but I just finished my 5th wooden board so will share what I have learned.


First no way after four coats should you be seeing weave so…

  1. What epoxy are you using
  2. what is your application technique
  3. are you thinning the epoxy at all
  4. How long are you working the epoxy before walking away


I agree with the previous post that you should keep sanding until those glossy spots are eliminated to know it is level; however, not to the point you are seeing weave. If you are hitting weave before eliminating those spots then I would think you aren’t getting enough epoxy on the board during the hot coat. Limited experience here, but no way is 200g enough on a 6’ board… I would think anyway… ?

I think the biggest question I would ask is are you putting those coats on with a squegee or those cheap chip brushes? I have seen both techniques and tried both. When I used the squegee technique it really didn’t work for me. Was going on way to thin and ended up with weave still present after hot coating. I have since only used the squegee for the lamination and then used the 4" chip brush for hot and gloss coat. I have found that with the chip brush hot coat I am able to put a thick enough coat on that I can sand fully removing all “gloss spots” to even the board prior to the gloss coat without seeing weave. 

I just finished a 6’2" fish (so similar size) and was using about 340g for both hot and gloss coat so I would say you aren’t getting enough on there IMO - and make me think you are using the squegee method? 

My process is to aggressively run my hand through the brush gripping and pulling to remove all the loose hairs, pour my Part A in a continuous pour to eliminate air bubbles, microwave for 10 sec, pour in Part B and stir. Then I will pour the entire amount onto the board to get it out of the bucket and maximize working time. Starting in the center I then run my brush up and down working center to rail in slow fluid motion keeping it from just pouring over the edge. I don’t scrape my brush at all here. Then starting at the nose make 45 degree angle strokes fully across the board with slight pressure on the brush at the rails to “squeeze” the loaded brush’s epoxy down the rails for full coverage. Once complete go back to the nose and make constant nose to tail passes with minimal pressure. Once reaching the tail now I will begin unloading the epoxy filled brush into the bucket and start the next pass. I have gotten better at this and find that I am complete then - typically around 7 minutes and walk away after checking that the entire board is covered and no missed runs or drops. I started by following this tutorial. I think it is a good baseline, but I have altered things slightly to suit my flow and what seems to work for me.



I think the key is to get all the epoxy on there and coated quickly so as to be walking away before it kicks so that it levels itself nicely on the board. Initially it was very tempting to keep working it to perfection but the more you work it the worse it gets in my experience. Get it on and walk away and it does the rest.


Hopefully someone will chime in and correct anything I put out here that might not be the best advice, but hopefully it helped somewhat. Board looks nice though mate! Looking forward to seeing it finished

Epoxy can be finicky. You are not the first or the only person to wrestle with this issue. Search the archives for epoxy problems, fisheyes, curdling, glassing with epoxy, etc.

The brand of epoxy used can be an issue, but there are a lot of other factors too.  Humidity, temperature, and others.

At 2 dozen boards I’m no expert, and my methods  might not be the best for your situation. But I will share this: I use a foam roller, and I do not try to put it on thick. If I want anything more than super thin, I roll a super thin coat on, then come back with a little more when that starts to get tacky.

I never walk away from epoxy before it starts to really harden. My worst experiences occurred when I got a smooth beautiful coat on, and walked away. Came back to a curdled fish-eye nightmare. I use a fast hardener and generally roll it out, with a progressively lighter touch, until it gets too sticky to continue.

Use the search function, a lot has been written on the subject over the years.  Much of it by people more savvy than me.

This does not look/sound like a hot coat/fill coat issue to me.


If you are sanding into the weave, yet there are still shiny depressions directly adjacent to that exposed weave, then your lamination was not pulled tight.  Did you use a chipbrush for lamination and if so did you ever pull  resin from rails or nose/tail towards middle?  Alway pull extra epoxy from middle to edges, and if you need to pull resin inward to saturate areas, use very light pressure on Squeegee/roller/brush to do so then once the cloth drinks in what it wants, go from middle to edges using more pressure  incase you pulled the cloth inward.  If you need to pull resin back to the middle often, your technique needs more work.


Lamming is not just about saturating the cloth until its clear.  You want the weave perpindicular and pulled tight and flat and only enough epoxy applied to saturate the cloth and the wood below.  If you use too much epoxy the cloth can float, especially if dry cloth was not pulled tight before.  Then when you fill coat it and sand, then you find youself sanding cloth and still have shiny depressions adjacent to that exposed weave.


Lots of techniques that work well or are of no consequence with PE resin on foam do not apply to epoxy on  foam or wood.


If your wood was dry when you laminated, this can also pose issues as different areas of the wood suck up more epoxy, makes the cloth look too dry, and you then come back and add more epoxy to these areas and then the cloth might float above of the wood and then ‘perfection’ almost requires starting again from middle pulling towards edges.


Saturating the wood first is an extra step, but  then the cloth can easily slide off the board when cutting the laps, and there are potential secondary bonding issues, but it eliminates the issue of some areas of wood being more thirsty than others.  Sometimes these extra thirsty areas of wood also swell when they drink in the epoxy which can lift the cloth if done in one step.


Stop sanding into the weave.  Scratch  only the depressed  shiny spots with sharp new uncontaminated paper under a finger.  Apply a thicker fillcoat and just accept the glass job will weigh more than it needed to, and is not as strong as it would have been if the cloth was pulled tighter.


Unfortunately the likelyhood of fisheyes/orangepeel is higher now. Might want to use soap and water  to remove the any amine blush, dry quickly thoroughly and use gloves and apply antidust techniques.before the next fill coat, and when that fill coat is just barely tacky, perhaps add another atop it, to  build the extra  thickness so that you do not have to sand into the weave.


But, since the wood is not really going to have a signifiant amount of strength added by the cloth, and the weave will disappear under another layer of epoxy, unless you overheated it sanding,  you can get away with sanding into the cloth in some high areas to leessen the amount of shiny depressions. Might save an oz or three of the final weight.  


I’ve given up on attaining polyester gloss coat type perfection using epoxy.  I will wetsand to 2000 grit or higher if I can find it, then spread  a tiny amount of epoxy, 7.5 to 10ML, across one side with a cleaned, thoroughly dried  small pore sponge using a lot of pressure to spread the epoxy super thin and flat. I call this a ‘smear coat’ and it yields a pretty gloss epoxy finish with no further work needed. Pretty hard on fingers and wrist and forearms and the boards racks need to be pretty close to nose and tail.  Good  above and side lighting is required to see any areas were to much epoxy resides and leaves ridges, as well as any potentially dry areas.  A month later I might hit it with polish/car wax.  It has never flaked off.  It can’t compare to a well done PE gloss coat though.


One’s sanding blocks are pretty darned important too.  I like using that antislip stuff one puts inside drawers inbetween paper and the sanding block as soon as one finds clumps forming on the sandpaper near the edges,  and leaving shiny streaks on the wood.  Never use folded sandpaper without a block  except on highly curved surfaces like rails or fins, and sometimes not even on those.


if you’re not seeking absolute perfection then the ‘smear coat’ technique works pretty well, in my opinion.  The finer the grit of wetsandpaper used the less epoxy needed and the easier it is smeared.  use good light and perhaps an extra set of eyes when doing it. Have a new clean dry sponge ready to go if it starts disintegrating. I usually use a piece no larger than 1 inch cubed, and use sharp scissors to remove any corners of the sponge to make it rounder.  Squeeze it inside  thumb and 2 fingers… Overworking it is to be avoided, as is using too much epoxy. That 7.5ml I quoted, is all i use on one side of a 9’7"x23" longboard’s smear coat.  Do not dump the content of mixing cup on the board, but dip sponge in mixing cup lightly and see how far you can smear that amount you picked up.


Doing this smear coat in non humid and warm conditions is also wise, and  let it cure much longer than usual before touching it as it is not thick enough to generate any of its own heat.


You have bumps and deep, sand up to touch fiber here and there, dry clean and brush or roll a new coat, let dry and sand. Next board take more time to sand your wood “flat” so it’ll be easier to laminate flat.

I stop laminate board for others, especially those how never lam a board, because they often let bumped blanks wich is a nightmare to laminate without lot of hot coat resin, or i flat their blank before, always easier to reshape foam than resin…

In addition to the above from everybody: The cloth has a great influence to the result. Although canvass is used very often in surfboardbuilding, i like to use the twill fabric. Canvas, in particular if not canvas from Hexcel which is especially made for surfboards, is rather stiff and does not follow the boards surface easily, especially if you use heavier fabric. The heavier and usually denser, the worse, if canvas you want a loose weave. Canvas must be applied tightly!

Twill is usually easier to be put on, it follows curves much better than canvas. I actually wonder, why canvas is used more often, twill is not only easier to work with, it is also stronger than a comparable canvas cloth.

Your board looks like Paulownia, so you do not need a heavy fabric anyway (of course depending on your material strength). Next time get a 2 or 3 oz twill cloth and you likely will have less problems, you can even use 4 oz, but it is definitely not necessary, with Paulownia, you usually need more water and surface protection properties, than technical. 

My boards are far from perfect and after some boards I do as follows; I always use rollers!:

do a first very light cheater coat directly on the prepared wood, i use about 60gr/m² and apply it very thin, but evenly. This seals the wood pores and prohibits sucking epoxy in the upcoming steps. all steps after this are much easier. 

use a light twill cloth (depending on availlabilty an price between 2 and 4oz) and laminate it with low viscosity epoxy resin, usually you need approximately the same amount of resin than the glass weight plus the resin, which is sucked up by the roller. My resin takes about 12 hours to harden, it is very transparent, clear and UV stable r and should not yellow very much

Do a fill or hot or gloss coat with a higher viscosity epoxy resin My resin is premixed, I do not add any thixotrophing agent and too very transparent and clear and ti takes at least another 12 hours to be able to touch it. 

Usually this is enough and the resin is quite glossy, but I do sand it wet with a 200-400 grit went sandpaper. Before sanding I wait some days, because not properly cured expoxy sands bad and clogs the paper immediately, the longer you wait, the better, but 3-4 days is usually enough.

This is the final sanding, no polishing anymore, because now I do aplly 2 coats of 2K polyurethane marine varnish. Unfortunately the 2nd coat is a little bit more trickier than the first, but if you get used to the stuff, its manageable. (I’m thinking about a spray gun, but by now I use my rollers…)

Although not perfect at al,  I’m quite happy with my achieved results, the Varnish gives the ultimate UV protection for the epoxy and it becomes much harder than the epoxy, but it will take 2 weeks. It shines without any additional treatment.

D14, I am self taught board builder and this is how I do it. 

GLASSING with fiber glass.  Start with bottom.  Notice you can see the weave in the fiberglass after lamination with epoxy




I now Do a FILLER COAT of that fresh lamination when it gets jus past sticky. In my wam climate and using quality resin GREEN ROOM blancho resin And GREEN ROOM west coast fast hardener this is about 20-30 minutes later. Using a disposable chip brush, I pound chip brush on a 5 gallon bucket opening and pull loose hairs off paint brush. Tape bottom part of brush to hold hairs on Brush. I fill in the Lap,(the part that goes over the rail also and have to return there every so often for about 20 minutes to sort out drips and thus saves sanding time.


Sand the Lap that went to deck side, feathering to wood. Havinbg a tight lap will make this chore quick and easy. If your lap is not so pretty, no worries, do get frustrated just sand off carefully. Having a rotary sander with a random orbital mode is best but carefull hand sanding would get it  done.


Now you fiberglass the deck side in the same manner as the bottom    Tight lamination wrapping rails to bottom, filler coat when just past sticky, babysit drips on bottom as necessary


Sand the lap from the deck that wrapped to bottom andI san the whole board with 100 or 120 grit sand paper to feather everything seamlessly, Fix the sharp coners that may ahave not gotten a proper fiberglass lamination with a fiberglass patch and sand. At this point The board should be water tight, A dull finish, dusty and I then wash with soap and water and search for any imperfections. The adequate FILLER COAT mad all this possible. Hand sanding is possible or random orbital sanding for beginners and orbital sanding for more experienced.


FINAL COAT. Epoxy is nice because you use the same product through the whole process. Geen Room Blancho with Green Room west coarst fast hardener is what I will be using for the  FINAL COAT.  Surfboard building lingo can be confusing so with EPOXY builds its LAMINATING COAT…FILLER COAT…FINAL COAT

I place board on a rack in a comfortable position to brush on your final coat. Prepare disposable paintbrush as described prior. I washed board with soap and water prior and it is been dried off with a clean rag, With clean, washed hands I wipe board off with hands . If it feels clean and smooth it’s good to go…  Tape off rails wilth tapeand let hang off do no drips get on bottom of board. I roll up small balls of tape and place behind taped rails to keep tape from wrapping over.

Paur a line of resin douln the middle length of board. Then start in center and stroke rail to rail to nose the to tail. When the deck is totally covered I go length wise starting in cent and working toward the rails on each side. Full brush strokes from end to end without stopping, Look for brush hairs in final coat. check every so few minutes  adding resin by toe drop for any dry spost that pop up . walk away, Pull tape in 45 minutes.



Last post.  FINAL SANDING  URETHANE SPRAY.   at this point you could sand only, sand wtih polish finish.  what I do works for me, looks great on any type board, Has UV protection which is not necessary with the quality resin used on this build.

Shinny board with a few pimples hear and there but overall an A grade. This was a highschool project board built by a 17yo as their first build start to finish. Sanding started at 180g. Lower grits might be needed if final coat was not this nice. So 180 grit, soap and water wash off, spray with WATER Soluble clear gloss or semigloss, Three coats each side. can flip board in my hoat houseafter on hour and do the other side. I let bake in hothouse for a day before sanding. Start and finishwith 1000g foam pad, beware after you do one side and flip board will fly off rask because it is so slippery smooth.


BB30 - nice photo essay / tutorial!

Hi all

Thanks for your reactions and sorry for my late answer. I’m very gratefull for all of your attempts to help me. However, the sight of the board depresses me… It’s not my habbit of giving up but I fear that everything I’ll do, will only make it worse. Since this board creation is a 1 time thing, I 've decided to throw in the towel and ask the help of a professional. I’ll let you know how it turns out. Very impressed by the skills you guys master, didn’t think it would be this hard…



Best epoxy finish on any timber board depends on one thing above all else - timber preparation …a quick wipe over the whole surface with metholated spitits (white spirit) , before laminating also helps to draw any moisture out of the wood surface .

Hey Dobbber,

As mentioned, epoxy can be tough to work with.  I just finished a couple of more epoxy boards myself and the stuff has a lot of rules that need following, the patience of a saint, and some good luck sprinkled in.  Honestly, from this home builder’s perspective, I only stay with it because it’s less toxic.  I may (big maybe) keep using epoxy for that reason, but it’s really tempting to switch back to poly for so many others.  

One place I’ve sworn to completely stop using epoxy, is trying to do any final coats of any sort.  There’s just not enough sandpaper in the world to keep using epoxy for that phase :) 


Consider not giving up on the board yourself yet.  You’ll get it - just sounds like you need to walk away from it for a while and then come back when you’re ready again.