major epoxy pin holes

Hello. I’ve been working with epoxy for a short while at home and wanted to make the lightest board i could. It seems I drained way too much resin out. I gave my lam a light sand. during my epoxy hot coat i noticed heaps of pin holes, I tried working them out with squeegee and a slightly thicker hot coat, No success. I glassed straight on EPS foam. Check the pictures. How can i finnish the board from here with the best results??? cheers

Well done Mick Fanning!

Hello Adrian.

long time no see. firstly epoxy is much thinner viscosity and slower gelling than polyester resin so it drains out much easier than poly. you will find lots to learn if you do a search on spackle. fill all the holes/cells in the eps blank first with a light, less expensive filler than epoxy. eps is very open cell, much more than a bad pu blank. or use additives in the resin when you glass like micro balloons to thicken the resin.

now to fix your current Hayden/ JS paralitic style board (you didnt see the ones i did 5-6 years ago when you were just up the road/next door because i kept them in black plastic to keep prying eyes off( well actually to cook/post cure the epoxy in my car) you could make a little mix of epoxy and milled fiber from fcs install kit and make a paste, squeegee this into the pinholes with a credit card. that should fill them up. sand the board and walla…

enjoy the epoxy learning curves

Yeah Dave, been a while. Sooo good to get out of the Gold Coast. waves here are amazing as you know. waves every day. You been surfing much? I herd the beachies have been ok…So you don’t think sand the board first then add the fiber/epoxy mix, if so, why not sand it first? wouldn’t it stick better to sanded resin? or is it that the pin holes would fill with resin dust if sanded?.. it is a carbon railed board, and yes they have been around for a while now. as you may remember i glass and sand all my persional boards and i’m really enjoying Epoxy and EPS foam. Cheers

I’d like to introduce my first son “Cruz Harper York” (nothing else matters)

What do you reckon about using a Qcell/epoxy mix to seal the blank?

that sounds like a perfect mix for spackle! . just use a credit card plastic squeegee to spread it out thin… congrats on the fresh kid. my 4th… a little boy is due in about a month!

sweet. all good. I got worried for a bit, they were the worst i’d see. That epoxy is thin stuff and it was quite hot when i did the bottom.

Does Epoxy get thinner when the surrounding temperature is quite hot? not blaming the temp for the pins, that was my dodgy glassing, should have got my glasser to do it if wanted a a1 job.

I just love all aspects of board making. and its a great joy making a board in its entirety as you all would understand.

Board details:-

5’ 10 x 18" x 2 1/8"

11" nose 13 7/8" tail

5 1/2" wide 1" deep sw tail

low rails

slight single concave 1/16"

moderate consistant rocker

No Hip

9 oz uni directional carbon rail tape two per rail (top and bottom)

4x4 plus back and front patches surf nine glass

fins 3 1/4" x 10 7/8" aim 1 15/16" off nose tip. 7 degrees of splay.

soar foam filled g3 size glassed on with carbon fibre 25mm tape.

#28 EPS blank (team mid strength)

%100 epoxy resin. epoxy filler with wax added.

post cured 55 degrees for 8 hr.

sanded weight 1.78 kg.


Major pin holes.

blending 9 oz carbon rails into 4 oz deck. (few extra layers of epoxy worked fine) two layers of glass on deck would have been better, or glass tape runners maybe.

design aim;-

to keep everything simple with no bumps or staggered rocker kicks

heres some pictures… i’m bored!

Give it a good sand a re hot coat would be my only suggestion.

It is really good to wipe the blank with denatured alcohol before you hot coat.

if it’s your hot coat, your going to have to sand it right, then your going to have to seal it with another coat of epoxy (gloss) or usr a spray acrylic…right?

I’d do an epoxy gloss, then sand it out. The epoxy should fill the pinholes. Do it when the temperature is falling, do it later in the afternoon. If you do it when the temperature is rising, those pinholes might become little volcanoes.

Ok. cool, been asking crew what denatured alcohol is (metho? is not hey!) Cleg laughed at me when i asked if they rub boards with alcohol before they filler with epoxy, he reckoned if they started, Mad Mick would end up shit faced by smoko… they never herd of doing that, another name?

Hi Yorky,

yep, Cleg and Mick would be old-school on epoxy, for sure…that is, they might have tried it and canned it as too hard a long time ago.

If you are doing EPS as opposed to composite/vac bagged skins, you want to seal your shaped blank, or else it will wind up airy. There will be endless input on the various merits of spackle techniques in the archives.

Also, theres no need to squeeze your resin overly hard to get a light lam…Epoxy does’nt have the fume-off factor of styrene based polyester, so what you mix in the pot all goes on the board, rather than 30-40% wafting off into space. This means you literally use less resin, and epoxy itself weighs less.

SP is one of the older systems which turned loads of crew off epoxy 20 odd years ago. In short, it was evil.

Unless they have changed the formula, and I apologise to any Gurit industry lurkers if this is the case, the stuff does’nt rate for surfboards. The metho- (Aust. for denatured Alchohol) rubbing thing has been surpassed as a necessity in recent resins that don’t do whats called “Amine Blush”. This is a greasy film that rises, much like wax in styrene does in a filler coat of Polyester. It needed to be removed, or you next lam layer, filler coat or laps will fall off. In the past, this meant scrubbing off with metho, which meant dirty laps.

I can recommend two Aussie made epoxies you should be able to find…ATL’s surfboard formula and Botecote with UV additive in the hardener.

All thats required with these for your laps and filler coats to adhere properly is a light scuff of the lam weave with 240 on a soft pad, or scotchbrite on an orbital.

Crew will stock all sorts of imported resins…avoid Nuplex and West-system, they fall into the same category as SP. If unsure, sniff the hardener…If it is piss-yellow and stinks like a slaughterhouse, its wrong.

BTW - add a capfull of normal wax in styrene for your filler coats.


Thanks Josh.

Did you end up glassing that first custom your that your mums friends did a foam test on?

what makes an epoxy a bad epoxy? meaning, is it worth giving the “SP” a run (its clear)

Can you give some bad epoxy characteristics?


Hey again Yorky,

Yes I glassed that board, with the foam holes bogged up. (It was all Poly back then…) To this day my mum thinks surfboards are frivolous plastic toys and that I should get a real job! At 36 I really can’t afford to pay attention to that. She, for one, has never had a job in her life…but anyway…

“Bad” Epoxy…well, it depends on the application, because there are more varieties of the stuff than I’ve seen sunrises. The surfboard industry hardly rates a blip in the scale and breadth of the uses of epoxy.

You can get really runny ones that drain out while lamming, theres ones which are too thick, ones with a really slow Gel time, which again can drain out. Some go yellow really quickly, some make your skin go funny, some don’t sand well and some have such a tight mix ratio that if you are, like, 1% out it won’t cure…

The good ones have a nice Gel time…some guys would get a nice surprise…the board can be flipped and the other side done in much the same time as polyester.

Definately give the SP a go…as I suggested, the formula may have been adjusted…I know that the company has been hearing the surfboard guys, and they make the best sandwich foam, Corecell. (Suck suck…)


try using add.f from resin research.

Ok thanks soul, I tried to get RR here in Australia but had no luck. Is there a substitute thats works with other epoxys. Thanks for your help.

how does AF work? does it make the RR thicker?


Hi again Yorky,

Additive F ain’t no mystery…and no, it does’nt make the resin thicker.

I’ve gotten well past the need to use it…as I’ve stated elsewhere, its Toulene with parrafin wax. You will find that normal Wax in Styrene, as added to polyester for filler coats, works as well or better for adding to any epoxy, without the clouding that some crew report when using Add.F.

The addition of wax, just as for polyester, makes sanding the filler coat less likely to clog your sanding discs.

You can thin the viscosity of the resin by adding styrene also, but it is ill-advised to add volume more than 4% of the volume of the resin, or else you begin weakening the resin significantly.

If you want your resin a little thicker, add a smidgin of milled fibre…same stuff crew add to resin when installing FCS plugs.

The surfboard formulas I’ve mentioned before are pretty good viscosity. Only in extreme conditions of heat or cold would you want to play with the thickness. (Glassing in Vicco in July is a chore…but with the resin warmed up its a treat.)

Promise you, there’s no need to source Additive F.


Good answer.