Epoxy glassing, weave showing?

Have done a few epoxies now and the weave has been showing up quite bight after a period of time once the boards have been well cured etc. The question is is it the weave showing up where it has been sanded previous to filler coating or is it sand throughs showing up through the two pot finish paint?? Hard to photograph but ill try to get a few images… Its a shame as really prefer to work with epoxy but this kinda is the only issue I’ve had with it. It seems to show up more with age , i had a wooden board that looked fine on completion and then one year later there are weave patterns showing all over the place and i have re sprayed it but it didn’t make a difference so I’m assuming its under the filler coat??
Anyone have similar issues?

There’s two causes of this, typically. Sand throughs, or a dry lam. Glass may look well saturated during the process, but dry lams will be evident after successive coats of resin.

Nocean, I figure you are pretty advanced in your epoxy skills so you would know a dry lam when you see it. I’d investigate the glass you are using.  I mostly use direct sized glass which is advertised to show a bit more weave.  If it is only where you hit it with the sander, then there’s your answer.  I never hit the weave.  (hahahahaha).  But when I do, I come back with a light finger full using a glove and lightly swipe it. Seems to work.  But I alway see weave around the fin boxes since that is heavily sanded for a smooth surface.

all the best

If your boards have been in the water, then it’s likely a whitener in the cloth that’s turning white with water wicking into it. Whatever you sealed it with either didn’t get into the exposed weave, or you glossed it and burned through when sanding.
Another thing that can happen is that the cloth will turn white from impacts.
You can light sand and reseal and see if clears up.

Thanks guys, im thinking dry lams may be the main cause… also the resin is extra white so ill investigat if its as much of an issue with the clear one im using presently…

I do not understand the problem. I bought a brand new longboard from the Swaylocks adds. Top Quality / Top Shaper / Top Glass work…I can see the weave, I’m happy that I can see the weave because I can tell that the board is glassed with 8 oz cloth…People at the beach love this board…they like the light blue tint and comment on the quality  glass job…and see the weave…and then we talk about volan cloth and classic logs and other stuff…

Is it you show weave of fiber but under resin so surface is flat, like an opaque tint, or do you show texture of fiber but cover with resin, so not as a sand through where fiber is exposed. Second is common with polyester board after some time, it´s resin rétractation of finish coat while résine ended to fully cure, resin loose volume while last solvent goes out. Because epoxy resin have minimal retractation, you don ´t see this except if you add more solvent in resin to reduce viscosity (alcool, xylène…)

Yeah don’t mind weave showing in terms of volan or 6 oz but this is appearing like broken fibres white ( thinking where the cloth has been sanded/cut) and soaks up resin so its not visible then it somehow dries out and becomes visible later again. Is this what you may be alluding to Lemat, don’t quite follow your post:) heres a pic of the worst of it:…

Is it after some use of the board? Before was it clean ? Do you feel texture now ? Wich fiberglass brand? Epoxy resin for finish? If you recoat with resin dose it go good again? On the photo it look like a pré hotcoat lam with a white finish fiber like some brand does. 

I read stuff all the time about 5-7 min lam jobs. Poly guys moving fast and making money…I do not make my living building surfboards. Speed is not a factor.

What I see in the photo???  It’s epoxy so I move slow… 3-5 min just mixing the resin…maybe more just to give it a little heat…pour it out and move slow to get the resin all over the board…I’ve talked to more than one guy…A quality epoxy Lam job takes about 20-30 min…Poly can be forced into the cloth…epoxy needs time to soak in. Gotta move slow to get it right. And then squeege it all out…Your photo tells me that the cloth did not get soaked with resin before squeege time…or you went way to heavy on squeege…balance…

edit…Plain white foam hides many problems.  Wood sucks resin at a different rate. Color makes and breaks deals…

nocean, I’m a big fan of the linen and natural cloths you’ve used in the past. Did you notice any more resin absorption than fiberglass? When I glassed my linen/cloth boards, they seemed to require 20-40 g more per side, but I had no idea what weight the cloth was. I used the lightest cloth I could find at the store. They felt really strong when I was sanding open the fin boxes. 

Ray , yep your right white hides well but im even seeing this on the ultra white boards too. its a combination of weave been hit by sander i think now but alkso like you say maybe lager areas are not enough resin ( slow down good call:) maybe more resin and more time spent squeeging , the epoxy seems to wet out really fast so its tempting to not squeege it as much but prob need to pay more attention to that part of process so thanks for all the advice guys… Ghost , The cloth linen/flax i use is very open weave very much like fiberglass so its not “sheet” linen and it takes resin really well. It soaks a bit more resin initially as the individual fibers are thirsty but you can squeege it well , i use two weights equivalent to 4oz and 6oz but they seem stronger than their glass counterparts and nice flex too so been using them on the bottoms to get more strength…

 

Lemat, board is unused new, no texture to be felt. Im using mainly Aeralite e cloth . This is filler coated with a local epoxy which is similar to kinetix i think, and then sealed with two pot auto paint, I have tried to spray again but does not affect it so im assuming its down in the lam layer. Have seen this on other wooden boards while i was in Bali and thought it was sand throughs…

I bet the problem come from glass sizing, aerialite use a specific finish that allow a whiter laminate but in fact it allow the fiber to be visible, even more when you ding it. Need to be well saturate. Use hexcel with 970 clear sizing. Over working epoxy is not a good way, make resin foaming, so only micro bubbles to expect. 

 

Hey thanks Lemat good tips , ill be trying the hexcel cloth which we can get here and see if it makes a difference:)

3-5 or more minutes just mixing the resin… I overmixed once by mistake and by the time I got to wrapping the rails I had a quickly gelling hot mess that got me thrown out of the glass shop for a few years. Nowadays I try to just mix for two minutes like it says to do on the label and lam it down in 19-29 minutes. Who are these guys you’ve talked to? 20-30 minutes me arse! Step it up man! 19-29!!