Ok so call me crazy but I’m considering skipping the Fill coat on this board, it’s s 6,1 19.5 x 2 squash thruster. EPS Stringer less.
Glass schedule has been
4 ounce flax on bottom wrapped around the rails
4 ounce flax deck patch
4 ounce s cloth bottom wrapped around the rails
6 ounce s cloth deck patch,
Was getting ready to tape it for the Fill coat and then thought,
Why add another 24 ounces of weight, this probably doesn’t make it stronger.
Surely I’m not the first to think this, I searched the forums didn’t find anything, now I’m thinking hand sand down the lap lines and baste some resin around those and my fin boxes and surf it tomorrow. talk me out of it. Tell me why I need a fill coat.
Far be it from me to talk you out of this. Go ahead and please let us know how it goes over the long run. Stringerless or not; You’ve already gone far beyond what would be a normal glass job. My Big question though is; Where did you come up with the 24 oz. figure?? Let’s see 16 oz equals a pound?? So what’s that? A fill coat that weighs a pound and a half?
Epoxy density is 67.4 to 68.7 lbs/cubic foot.
Weight of a fill coat would be volume (oz) of epoxy applied divided by oz in a cubic foot times 67.4.
A cubic foot is roughly 7.5 gallons and there are 128 oz/gallon by volume (7.5 X 128 oz = 960 oz).
“If a fill coat uses 24 oz of resin” (by volume), 24 oz/960 oz = 0.025 cubic feet. 0.025 X 67.4 = 1.685 lb.
@ Vido, BTW I surfed a board I made with polyester resin before adding hot coat to the deck. A hard textured surface can be tough on the skin. How will you insure there are no pinholes in your laminated cloth?
The point of the fill coat is to fill in the texture of the weave. It doesn’t add much weight, and is necessary for a smooth surface finish. You can do whatever you want with your board, but I can’t see any logical advantage to not completing the final layer of glass at least to the point of a smooth surface.
My guess that you’d only need about 8oz total epoxy to fill coat, assuming that the board area to hotcoat is 2.05sqyd and the epoxy coating would be about as thick/what is needed to saturate 4oz/sqyd cloth. By rights you should be using less since you are not really saturating cloth and not doing polyester things like waterfalling or loosing volume to solvents.
Edit: I try to purposely mix epoxy batches ‘short’ and then make up a litttle more to finish (edit: if needed, or pour the extra into divots in my garage floor…) I also weight the cut cloth in grams and use that weight as a starting point for mixed epoxy when laminating.
Ha so I sanded it down and surfed it today, goes good.
I didn’t even bother to throw epoxy on the laps I sanded down And sent it. I think I’ll probably do a do a bottom fill coat that wraps around to cover the lap lines, (my legs where a little itchy after my surf).
Hit the bottom by hand with some 120 and then 220 wet.
Yes you can…But : fill coat is to fill space in textures fiber lam. Normaly you lam fiber and leave a fiber texture, resin only soak in fiber. Not cool to put your fit on it. Probably not fully waterproof so fill coat, sand flat then add finish coat (resin, varnish…) to final sealing the sand fiber here and there.
But you can lam on rich resin side, sand all flat, cut fiber here and there, then wipe secret sauce varnish to seal. Light way but not the most durable. Seems you use lot of fiber and double stage lam process so you can go this way.
I have a board where i made the same decision ,…it’s now 10+ years old and the spots where the glass is not properly covered started to show after some time. Looks like dry lamination now. The spots are growing bigger , and I was actually thinking of taking some photos and asking for advice over here how to deal with it- but then decided to do a 2k rattle can solution next time I’m there.
I don’t think the board takes in water or is breaking down, it feels and looks ok as of now.
I see you already made your own decision, keep in mind that the flax can be a bit hairy with water intake .
Good looking board!
What usually happens over a period of time is brown spots appear here and there. Very similar to an amateur sander who does a fill coat, but then turns around and over sands all over the place. The browns spots are where water is gradually seeping through the fiberglass cloth and turning the foam brown.
If you don’t want to do a traditional fill coat, you can do a thickened slurry. Look up Jimmy Lewis, he did a series of videos showing how he used plastic sheeting as a poor man’s vac bag. He uses a small amount of resin and the same amount of filler then forces it into the lamination to fill any pin holes.
I do that, then for a board that size, I only use about 8 ounces of resin for the fill coat.
My understanding is that you add the fill coat/hot coat for PU and sand most of it off to get a nice smooth finish, then you do the final coat/gloss coat.
I use a satin floor sealer as the final coat instead of resin.
In vids of Jimmy Lewis it’s not the lightweight mastic tech he use, he use cabosil past squegge hard just before brush clear hotcoat, it’s a good way to avoid zits and fish eyes with epoxy hot coat. I like more the epoxy liteweight slurry too but not clear.
That was a terrible idea, i will never do it again.
Not having a fill/hot coat on the bottom was very slow, I addded one almost immediately. The top was less important and it held wax fine.
I’ve surfed it for a few months now and decided to do a proper hotcoat on the top. So I stripped the wax, cleaned it the best i could and pulled the pad. Then i sanded it with 80 grit. Then i hotcoated it.
What a fucking disaster, never gotten fish eyes before but they were terrible and the epoxy never fully kicked. it just left like a waxy slime. I’ve stripped that off, going to sand it again with 80 grit then come at it again with some acetone to really try to get the surface clean. But that was a nightmare.
What a fucking disaster. 10 out 10 will never do this again and highly recommend against doing it to others.
you won’t be able to to do a nice hotcoat with epoxy. This stuff hates any grease/ oily surface. Event if you touch the board with your fingers before doing a hotcoat, you get fisheyes. With wax being stuck in the weaves of the fiberglass, you would have to sand down the whole first layer of glass to get an oil free surface. Honestly I would just take the L and make a new board. Plus, its a great excuse to shape yourself a new toy
You’ll never get a decent coat of Epoxy over a previously waxed surface. Not gonna happen. A Poly hotcoat and then sand. The only possible way to cure your ill.
up until this point its been pretty forgiving, and this was relatively self inflicted. I dont have any poly so just gunna hit with acetone, sand the shit out of it and and then hit again with acetone and hope that gets it clean enough.
Add a water wash in your process. Acetone is a fast solvent, dissolve chemicals but need a lot anf fast work to pull out effectively.
Water wash with scourer (scoth brit or water sand paper) and rinse well could be realy effective after acetone.
so, just read the last half of your thread,sounds like you are talking yourself out of skipping the zen process of surfboard completion.fill coat is definitly a dicy step to skip.no fillcoat is a planned obsolescence expressway.all post waxing use and desperate attempts at saving the project are heartbreaking. bite the bullet,hang it on a wall ,make another do the fillcoat and then a gloss the best surfboard in the history is waiting to become a tactile reality. the best ride of your life awaits your future only after you have ridden a substantial number of waves to get the board wired. what do I know … your board your learning more with every miss take you make, some shortcuts are like self inflicted wounds even treated the scars never go away. …ambrose… the former best board in the history of the known universe radiates the love of the act of riding an ocean wave. cherish it. the next one will be better…
Hahaha, if you only made it halfway through, then you didn’t read about the pain and suffering I inflicted on myself by not doing a full coat. That was a one-and-done lesson. Never again.
