Hi. I’m new to Swaylocks (I recognize many from longboard.net). I searched the archives & the current topics first, and I apologize if this has already been dealt with.
I have about 20 years of ding repair experience, even putting back together broken boards with added stringers, ‘donor’ noses, etc. I have done ding repair on hand- laid epoxy boards like Patagonia & Velzy XTR.
I have completed shaping of an EPS longboard blank. I made it by gluing together 8’x 2" thick sheets of Home Depot insulation. I took my time, weighed everything down carefully & long, and it worked out well. I cut in a pre-sized plywood stringer to shape the foam down to, once the glue was set. I filled errors and gaps along the stringer with spackle. The shaped blank looks great. Its 10’1".
I’m planning on using clear epoxy resin & catalyst type B from Tap Plastics. This is a 2:1 ratio, so the mixing won’t be too difficult. Gel time is 25-35 minutes, and it comes out colorless. I’m doing double 7.57 oz s-cloth top & bottom. Cut-lapping the rails.
The questions (thanks for your patience, anyone still reading!)…
Do I really need to seal the whole blank? Is it to aviod delamination, or just to save use of resin?
How much resin + hardener should I mix for each lamination (bottom & deck) for a 10’1" x 23.5" longboard with double 7.57 oz? I was thinking about 1.5 gal each, but don’t really know how to estimate in a scientific way.
Any problem with doing the gloss / top coats with poly resin, surfacing wax, & MEKP, once the EPS is totally sealed?
I seal my eps , from my understanding it is so (as you said…) it doesn’t wick a lot of resin in while laminating. I would use RR epoxy resin, very easy to use and almost no fumes, easy clean up,flows fantastic…why go back and use that poly crap(my opinion…) after starting with epoxy?? Use the RR epoxy…you won’t be sorry. Have fun…peace and waves…
benny I’m finishing up my EPS board 9’6" in the next day or two. Sealing it keeps the resin from soaking in and leaving dry patches under your cloth causeing delam. It’s VERY easy to seal. Just go to west systems and get some Collodial silicate (basically q cell) mix it up to a paste and put it in your clear resin. Don’t use west epoxies as they turn yellow
you can also use lightweight spackling…easier to sand, just be sure to let it dry completely. I add water to mine and it flows out really smooth …very little sanding needed…have fun…
I buy sheet plastics from TAP when I absolutely need it NOW, but their prices are way high when compared to other sources. Resin prices??? I don’t know, but it would be wise to look around…
here is some info from G.Loehr on amounts for a general idea…
6’ and under - 9 -12 oz. bottom 12-15oz. deck 7’ and under - 12 -15oz bottom 15-18 oz. deck 8’ and under - 18 - 21 oz bottom 21- 24 oz. deck 9’ and under - 24 - 27 oz bottom 27- 33 oz deck
Hot coats run just a bit more than an ounce per foot. For instance a 6’ board would take about 7 oz. per side. Longboards, 9’, take about 12-15 oz. per side. If your glossing use a bit less than a hot coat. We use 3" disposable white bristle brushes for hot coating. We don’t clean them. We use them for one batch and pitch em. Not only do we feel that their not worth cleaning but we’ve also had problems in the past with contamination from cleaned brushes which manifested itself in bad hot coats. New brushes always make for clean hot coats.
I’ve tried a few things, spackle, cheater coat with just epoxy and no sealing at all. I guess it depends on the EPS, but IMHO sealing the blanks is more hassle than anything else. If you must have the lightest possible board, then it might be worth the trouble. But you add weight when spackling as well. Unless you save more than the equivalent weight in epoxy, the spackle was a waste of time IMHO. Then again I tend to glass boards heavy and strong(2x6oz bottom + 3x6oz deck + patches) so a pound or two is not going to make a huge difference for me. Bdw. I’m using less resin than Gregs guidelines even without sealing and I’m a crappy two board a year hobby builder.
I figured I was bound to get a little conflicting info if I paid attention long enough. Sorry if it seems like I’m replying to every post - I’m trying not to, I swear.
I think that’s why I was looking at so much mixed resin. I had to skin & re-glass a whole longboard hull once before when I cut in a second stringer. I used, on advice, about 12 oz and it was just right. That was for 1 x 10 oz volan. I figured 2 x 7.57 oz and I’d bump it up to 16 oz, and then 8 oz more in case the soaking in was extreme.
My daily driver is a 28# 10’4" Velzy '63 model. And I’m 220#. An extra half pound of resin ain’t gonna break me up any…
If not, I wouldn’t reccomend it in particular, I found Resin Research to be excellent, much easier to work with…If you already have the Tap stuff, it’s not the worst stuff ever, but it blushes a little, and yellows. I got some to familiarize myself with epoxy and lay up some foam tests, and batches I left outside began to yellow in the thicker parts…I don’t think it makes it weaker per se, but doesn’t look as nice, and it may need to be protected with paint or poly.
As for the blushing, it’s very slight, but enough to cause poly adhesion problems. Sand extra well, and wash with denatured alcohol. I didn’t test it with poly, so it might be fine, or not.
Wells-I did already buy the Tap. I’ve used it before, and as long as you use the type B (Medium) hardener, it stays clear. I’ve also used the type C (long) because it stays open for 35-40 minutes and I was turning a squash into a swallow tail and knew I’d want to work it to death. But it yellowed.
I also tried the west systems (from West Marine…go figure) on a Patagonia ding repair. It yellowed, spidered, and eventually became so brittle it cracked off. And it was just a re-lam over a 50/50 rail…
I’ll get some RR next time. Or maybe I’ll hot coat with it, if I run low on the Tap. Thanks again
No problems with pigmenting epoxy to achieve light tints. Add some white pigment and your colors take on an opaque quality. This takes care of your discoloration and give you some UV protection for the foam. Test the TAP product first if you decide to color it.
I agree on the quality of R/R epoxy products (don’t forget the Additive F advantages). Greg’s products are time tested and made specifically for board building.
Hmm can’t find my reply post I must have gone off line accidentally and then tried to post it so here goes again.
I mix 150mls of resin with qcell into a really, really thick paste and sqeegee this into the foam on one side, then straight away while this mix is still wet I laminate on top of this. As it is so thick the resin doesn’t go thru into the eps foam. As for the amount of lam resin, I weigh my glass and then mix the same in resin weight plus I add another 25%.
I tried poly over epoxy as a gloss coat with bad results and posted here in the forums for advice and a few guys didn’t recomend doing it. I also contacted my resin supplier and here is a copy of his email to me. “Firstly, polyester does not go well over epoxy. The reason is that unreacted chemical amine groups in the epoxy deactivate the polyester catalyst. This results in the polyester next to the epoxy not curing fully.Epoxy can have its cure speed accelerated, firstly by using fast hardener and then by using epoxy accelerator. I bleieve that it would be possible to arrive at a cure speed which would suit your needs.As to the final shine. You may have a point there. Epoxy is not suitable as the final coat on a surfboard as it is not UV light stable. AFter 6 months or so of sun exposure it will start to chalk. If normal hardners have been used, it will also yellow. (Non yellowing hardener is needed to avoid this.)Those really glossy clear finishes you see on boats are a combination of an epoxy coating followed by epoxy two pack high build easy sanding primer and a two pack polyurethane top coat. The top coat conatins the UV screens which overcomes the UV problem.Whether this is economic for a surfboard, I am uncertain.I am aware that some surfboard manuafcturers are using polyester over epoxy. This is done either by using a specialised epoxy which does not disrupt the polyester or by using a barrier coat (e.g. 2 pack polyurethane) to prevent the amines from coming into contact with the polyester.”
After reading about EPS/epoxy homebuilts here at Swaylocks, and chatting with Oceans23 and Greg Loehr, I’m in the process of shaping/glassing a Lis Fish … Greg recommends DAP Fast’n’Final spackling watered down to a creamy consistency, brushing it on and sanding it smooth prior to laminating. Since it’ll improve the bond and lighten the finished board, makes sense to me. I’m using RR 2000 resin, fast hardener and “F” additive, and 6oz E-glass. Haven’t decided whether to do rail channels or stringer the EPS. Good luck with yer board, Benny!
Hotwire cutter for the rocker. It’s way easy to make and will save you much time compared to shaping the rocker from a square block of foam. Check the archive.
