I am making my first board and I will be using epoxy over a EPS blank. I want to glass it to last. the board is a 7’9" I was thinking 6oz times 3 on the deck and 6oz times two on the bottom. Is that going to make the final board weigh more than a poly board of the exact same dimensions with 6+6 on top and 6oz+4oz? Also is S glass worth the extra money for my glassing schedule? Will I really gain significant strength or is 6oz times 3 of e-glass already stronger than I need. I hope to end up with a board a little lighter than a poly board of the same dimensions but that will be much stronger and last longer. Last question, will s-glass make tinted epoxy glassing look differently? What is the best way to gloss epoxy resin? Thanks
i’ve been trying to determine with certainty the differences between S, E, and K glass for a couple weeks now…and here’s what i’ve learned thus far…
S is about 30% stronger than E, but about 2.5 times more costly
S is stiffer than E, making it more difficult to lap around fuller rails
S was designed for use with epoxy resin (says Greg Loehr)
as for K-glass…it’s strength is supposedly close to S, but not quite, although still far greater than E…it’s cost is LESS than that of E-glass…some say it’s super clear, others say it’s kinda cloudy…and there are some other conflicting opinions on K-glass. all i know for sure is that i’m confused as hell on this subject.
i’ve never glassed EPS before, but your glassing schedule sounds a bit heavy…especially if you go with the S-glass. at least that’s my initial, completely inexperienced, uneducated impression. good luck!
Unless you’re planning a trip to Teahupo 3x/2x 6oz on a 7’9" is overkill. Unless weight really isn’t that much of an issue I would definitely go with s-glass and less glass, perhaps use a stronger stringer. If this is going to be the kids learner board to just ride right up on to the beach/rocks then go for the layered style.
Your EPS blank, unless you botched the stringer install, weighs right around 4 lbs.
Equivelent Clark closer to 8 lbs.
Also, your blank is 1lbs. density foam (about). Clark is closer to 3.5.
You spec glass is average for EPS, any less, you will have dent problems.
Possibly one reason S is stronger is that it’s more 3D, thicker than E or K, and soaks up more resin in a thicker form.
K is flattest weave, but also the stiffest of the 3, so laminations are harder to go around corners, cutting it is tougher, and you can’t move or fudge it around once you pour the initial puddle of resin. It can be easily damaged with careless handling, and also is harder to saturate evenly and clean. It can be much stronger than E, but it can also easily be botched during lam.
You can feel the differences when you surf them. S is stiffest, almost dead. K feels stiff, and rebounds super fast, but more forgiving, and more “plasticy”.
E is softest, easiest on your body, and feels “right” to most surfers.
6 oz, triple deck, double bottom is just about the standard for EPS. I’d go E if its a shortboard, S if its a longboard. But either will be fine for either type of board. No problems wrapping S. Get your blank, your room, your cloth, and your resin nice & warm first.
I glassed a 10’1" EPS longboard with S & the above schedule. Came out 14 lb. My other longboards: a 9’10" Epoxy Pro = 17 lb, everything poly/poly is over 20#.
On 1# density foam use 2 - 6oz. bottom 3- 6 oz deck.
On 1.5 # density do a 1 - 4 and 1- 6 bottom and 2 - 4 and 1 - 6 deck.
For 2# density use 1- 6 or 2 - 4 bottom, 2 - 6 or 3 - 4 on the deck.
All of these will come out weighing less than your standard urethane board and will be strong. For most purposes e-glass is fine, S is a bit stronger and K is just an e-glass that has a very flat weave and is direct sized. Direct sized means they don’t heat treat the cloth before they put the silane sizing on.
warp glass is basically the same as e-glass except rather than being a 50/50 split between the weave in the vertical and horizontal direction, it’s kicked up to about 60/40, increasing the amount of glass in the vertical direction (called the “warp”)…same weight glass but the different distribution of the weave would make for a board more resistant to breakage.