I just laminated my board (EPS with epoxy) and something went wrong.
The lam (whole bottom) hardened, but it’s not rock solid as it is supposed to be. I can easily push down the lam into the foam with my thumb even if it seems to have cured. I gave the resin 2 days to cure and it’s still kind of “oily”. I was using a local resin with a 5 to 1 ratio resin-catalyst. The temp was about 24 C and it was humid but I still used the 5 to 1 ratio. Didn’t seem to cause a problem for the resin to kick in because when I was laminating the resin did “kick-in” in about 10-15 minutes and it got incredibly hot (almost burnt myself) and the resin hardened in the pot.
Do you guys know what might have happened and if there is a way to salvage the lam?
If you used 1# EPS, it just sounds like you need more glass cloth. You didn’t say how much you used & what weight, but double or triple 6oz is just about minimum for 1# EPS.
The ‘oily’ feeling on the glass is the amines that ooze up during hardening. You can wash them off with water if you can then make sure your board is totally dry afterwards. Using alcohol is better - denatured is best but vodka would probably work too - and it will evaporate clean & dry. You have to get that off before you can add more glass or a hotcoat.
You can also get spongy EPS/epoxy if you laminated way too wet. That means your fiber/resin ratio is way off and the skin is too flexible. Or you worked really slow & too much resin drained into the EPS. Did you seal your blank? How many oz of resin did you use with what size board & how much glass? Beware - might be bad news.
Some epoxies go off quicker than others but with all of them it’s a good idea to get it out of the pot and on to the board when you are done mixing. Resin in a confined space gets very hot and goes off quick just as you describe. Greg Loehr has posted heaps of great info on laminating with epoxy. Check the ar…
As far as denting easily you could add more glass. Or you could just surf it. One of my favorite short boards has a concave deck, though it didn’t start off that way if you know what I mean.
The EPS was from Home Depot (in Canada) so it might be # 1, I tried to find out with the clerks, but it wasn’t too successful. Anyway, I used the only EPS they carry.
I had sealed the EPS with spackle. I can’t really tell you how much resin I used. (some on the board, some on the floor, some cured in the pot) What I can tell is that it really looked like a regular Poly lam. I don’t think it was too wet beacause I worked it in probably around 10 mins and I squeegeed it pretty well.
How much resin should I use for a floaty 6’5’’ x 19.5’’ x 2.5’'?
I have a feeling it could be because EPS #1 because I only did 1 x 6 oz. It just felt so different from a polyurethane/polyester. Just so spongy (a nightmare for the dents on the deck!) But after 2 other 6 oz layers it should feel decent, right?
As for the amines, I’ll probably use the Vodka as I prefer the bitter taste of denatured alcohol!!!
The oil is blush, real bad on most 5 to 1 resins. Sounds like you’ve got a West System knock off. Not the best for boards. Be REAL careful if your putting in boxes. That stuff will melt the foam away real quick.
This is not a surfboard epoxy. Next time use a surfboard epoxy and things will be much easier.
Oooo. sanding that stuff is a nightmare. Been there dude, it’s no fun.
You’re right, if it was from HD, it’s 1#. I’ve been there.
1 layer of 6 oz is impossibly light for that foam. Add 2 more & you’ll still have a lighter board than if it was pu/pe.
For a sealed blank (or a board with a layer already on it ) 1.5 oz per foot of board for one layer of glass. 2 oz/ft. or so for 2-3 layers. And that should give you enough to play with the laps & spill a little on the floor. But get it all out of the bucket as soon as you start pouring…
Where you at up here? We get a little more water in the air than they do down in the states so HD does carry some 1.5#; it’s slightly green in comparison to the ultrawhite 1# they have in stock…it’s a wee bit more money too, but worth it as it’s easier to shape (not so floppy), won’t suck up as much resin or moisture and comes in 3" thickness if you want it. I bought mine from HD here in Vancouver. Your core will be substantially lighter than a corresponding clark blank…use the weight advantage and lam as recommended above; 2 x 6 bottom, 3 x 6 top and you’ll be laughing as far as dents and dings are concerned.
As for the epoxy…you’re on your own there…5:1 mix ratio is pretty tight; doesn’t take much of a screw up to get yourself in the 4:1 or 6:1 range; hope you’ve got pumps. I used West 105/207 for board #1; 3:1 ratio with pumps; didn’t exotherm; didn’t blush; is yellow; does smell a bit; quite pricey; using RR this time around on board #2. Best to look for alternatives in the future…there are some available up here; barring that, if you’re like the rest of Canada and in the 90+ percentile that lives within 20 kilometers of the border, get some RR shipped to the south side of the nearest crossing and go pick it up…
I’ll be doing 2 or 3 layers bottom and 3 on the deck all 6oz. If it lasts, good. If it doesn’t, next board will be better!
I think the combination of #1 EPS and bad resin (West Systems knock off indeed) was probably the problem.
Thanks Benny1 and Greg for the info on the amount of resin.
I’ll use RR next time and go pick it up in the US. Luckily, I have a friend in Vermont so it won’t be too difficult to go pick it up.
GreatWhiteNorth, I’m in Montreal. I wish I could have the waves you guys have on the West Coast! This summer wasn’t very good here on the East Coast. I’m pretty happy though because even though I live 6 hours from the nearest spot, I still get to surf about every other week. I’m thankful I have a girlfriend that also surfs !!!
) 1.5 oz per foot of board for one layer of glass. 2 oz/ft. or so for 2-3 layers. And that should give you enough to play with the laps & spill a little on the floor. But get it all out of the bucket as soon as you start pouring…