epoxy, eps and glassing color

General Discussion
1

OK I’ve gone through countless posts and can’t seem to find the answer so here goes.

I’ve always done poly and free laps and thought I’d give EPS and epoxy a try. I thought while I’m at it I might as well do cut laps, resin tint, and the whole shebang.

First If I seal the EPS blank first with epoxy and Qcell how well will the resin tint work done in the lam? Since the color won’t hit foam is it going to get patchy looking when I sand the lam?

How do I go about the cut lap? If I lam the bottom and then flip and cut the lap line won’t the small cut to the foam allow more color from the top lam to seep over the lap line? I hear it’s going to run a little anyway so I’d like to minimize it as much as possible.

Last (and I know this is a stupid question but I really couldn’t find the answer) being my first cut lap how do you do the top after you’ve cut the lap line from the bottom lam. Do you not wrap the rails with this lam? and if you do, can you not use color in that lam; as wouldn’t it change the color of the rails where it meets the bottom lam?

2

I can’t help you on the first one, as I’ve been wondering that for a while myself…

But the second two, I think I can.

On cutting your lap, you really only need to cut down into the lap on your initial cut. If you are careful, and you cut at the right level of cured-ness (I have a harder time with epoxy than poly), you can hold the razor level and pull the tape up to the blade edge, cutting it as it lifts.

Try to picture this: You’re standing to the right of the board facing the nose, beginning to cut your lap on the nose end. you cut along the stringer to the edge of the tape to give you a loose end, then cut along the tape towards you to free up a couple of inches of “cut off”. Now, if the razor is sharp (expect to use a few) and the lam is at the right stage of cure (not too hard- won’t cut, or too soft- will pull) you should be able to hold the razor almost flat to the lam with your right hand, and pull the loose end of the lap cut off towards you with your left hand. If the cure is at the right stage, you can hold the razor against the loose end you’re pulling up, letting the tape guide it, and it will feel like it’s “unzipping” against the edge of the blade. I’ve only done cutlaps with poly, but if done carefully, you can use this method to make nice clean cutlaps.

As for the color, if you use color top and bottom, then yes, it will change color where it laps the rails. That’s one of the cool things about classic tint jobs, the rails are slightly darker from two layers of color. Here’s an example:

3

I’m relatively new to epoxy. No doubt it is a tougher material than polyester. The fact that it doesn’t stink out the wife and neighbors is a big plus too. There are some differences if you are used to working with poly. I can share some stuff I learned the hard way…

“First If I seal the EPS blank first with epoxy and Qcell how well will the resin tint work done in the lam? Since the color won’t hit foam is it going to get patchy looking when I sand the lam?” - If the seal coat is applied smooth and the lamination is squeegeed evenly, it should be OK. The color won’t be as deep since the foam won’t be absorbing any of the color. Try a test sample of foam with and without seal coat and you’ll see what I mean. On the sealed foam the color will be mainly in the cloth.

“How do I go about the cut lap? If I lam the bottom and then flip and cut the lap line won’t the small cut to the foam allow more color from the top lam to seep over the lap line? I hear it’s going to run a little anyway so I’d like to minimize it as much as possible.” - If you use good tape and don’t cut into the foam, it shouldn’t be a problem. If you laminate a tinted deck and rail lap, expect some deeper color right along the cutlap and where the rails are double layered. Or, you could do a deck insert… trim the deck lam right at the cutline and then do a clear deck lam/rail lap over that.

That is where I ran into some trouble. By the time the bottom and deck insert laminations cured, everything trimmed and the clear deck lam was done, the epoxy on the bottom and rails was fully cured and I had some adhesion issues. Greg Loehr suggested that in the future I lightly scuff the cured epoxy between coats.

It’s not like with polyester laminating resin where you can build up multiple layers without sanding even after days of sitting around. Epoxy doesn’t stick very well to fully cured epoxy (even with additive F.) Also, I was working in sub par temperatures so even though the epoxy cured OK, it did the amine blush thing.

As has been pointed out by someone on a different thread, timing the cut is really important… too early and the glass will shift, too late and it’s really hard to cut. At the right time, a razor blade will slice right through. Lift the tape a little with one hand and cut with the blade at a bit of an angle.

Greg Loehr, Tom Sterne and others have the epoxy color lamination worked out. On the other hand, some professional epoxy shops will only do clear. Here is a line from Pointblanks website… not sure if everyone agrees:

“We do not offer color currently as any color other than white absorbs heat from sunlight and interferes with the bond between foam and glass.”

4

I did a resin tint & cutlaps over EPS once. Just once. :slight_smile:

I didn’t seal the blank. I’m convinced I like sealing EPS if I’m bagging a skin on, so the vac pressure doesn’t dry out my glass & sink the resin into the foam. But I’m still not convinced its necessary with hand-laminated glass over EPS.

I flipped the board too early - you’d think 2 hours should have been enough - and, even though the cuts went well, when I flipped it back over, the deck glass pulled up in a couple spots. And yes, I had wax paper on my racks. Fortunately, the glass was still soft enough that I could press it back down, but I just didn’t like it. Maybe I laminated too dry, but with unsealed EPS, I don’t think so. Maybe too much resin went straight through the glass & into the foam…yeah, that’s probably it. But still uncomfortable.

Oh yeah, don’t sand your lam. Surform the edges if they’re sitting up and surform off the folds. If your lam is so bumpy it needs sanding, you need to do more lams before you worry about colors & cutlaps.

5

Thanks for all the advice this is kind of how I thought things would go. I wanted to get away from the darker rails and didn’t want to just do an insert. Thinking about things now perhaps I should just add color to my sealing coat and then tape off where the cut line will be. I could pull the tape up there and finish that area with clear and then pin line there after my clear lam cut laps.

Benny the only thing I sand on my lam’s is the edge of the freelap to help it blend but once in a while there is a spot that sticks up and has to be sureformed. This is where I thought the color would be disturbed.

Now I’m a little disturbed by not being able to let the epoxy cure. Does this mean I have to do the sealing coat, lam coat, and hot coat all in one day? With the cooler temps here and extra moisture I think my hardening times are going to be quite long.

6

If you seal with spackle, you want it dry (and sanded smooth) before you epoxy or the moisture from the spackle will bring problems with your epoxy cure.

If you seal with epoxy & lots of cabosil or microballoons or microspheres, you can seal, squeegee off the excess, go have a beer, come back & laminate. You don’t need it to go off very hard because its thick. Its not like doing a step, waiting a crucial 7 hours, 16 minutes, and 41 seconds, exactly and having to run back & nail your lam in the next 8 minutes. :slight_smile:

You might want to look at paint, especially if you don’t want the rails double-colored…

7

Thanks benny good call on the spakel. I’m actually going to spakel let dry overnight, at least, and then seal again with epoxy and microballoons. Now how about time between lam coats (top and bottom) and hot coats. I’m not about to stay up all night glassing (been there done that). So if I do the bottom lam and then wait 8 hours (or hwhatever obscene amount of time it takes), and then do the top lam, how long have I got before this thing fully cures and I’m screwed doing my hot coat?

8

Big A,

only board I’ve done was epoxy and cutlaps.

did a tinted bottom with a cutlap and did a deck insert as decribed above. Had very little bleed issue on the foam; some did squeeze out under the tape on to the lap from where I was remiss in properly sealing the tape to the lam.

as for not sealing the blank; if you want a solid colour, seal. otherwise all those little beads are going to show more colour than the even spots.

if you’re sealing with spackle, going back over with q-cell in epoxy is just going to add colour and work. a better idea, if you really want a good uniform seal, is to spackle, let it dry, sand lightly to take off any high spots and then apply a thin layer of epoxy with a roller; NO FILLER; it’s very easy to judge that you’ve got an even coat in this manner and any little beads will be filled without applying something that will take colour to varying degrees (like filler). The ultralightweight spackle is nice and white.

as has been said above; you gotta work on a relative schedule when you’re working with epoxy; if you lam, then try and get the next lam on with 24h. This is mellow; lam; go have a beer; hang with yer gurl; go to bed; wake up and trim carefully; go to work; come home; surform yer laps; clean up; lam; repeat until complete. If you leave it longer than 48h, chances are you’re going to be sanding a bit to insure good adhesion; otherwise, you should be fine. Same goes for hotcoating; just try and get it on not too longer after your lam went on…this can be any time from when the epoxy is sludgy (kicked but not cured) to relatively hard (tack-free but not ultimately cured).

You comin to grab that variac or whut?

9

Hey GWN, I know I should have called you first.

Ok here is what I’m thinking.

spakel to seal

light epoxy with color tint over intire board (here’s where I was thinking to add a decrotive veneer, Ya i can’t do anything simple)

Lam, with my cut laps ending at the veneer.

hot coat.

Two questions then;

should I add the color to the sealing epoxy or to the lam?

Should I adhere the wood veneer first and then seal with epoxy? I was thinking the epoxy sealer could also be used to adhere the veneer.

Yes I’m still coming for that variac thanks. I’ll call you later. Sorry I have a film that needs to be done by this friday and my editor hasn’t even let me see it yet.

10

I didn’t mean to imply that you had to set a stopwatch or anything. As GWN points out, “you gotta work on a relative schedule.”

A fair amount of time had lapsed while letting the bottom cure, getting the rail line cut, laminating the deck insert, letting it cure, cut the deck insert, etc. The clear deck lam ended up going over the initial bottom/rail lam after a couple of days. The best epoxy bond will occur if multiple lams are done before complete curing of previous layer.

I would not advise trying to do your color in the seal coat… as you squeegee it on, the color will collect in the voids and get scraped off of the EPS beads leaving a blotchy color.

Greg Loehr provides really good customer support from start to finish. I will be using his epoxy again. When I asked him what I could do to avoid any future problems… here is his e-mail:

Generally Additive F does makes bonding reliable. You may have had some

extreme wether conditions that could have run this to it’s limit. Very wet and

cold conditions can make blush issues much worse. Also cold resin when you

begin your laminate. In the future I would suggest warming the resin slightly in

hot water or in a microwave for about 20 seconds before mixing in the

hardener. This will cut down on blush. Perhaps using a bit higher Additive F

concentration 1.5 to 2% instead of the prescribed 1% may help as well. Getting

things done in a timely manner gives better bond as well. I don’t like leaving

areas to be recoated more than 48 hours.

It is fairly rare for this to happen since Additive F made it’s debut.

Sanding any recoat areas will solve all these issues for sure. We usually do some

sanding between each coat just to make our laminates cleaner.

Hope this helps,

Greg

11

Don’t use both spackle & epoxy with microballoons. Completely redundant steps. Don’t tint either one of those either, it won’t come out even.

Paint on spackle looks very even. Then clear lams with freelaps.

24 hours is fine, just don’t go much over. Since I want max. strength in the deck, I usually lam the bottom the first afternoon (falling temp = inhaling foam), lam the deck the next afternoon, hotcoat the DECK the 3rd afternoon. Then, finally, and whenever you get to it - who can commit to more than 3 days in a row, anyway? :slight_smile: - give the bottom a quick sanding & hotcoat that with the mechanical bond of hotcoat in weave & sanding marks being plenty.

I haven’t had any epoxy hotcoats chip off the lams.

I do have an XTR board which has a few chips where the poly hotcoat came off the epoxy lam from a kind of scratching ding, not an impact one.

You also might get a nice result if you just tint & cutlap your deck lam. Do a clear bottom lam with freelaps onto the deck. Next day, tape off the bottom area you want to keep clear and lam the deck glass with tint. That way, your cut will be onto a finished layer of glass and not right into the foam and your tint layer will bond to the rail glass from the clear one. You’ll only get one color but when you’re in the water the color is what will be visible. And when you’re on the beach you can turn the white side up so it doesn’t get too hot & so your wax doesn’t all melt off…

And did you say something about wood veneer too, or is that another project???

12

“Do a clear bottom lam with freelaps onto the deck. Next day, tape off the bottom area you want to keep clear and lam the deck glass with tint.”

If cosmetics are a concern, laminating a tint over freelaps might not be what you want… the irregular edges of the freelap on the deck will collect resin and leave a deeper color.

It is also difficult to get a good tape seal over laminated glass. Colored lamination over a clear lamination might bleed where the tape doesn’t contact the weave of the first layer.

Try it on a piece of scrap foam and see if you get acceptable results before doing a whole board.

13

Well I want to spackel so I get a nice even coat. I also want to make sure that my lam doesn’t run dry by the foam sucking resin as I’ve heard it can even with spackel. Hence the reason for both. As well yes I was thinking of doing the deck with a wood veneer. So I thought that the epoxy sealer layer would help hold the veneer. I will leave these clear and then I will do the bottom lam with a tint so that the color wraps the rails and cut my lap where the veneer begins. Then do a clear top lam and then hot coat.

If this double sealing layer is really redundant then what would be a better way to fix the veneer?

14

HG:

I read through the posts pretty quickly, but maybe this will help. Perhaps the confusion is that you are either going to use spackle or the alternative (which I prefer) epoxy and filler. You don’t need both. The idea is to fill the EPS voids and put a seal coat on the foam to improve your cosmetics and surface finish. Also by doing this you reduce the ammount of resin that will be sucked into to foam, adding weight and possibly creating a dry lam.

Regarding the cutlaps, everyone has covered the bases for you, might add that if you hold your razor blade at an angle when cutting the lap you can reduce your visible cuts into the foam. If you used epoxy/filler on the blank you have the added stiffness of this layer to cut against.

If you don’t want the two tone laps you might consider using acryllics to tint the foam first then lam with clear epoxy. Tape lines sealed with floor sealer can give you a really crisp line. Good luck and lets see some photos.

Tom S

15

Epoxy Color work 2010 with RR2011 Poly Pin Line

 

 

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16

If your finish on the blank is clean spackling or epoxy back filling is not needed.  But because so many shapers are unfamilar with the deft touch neede to produce a clean shape with eps backfilling is necessary.  Make sure that the blank gets reshaped after backfilling to the top of the bead. and blow it off well. 

OK here a good hint, use good tape like a 231 or 233 and double or triple tape and then seal the tape with the edge of a razor blade in both directions.  Remembering it not a race and you will spend more time explaining bad craftsmanship and your reputation will be ruined- even if its the materials fault.  Epoxies weep under the tape at least for me.

After laminating, let the resin cure and sand along the tape line with the tool you have the most control with.  Do not sand past the tape and you will have a nice lap line… 

 

 

17

Don’t forget… you can roll your tinted cutlap edge down into the foam to avoid sanding, particularly with epoxy when it’s cured, but not hard… right after you cut the lap. A wallpaper seam roller works great, but you can use anything. Rolling is better than dragging something, as the friction will tend to fray the edge. I used to simply press it down with the edge of a tongue depresser (one of those little stir sticks), but ever since I switched to the roller, my results have improved.