This problem seems to come and go for me and I’m beginning to think it’s temperature. Has any else had this sort of problem and made it go away? How’d you do it? Was it temperature?
I just finished my second EPS epoxy only a few weeks agao and had terrible problems...I had the blank gas whilst the laminate was curing in hot box - air bubbles blown through everywhere. I then took the top off the bubble with 80 grit before hotcoating - went on lovely but guess what - again it went on to gas off leaving holes right through to the foam...then sanded back ready for attempt 2 - but not before spending a night scouring the archives...where I found some valuable advice that worked!!! Make sure you really push the hotcoat in with a stiff squeegee before brushing it out and make sure room is nice and warm for an hour before starting...once you've brushed it out turn off the heat and allow the room cool - so the epoxy is gelling off in a colling temperature - that way apparently it encourages the blank to suck rather than gas off thus pulling resin into the holes...I let it go off completely before cooking it in the hotbox...amazing result - came out perfect! Ended up as one of the best glass jobs I've ever done!
You can see the mess I had to deal with in the pic!
Cheers
Rich
Are we talking fish eye or bubbles here?
Thurdshade hit it on the head, never glass or hotcoat a EPS blank when the blank is heating up. If its a warm day. Put the blank outside in the sun, then move it back to the garage...in the shade. EPS gasses a bit when it warms up, and they suck in when cooling down. Always work on the cooling down side of things.
Fish Eyes are always an issue of comtamination......always. Used sand paper, old rags, lotion on you hands, dish washing soap, bad quality laytex gloves, something in the old epoxy cup, something in the epoxy bottle (water? Condensation). Final sand before hotcoat should go like this:
1) hands washed with bar soap and hot water. Dry with PAPER towel.....Not the towel your wife uses in the kitchen (wifes and the diseases they carry are the #1 cause of surfboard contamination...make-up, lotions, purfume, sprays etc, etc...all lodge in that contaminated thing they call a towel.)
2) sand with fresh sheet of 150 grit from middle of stack.
3) make sure during this time you didn't go anywhere and contaminate your hands and come back....(think about that front door handle you wife has lotion or lords knows what all over, or that bathroom door knob you slathered with vasoline from your last solo romantic encounter.)
3) Wipe board off with fresh PAPER towel.
3a) Check you racks for disease......fresh tape on the glassing stand is a must, (I've had 4 little contimation spots on a board before, right where the tape hits the bottom or deck.....I used old tape because it was still sticky, but the board before was a ding repair, and surfboard wax as left behind)
4) New fresh container to mix ingredients, 5) look for condensation in all containers of epoxy, if possible keep ingredients in smaller and smaller containers as material dwindles. A full container will get less condensation than an empty one.
5) Do not dilute epoxy with anything....no denatured nothing. If it's too cold don't laminate, or hotcoat. Make sure you are working in the proper temperature for the material you are working with....It's simple, keep it simple
6) Use a throw away brush to hot coat. If laminating clean you spreader with a old chunks of fiberglass cloth. Don't clean then with "acetone, denatured whatever, simple green stuff, or orange gogoju.
Paraniod..maybe, over doing it...more than likely. But I don't get fisheyes of volcano blowouts on my boards.
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After my very first epoxy lamination and and several foot ball sized delams that appeared while I was in watching the Padres game, I have sealer coated ALL my EPS blanks with RR epoxy and micro balloon mixture. As of late I have started using baking soda for the thickining agent, it doesn’t disolve and is inert in epoxy.
After sealing both sides, a nice #150 sand to smooth it out and a new trick I have been shown, where ever you are putting in boxes or leash plug, poke a nice hole in the blank for it to gas out at while going off, haven’t had a one f-up after taking the time to do it right, cuz’ I hated doing it over
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“poke a nice hole inthe blank” good one, Jim.
and use better EPS foam. I just shaped one out of Kens (Segway) super fused foam (1.5 pound) yesterday and dang, that is some good shaping foam. I did not seal it. No gassing. Of course we are having a heat wave here in Florida (that pesky global warming came back), and it is, and I am not kidding you, 95 F in my garage. Couldn’t out gass if it tried.
“Why, it’s so hot were I come from, the people have to live in other places.”
I’d be interested in what GL says about laminating in Tucson.
Resinhead, Just because you are paranoid doesn’t mean the fish eyes aren’t out to get you. To coin a phrase. I clipped this a long time ago from GL:
Epoxy Hot Coat Gloss
Per G Loehr: You’re working too hard to try to make everything perfect and in the mean time you’re adding a bunch of potential problems. After the laminate you sand lightly mostly getting the laps flat and all the high spots down. (He lightly sands all over the board) Wipe the excess sanding dust off with a white Tshirt or a paper towel. Tape off around the perimeter and sqeegee your cheater on if needed. Let that tack up and then brush on your hot coat. I only use 1 cc Add F per ounce of hardener. That's adequate and using more may give you problems. I only use more if it's extremely hot (which it never is in SD) or on a gloss. Rolling on the hot coat may have made it too thin which could have made it bead. Use a brush, a new one, a 3" chip brush. If you push the bristles into the sticky side of a piece of tape before you hot coat you can remove loose hairs. If you don't the brush may shed a bit but unless the board is colored you probably wouldn't see them anyway. Brush on a normal hot coat. It should flow perfectly. This is the way I do it .... simple. I never get fish eyes.
My fisheye days are long over:
Once the board is laminated, I never touch it again without gloves on.
I sand down the laps with 80 grit, then wrap it around the soft block and SCRATCH the entire board. I don’t sand it, I just scratch it up evenly, all over.
Tape off the rails, then take a new, clean paper towel and wipe with DNA… twice. It gets the dust off and minimizes zits. It also removes any oils or adhesives from the tape, your hands, whatever.
I use a new bucket for the hotcoat, and re-use it only for my next hotcoat, and only if it comes out clean when I peel out the old film of hardened resin. Then I re-use that bucket for my next lamination. It’s the wiping of the squeegee off into the bucket when laminating that I’m afraid puts contamination in the bucket…maybe the cleaner I used to clean the sqeegee? I don’t know if it does, I just think it could, so I take the precaution.
I make sure to NEVER touch the bristles of the brush with ANYTHING but a gloved hand. NO TAPE. I’m afraid the adhesive might stick to the bristles and contaminate the brush. I use the brush once and throw it away, unless I have two or more boards lined up to hotcoat… I’ll do them one after the other with the same brush.
No more fisheyes for me.
In nearly all the instances where people have had actual fish eyes and not blows, they have said they wiped down the board with alcohol and fish eyes seem to come and go also with no apparent reason, but back to alcohol.
A result of rapid evaporation, is the condensation of water vapor.
Lamming the bottom on an unsealed blank is a piece of cake, the entire deck lets the atmospheric pressure vent off, but add multiple layers for a deck, this is where roll the dice comes into play, I’d rather add a day to my build and be confident there will be no teeth in my ass when least expected
as Jim said , the holes in the fin area after the first lam helps to gas for the other side lamination and hot coating
and yes some of the new blanks barely gas but erring on the side of caution is a safe bet
Any ideas on how to fix minor fish eyes once they are there? I was thinking to ruff up the spots with 100 grit and then squeegee some hot coat resin back over them. Any other ideas?
he guys, Seeing this image I had the same problem multiple times. I started building awooden board. I did try 4 hotcoats already, bottom, top, complete disaster, then sand everything down, then again, bottom, top, then sand everything down again. So I now have a sanded board but scared to try again. I have been practising on a smaller piece, but I noticed that with the brush I use, I bring in bubble straight away, so is it the brush makes the bubbles? or is it gas coming through the wood and then the brush opens the epoxy for air to bubble? it’s a pretty thick brush I used, but it totally sucks… I tried the trick with the alchohol spray, and it does work, lots of bubble go away, but as soon as I brush it again, bubbles appear again? is the trick first squeezy a bit of epoxy, and then after 1 or 2 hours when epoxy gets tacky do the ‘real’ coating with the brush? please help!
Fish eyes or bubbles?
What type of wood did you use?
I had big fish eye problems trying to use epoxy as a finish for fir.
Do try a change of brush (definitely a cheaper experiment) and what brand of epoxy are you using? I also wonder if epoxy thinner might help. It’s almost as though the air bubbles cant pop through the surface and then flatten when that type of ‘fish eyes’ shows up. Isn’t resin separation (fish eyes fish eyes).
I would guess the air or oils in the wood are probably causing the issue. Similar to a lam that isn’t clean or has a lot of fingerprint oil on it. I would try a second coat on top of the first where the fisheyes are once it sets up, then just sand it good. If it is air, working in an environment that cools just a little while the epoxy sets should help the board shrink vs expand while the epoxy is curing and cause less bubbles.
I felt comfortable checking tackiness with the back of my hand… Never fingertips…