hey guys new here on the forum. Currently making my first board pu blank, epoxy resin, 4 oz cloth with a 6 oz deck patch etc. shaping went really well and now the lam is being a nightmare. Finished my first bottom lamination last night and it’s got what look like big air bubbles all through it. I’d love some advice on what to do and tips for laminating the deck.
Welcome to swaylocks!
I can’t tell exactly what’s going on there from the pics, but looks like too much resin, and the cloth "floated’ in areas, resin appears as pooling in others, but in reality too much resin everywhere methinks. You just need enough resin to wet out the cloth decent, then the fill coat fills in the weave. Can’t generally do both in one coat.
I don’t actually see any air bubbles, but maybe its just the pics. I don’t know what to say, but if it were mine I would block sand the whole thing down to the weave (sand out all the lumps and bumps), and re-glass it. 4 oz. is a bit harder to work with than 6 oz, I would glass with 6 oz. until you get the hang of it. Bummer, but fixable.
Including couple pics of an epoxy lamination over poly foam awhile back, this is how I like it, then I fill the weave next coat, as I say.
Others may have better suggestions, I’m just a backyard builder.
For epoxy novices, I recommend adjusting your technique to suit your skill level. The pros can laminate a bottom in 8 minutes and get a nice tight lam with the primo balance between resin and cloth. They’ve acquired the eye and the feel for that as a result of completing hundreds and thousands of these glass jobs.
The rest of us mere mortals will be working more slowly and deliberately. That can be a problem with epoxy, so ONE WAY of compensating for that is to work in smaller batches.
Here’s what I do.
I use a cheap digital kitchen scale ($20) to mix my resins. That will enable you to accurately mix even the smallest batches of epoxy, like for ding repairs or leash plugs. You’ll recover the cost in resin savings in your first couple boards. And you can use any type of plastic cup. i often use the cheap 8oz plastic cups they sell at the store for $5/50. If you measure by weight you can resuse your cups.
I mix 1/3 of the amount I plan to use at a time - mix slooowly and smoothly and try not to add any more air bubbles to your cup
I pour the first 1/3 onto the bottom by pouring it out in ribbons all over the flats of the board. Empty your cup completely. It looks like pouring honey out of a squeeze bottle. The reason for pouring it out all over the board that way is to limit how far it needs to be spread before wetting out the cloth. The more you move epoxy around the more likely it is you’ll cause it to froth or otherwise add bubbles. As well, letting epoxy sit in a puddle or at the bottom of a cup will lead to it setting up faster. Sometimes fast enough to smoke (aka exotherm). Distributing it out all over your working area means none of it is puddling. The other thing it does is by pouring ribbons you won’t get as many resin-rich spots in your lam from not spreading the resin out evenly.
I let the resin soak into the cloth for a minute before moving any of it around, and then I use the spreader to work the resin from the inside-out. If you move at a slow-to-moderate pace you won’t be getting any froth and you can go back-n-forth a little until you get your saturation. Epoxy doesn’t “soak” as quickly as regular PE resin so the technique that works for the PE glassers is too quick for novices to use with epoxy.
Alternately, some backyarders will mix half their resin at one time and work from the stringer out to the laps, one side at a time.
After you’ve spread out all your resin, go back, mix another batch and go after your sides, rails and laps. One side at a time. That way when you go to wrap your laps the resin will still be reasonably fresh and you’ll have plenty of time to wrap your laps before the resin gets going.
That’s not the only way to laminate with epoxy but it is one way, and it takes all the time pressure off you. I think you’ll get a more even distribution, too.
Go to the sticky links at the top of the general discussion. John put up some great links one of which talks about epoxy for beginners.
hey thanks for all the replies that board and logo looks sick. do you think i could just sand back the resin and get away with not putting another layer of glass on? im afraid if i put another layer on the board it would be really heavy
Just telling you what I would do if it happened to me. Like I said, the pics are hard to know for sure what happened, but if the cloth floated you’re gonna have to sand through it, because there is resin pooled underneath the cloth. The main issue isn’t weight, but its the rippled surface. You’ve got to sand until it flattens back out again, and I strongly suspect that’s gonna entail sanding through the cloth.
I can see that you’re focused on getting the lightest possible glass job, but to do that you kinda have to get it right the first time, not too much resin, or too little. Anyway, the next one’ll probably be lighter.
I would still recommend glassing with 6 oz., & follow godaddy’s and Greg Tates’ suggestions. Pros use boards with 4 oz cuz they get their boards free, by the dozen, so they can afford to snap em & replace em, no big deal. The board will still be rideable, but you may have to cut back on dessert for a couple weeks to make up the difference, haha, just kidding.
Anyway, that’s my take on it, maybe someone else has another idea.
Would like to see a much closer pic. Those look more like dimples. Can’t tell if they are dry or blistered. It actually looks like a problem related to air temp or mixing. The only time I have seen “dimples” they are temp related. Caused usually by a sharp cooling and the rise back to norm is what I have always assumed. Could be contamination also. Without a closer look I would say they are not air bubbles. Dry spots from pulling the squeege to hard maybe.
Gdaddy’s advice is excellent for anyone who wants to insure NO issues with an Epoxy lay up. I admit that other than dumping my pot out on the blank, I don’t do it exactly the same because I have never had any real issues when Glassing with Epoxy. I have a history with Poly and actually find Epoxy to be easier overall to work with than Poly. Poly is fraught with little issues that require “avoidance thinking”.