lamination question

[Basketcase]

Hey all. I've had an issue that may or may not be a big deal. Im using 1708 and vinyl ester to raise my stringers. Its a 4 stringer 20. So far I have one complete but in certain spots the glass is slightly white like there's air in there. They are small spots and not many of them but I just have to ask. I know that I originally got plenty of resin in there. I used the squeegee and worked the resin bubble back and forth many times before removing the excess. Could it be a viscosity thing and resin is draining out after I leave it? Thicken with cabosil just a tad? Ill post up a pic of what I mean but I suspect you may understand already. I've been doing fiberglass for years and never had this happen. Any input? Thanks!

[wattaway2]

Down this way I would think it would be water (more likely sweat) that got under the glass

[flyingfrizzle]

Originally Posted by Basketcase

Hey all. I've had an issue that may or may not be a big deal. Im using 1708 and vinyl ester to raise my stringers. Its a 4 stringer 20. So far I have one complete but in certain spots the glass is slightly white like there's air in there. They are small spots and not many of them but I just have to ask. I know that I originally got plenty of resin in there. I used the squeegee and worked the resin bubble back and forth many times before removing the excess. Could it be a viscosity thing and resin is draining out after I leave it? Thicken with cabosil just a tad? Ill post up a pic of what I mean but I suspect you may understand already. I've been doing fiberglass for years and never had this happen. Any input? Thanks!

If you are using a good fiberglass roller and getting the all the air spots out then they reappear then it very well could be from a thin viscosity letting it flow back out. If it happens just on the vertical areas and all the flat spots are fine then that would confirm it. If it is every where even in low spots then you need to roll it out with your roller longer and keep rolling it to it starts to tack up. Thickeners will help a bunch, cabosil and also cabosil-aerosol will keep it from running so bad. Also you can kick it off a little faster so that it dose not have as much time to run out of the vertical areas.

[cdavisdb]

I had the same problem with a runny, slow kick epoxy on vertical surfaces. Adding some cabosil solved the viscosity problem, but I wonder how it effects flexibility of the resin/glass matrix.

[FishStretcher]

I just spent a summer grinding a hull of a 25 footer. There are voids in there. This year's vinylester will be way better than 40 year old poly- I suspect you are fine. But sections that are white might mean you are a bit dry. I found that the vipel vinylester is runny enough to flow out of the cloth. I found it fairly easy to dry out the cloth when using peel ply and vinylester. I wound up floating the excess resin on top of peel ply worked for me. Especially on vertical surfaces. Mixing at 1.5-2% MEKP helped, too, but the gel doesn't sneak up on you. It hits like a freight train. From liquid to molasses in 60 seconds. 15 minute pot life.

[Basketcase]

Sweat could definitely be an issue. Lol. But probably not what I'm dealing with here. It must be thin resin. On this lamination I did not use a roller actually. I used a squeegee and worked the resin hard back and forth into the fibers. I could see the wave moving under the glass. First I worked at a really low angle with moderate pressure back and forth back and forth. Then at a sharper angle to move excess resin further up the stringer to dry glass. Perhaps I squeezed too much out but I know it looked damn near perfect when I left it. Checked on it this morning and I was a little disappointed. Its an acceptable lamination but just not my best. If this were a more crucial part I may be tempted to grind it but I do know its better than a lot of the factory work on this boat and with better materials. Im going to try a little cabosil (I actually have a huge bag of aerosil) on the next one and see how it goes. Fishstretcher, I will also try to float it as you suggest and maybe it won't dry out as much. thanks guys. Ill upload a pic so y'all can see.

[Basketcase]

Here is some of what I mean. It really just looks like the resin flowed out of it. This vipel is fairly thin.

[billythekid]

You are fine. That is nothing to worry about. No squeege, use a laminating roller and a 3/8 nap paint roller to wet it out then lay your 1708. Smooth out with the paint roller then go to the laminating after about 7-10 minutes. You need the resin to dissolve the starches in the fabric so it has no memory left it before you start with the laminating roller. Also if you are laying smaller stuff up put a piece of mat behind the 1708, it will solve the problem of the little air bubbles.

[Basketcase]

Great info. Thank you all. I will report back how my next one goes. Transom came out great but it was different cloth and different resin. Although I did use uncounted yards of 1708 and many pails of polyester on my bass boat and never had this issue.

[Basketcase]

My second stringer came out perfect. I skipped the squeegee and just rolled it. I tried using my fiberglass roller but the surface was too irregular and was making matters worse. I put a tiny bit of cabosil in the resin and worked the roller till it was just about jelly. Came out great. Thanks guys.