Fiberglass question

Joker2

Joker2

Junior Member
I am glassing up my new transom with 17oz. bidirectional cloth (pretty thick), I put the first layer on and spread out the resin, after rolling out all the air ( or so I thought ) there were a couple of small areas that remained a little white in color. After it dried I tapped on those areas and I could tell that the resin did not soak through. I have already done the outside of the transom and it came out nice, I guess I was rushing or somthing that day. My question is what is the best way to correct it so I can continue with more coats of resin?
 
Hard to say without a picture, I'll stick to the simple rule if you think its not right then correct it now, remember the best material in the world will fail if not done correctly.
 
Are you using epoxy with 1708? The glue binder in 1708 does not breakdown with epoxy and makes a nice milky looking color like that when it cures. It also can make the laminate cure to a rubbery consistency. If that's not epoxy . . . then make sure you sand and wipe the surface before adding additional layers of material. Roll resin on the surface before laying the 1708 on it.
 
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I am using west system epoxy 105/205, yes I sanded the pre resined wood and then wiped with lacquer thinner, then wet out some resin, then added the cloth (backed with 3/4 oz. mat) then put more resin, I did other areas on the transom which came out good, think I just didn't work it in enough in these spots, tried sanding one of them down pretty far ( almost through to wood then resined the spot and it did go through to the wood, also cut out one, and I will add a patch, this will create more coats of resin to level things out, not sure if I want to do that all around. Not sure what the best way to go is?
 
Why is there never enough time to do the job right the first time, but always time to do the job right the second time? (Sorry, not meaning ANYONE here, just an old saying that seems somehow appropriate.) Like Nymack66 said, if it's not done correctly it will fail prematurely. If you think it's wrong it probably is. IMHO I would remove it and redo it.. a little time now will save you huge time later.
 
more coats will never fix that issue now as it can't soak in threw the current epoxy. you could try drilling several small holes in just the glass in those areas and the pump epoxy in and let it bond the areas together. drill size i wouldn't drill any larger than a 1/4 hole. drill an inspection hole anyway to see if it is a vold or just a flush issue that made the epoxy to drt milky from moisture in the air or air temps. it may be find as it is if it was just a temp / moisture issue making it milky.
 
I cut away a little piece that I know was a bubble and forced resin behind it with a brush, it worked. I know it is not a climate issue because I only work with the resin/glass on dry sunny days. It seems like a pain to do that in all the areas but i may have to.
 
On Vertical glassing

I have had that happen before. Not a good situation to say the least. I was sure that my surface was clean and prepped (ground with 40 grit on grinder). The glass and resin were new and everything was dry. I believe the substrate(plywood) wicked the resin out of the glass before it had time to kick. Moisture can also cause the glass to fail to properly wet out but if you are sure it was once clear like the surrounding areas the super soaking capacity of the plywood might be to blame. Try to coat the area with resin before laying the glass in. If you were using poly resin I would say to mop on a hot coat first by thinning the resin with acetone and adding a little more hardener to enhance penetration and soak the plywood before proceeding with glassing. I am at a loss with epoxy.
On vertical work I have seen the resin run out of the glass before the resin kicked up it is not for the faint at heart. If you catch it early enough you can recover. (ie get frantic with the bubble popper and resin)
In your case, it is really about sealing the wood and it is structural. There are a couple solid milky areas that need to be redone IMO.
I don't think you will ever get it to be clear and free of air. Prepare to itch. Good luck.
 
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I am not professing to be a pro. Just observations of what I think I experienced. Since you coated the wood with resin two weeks before the plywood soaking up resin theory is a bust. What produces the beige like color I see on the picture of the outside? Did you thicken it with cabosil or something?
 
When you get to the fairing stage of this project. Systems 3 makes a nice product called Quickfair . . . it's an epoxy fairing compound. It goes on like butter and sands nicely.
 
Epoxy resin along with roven during the same process should have been solid enough to do your job. Cloth/resin(as a builder) would have been an in-between before the next stage of resin and roven and so on. Not much ya can do now except use a grinder to grind off the bubbles and repair that area. Gelcoat does wonders to repair a mistake,just gotta make sure the repair behind it will last and not come back to haunt ya. Just sayin.
 
My opinion, it looks like you should have used a little more resin. From the pictures of the outside of the transom you look to have some dry edges and once you wet it out it should have had a clear appearance unless I am missing something.
The wood replacement looks tight. You should definitely glass over the top of the transom as resin alone will crack and allow moisture to get to the core. What year is your 20? and how did you remedy the stringer rot?
 
1975 V20, planning on sistering new resined marine ply thu bolted, then glass over both and also glass to transom. In that pic of the outside I hadn't put any resin on yet except enought to wet it out, needs more coats then fairing. Planning on glassing the top also. Thanks for all your comments, it all helps.
 
Skools Out said:
the 2 inch transom is scary most boats with a rating of 200 hp or more has a min of 2 1/2 transom.
Click to expand...

My 20 was rated for 200 or more and it had 1 1/2" core from the factory. It did have an east 1/4" worth of glass on the outside and a courtesy layer on the inside maybe 1/8".
 
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