Bubble rash and poor lamination

[dOb]

Before leaving town last week, I decided that I would fiberglass the outside of my transom so that it would be closer to installing when I returned.
I wet out the wood, laid a layer of CSM, and then a layer of cloth. I tried a roller instead of pour and spread like I had done before.
I checked back after about an hour, and it looked great. I tried to saturate the glass, no more, no less.
A few hours later, I checked it again right before I left, and noticed that there were a few mini bubbles showing up. When I got home after 4 days, it had a rash of bubbles. I assume that the wood must have soaked up the resin, but I had coated the wood weeks before after it was dry.

Also, I gave it a good pull, and the cloth came up up in one corner as you can see in the picture.

Question - can I re-coat the whole thing with resin again? Will the cloth absorb it after this much time?

 

[Yacht Dr.]

Re: Bubble rash and poor lamination

Hello dOb...and welcome to Iboats..

This is Exactly Why I say dont use Finish cloth for boats...

Ill bet 10 bucks that you can rip that cloth that you peeled up like paper..

Now wet out mat and you will never peel it .. or rip it..

My suggestion..just keep peeling that stuff off there..reprep/grind your layer of mat ( which is solid ) and glass with 1708 or mat+woving.

Finishing your lams with mat will give a better layup because stitched glass has an ez time lifting from air going between the stitches thus creating voids.

If you dont believe me.. just take a 1' square lam ( 1708 or whatever..) without mat and put it on a test cardboard overhang.

Now do another with 1 layer of 1.5 oz mat..then your 1' square lam with 1.5 oz or 2 on that..and see what kinda "suction cup" affect it has .

Mat first..mat last .. Will help any glass guy with 90% of there problems.

YD.

 

[dOb]

Re: Bubble rash and poor lamination

Great! Thanks YD.
I just want to be sure I understand.
After I peel off the cloth, and then grind/prep the CSM that's already there, I can lay a layer of 1708 and be done with it? Is that correct? I just want to be sure I get it right this time.

Thanks again.

 

[Yacht Dr.]

Re: Bubble rash and poor lamination

You are correct..

but I dont know if just on layer is gonna do it.. I dont know ..

Are you just prepping the trans for clamping on your old trans glass ? .. If so then Id skip the 1708 .. prep the mat .. putty,smooze,clamp and glass your trans in.

YD.

Pics of transom ?

 

[dOb]

Re: Bubble rash and poor lamination

This will actually become the inner skin of the transom. I have to be careful of thickness because of the way the splash well covers the transom. The original transom had a paper thin layer of what looked like sprayed on strands. I hope one layer of 1708 will be enough because if it gets to thick, the cap may not fit right.

I'll try to get some pics.

 

[proshine43]

Re: Bubble rash and poor lamination

Hello. Im in the middle of my restore. I was told on here to lay my deck with 2 layers of 6oz eglass from us composites. Is that the cloth i shouldnt be using. I have 1708 for transomstringers

 

[rockyrude]

Re: Bubble rash and poor lamination

You didn't say if you were using poly resin or not, but all poly layups start with CSM. As YD said ending with CSM gives the best layup and a really smooth finish.

 

[proshine43]

Re: Bubble rash and poor lamination

Sorry im using epoxy if that question was for me.

 

[dOb]

Re: Bubble rash and poor lamination

Here is a picture of the boat transom skin in the boat and the transom core as it is right now. I'm thinking that one layer of 1708 should do the trick. I'll also be using the 1708 to tab the transom in.
And I'm using Poly.

 

[Yacht Dr.]

Re: Bubble rash and poor lamination

I would use more then one 1708..mebbe 3.

But you dont have to lam all the way up to your cap with 3 layers.

YD.