Air pockets in fibreglass

[Smokin'Mo]

I recently replaced the transom on my 21' fishing boat with new 1/4" marine ply laminations for a 2" thickness. It was done from the outside by cutting off the outer transom skin while leaving approx. 6" around the cut line. I have since re-attached the skin and have started on the inside. I used a peanut butter mix of resin, sawdust & chopped strand to fillet around the edges where the transom meets the hull and sides. After the fillet had cured I started applying the matt & roving around the perimeter to attach to the hull and sides. Once this cured I noticed air pockets beneath the glass as I was unable to completely roll all of the air out (I'm sure it's because of the fact I didn't ensure the filleting was smooth). Does anyone think this will pose much of a problem? The air pockets are not large, maybe 1/2" across at most and there are not that many and mostly in the filleted corners. 90% of the layup looks perfect. The lapp I used on the layups are 2" for the first unit & 4" for the second. Next weekend the stringers go in (4 of them) and will be bedded in PL Premium followed by more peanut butter filleting and finally covered with 2 units of matt & 18oz. roving. All of what I have learned is thanks to you guys. I would not have attempted any of this if it weren't for this forum. I just wanted to say thanks for all the great posts and advice.

 

[oops!]

Re: Air pockets in fibreglass

hey mo.....

in a perfect world there is no air in glass......

there is in mine......just no big ones.....where there is air...there is no lamination to the glass.....a "void" in strength.

if they are big pockets of air, or a place where microbubbles formed every where...it has to come out....a 1/2 inch spot ...is right on the edge.

some layers are less crutial than others....ie if your adding a double stiffining section......

but ....basically....when you look at it.....youll know if it will hold

 

[SFT2]

Re: Air pockets in fibreglass

Personally, I'd grind 'em out and patch it. Unfortunately voids are just a fact of life we have to deal with unless we can vacuum bag everything.

 

[i386]

Re: Air pockets in fibreglass

there is in mine......just no big ones.

Glad I'm not the only one that's not perfect. I had a few bubble spots on my center piece of cloth that I laid just for good measure.

 

[ondarvr]

Re: Air pockets in fibreglass

Like oops! said, in a perfect world there would be no air, but air happens.

In a new boat when air is left near the gel coat it's removed, when it's left deeper in the laminated it normally stays.