Air bubbles in fiberglass?

[TenE307]

As i have been looking at my project waiting to buy more epoxy to put my floor in, i have noticed more and more places where the fiberglass has an air bubble or is raised up from the wood in the corners and at the 90 deg angles. how bad are the air bubbles underneath the fibergalss. my solution to the tops of the stringers was to grind it off where the seperation has occured. i am using 8oz woven fiberglass. is there a lighter weight fiberglass that can be used for 90 deg angles and not bow out. my current plan is to re-epoxy the whole tops of the stringers before putting on the floor. for the corners i plan on putting a mixture of thinkened epoxy with some milled fibers to connect these areas.

 

[AaronG]

Re: Air bubbles in fiberglass?

When I redid the deck on my old deck boat, I ran into the same problem. I just ground the bubble open, and poured resin into the void.

 

[jim dozier]

Re: Air bubbles in fiberglass?

Or next time you can vacuum bag the entire project . Actually I have found that for some projects where the glass doesn't want to lay flat and tends to make an air bubble you can lay some polyethylene sheeting (Visquene) over the top of the resin and then press the bubbles out and they are less likely to return because the weight of the plastic and the seal keeps the air out. Kind of a cheap vacuum bag. Then you can rip the sheet off when its cures. Epoxy won't stick well to polyethylene plastic. May help reduce the need for sanding bumps out also.

 

[TenE307]

Re: Air bubbles in fiberglass?

now i have to decide how big of a bubble is too big. i think i will start by seeing how many i have that are about the size of a dime. i have tons on tiny pen cap sized bubbles on my transom, because when i put the three layers of glass and all the weght of the eopoxy i noticed about ten minutes after puuting it on that it had slid down about 4 inches from where i placed it. so i had to lift all three layers up and place them so there was enough to go over the top for something to hold on to. should i fix all the tiny bubbles too.

 

[crab bait]

Re: Air bubbles in fiberglass?

glass cloth wont stick/lay flat on 90 's .. be it inside an/or outside 90 deg angles.. <br /><br /><br />on inside 90's ,, you gotta mix up putty ( filler's an epoxy ) an apply a 'fillet'/sweal/half pipe shape..so cloth lays but not in a tite angle..<br /><br />on outside 90's,, not much you can do.. there's a trick but it's impossible to 'type explain'.. <br /><br />just go up to the edge an stop.. there's no good reason to go over the top anyway.. there's no strength there..<br /><br />i'd grind the 'pucker' off the top an that's that..<br /><br />before you lay the floor.. mix up putty with fillers to a 'peanut butter'.. <br /><br />apply some wet epoxy ( honey) to the tops of stringers,, then a ribbon of 'peanut butter' then pour some 'honey' on top of that.. <br /><br />the peanut butter handels imperfections.. the honey keeps a good non-dry joint.. <br /><br />thin epoxy SHOULD NEVER be used as a glue without thickening with fillers ..EVER..<br /><br />'peanut butter & honey' goes hand-in-hand..

 

[Realgun]

Re: Air bubbles in fiberglass?

mix up putty with fillers to a 'peanut butter'..

I think he means THIS .<br />8oz of epoxy mixed throughly then 8 oz of milled glass fibers neat eh?

 

[Realgun]

Re: Air bubbles in fiberglass?

You may also want to use 1 of THESE after you lay down the epoxy on the glass and have spread it out.<br /><br />Check out the EPOXY and fiberglass stuff now on iBoats!

 

[BillP]

Re: Air bubbles in fiberglass?

Top of stringers are difficult to do no matter what material is used. Like already posted, use thickened resin to help. I use staples to hold the material down too. Set the floor down on the stringers with thickened epoxy and forget about it. Old car batts make good weights to hold the floor down while the resin is kicking. Be aware that thickened epoxy usually gets thinner and will drain down as it kicks. Mix a test batch to see. 50/50 glass fibers or cabosil usually drains for me after it sits a few minutes. I go more fibers but the strength is compromised with heavy thickening.

 

[crab bait]

Re: Air bubbles in fiberglass?

exactly.. that's the purpose of the 'honey' with the 'peanut butter'..

 

[Peter J Fraser]

Re: Air bubbles in fiberglass?

West Systems have a good publication that covers all these issues very well. Even if you are not using WEST it's worth getting a copy and using it as a guide. It's a good read.<br />West User guide <br />Good luck<br />Peter