Effect of bubbles in fiberglass?

[JASinIL2006]

Hi, I've read in several places that the presence of bubbles is bad in newly laid fiberglass. What problems do bubbles cause, and do they always need to be ground out and re-done?

Thanks,
Jim

 

[TruckDrivingFool]

Re: Effect of bubbles in fiberglass?

The two things I've gathered is depending on size it will effect the strength of your lamination/layup and an air pocket is a place for water to gather which in a seal coat on wood can lead to rot.

Best I got for an amateur's answer.

 

[tpenfield]

Re: Effect of bubbles in fiberglass?

Hi, I've read in several places that the presence of bubbles is bad in newly laid fiberglass. What problems do bubbles cause, and do they always need to be ground out and re-done?

Thanks,
Jim

reduced strength . . . increased water retention.

Judgement call on if they need to be re-done.

 

[JASinIL2006]

Re: Effect of bubbles in fiberglass?

I've decided to grind the bubbles and re-do those areas. I have to say, I am NOT enjoying glassing with the CSM. It doesn't like to be wrapped around corners much...

 

[Trooper82]

Re: Effect of bubbles in fiberglass?

They say to shred the edges to get it to lay down....didn't work too well for me though...

 

[tpenfield]

Re: Effect of bubbles in fiberglass?

I've decided to grind the bubbles and re-do those areas. I have to say, I am NOT enjoying glassing with the CSM. It doesn't like to be wrapped around corners much...

Yea, an outside corner . . . I try to overlay it with some clear plastic drop cloth material (or something like that), in order to get it to stay tight. also, the plastic does not allow air to get under the CSM once it is rolled out.

 

[JASinIL2006]

Re: Effect of bubbles in fiberglass?

I might have to try that, Ted. My CSM corners definitely look like a beginner's work!

Jim

 

[Georgesalmon]

Re: Effect of bubbles in fiberglass?

If you are going to use plastic over the glass to help with rolling over corners it will probably help. The only problem is if your going to add more layers over it. If you are you adding more layers you will need to sand the glass first. The plastic will keep air from the surface and have a similiar effect as using waxed resin. The surfacing agent (wax) rises to the surface when curing and stops air from reaching the surface. Air inhibits the cure and lets you glass over with with a good bond up to about 16 hours. JMHO

 

[JASinIL2006]

Re: Effect of bubbles in fiberglass?

I had a couple big bubbles that I mostly wanted to do something about to prevent a place for water to intrude and be retained. I used a large hypodermic needle (like you might use to give a pig or goat an injection) to fill the bubble with resin. They looked pretty good as I filled them, but it hasn't been long enough to see if it made any difference. I figure this wouldn't help much from a strength perspective, but I'm hoping it will take care of the water intrusion worry. If it doesn't look good, I'll just grind it down tomorrow and patch in piece of CSM.

Jim

 

[JASinIL2006]

Re: Effect of bubbles in fiberglass?

Just went out and looked at it, and the bubble are gone. Gonna wait to see it in the daylight before I get too excited.

Jim

 

[sphelps]

Re: Effect of bubbles in fiberglass?

You can also use stick pins to hold problem area,s down . Torn up / loosened up csm is about the best way I have found for corners .

 

[Yacht Dr.]

Re: Effect of bubbles in fiberglass?

I've decided to grind the bubbles and re-do those areas. I have to say, I am NOT enjoying glassing with the CSM. It doesn't like to be wrapped around corners much...

CSM is the best glass for wrapping corners IMHO ( aside from some cheesy Vail cloth ).

But.. for Sharp corners your will find that Nothing will work that well. You need a radius of some kind. No matter if its an inside or outside corner.

Prep is KEY.

Also .. dont even try to roll out just one layer of glass. It wont work. You need about 3 layers before busting out the ol' bubble/resin roller.

I dont know if your doing this .. but depending on how complex the curves are you might want to sit there and baby the glass. Meaning you just dont coat it/roll it and leave for a beer. Stay there until it starts to gel up.. move that resin back into the spots that got drained out.

YD.