Touching fiberglass with your hands

[bfeist]

Ok, so what's the deal? I'm going to by glassing my nooner using water-based polyurethane. The polyurethane is ok to handle without gloves, but is the fiberglass itself? Advice?

Ben

[Ededge2002]

Do you have a chemical allergy to epoxy?  I have a friend I worked with that developed one to automotive body fillers.

As for the exposure to fiberglass most of the fabrics we use are in a weave. They are not free fibers and are quite contained. High speed sanding,  filling or grinding I guess could cause some to become airborne and a mask should be used.  In our application I do not see any need to worry with skin exposure.

[bfeist]

Thanks Ed. No, i'm not allergic, I just want to casually glass my plane instead of frantically glass my plane

[Frank v B]

I would not worry about handling woven fibreglass with your bare hands.  I have built several planes using .75 oz cloth and water based urethane.  I have been around fibreglass since I was a teenager* with models and full size boats and it has never bothered me.  Roving and mat are a little different because the fibres are stronger and can get into the skin.

One caution.  Apply the first coat of water based urethane really sparingly or the moisture will expand the balsa wood and pop the skin from the foam cores.  I usually use the first very thin coat to seal the wood, let it dry, then apply the cloth with urethane using a sponge brush.

I had the 1/16 balsa on the fuselage side of my 46" scratch-built Spitfire pop when I applied the water based urethane and create a 6" bulge.  It is still there today... about 10 years later.

If the balsa blisters, let it dry, slit the blister with an 11 blade and apply 5 minute epoxy and squeeze it under the skin. Cover the split with masking tape and leave overnight.  You will find a missed glue spot on the wing skin very quickly.  It will pop within 5 minutes of applying water based urethane.


Frank

*maybe the reason I am a space cadet.  Breathing too many fumes.

[Ededge2002]

An easy way to slow epoxy way down is to thin 30 minute epoxy with rubbing alcohol.
I used that method on mine and glassed out past the servos with 0.6oz glass. The thinned epoxy goes on like paint with a 1/4" brush.

[bfeist]

Thanks for the help guys. I picked up some sanding sealer to seal the wings before the first coat of polyurethane. That will be my project for this coming weekend.