RE: fiberglass covering question-blisters in sun
Zula good tips,
The funny thing is I've heard the exact opposite, that sealing the balsa is the problem. Guys were complaining in the warbird forums that they to were getting blisters... one member said that he used to get blister then discovered it was the gassing of the lacquer based sealer being trapped under the ploy c....
it then went to apply light coats of poly c straight to the model... he said that he got no warpping and no bubbles
To me what he said really made sence, having that lacquer under the poly c sounds like a bad idea.. I also don't like mixing products.... mean if your going water based go all water based
I'm going to try an experiment that I have wanted to try for some time on an old wing... stick with one product for the whole finish... meaning all water based
I had the idea of sealing the wood with water based sanding sealer, but put it in my spray gun and build it up in three very light coats to not warp the wood. Then glass as normal with poly c.
If any filler is need I wood use hobby grade epoxy and micro ballons.. not harsh automotive filler used for metal cars. Then for primer use water based laytex... I have found that kiltz primer when sprayed on and thinned with washer fuild sands pretty well... then paint with water based paint.
This way we don't mix products and have a reaction... I'm going to give it a try soon. I know one member is also just putting on silkspan with poly c straight without sealer and having no problem with warping... you will get bad warping if there is no structure under the sheeting, but I think with a few light coats first you will be fine....
I'll let you guys know how the experiment goes