Hey guys,
I am working on my second scale plane and using the Tom Pierce method of applying the fiberglass cloth.
http://www.tompierce.net/190/html/paint/glassing.htm
My problem shows up after the glasscloth and all the poly has been applied, sanded, primed and finished sanded. I had a bit of puttying to do in order to blend in a fairing. I set the fuselage out in the sun to hasten the putty hardening. When I came back to it after 15-20 minutes the glass work had numerous blisters and bubbles where the sun had heated the light gray primer. At this time there were no blisters in places where the primer had been completely removed during the finish sanding. The blisters this time are only 1mm-3mm in size...so far.[
]
I had this problem on my P51 build last year where the glass work delaminated in thumbnail sized blisters on the worst places. It happened mainly on the cowl where it was painted olive drab, I guess due to the darkness of the color/heat absorbtion. I cut most of them out and CA'd putty and filler in the spots and spot-paint repaired the areas satisfactorily, but it was a hassle. I have yet to leave the wing out in direct sun for any period of time. Haven't had it at the field yet for maiden, quite frankly I am a little worried to take it outdoors for any length of time in the sun.
This really sucks if it is inherent to the method, since these planes will be exposed to direct sunlight if you want to ever fly them. I am not interested in building them just to hang them on the ceiling.
Has anyone else experienced this? Has anyone got any ideas on rectifying the situation? Anyone know why it is happening?
If I can't figure this out I suppose I will have to just start using the epoxy method.
A few pics below. The P51 is a bit blurry, but you get the idea of where thespots had been(repaired now) The KI-61 fuse and some close ups...Kind of difficult to get the blisters to show up. most circles have 2-5 blisters in them.
Thanks.