Bubbles appearing... (not solvent pop)

[Taylor Blair]

I'm painting a set of bodywork for a race bike... the fiberglass bodywork was scuffed, primed and sat for a couple days. Before I sprayed the base coat I scuffed it up and wiped it down with wax and grease remover. Everything looked good to go.

Took it in the booth and tack ragged the piece down. Started spraying and as I came back to that side of the piece I noticed what looked like a wart under the paint about the size of your pinky fingernail.

Any ideas? I'm pretty new to this. Should I have sealed the fiberglass in some way other than just Transtar Primer. I'm spraying Spies Hecker - Permacron Series 293 Base Coat.

About the fiberglass - this is the stuff you get from some place like AirTech or Sharkskin.

Thanks,
Taylor

 

[Taylor Blair]

The fairing has been sitting now for a couple hours and the base coat was dry so I put the piece on the bench and got after the bubble with a pair of fine tweezers. It wasn't the paint that bubbled, it was the gel coat.

Thanks,
Taylor

 

[rex]

Welcome,to the board and the world of fiberglass.That can be a common problem nowadays with poorly laid up glass.I never investigated it but I believe the problem is either the gelcoat is thin there or the gelcoat is covering a crater (very big pinhole).Alot of these urethanes are pretty hot and the solvents eat down pretty far.A sealer may have helped but I doubt it.All you can do is repair the spot or spots and start over.Dig the spot out,putty or mud it and prime it.You shouldn't have a problem there again but just scuff the rest to respray it,don't get down and sand it hard or another spot may pop up.I don't guarantee glass at all any more,it seems most of it is poor quality anymore.I don't know how many custom hoods and spoilers I've spent all kinds of time straightening and if you don't mud the whole thing they turn to crap in no time-bonding strips show,they turn wavy,etc.Really sucks.

 

[Taylor Blair]

Thanks Rex

I did just that. Cracked the top off the bubble (you could see the exposed fibers below looked as if they had never had the gel coat bonded to them). Puttied over them, primed and just like you said no problem. This is the second set of bodywork that I've done that was this brand, I wont say who (Multitech, Ooops)... and this was the second time that I've run into this problem (last job though was a rush and the guy said he didn't care - it was a race bike as well and not in a noticeable location).

I'm just to much of a perfectionist and hate to see crap like this. As well as the seams and the poor finish quality that does nothing but make it look like I was at fault some where in the paint process.

Oh well, I'll just bitch n' moan and keep chugging along. I really appreciate the info.

Taylor

 

[shaunboy]

I used to do heaps of figreglass painting (not alot these days thank god} but when we exposed those CRATORS

with the unbonded fibres in them, we would drip Super Glue on them and found that the best and quickest way to hold them down before filling the crators

 

[shaunboy]

P.S the best fibreglassing work ive come across in my time has been by who'ever does KENWORTH TRUCKS genuine Hoods and other panels

to you guys .
Good solid hard panels and you obvioulsly throw out the reject or repair them properly ,,, not just hide the defects like others may do,, and do!!!!!!!!