Painting fibreglass!

[Steve]

Hi folks Managed to restore my fibreglass observatory to one piece again after much needed help and advice from the group. Now I wonder what primer and paints would be suitable to use to finish it off and wondered if anyone could advise me please?. It seems that 120 grade paper rubs the slight scratches out ok so need to maybe make a bit smoother before painting. As its outside it obviously needs to be waterproof, flexible and adhere to fibreglass. Should I use any special primer and paints for this?. I don`t need the high gloss finish like for cars just a nice smooth surface would be fine. Brushed or spray?. Any advice very welcome. Cheers Steve

[Stuart Noble]

Standard oil based undercoat/gloss takes well on fibreglass. Better than on wood usually.

[T i m]

I *think* go along with that ..

Yeas ago my Dad wanted to paint the inside of a fiberglass boat to tidy it up and bought the special cleaner / primer / top coat and did it all by the book in the right conditions etc. Several months later it all fell off in big lumps ;-(

I was rebuilding my 14' 'composite' dinghy (ply deck and wood gunwales / transom / seats on a fiberglass hull) and must have spilt a few drips of polyurethane varnish inside the dusty hull. When I found them later I went to remove them and they were stuck like a s to a b! ;-)

Based on that observation I thoroughly cleaned the inside of the boat out and painted it with some *slightly* thinned white polyurethane yacht paint (International) followed by an un thinned top cot. It was as hard as nails and is still on there 20 years later ;-)

All the best ..

T i m

[Stuart Noble]

Look at how well gloss paint takes to glass. Runs (not on my paintwork of course) are often still rock solid when it has long since flaked off the surrounding woodwork.

[Steve]

Standard oil based undercoat/gloss takes well on fibreglass. Better than on wood usually.

Would this be flexible enough for a fibreglass dome do you think?. Steve

[Stuart Noble]

Dunno. I guess it depends on the type of resin. Some are more flexible than others. I don't imagine any of them will move more than wood

[Steve]

Thanks for that Stuart. Didn`t think of normal undercoat/gloss oil based paints. Lads at work been scaring me off with tales of special car paints, specialist breathing gear, full body protective overalls etc etc. a bit over the top I think. Cheers Steve

[Stuart Noble]

Depends whether what you're painting needs to have an auto quality finish. Oil paint looks like oil paint, whatever you apply it to, but I'm sure it will take alright if the surface is tack free. Don't know too much about fibreglass but ISTR you are left with a slightly sticky surface when it cures

[T i m]

I think I did mention my boat was fiberglass and likely to sustain more flexing (and abrasion) in use than most roof domes?

All the best ..

T i m

[Steve]

Cheers for that Tim. That white polyurethane yacht paint you mentioned is that a special paint or just oil based like the other paints mentioned?. Steve