Fiberglass post nightmare! Need Help!!

8 foot fiberglass posts on my porch were painted by the builder using indoor water based paint. Whenever it rained there would be puddles of paint on my porch. It quickly began to crack and peel right to the substrate. I tried powerwashing it off and it only took the weak portions off in spots.

I decided to strip to the substrate which has turned into a disaster of a mess. I used SmartStrip product without Methylene Chloride to prevent fiberglass damage. It removed only about 50% of the paint leaving the surface deeply pitted and patchy everywhere. I tried a second time and it ended up taking a plastic surface layer off of the fiberglass in spots. Just a disaster of a mess.

Not sure what to do now?? Please help

 

That plastic layer is likely gel coat.
Gel coat is sprayed on in a thick layer when the fiberglass is made and becomes part of the fibreglass.
If it is gel coat you would have to do a search on gel coat repair to learn what you can do to smooth the surface.

Because gel coat is such a durable surface normally not much will stick to it.
Do you have any info on the brand and type of the posts and pics posted to a free site like Photo Bucket and a link would help.

 

Treat it like a fiberglass part on a car. I could try and go in to detail...but you'd be better off going to a body shop or reading up on it. A boat shop also might be a good source.

Basically...sand old paint, wipe clean with a solvent, fill imperfections with a body filler or auto glazing putty for fiberglass, sand smooth, prime and paint with a quality exterior paint.

You will need to hand sand...power sanders don't work well on rounded surfaces.

 

Looks like if I use the right angle with a blade I can take the damaged gel coat off the entire post leaving bare fiberglass without damage (smooth). Should I take all the gel coat off? This would leave me a perfectly smooth surface to prime and paint properly. I plan on using 123 for prime.

FYI the post is square 10" per side.

 

I don't know if it would be better to finish removing the gel coat or repair what you have like Vic suggested. Once you get the substrate in a paintable condition, I'd use an exterior oil base primer. Sand when dry and then apply 2 coats of a quality exterior latex house paint.

 

Problem solved. Looks like I was not using a thick enough coat of stripper. I put on a really thick coat ~1/8 to 1/4" and everything came off like butter right down to the fiberglass. Power washed the residue and it looks perfect.

A second unresolved problem is the cap and base of the post is dense polyurethane. It has some chips and gouges I would like to fill and sand before painting. Is there a filler for polyurethane?

 

Bondo should work ok. If it's very minor damage you can use spot putty [automotive]