diy fiberglass - repairing uncured spots

[fish4me]

I have completed the fiberglassing of my tank. I am somewhat stuck as to how to resolve two main issues.

1. Even though my tank has been allowed to sit and cure for several months now, there are still some spots in the fiberglass that are tacky. It is not severly sticky, but they are not fully cured. Again, this tank has been allowed to sit for a long time and still is not cured.
Any suggestions.

2. What is the best way to get bubbles or raised areas out of the fiberglass to bring it to a smooth surface?
I am guessing simply slicing the bubbled portion, sanding and refilling with fiberglass?

 

[cvermeulen]

1) Depending on what kind of resin you used - this is normal. Some resin is waxed, and some is unwaxed. this refers to the addition of paraffin to the resin, that is supposed to form an airtight skin over the resin to allow it to properly cure. If you used unwaxed resin, or low quality resin, then the surface will not properly cure. There are a couple of fixes - one is to put a coat of waxed resin or gelcoat over the existing tacky surface, another is to get a product called PVA from your local plastic shop and spray it on to seal the resin from the air. You then need to wash the PVA off. A third way would be to paint with sweetwater epoxy paint or something, which might be a good idea if you're at all unsure about the quality of your fiberglass curing.

2) Only proper way to get bubbles out is to grind or sand them out and re-fiberglass, or fill with resin/filler. It's not a fun thing to do, but you have to believe me when I say I've tried nearly everything else.

 

[cvermeulen]

A third way would be to paint with sweetwater epoxy paint or something, which might be a good idea if you're at all unsure about the quality of your fiberglass curing.

Correction - I let my typing get ahead of my brain here. Painting anything over uncured fiberglass could be a recipe for disaster - please ignore this suggestion.