Bottom Degradation

[CTsalt12]

Hi All,

I have bottom bottom painted my boat before every season.  For prep work I really just chip the old stuff that comes off easy, and rough up the rest of the hull with a scotch brite pad so the new paint sticks well.

This season I noticed large areas where the bottom paint came off, and what I think is raw fiberglass was underneath.  The raw fiberglass seemed to be degrading as well, or it had growth from last season.  The raw areas were brown in color, and felt solid when I knocked on it, but the outside texture was fuzzy.  It almost looked like the outside of a kiwi.

How much trouble am I in here?  How do I fix this?  Or do I send to the pros?

[Georgie]

Hmmm....sounds like a potential issue.    Gonna need pics, Jimbo.

[wingtime]

Sounds like blisters due to osmosis.

[CTsalt12]

I don't have pictures on hand, but below are links to pictures that pretty much describe what my hull looks like across the board.  

https://www.google.com/search?q=osmosis ... B600%3B400



https://www.google.com/search?q=osmosis ... B300%3B225

[Georgie]

Looks like Bruce was right if that's what you're seeing.     Blisters are ugly, and a pain to repair, but not really a big deal in the whole scheme of things because they don't really compromise structure unless they are SEVERE....but that doesn't mean let them sit.  Can we safely assume all the issues you see are under your existing bottom paint?  If so, and if you have multiple spots that look the same, it's probably time to strip her down to gelcoat, grind out the blisters, and repair them properly prior to applying more antifouling paint.  Not cheap and not easy though.   :x

Sorry Jimbo....

[wingtime]

If it is just a few repair them and repaint.  Then keep an eye out for more.  Even better if the boat is going to be out of the water.  Grind the blisters out and let them dry.  Here is a good article:  http://www.boatus.com/magazine/2013/Jun ... isters.asp