Blistering above waterline

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baldpaul

Veteran Member
Joined
Apr 16, 2012
Messages
61
Location
Canada
Vessel Name
Big Tuna
Vessel Make
Defever 49 RPH
I recently found a patch about one foot wide by two feet long with many tiny blisters. This is on the upper sides of my boat, just below the metal Defever 49 sign that is screwed into the hull. I am pretty certain it is from water getting into the screw holes. The screws obviously need to be re-bed. The blisters are noticeable by me and bug me, but as long as I resolve the suspected cause, I am wondering if you gentlemen on the forum would spend the money (I don't do gelcoat) to repair the area or just leave it? If the cause is fixed, I don't expect the area to get worse...or could it?
 
Is the finish definitely gelcoat, or is it painted?
 
Actually, I do believe that area may be painted. I had a tiny piece chip off near where it meets the teak handrail. It seemed quite thin, like paint rather than Gelcoat.
 
You're on the right track, find how the moisture is getting to the affected area and stop it. Over time the blisters/bubbles should (may) decrease in size.

Can the repairs be done in the water? Cost would be significantly less. We are just finishing new paint and new gel-coat on Hobo. We had areas that had been repaired on both surfaces. Old gel-coat can usually be matched so it looks perfect when its done but over time the new and old gelcoats age at different rates. In a few years you can see the and repaired area, particularly if it is a large flat surface. If it's paint find the best repair painter you can find (the same for the gel-coat repair). It's an art. If it's Awlcraft 2000, this paint is made to be repaired. If it's Awlgrip Top Coat it can be done according to some but the surrounding area like the gel-coat may age at a different rate. Good luck.
 
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Yes, fix it, properly. Water intrusion may not be due to the screw holes. In the wet PNW it will only get worse. The nameplate is on the hull? Usually with DFs they are on the cabin sides or hurricane boards.
 
It is hard to see....but you can see the shiny Defever insignia below and to the right of where it says BIG TUNA midship. It is screwed on with 4-5 screws. There is a tiny bit of rust staining around the screws. There is no blistering above the insignia, just directly below. I will have the screws sealed I think and monitor the issue and likely have the blistering addressed at some point.
 

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As it seems the boat has been painted, it is likely the name plate was removed and the screws were not sealed, or the plate not bedded, or both, when refitted. Screws can be dipped in your choice of sealant before screwing back in.
 
It would be unusual for the DF to be painted at that location. It is most likely cored FRP. If you have blistering, the core may be wet. I'd suggest a drill hole or two into the core material below the name plate to see if you have any saturated core - if yes water would show up. Do it now, during the current PNW dry period.
 
The screws obviously need to be re-bed.

A time goes buy (about 8 years) EVERY item that relies on bedding needs to be rebedded.

That is Every item on deck or on the PH and fly bridge..
 
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