Cure for 19-6 Skin Disease?

[MarshMarlowe196]

My boat seems to have some kind of Dermatitis...  There's some kind of ripples/blisters that are forming on the boat, and they're spreading  

The ripples/blisters only started out near the fuel vent on the starboard hull-side, and the affected area was smaller than it is now.  I figured it was just some kind of reaction with the gas fumes/overfill and the ancient gelcoat, but the affliction has since spread to other areas of the boat, and seems like its continuing to spread.

The ripples aren't spongy in any way; they are hard to the touch.

What is causing this?  

I've heard a few theories-

Water Blisters
Ok, if it is water blisters, why are they forming on a location of the boat that doesn't have continuous contact with the water?  I've seen water blisters on hulls before, but it's almost always on the hull and almost always on boats that are left moored in the water continuously.

Uncured resin that is curing sporadically and causing tension, and the ripples are the result
Seems plausible, but the resin's had 38 years to cure now...

Air bubbles forming under the Gelcoat
This seems to make the most sense to me, but this theory was given by my Dad and I'm naturally more biased to his opinion.  He says he's seen this occur on new boats fresh out of the mold, and has seen it continue to spread like it has on my hull.

Normally, I wouldn't care about this because it's not affecting the structure or fishability of my boat in any way.  BUT- I was going to paint the boat here soon, and I don't want to do all prep required getting rid of these blisters only to have them come back in a fresh coat of paint.  That would really hurt my feelings.

Any thoughts on this guys?  Here's some pictures of my boat's ailment-

Starboard Stern-









Starboard, hullside, midway between stern and console-







Near the Fuel Vent, Starboard side





Thanks guys  

[fitz73222]

Well she's 38 know; maybe stretchmarks, you know these boats put on weight as they get older and start losing muscle tone! Seriously, what about an old repair area from years ago thats begining to delaminate, any indication that the hull has been touched up in that area? Pop one of the blisters and see if there is any funcky colored primer or body work that looks suspect. That would be my best guess...

[gran398]

Damn, that's weird Jess.

I'll call Chris at Seamark in the morning and get his spin, and report back.

[seabob4]

Jess,
You say they are hard to the touch.  Have you tried the old starboard trick?  Take a stout piece of starboard and give them a good rap.  If it's air, well, you know what will happen there.  But I doubt it's air under the gel, I'm betting delam...

If you drilled into one, you'd probably find a void about 3/32" in...

[flounderpounder225]

Well she's 38 know; maybe stretchmarks, you know these boats put on weight as they get older and start losing muscle tone! Seriously, what about an old repair area from years ago thats begining to delaminate, any indication that the hull has been touched up in that area? Pop one of the blisters and see if there is any funcky colored primer or body work that looks suspect. That would be my best guess...

Jess
showed my neighbor Kenneth who has built boats and had his own business, agree with Fitz 100%, somewhere sometime in the past she has been painted, and someone used something underneath that is now beginning to absorb moisture, a primer, body filler etc...
Marc

[gran398]

That makes good sense, particularly how its almost a straight line in that one pic.

[slvrlng]

Get a 1/8" drill bit and drill one near the cap and see what comes out. If water comes out I think you know the solution. If nothing comes out I would grind a small place around the hole and see just what is under there. Taper it out so you can see the layers.  Post some pics of what you find.

[MarshMarlowe196]

Thanks for all the input guys!   :)

The idea of a repair done in the past that is now soaking up moisture seems to be a good theory, but it would have had to be a big repair.  These ripples/blisters run almost completely down the starboard side of the boat now, starting at the fill vent and ending at the transom.  There's also some beginning to form on the port hull-side as well... I'm pretty familiar with the history of this boat- one previous owner, a factory here in town; a spill clean up boat that was barely used.  According to my Uncle (who worked at the plant), the boats never had a repair.  Almost seems more like a layup botch-up in Hialeah, but if that's true, will these blisters ever stop?  

Of course, this is all just speculation on my part.  Lewis, Seabob, Fitz- I will try your methods of diagnosis, and will report back with my findings.  Thanks a lot guys

 

[Capt. Bob]

Hope it's not the GPS.

You didn't have any problems till ya hooked it up.

[seabob4]

Hope it's not the GPS.

You didn't have any problems till ya hooked it up.

That's it!!  Massive stray DC current (???) going straight into the glass.....
















J/K!!  

[Capt. Bob]

Hope it's not the GPS.

You didn't have any problems till ya hooked it up.

That's it!!  Massive stray DC current (???) going straight into the glass.....J/K!!  

I was thinkin' maybe the Lowrance was picking up transmission signals around 1381.05 MGz. :bom:

Jess, have you noticed any unexplained hair loss lately? :o

[fitz73222]

"Spill response clean up vessel" Interesting potential for hull contamination and degrade depending on the level of exposure and what it was. Just covering all the bases. It's very strange whats happening to that hull and I doubt a bad layup job from almost 40 years ago is starting to show up now. The hull is past its designed life expectancy by what,20 years anyway? What doesn't make sense is that this is above the waterline.

[gran398]

Just spoke with Chris at Seamark.

His thoughts:

Gelcoat as it ages degrades. He feels that since the problem began near the fuel fill, maybe as the boat was running ethanol gas blew out of the vent towards the stern. The ethanol may have invaded through pinholes in the gel.

He says he's noticed a bunch of pinholes in my gel as he's been working on my mess. More he digs, the more he finds. Especially in what he terms the "skincoat". Mine is a '73.

He says the fix isn't as bad as we may think. Either sandblast it or sand it down. Get it all off  to where its all out and exposed. Then prime and spray gel or Awlgrip.

Don't know if that's the cause or not, but at least we have some solid direction on the fix.

Merrry Christmas to you guys! :santa:

[MarshMarlowe196]

Bob-

Hairloss?  Yes :(  As far as it being unexplained, I had a few pre-marriage related theories, but yours now makes the most sense.  Still lovin' the GPS by the way   , I hope my owning it is still serving your purposes as well.  

Fitz-  You know, I didn't want to reach too far on this, but I had the same thoughts.  Would be very interesting if that were truly the cause, and if it were I don't know how I would prove it...  The spill would have been a coolant if there were a spill.  

Gran-  I think your guy's got it.  Sounds completely feasible, and would explain the spread.  The boat saw very little use in its past life, and when I got the boat it was full of old disgusting dino gas.  The first time it was subjected to ethanol vapors was when I owned it, and I have admittedly overfilled the tank a time or two.

We'll know more when I cut into one of the blisters; don't think it'll be today.  It's miserably cold, wet, and rainy here right now.  

 I'll look at it this way- these ugly boils are giving me that much more incentive to paint the boat, and after that my boat might be half as attractive as Skidaway.

 :flower:

[gran398]

Hey remember how she got that name?

A flatlander Georgia Cracker was running a boat wide open throttle and went into a hard turn...and the steering wheel fell right off!!

Then we heard someone say "Wow, look at that thing skid away!!"

 :flower: