Cure for 19-6 Skin Disease?

[akbridge]

I have something similar on my 170.  One side is from a repair.  The other side looks just like yours.  My boat is a '71.  I think we need to email the Q/C department at AS back in 1970!  The gelcoat is bubbling after 40 years.  Overall it does not bother me.  I can't see it unless the glare is just right.

[Group W Bench]

I think that Scott’s boy up in North Cackalaky is probably right about the ethanol from the fuel vent triggering the flare up of your boat’s latent case of fiberglass herpes. I am not a chemist, nor do I play one on TV. However, here is my hypothesis on what is going on within the laminates of your boat.

Polyester catalyst is a combination methyl ethyl ketone peroxide in dibutyl phthalate and cobalt napthenate solution that provides the plasticizers and set/curing agents.  The solution also prevents the fairly unstable methyl ethyl ketone peroxide from blowing up from heat and shocks. This solution is generally called MEKP. These boats were all laid up in the skin coat with a chopper gun which simultaneously chops/sprays strands of mat, polyester resin and MEKP from a chopper gun head. Sometimes, the catalyst is not mixing properly with resin from the gun head and the long chopped strands of glass suck up excess MEKP into the fibers. It is well mixed enough to kick the resin solution encapsulating the chopped strands of fiber, but there still resides higher levels of methyl ethyl ketone peroxide, dibutyl phthalate and cobalt napthenate within the laminate than would be ideal.

Generally, we hear about these issues when newer boats have severe underwater blistering in a relatively short time period of the boat being in the water. In these cases, the methyl ethyl ketone that remains after catalyzing of the resin wicks in moisture as it is water soluble. The wicking of the water creates osmotic pressure and underwater blistering. Your blistering seems to have occurred some 4 decades later above the waterline, so that doesn’t really seem like our plausible huckleberry. Both the cobalt napthenate and the dibutyl phthalate, on the other hand, are alcohol soluble. These are the plasticizers/set promoters that are in the catalyst. If excess levels of these solutions remained in the chopped strands, this may very well explain why the blistering began at the fuel vent. The introduction of alcohol/ethanol may have triggered the chemical stressing and decomposition of the skin coat at that location. As the decomposition continued, the pox spread all over the boat separating the gel from the skin coat. More than likely, the skin coat is separating from the roving laminates or you would be seeing cracking in the porous gelcoat.

While intriguing, figuring out what happened is pretty much a game of mental masturbation, as it doesn’t change the remedy of a whole helluva lotta sanding and fairing.

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:

[fitz73222]

I'm still troubled by these damn boat hives on young Jesse' hull. I could see if it was getting bathed in an ethanol solution and having a reaction. But this blistering caused by venting fumes? I don't want to beat this dead Aquasport but whats to say that this hasn't imbedded itself right into the micro grains of the actual resin bond. Whats to say it won't comeback after a strip and new paint job? Maybe time to hunt another hull...

[MarshMarlowe196]

I'm still troubled by these damn boat hives on young Jesse' hull. I could see if it was getting bathed in an ethanol solution and having a reaction. But this blistering caused by venting fumes? I don't want to beat this dead Aquasport but whats to say that this hasn't imbedded itself right into the micro grains of the actual resin bond. Whats to say it won't comeback after a strip and new paint job? Maybe time to hunt another hull...

Yep.

That's been my concern all along, and also why I wanted to get some input on this.  All of these weighted theories, as interesting as they've been, seem to point to the idea that Yes, these blisters will continue to form regardless of any refinishing I attempt.

I have been considering a new hull. Its a little bittersweet.

[fitz73222]

I'm still troubled by these damn boat hives on young Jesse' hull. I could see if it was getting bathed in an ethanol solution and having a reaction. But this blistering caused by venting fumes? I don't want to beat this dead Aquasport but whats to say that this hasn't imbedded itself right into the micro grains of the actual resin bond. Whats to say it won't comeback after a strip and new paint job? Maybe time to hunt another hull...

Yep.

That's been my concern all along, and also why I wanted to get some input on this.  All of these weighted theories, as interesting as they've been, seem to point to the idea that Yes, these blisters will continue to form regardless of any refinishing I attempt.

I have been considering a new hull. Its a little bittersweet.

It sucks Jesse but may be inevitable. You have a brand new engine, rigging, console, trolling motor, etc. Plenty of components to upgrade another hull if you choose to. Assuming you want another AS, just say the word and the process will begin.

[gran398]

Jess, absolutely, bittersweet.

Most of us have reached the same conclusion.... kudos to Fitz for stating such.

The good news is that there are a TON of 19-6's out there at present.

The 22-2's are tougher to find, but your 140 Suzuki was a pleasure to run, a honey...and plenty of motor (perhaps the ideal motor, original open transom)  if you wanted to go to a 22-2.

Know you have that 20 Potter Seacraft too...lot to think about.

[Blue Agave]

Jesse,

Here are a couple of 19'6" to replace the current hull.....

[Circle Hooked]

I really like that first one.

[MarshMarlowe196]

Thanks guys. I'm not a big fan of the post 75' hulls when they changed the gunwales  and also I'm located in South Carolina... Florida is a bit of a haul to check out a hull.  

I've really been considering one of these. I can pick it up for a steal, and it would suit me better for the type of fishing I do. Would never rot... Would you guys kick me out if I bought it?

 

That's my brother driving. Any thoughts or persuasive input against this boat?

[gran398]

Heck no...I'd be all about it.

That sweet 140 would push it like a bat outta hades.

That is a great hull too...modified "soft" cathedral...I'll put the thinking cap on and try and remember a first gen version

[Capt. Bob]

Would you guys kick me out if I bought it?

No, you can stay but your GPS would never work in that hull.

You have the return address. I'll split the shipping.

[akbridge]

Well since your are getting rid of your AS...  I want first dibs on it when you scrap out the old hull.  

[SC170nFL]

Your contributions would be missed, so you hang around. If you get rid of it,I want dibs on your bait boxes.