Blisters

[southport]

Well we're bummed- had tons of work done and ended up with all kinds of blisters above the waterline in the awlgrip. Yet to find out what layer(s) they are originating from.

The company that did the work is very good- in business for years and is very well known, etc. They are going to fix it.

The awlgrip rep came and looked and thought it would be a good idea to have a surveyor do a moisture meter survey so I called the one who did our purchase survey. Of course it was pouring rain so one was not done at that time. When I contacted him last month he mentioned that this was a recurring problem with these Aldens with water intruding under the toe rail and it was almost impossible to prevent or stop. I had never heard of this and wonder what experience others have had. There were a few blisters that were ground out, filled, etc but there seems to be alot more than before.

 

[Whit]

Water under the toe rail? I replaced my toe rail and don't see how that could be a problem. Unless there is damage, the toe rail has no affect on the hull to deck joint. I will dig out pictures or post a diagram for you.

 

[TomY]

This is a problem we're seeing. Dan, from Bangor Maine who's boat was in Rockport this summer had a large area of lifted awlgrip. My boat which was awlgripped long ago, had an extreme failure in 2000. It was mostly due to incorrect shrinkwrapping (tight to and covering the entire topsides) but some of the coating had blistered off in a few spots around stem.

I took mine as simple failure of the coating due to age. In removing the coating, the failure appeared to be in the primer. There were two coats of high build primer. I'm certain the failure was in a lower coating layer and not the original gelcoat. For whatever it's worth, the blisters were generally close but not below the waterline. Some proof in the failure being strickly coating, is the fact there is no blistering below the waterline. I have never barrier coated my hull.

After removal and recoating with Easypoxy, some very small bubbles appeared over the following 5 years. Small and nothing like the large awlgrip bubbles. I just sanded down the easypoxy into the primer, spot primed only, and recoated with a new coat of easypoxy.

For what it's worth, I have a hunch these old hulls are just porous enough, mostly due to age, that they will absorb some moisture. I don't think the toe rail thing makes much sense, it would be a problem mostly or more severe just below. At times I feel these old boats and their owners are on the front edge of many issues like this that will face a flood of aging boats soon. Our boats are in the stage past gelcoat and into second and third or more topside coatings.

I hope we get more feedback from others with or without coatings blistering.

 

[southport]

Muskrat was stored outside under shrink wrap and the in early May it was removed. They started sanding and called us in because it was apparent there were more blisters and they were deeper than just the surface. For double the money they could use awlgrip high build after gringing out the blisters and then fairing the hull. Next was the primer and finish coat. They said if we did not grind out and use the high build the paint would blister in 2-3 years. Hmmmm.

The process of sanding/grinding etc. took 3 weeks-there was a big tarp draped over the boat but we had over 2.5" of rain. Then the high build went on and alot of fairing was done while the boat was outside ( just over two weeks). During that time we had about 2" of rain- what a lovely spring. Then the boat was put inside and about 6 days later the primer was applied (545?). I just wonder if moisture was absorbed into the high build. They were very concerned that the hull not get wet but I'm sure there were times when it did. Once in the building there was no heat at that time of year but it did get warm, especially higher up in the building. As I said there were blisters before but this crop is ten fold what was there.

The rep said it was important that the surveyor try and determine where (how deep) the moisture/ liquid was coming from. Can you test for this stuff when the weather is so cold?

 

[CaravelaofExe]

Solvent entrapment?

 

[Whit]

I have always been told to never Shrinkwrap over awlgrip as the heat and mosture gets traped under the shrinkwrap. The hull is defintely porous as can be seen by the stain from the chain plate bleeding through.

 

[Quetzalsailor]

I've got blisters in my Awlgrip boottop. Appears to be only between paint layers, not in the 'glass or barrier coating. A few after our first winter owning the boat, 05, a few more in 06, lots by spring of 07. Pretty annoying since the coating was a few years old and showed no blisters when we bought her. They showed first on the southwest side of the boat. It happens that the southwest side is her starboard side since the prevailing wind is south on the Chesapeake. She used to list a bit to starboard and trim down by the stern until I got draconian with restowing the anchor and drinks. I attributed the blisters to water on the Awlgrip, and given enough hours this spring, will probably repaint the boottop in Brightside Polyurethane.

Awlgrip is said to be susceptable to failure when kept wet. Under bedded fittings, under line left on a 'gripped deck, under shrinkwrap, etc. Apparently just not good enough for boats!

D

 

[southport]

We have them there as well- and the first thing the rep said was Ah- there in the boot top where there is alot of weater. However our's is a good 3-4" above the water line- I think hopefully the high build absorbed enough moisture to cause problems- otherwise we live them- as my mother-in-law used to say "it'll never show on a trottin' horse".

 

[Dan Cassidy]

We have had a major awlgrip failure which came to light when our dark hulled boat was in warmer climes. We first noted a problem in the Med in '06, and then had major problems on the way home last Spring. There were areas that separated that were up to 2 feet square. On close inspection, including viewing paint "chips" (depressingly more like paint sheets) under a disecting microscope, the level of separation appears to be at the level the earliest application to the gelcoat.

Stripping the Awlgrip and primer layers can be done (in our case at least) by heating the surface with a heat gun to get it only to "warm to touch" and lifting it off with a putty knife. Note that care is taken to not heat the glass to any more than "warm to touch" (i.e. about 110-115 Farenheit). There is good separation the gelcoat level, and I am able to get 75% off in this manner. The remainder (mostly where prior preps have disrupted the gelcoat layer) will need to be sanded off.

I am not certain if there is something in the gelcoat that is causing this separation. The awlgrip I had applied in 2000 is coming off along with additional base layers applied over the years. I believe the awlgrip we put on in 2000 was the 3rd time the entire hull was refinished. The hull story I am extracting is indicating to me that this difficulty occured in different areas in the past, with periodic spot repairs being done. It is interesting that none of the refinishing jobs (all done in professional yards) achieved a satisfactory prep of the gelcoat surface.

Fleana is in a boat barn down the street and our winter project is getting the awlgrip and other paints/primers off. She is a longterm boat for us so we are determined to do it right this time. It is interesting to see that some of our sister boats have had a similar experience.

Dan Cassidy
s/v Fleana 949-O