Gelcoat blisters

[balance]

We recently purchased a Morgan 382 Hull - 68. During the survey
the surveyor noted that there was numerous but small blisters
(size of small finger tip) over much of the Hull. Using a
moisture meter he indicated that overall the moisture content of
the hull was less than 10% and that the blisters were cosmetic
but to keep an eye on them and repair as necessary. We have
since hauled the boat and are in the refurbishment process.
When checking with the Yard about removing the 20 years of
bottom paint they told us that we have a severe blister problem
that can only be repaired by grinding back to the laminate,
force drying then putting an epoxy barrier coat...about 8-12
thousand for the work. Does anyone have any experience with
this kind of blistering on Morgans and we would welcome any
experienced opinions on who may be right.

 

[dhoneycutt]

THe 382's were built with fire retardent resin, this resin is now noted as one of the worst out there. It also was isothalic(the best out there). I have owned my 382 since new and striped the bottom two years ago, corncob was used as the sandblast element and as a result the original gelcoat was saved. I had thousands of voids not much bigger than a sewinig needle diameter.These are caused by moisture during layup. Filled with epoxy and barrier coated and feel the boat will last longer than I will. My boat is in northern waters and is out of the water 6 months a year. I also inquired to a charter company in Marblehead, Ma. who had a fleet in charter with a number of 382's and they said they had no blister problems. Strip it and see what you have.

 

[actigner]

There is an excellent article and advice regarding the repair of blisters at www.yachtsurvey.com I believe the conclusion is that more repairs are done incorrectly and worsen the problem. I hope this helps

 

[bschnur]

I have M382 hull #179 and recently had the bottom completely stripped down to the original gelcoat for new paint, etc. There were no blisters and the hull moisture content was less than 5% -- if the meter was being used corectly. Probably the most that can be generalized is that blister "problems" appears to be random amongst the Morgan 38X fleet.
As you consider what to do, remember that the repair yards have put themselves in the position of the fox guarding the henhouse. I'd like to second the suggestion that you read EVERYTHING you find regarding blisters on the www.yachtsurvey.com website. It's eye opening, to say the least.
Good luck....

 

[aurora]

Stewart and Diana: I have a Charley 38 built in 1971 and have owned the boat since 1979. Always had problems with blisters on mostly the port side of the boat. Every year was a nightmare of opening, filling and sanding blister holes until five years ago. Then I cracked open every blister I could find at the fall layup, let them bleed all winter and in the spring applied the Interlux 1000/2000 system according to their instructions. I have had few blister problems since. It is a lot of work, but it can be done by you successfully with good results for less than $1,000. I cannot comment on which is the best method of application, spray or roll, because I sprayed it on. If you spray you must protect the boats around you---I didn't and ended up having my insurance company cleaning up another club members boat. Any other questions, see e-mail address. Jim Hudnut

 

[captrob]

<div>I would like to second what another member said. Read before you spend the $ to strip and replace the bottom. I have had 2 surveryors here tell me stripping is many times not necessary. I also suggest Don Cacey's book "This Old Boat". It has an exellent chapter on blister repair. His approch is simple and appears to effective. I used it on my Ranger before I bought the Morgan. 1. Pop the blisters & grind to clean glass. Wipe with acetone and let dry for as much time as you can afford (I belive he said 2 or 3 days).2. Fill with a mixture of standard polystyrene resein and cut glass fibers. 3. Sand fair.4. Paint with acrylic enamel.Don feels that poorly preped and applied epoxy can create more problems than they solve. Any mosture left in the glass will be traped by the epoxy barrier coat and thus make a mess of your hard work. With his approach if you screw up a few of the patches it will be easy to redo.There are lots of strong feeling about blister repair you just have to read, talk to as many knowledgeable people as you can and make the decision you are comfortable with.Good luck on your project.Vic C.
</div>

 

[doc]

Our M384 had the same report when we bought the boat. On the 2nd haulout I deceided that the problem had increased and needed to be repaired. After sanding off all the bottom paint I had about 3500-4000 little blisters. 80% were little dark spots of moisture no larger than a dime. Due to the cost of stripping the gel coat I ground out all the spots and filled with West System epoxy with filler added.
After sanding 6 coats of the Interlux 1000/2000 system was rolled on plus 3 coats of bottom paint.
This past spring the boat was hauled out after 2 years in Alabama waters. Could not find any sign of a blister. This work took about 12-15 weekends plus some evenings. If you have the time (time vs money) it wasn't that bad a job. Learned a lot about the boat. Also had the engine removed to replace the rear seal and cleaned and painted the engine compartment. Good luck!
Gus