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salecm 05-18-2003 07:31 PM

I''m considering purchasing a 1979 Morgan Out Island 41. Broker tells me that owner''s survey has revealed blisters. If left untreated how big a deal is it? Found a web site that suggested $300 to $400 per foot of waterline to correct this problem. How long can I postpone repair?

jbanta 05-18-2003 08:45 PM

Postpone Blister repair? You can''t, you have to take care of them now!!. A Blister is water penetrating the bottom of your boat. If left uncared for you could lose the whole hull. Blister are nothing to fool with. If you have any confidence working with glass you can do this job yourself.I had three first time I pulled my boat. I dug out all the effected area sanded it down smooth leaving a cupped area to lay in new glass. It is a big job and I understand why a $300 to $400 a foot figure is given. But do it yourself or pay but it has to be done and has to be done now. When it all repaired don''t let it happen again use a top grade epoxy paint and solve that problem forever..

ABullard 05-19-2003 05:09 AM

Blisters are really not the problem everyone makes them out to be. Most of the hype was created by companies selling repair regimes. Water is always flowing in and out of your gelcoat. Blisters are just that, a pocket of water between the gel coat and the glass. The glass is not affected by the water, as long as it is sound.

In reality it is simply a image thing.

If you don''t believe me ask a Surveyor. I currently have about 12 blisters on the bottom of my boat and when refinancing neither the bank or insurance company cared one bit about the blisters. Why, they don''t affect the structural soundness of the boat. Maybe the resale value for cosmetic reasons, but not the sea worthyness of the boat.

The best approach is that every time you do a bottom job, fix the worst blisters, budget considered and don''t worry about the rest. Over time you may solve the blister problem without breaking the bank.


jbanta 05-19-2003 07:38 AM

Ok, When the hull starts getting soft and you can just about push you hand thur the hull tell me it''s not a problem. Left uncared for thats what happends. I still say take care of them NOW. And use the epoxy and rid yourself of blisters forever.

Jeff_H 05-19-2003 09:03 AM

Actually there are a variety of causes for blisters and in most cases leaving them alone greatly increases the likelihood of needing a more serious repair. The most common form of blistering occurs when water reaches the by products of the particular thermo-chemical reaction that occurs in some kinds polyester resins. This reaction produces acids that attack the bond between the fiberglass and the resin in the laminate. In doing so the blisters are able to expand deeper into the laminate by traveling down the surface of fiber bundles in the laminate. Over time this can greatly weaken a hull.

On the other hand, Tony, a dozen or so blisters is nothing to worry about, assuming that you seal them. You also do not say where the blisters are occuring. It is posible to have blisters between the gelcoat or barrier coat, and the laminate. In that case, the blisters are not structural but still should be addressed. I don''t know why you think this is hype but having been around cases where blisters were allowed to continue unchecked until the hull had pretty much delaminated through to the interior in large areas of the bottom, I assure you that it is not just an ''image thing''.

With regard to Jbanta''s comments, one minor point here, you do not want to use an epoxy paint to repair blisters as most epoxy paints are not really made to function as barrier. The best barrier coats are either epoxy resin or vinylester resins (there are advantages and disadvantages to both). In any case where the bliter extends into the laminate a repair with fiberglass and either epoxy or vinylester resin is warranted.


jbanta 05-19-2003 01:52 PM

I know I havn''t got the technical speak you seems to have. And yes when repaired my blisters and filled them back in with good glass I used a top quility epoxy resin barrier in six coats.. Maybe a bit of over kill but after repairing blister on my own I made sure I wouldn''t be doing it again...

GoLikeaFish 09-25-2006 12:22 AM

The one thing that scares the crap out of me about owning a boat is all of the FUD about blisters. Here are some good links concerning research on the problem:

The main point I took away from this is that you need to keep your bilge dry.

I skimmed through this and may have misunderstood, but my impression is that blistering is more of a problem is warmer waters.

Question: Is a boat that spent its life in Northern California and northward less prone to blistering?

Fstbttms 09-25-2006 12:43 AM


Originally Posted by GoLikeaFish
Question: Is a boat that spent its life in Northern California and northward less prone to blistering?

No. The only possible difference is that the cooler water temperatures may slow down any chemical processes, but the the underlying causes of blistering remain, regardless of where the boat lives.

GoLikeaFish 09-25-2006 01:05 AM


Originally Posted by Fstbttms
No. The only possible difference is that the cooler water temperatures may slow down any chemical processes, but the the underlying causes of blistering remain, regardless of where the boat lives.

Fstbttms, I was hoping you'd chime in on this. Good to know that water temperature retards the problem, even if itís a little bit.

My concern is with the type of blistering that threatens the structural integrity of the hull. In your experience, can you minimize the damage by keeping a dry bilge? (Iím sure no one would argue the benefits of a dry bilge, but its relationship to blisters may not be entirely clear.) Are there ways for a surveyor to detect ďbilge neglect"?

camaraderie 09-25-2006 10:24 AM

Don't know where the dry bilge came from but the vast majority of blisters are caused by water outside the hull...not inside. Couldn't hurt to keep it dry but I've had several boats with wet bilges over the last 30 years and no blister issues associated with them.
I'd walk away from the Morgan if you have more than a handful of blisters to deal with. Too much time and $$ involved to fix properly and there are lots of boats without blisters out there. You can get a discount for the cost of repair...but not the time!

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