Widespread Blistering of Hull

[patrick and linda]

thanks charlie,
sounds like a great time. we're hoping to attend.
pat

ps: had 14" of snow this past weekend, it's all but melted now, we're heading south thursday, will be on the water at lake cumberland friday, should be anchored in a cove having lunch and i might dare say, a finer glass of wine, by 2:00pm. the lake is up 7' of water from just two weeks ago.

[SEA3PO]

On my initial post I didn't think to ask if this boat was purchased new or a resale..... that will make a difference as I doubt the factory will honor the warrantee from owner to owner.... not generally done.

But Gel coat is a barrier coat.... all a barrier coat is a layer of resin, nothing more... and what gel coat is thickened resin with a color added...it has no reinforcement other than it's bond with the fiber layup in the following layers of the boat.... it should be non poris...period... if the gel coat is done properly with quality material it should have a totally sealed surface.... blistering is never acceptable.. a bottom coat is to prevent marine growth.... yes it helps to protect the gel coat...but that is not it's major purpose..

Yes there are boats that are known to blister... but it always comes down to poor quality resin, or improperly applied resin...
C-Dories are not know to have either problem....

A Marine Surveyor needs to be contacted and the bottom needs to be professionally inspected.

Yes, I do have a Plastics Engineering Degree.

Joel
SEA3PO

[westward]

Joel: I've always assumed gelcoat to be porous, and that epoxy is specified as barrier coat material due to much lower water permeability. I will defer to your recommendations in this regard given your educational background. On our Dory (bare hull/never painted) I plan to have the hull de-waxed, abraded, barrier-coated with 4-5 coats of epoxy, and finally bottom-painted with anti-fouling paint. Any thoughts? Mike.

[SEA3PO]

On a boat that new.... I sure would not repair anything until I talked to an attorney.... Blisters are a uncommon problem on a C-Dory... this could cost you thousands ..... Lots of boat are kept in the water without bottom paint...and they don't blister...

Don't go easy.....scream loud and clear...

Joel
SEA3O

[SEA3PO]

Yes, to answer you question....Epoxy is a great barrier coat, it's about 3 times more expensive as Polyester or more common resins...it does a great job as a barrier coat... nothing will get through.. I also have been looking at some of the non copper bottom coats... they are getting much better... I put a new bottom on the tug a year ago and it was really expensive.... something like $175 a gallon for the paint...and it barely did my 22' bottom... the tug sits in the water 6 months a year...(fresh water)

Joel
SEA3PO

[ryder]

A two year old boat blistering? I don't care what boat it is with or without bottom paint. It will not blister unless there is a defect. The factory needs to make good. Period.

Polyester resin is least resistant to water intrusion, followed by vinylester resin and of course epoxy being the most resistant. The only time I would would waste my money on an epoxy barrier coat is if the boat sat permanently in the water and even then I may not. There are many boats in the water without Epoxy barrier coats that have never had any issues.

Sounds like this may be a case of a Friday afternoon boat.
regards

Ryder

[RJD Wannabe]

Ditto, this is BS in that new of a boat.

I had a Cobalt 193, kept in the Sacramento river 2 years. Major outdrive galvanic problems, required repainting. BUT the gelcoat was perfect after scrubbing. PERFECT, not 1 blister, and no bottom paint.

I agree, go after them.

[nzfisher]

Hi potential blister fixers. While I don't have a C dory I am interested in purchasing a boat so I visit boat owners sites to hear about problems and how the factory deals with them. Getting to the point, resins and fiber glass work, especially micro grind products like cabosil have caused lung problems with industrial and "artist" users. Please be wary and have really good masks when working with these substances. Accumulation of glass dust on clothing is also bad news.

Thanks for allowing me to peer into the C dory owners world,

NZFISHER

[thataway]

First: carpediemvz has only posted the one post---and not provided us with photos or other information over a peroid of several days--and this apparently was his first post. Hopefully he will give more information and photos.

Second: at this point it would seem far more sensiable to work with the factory, than to hire an attorney. With appologies to any attornies present, at this stage often solutions grind to a hault once litigation is threatened--and that is not what we want.

Third: Ryder's analysis of the various resins is correct. Even epoxy has some degree of permeability. It depends on the characteristics of the various resins, and additives.

Fourth: C dory in the past has used Cook Composites Gel coat. This is a high quality gel coat, which is certainly in common use. But CCP has a number of gel coat products, and I am not certain which one is utalized by C Dory Marine. There are different characteristics for each type of gel coat. There are also different qualities of polyester resin. We don't know exactly what resins are used currently (or in 2006) on specific boats.

Fifth: Basically the boat has to be built all at once to have good primary bonds in the hull lamination. The hull mold is cleaned, polished and sprayed with mold release. Then the gelcoat is sprayed down, next an opaque layer--generally it appears that the trim color gel coat (blue green, gray, etc) is applied to keep the light from shining thru the hull),
Then a layer of vinlyester resin (at least in some of the c Dory Marine products)--next a layer of mat, more laminating resin, coremat, or woven wroving, mat, roving mat and finally gel coat painted on the inside. There may be more or less layers depending on what part of the hull this is. If the process is interupted, or the resin (including gel coat) is not properly catalyzed, then there will be a defect--and separation can occur.
For example the boat's gelcoat is sprayed, and allowed to catalize, and the next layer is not sprayed until 2 days later, there could be poor bonding between the outer layer of gel coat and opaque layer. There have also been some isolated cases of poor bonding in other parts of C Dory construction (as with probably most other boating lines). The question is what the company does about the problem!

"Osmotic blistering" is fairly specific--and is related to the migration of water/water vapor thru the semi permiable gelcoat and resin to the mat layer, and wicking of moisture, then hydrolysis, of water soluable products in the resins, further pressure build up in the laminate and finally blisters. There can be laminate damage without blistering--for example the "floppy hull"--where there is extensive wicking of moisture, but no actual blisters. If you want to read further then one of the good articles is by David Pascoe: http://marinesurvey.com/yacht/blisters.htm. (Read all of his articles on blistering while you are there).

Agree that if a boat is only kept in the water for short times and then is taken back out of the water and allowed to dry, that a barrier coat is not necessary. But, if one is going to go to the trouble to put on bottom paint, then it only makes sense to put the epoxy barrier coat on first. Trying to remove bottom paint is not easy physically and it is a toxic product.

Sure, some boats are in the water 1 year, 2 years, 5 years, 10 years or even 20 years--and don't show blistering--but I have seen a number of boats free of blisters for XX years and then all of a sudden have extensive blistering appear. In some boats there has been some breakdown in the laminate during this time, but it had not reached a critical point--either of hydrolysis or of osmotic pressure. Other brands or models don't ever seem to have blistering/osmosis or if they do minimal amounts.

Should a 2 year old boat develope blisters? No--do they? Ocassionally.
I realize that in some parts of the country (especially colder waters, or where the boat is not in the water for the entire year,) that barrier coats are not applied. However, there are processes going on which may eventually cause damage. The factory suggests that boats which are going to be kept in the water be epoxy barrier coated.

The 5 year warantee specifically excludes gel coat. But it does not have any statement about osmosis or blistering. It does address factory defects or workmanship.

Boat bottom paint has zero protective effect against blistering.

[Swee Pea]

A quick question for the uninformed - me. This barrier coat that you are talking about. Is it some sort of clear coat, like on an automobile, that protects/waterproofs the gel coat underneath? Does such a product exist? I have been using the Aurora VS721 product to protect the bottom of my boat (no bottom paint). I have not kept my boat in the water for extended periods, so I don't know if it works like advertised. It does keep the bottom clean and "slippery". It is supposed to protect from osmosis blisters (claims to anyway).
Just wondering if there is a "clear coat" that can go over the bottom of the boat, sealing out water, thus preventing osmosis blisters, while at the same time, not having to bottom paint. I know the clear coat would not stop critters from growing; just to prevent osmosis blisters.

John
Swee Pea

[SEA3PO]

No...Your gel coat does not need anything to protect it.,...wax might be nice... but the gel coat is a finished surface....and is not poris...
C-Dorys don't blister... it's is a rare problem that is from poor material or application... not a problem with C-Dory...

The boat that has blisters....is very strange.. ...so don't think you need to do anything to protect your boat...

If the boat is to be kept in the water for a long period of time most folks put a anti-fowling paint on the boat to prevent marine growth from attaching to the bottom.... the barrier coat is to prevent water from forming between the gel coat and the barrier coat... it is a sealer and a bonding for the bottom paint... not needed if you don't keep your boat in the water for long periods...

Joel
SEA3PO

[journey on]

Swee Pea,

I'm trying to keep from going outside and doing something worthwhile. So, the barrier coat is a two part epoxy "system" or paint. Comes in two colours: white or gray. You put about 4 coats on, with each coat about 4 mils thick. The bottom has to be free of bottom paint, and the gelcoat free of any wax or other stuff. One coat every 4 hrs.

The idea is to put a coating of something that water will not go through. It's sort of a plastic bag for the hull. If C-Dory is using vineylester gel coat, that's also a good barrier.

Boris

[carpediemvz]

Wow! The Forum on C-Brats website is very impressive. I mentioned in my posting earlier this week that I’m relatively new to boating, but I didn’t mention that this was my first posting. I’m a little overwhelmed at the amount of information I’ve received as a result of just asking a couple questions to the C-Brats. I really appreciate the responses. I now know infinitely more about blistering that I did prior to my posting (when I knew almost nothing).

First, to answer some of the questions asked in the replies:

1) My boat has a blue gelcoat.
2) I am the original owner
3) I don’t have photos of the blisters as the boat is in the shop some distance from me. That said, I will try to get some if I’m at the shop anytime soon and then post them. I can tell you that there are hundreds of blisters covering the entire bottom of the hull up to and, in a few spots, just above the waterline.
4) As to following up with the dealer (who, like the C-Dory company manuals, said nothing about needing to coat the bottom of the boat), I can’t since he went out of business shortly after I bought my C-Dory.

Since I posted my question on C-Brats, I also have done more research into the problem. In addition to receiving considerable input from C-Brats, I've talked to two marine surveyors, folks at BoatUS, three marine repair/maintenance shops and an "old salt" who has been researching and repairing these problems for 40 years. Based on all this, I’ve come away with two observations that appear to be shared by most. First, by far the most common response I get when I explain the factory's position that the problem is solely due to keeping a new boat in fresh water over one and a half summers is essentially (and often exactly) "that's BS". Second, I’ve also heard from several sources that C-Dory is a reputable company that stands behind its products and will work with boat owners to resolve problems fairly.

I have gotten an estimate from folks at a well-regarded repair facility who have looked at the problem and suggest repairing via lots of sanding and then applying three coats of epoxy and two of bottom paint (which probably will cost in the 3-4k$ range). I've discussed the situation and the estimate with the factory and they said they would talk to the repair folks today to better understand the problem and what is being proposed. They also indicated that they might be willing to make some "contribution" to the cost of repairs but the actual amount remains to be specified.

I'll provide an update via C-Brats Forum on the outcome. In fact, I plan to communicate the outcome far and wide, whether it ends well or ends badly. That will include not only via the C-Brats website but also BoatUS (who have asked to be updated) and through other public boating forums/media. My communications will either say that, based on my experience, C-Dory is a fine company that stands behind a good product or it will be cautionary information for others who are considering the purchase of a boat. Hopefully it will be the former based on a fair and mutually satisfactory resolution with the C-Dory company. More to come.

Roger
“Funky Dory”

P.S. I still love my C-Dory and we’re committed to a long-term relationship. Just need to get this one problem and associated aggravation behind us.

[matt_unique]

[flrockytop]

[quote="matt_unique"]