2003 c-dory 22' blister problem

[Captains Cat]

Have been following this with some interest and a lot of dismay. Sorry Capt Pat for your problems! Has it ever happened on any color other than green or in other than fresh water? I don't think I've seen any cases other than those two cases.

I remember several years ago when "Wooden Boats" published an article on a worm that attacked fiberglass boats. They recommended sheathing the boat in wood!

charlie

[patrick and linda]

CAPT. "D" AND CHARLIE,
GOOD TO HEAR FROM YOU GUYS, AND THANKS FOR TAKING THE TIME TO RESPOND.
FIRST AND FOREMOST; HAPPY BIRTHDAY TO ALL MY FELLOW JAR HEADS!
SECOND, I KNOW OF THREE C-DORYS, INCLUDING MY OWN, ALL FRESH WATER AND ALL GREEN, HAVING EXPERIENCED THIS BLISTERING PROBLEM. I FEEL CONFIDENT THAT IF I CONTACTED ALL GREEN C-DORY OWNERS, MORE WOULD POP UP.
TODAY, MY BRIDE OF 30 YEARS AND I FLY TO THE SUNSHINE STATE OF FLORIDA FOR A MUCH NEEDED WEEK OF R&R. NOT GOING TO THINK TO MUCH ABOUT THIS SUBJECT WHILE ON VACATION, BUT AS SOON AS I RETURN HOME I'LL TRAILER THE BOAT TO "WASHINGTON MARINE SERVICE", LOCATED HERE IN CINCINNATI, AND HAVE THEM SURVEY AND ESTIMATE COST OF REPAIR. AFTER THAT OCCURS, I'LL CALL C-DORY, SHARE THE FINDINGS WITH THEM, AND GO FROM THERE. I'M EXPECTING A POSITIVE RESOLUTION.
SO, YOU GUYS HAVE A GREAT DAY, AND,
MAY THE WATERS RISE UP TO MEET YOU,
MAY THE WIND BE ALWAYS AT YOUR BACK,
MAY THE SUNSHINE WARM YOUR FACE
AND THE RAINS FALL SOFTLY UPON YOUR BOW,
OR WHATEVER!
PAT

[Sea Wolf]

[Stanley-J]

First Semper-Fi Pat, and to all my fellow Veterans.
Pat I had a green hull and have no blister...just thought I'd contribute to the survey

[Jammin]

Since we have a green 2003 I was interested in these posts.

We are in the water in Marina San Carlos now and I don't feel like diving on the bottom but the last time I looked we had no blisters. Jammin has spent as long as six months in saltwater and a month or so in fresh.

We did have small blisters on our 1980 Cal 31 Backstreets less than a year after we bought it in 1990. There were large areas with hundreds if not thousands of small blisters. The largest were pencil eraser size.

After consulting our purchase surveyor, who's major advice was to not over react, we ground the gelcoat off in the areas with blisters and left the boat to dry for less than a month in a boatyard near San Francisco. We then filled the ground areas with epoxy and a high density filler. Probably something recommended in the Gougeon (West Epoxy) Brother's book.

We did not apply any barrier coat just an ablative bottom paint. When we sold Backstreets in 2004, after being in saltwater continuously for five years, there was no reoccurance of blisters.

During our 12 years of cruising in Mexico I have seen many boats, on the hard, with blister problems. My very amature opinion of these small gelcoat blisters is that they are more of a cosmetic, emotional problem than anything else.

Good luck.

[patrick and linda]

UP DATE FOR ANYONE WHO MIGHT HAVE BEEN FOLLOWING THIS TALE.
I RECEIVED A PHONE CALL FROM WASHINGTON MARINE YESTERDAY. BOATS FINISHED!
AFTER THE SANDBLASTING, FILLING OF VOIDS IN THE HULL, THREE COATS OF EPOXY AND THEN TWO COATS OF ANTIFOUL PAINT, WASH, WAX AND BUFF, "MISTY SEAS" LOOKS AS GOOD AS NEW!
IT'S A GREAT DAY TO BE AN AMERICAN AND A C-DORY OWNER.
NOW LOOKING FORWARD TO THE UPCOMING BOATING SEASON.
YOUR IMPUTE REGARDING THIS MATTER HAS BEEN GREATLY APPRECIATED. I OWE EACH OF YOU A COLD BEER.
BEST REGARDS AS ALWAYS,
PAT

[commander bill]

A C-Dory dealer recently told me that the 22CD had a diffen\rent resin composit than the 25CD or Tomcat. He also stated that the 22CD was more vunerable to blistering than larger boats because of that. He also said fresh water was more of a problem. Any info out there to validate this?

[thataway]

I wonder why the repair involved sand blasting rather than the more common carbide cutter peel?

I am glad that the boat has been repaired and you are happy with it.

[oldgrowth]

[Alok]

[Sea Wolf]

Does anyone remember any discussion of resin types in the past?

Have the 22's always been made of polyester, and the larger boats of vinyester?

Are the 16's, and 19's made of polyester, too?

To my recollection, the historical record does show very few blister problems with any of the C-Dorys in the past, at least until the green trim problem more recently.

Maybe the resin composition has been changed?

The smaller boats are more likely to be dry-stored on trailers, and the larger ones perhaps more likely to be kept in the water, but that generalization is too overly general and unreliable to base a decision on concerning what materials to use in constructing a boat, I would think.

?????

Joe.

[thataway]

The blister problem is fairly complex. As Alok says, it is related to osmosis. Some have been due to poor lamination, addatives to the resin, and contaminates/particles. All resins have some minor permeability to water--even though it does not appear to be so. The more permeable are the polyester resins, less so the vinlyester resins and least the epoxy resins. By placing solid additatives in the epoxy resins they can be made even less permeable. Some boats--such at the Uniflites and Valants from the mid 1976 to 1981 all had severe blistering due to fire retardants added to the polyester resins. Many of these boats even had blistering of the hull well above the waterline and on the cabin sides and deck.

It seems that boats which were allowed to cure in the mold longer had less blistering, and boats which were laminated in cold climates and then taken to warmer climates seemed more susceptable to blistering.

An excellent report on blistering is at:
http://www.daviscoltd.com/nams/Documents/Blister_Report.html
This is by two PhD chemists from University of Rhode Island and covers the topic far better than any other single article.

Also the several articles by David Pascoe: http://www.yachtsurvey.com/blisters.htm
Cover the subject from a slightly different prospective.

Having many of our boats on trailers tends allow the hulls to dry and minimizes blistering. There are several philosophies on repair--one is to just repair those blisters which occur--grind out the blister with a carbide cutter, wash the laminate, and dry it well. Another is to peel the hull and then relaminate--either using a layer or two of cloth if one has to go deep, or just build back with epoxy and barrier material is minimal material is removed. The peel is usually done with carbide cutters. The biggest problem in repairs has been that boats were not adequate dryed out. This requires either hot washing and then vacuum bagging after peeling, or dehumidifying--heat, dehumidifiers on the inside and outside of a sealed and tented boat. This drying is essential in the repair process and lack of it has been the root of many failed repair jobs.

I first become aware of the dangers of sand blasting on my fathers Cal 25. The boat was about 14 years old, and had been in salt water in S. Calif with no blisters. Because of paint buildup, he elected to sandblast the bottom and put on several coats of epoxy and new bottom paint. His health was in decline, and I raced the boat for a year before putting it on the market. One year after the sandblasting, the boat had thousands of small blisters on survey--and they only got worse. Eventually the boat had to be peeled and a layer of cloth and multiple layers of epoxy applied to make the hull free of blisters. I have seen this same thing happen on a number of other occasions. The general theory is that sand blasting leaves some contaminates embeded in the laminate, and exposes the glass flibers more than a simple sharp carbide cutter.

Are boats ruined by osmotic blistering? I have seen several boats with holes in the bottom. I have seen one boat which was going to sell for $135,000 (back in the 80's) and after the survey finding of severe osmosis, the boat sold for $50,000! I have also seen "floppy hulls". This is only partly related to osmosis--the adhesion of the resin to the mat and cloth is poor, there is breakdown of the structure, and the hull can actually be indented. This is also a serious defect.



As Alok, I was also a Nephrologist, and since the human kidney uses osmotic processes, the boat osmosis became an interest of mine about 35 years ago, when the problem began to recieve attention. I have looked at many boats with osmosis both in the US, Europe and in the S. Pacific.

Most likely the C Dory 22 in this case will do fine with the epoxy bottom job. But it bears watching. I understand older boats were all polyester resin. I also understand that at least the 25's and 255's have several coats of vinlyester resin just under the gel coat--but the factory can clarify this and I am not positive. I anticipate that osmotic blistering will remain to be a minimal problem with the C Dory line. I tend to believe that the green gelcoat may not be typical osmotic blistering, but instead is a gel coat adherance issue--but I would have to do tests to be sure.

[patrick and linda]

hi guys,
thanks for the additional information regarding this matter.
located here, on the ohio river, cincinnati area, are only 3 or 4 marine repair facilities. they know each other and have the tendency to run their shops simular. so, you take the best pick of the litter and pray for a favorable outcome. B-O-A-T, ( break-out-another-thousand) becomes ingrained into our boating experience and as such we know nothing is for sure, nothing last as long as one might expect, warranties are subject to interpretation, and it's always their interpretation, and if something can get snagged, it will.
semper fi!
pat