I think the 'perfect' vessel has been found with ONE exception - blisters . So not so perfect :-( At the haul-out last year, in June, was the first time that the blisters showed up (according to the yard that has maintained since new) all are reported to be small but covering the bottom as a Dalmatian is spotted The cure is - hull peel and epoxy with 2 coats of 1000 epoxy and 10 coats of 2000 epoxy 2 coats bottom paint Questions: 1- What % should the moisture content be before starting the epoxy 2- Is this the correct application / cure 3- any other advice much appreciated Off-line response ok "The Secret of Success is Consistency of Purpose" Benjamin Disraeli Jim Cobb e-mail address otisltd@mysc.com

If these blisters are uniform and disppear after an hour or so of being hauled, you can ignore them. If they remain and are deep when exposed with a knife, then you should consider this process. However, the peel removes a portion of the lay-up, not just the gelcoat - because the blisters are deep. Therefore, some type of fiberglass has to replace that which has been removed. Ron Rogers

Here's my report on blister repairs done to my boat, posted a while back: Boat: 1986 Krogen 42, hull #99. Had severe blistering when I purchased her, and planned to do a hull peel and drying to cure this. After a lot of research, I decided to use the HotVac system to dry the hull. http://www.hotvac.com/. Seabrook Shipyard did all the work. This was their first time using the HotVac system, so we all learned a lot. I am very pleased with their work and the results. Time: I took her into the yard on Oct. 21, 2002. They started peeling the hull almost immediately, and started using the HotVac system around November 15, 2002. While the HotVac folks said it would take a dwell time of about 6 hrs at 100 degrees C to dry each section, we had to operate at 80 degrees C because of the Airex PVC coring in my hull. It took about 18 hrs. /section to dry the hull to acceptable levels. The HotVac system uses three heat/vacuum pads at a time, each are about 2' x 3' or so. Several areas needed to have the application done 2 or three times, and a few areas just wouldn't dry, so we had to grind out a few places and re-fiberglass. The hull was finished drying sometime around January 13, 2003, about two months. The pads were usually applied and running 5-6 days a week, sometimes less if the weather didn't cooperate. While the boat was in a shed, when warm fronts or rain would come through, the hull would sweat and the pads couldn't get a seal. We started relaminating new fiberglass on January 27, 2003. Started applying the first barrier coat on February 24. 3rd. coat of barrier were put on around Feb. 27. 1st. coat of anti-fouling put on around March 8. New boot stripe painted around March 18. Final coat of anti-fouling applied around March 20. A little touchup on bottom paint on March 25 after lifting off the blocks onto the sled, then splashed on March 26, a bit over 5 months after starting. I took a LOT of pictures of all of this, and the automatic date stamp in the digital camera was very useful, and allows me to give you these dates. I highly recommend you use one of these for any major project you do. You can see the pics of the process start to finish at: http://photos.yahoo.com/klemmons69. Click on "blister repair". After peeling and drying the hull, here is what we applied: 3 sessions of 1.5 oz. fiberglass mat with vinylester resin 2 coats Interprotect 1000 - High build epoxy primer 2 coats Interprotect 2000 - 2 part epoxy barrier coat 1 heavy sweep Interprotect VC tar2 - Watertight 2 part epoxy putty 3 coats Interprotect 2000 - 2 part epoxy barrier coat 2 coats antifouling - Petit Trinidad SR (4 gallons). The relamination of new fiberglass was in addition to the bottom job, and should be considered as an additional expense if you are doing estimates. Labor was $7100 and parts were $3060. We had to do this due to the amount of FG we ground off during the peel. I prepped all the underwater metal except the prop with Petit's underwater metal kit. This has a two-component acid etching primer followed by two coats of a tie coat primer. I'll let everyone know how this works out long term, but it sure was some tenacious stuff! The prop and thruster props were prepped by the yard with Interlux 260R primer. Costs: After doing my hull, Seabrook Shipyard has set their pricing as follows: Complete blister job including hull peel: $250/ft. - Sail, $300/ft. - Power. Powerboats are a bit more expensive due to the more complicated hull shape. However, if you have a trawler with a "sailboat" shaped hull, they'll probably charge you the "sail" price. Use of the HotVac system to post cure (dry) the hull: $200/day. Estimated drying times based on a 40' hull would be: Solid hull (no coring) - 20 days. Cored hulls - 40 days. Different types of coring requires different drying times, so these are only rough estimates. My hull was a little less expensive, since it was their first time, and we were at the bottom of the learning curve. Moisture meters are more of an art than a science. Most measurements are relative, not absolute. When a meter says "x%" moisture, it usually doesn't mean it. It's just a relative number, not really a weight or volume percent. Any metal in the hull or near the measurement site will show a higher value. Don't go crazy over this, just calibrate on some known dry fiberglass. Here are some other references to read up on to understand blistering and it's repair. http://www.yachtsurvey.com/blisters.htm http://www.marinesurvey.com/yacht/BlisterRepairFail.htm http://www.osmosisinfo.com/ http://www.daviscoltd.com/nams/Documents/Blister_Report.html Keith __ What hair color do they put on the driver's licenses of bald men? ----- Original Message ----- From: "Otis ltd" <otisltd@mysc.com> >I think the 'perfect' vessel has been found > with ONE exception - blisters . So not so perfect :-( > At the haul-out last year, in June, was the first time that the blisters > showed up > (according to the yard that has maintained since new) > all are reported to be small but covering the bottom as a Dalmatian is > spotted > The cure is - hull peel and epoxy > with 2 coats of 1000 epoxy and 10 coats of 2000 epoxy > 2 coats bottom paint > Questions: > 1- What % should the moisture content be before starting the epoxy > 2- Is this the correct application / cure > 3- any other advice much appreciated