You Can Do It!
Hang on, here we go................ When we were ready to sell our Hunter 25.5 about five years ago and had it hoisted for a bottom paint, we were upset when we counted over 900 blisters on the hull! PANIC!! After getting quotes on labor and repair charges (ouch)I decided to read up on blisters (tons of literature), invest in a decent but cheap grinder and orbital sander and go about repairing the blisters myself. I probably saved $1000, and although laborious, it was very easy in technique. If you at all handy with power tools this is really not hard at all. The first thing I did was observe in the yard other individuals repairing their blistered hulls, asked alot of questions and procured all my necessary tools, safety equipment (goggles, gloves, masks), chemicals (a swimming pool worth of acetone) and purchased the best seal materials from West Marine (3M). The blisters simply are filled with water "osmotic fluid", and a slight wave of the grinder (use varying sanding discs)cuts off the outer shell or gel coat to release the fluid. Under the gel coat you will see the fiberglass layers, and roving and you can visually evaluate the depth of the "soft spot" or saturated impacted material. Experts use varying tools to grind, pick, drill, gouge, or otherwise remove the soft decay like a dentist working on a bad cavity. Never do you want to go thru the hull!! Technique!! Finesse!! As you work on blisters and know just how far to go you only improve along the way. One critical need I must emphasize is to avoid cleaned blister exposure to rain, so the easiest way to deal with that is purchase a roll of visqueen, use duct tape and tape along just above the waterline since your blister impact is no higher then the waterline. Since we have two halves (port and starboard sides) you can flip them or roll them up and secure them while working. I laced the two pieces up at the bow each day I finished to keep the plastic from blowing up and weighted them at the bottom as well. Make sure that they are long enough to come down to the ground. Either way, thats job number one. No doubt summer is the best time to work for the benefit of heat and drying affect, but you wil probably shoot for the spring. Blisters on average are less then a quarter in size, so after the grinding is complete and your satisified they are clean, apply copious quantities of acetone to remove residual dust and debris. Some of the other folks would use a hand hair dryer for a moment or two to blow out the void and aid in more rapid drying. However, according to many, any residual moisture in the void will be driven out by the sealer. I think the hype about setting the hull in a tent to dry for a year with heat lamps and special chemicals as far as I was concerned is just that, hype! Their are some fantastic products (3M) used to fill in the voids that are easy to mix (like spackle) and apply. They make it easy for you, because the epoxy filler in two parts turns a nive light green when mixed properly. The toughest part of the job was not the grinding, but the application of the filler material, fairing and sanding. The stuff dries like a ROCK and you learn after awhile to apply it in two stages depending on the size of the blister. If you apply too much and do not fair it well it will require lots of sanding. It will expand slightly, so steady as you go. Application is in two-parts then for larger voids. I would be lying to you if I did not say, it'll keep you bentover a lot and raised hell on my back! I used several stools to make it easier. Upon completion, the job was accomplished with just as good a result as any professional. In fact I was lucky enough to witness several blistered repaired hulls in the yard and one of the repair guys would critique my work and give me pointers along the way. I saved a bundle and took great pride in taking up the challenge. One the voids are filled and faired it almost seems like the hull is the strongest its ever been. That 3M filler material is incredible!! I would have a professional take a look at the blisters (diameter does not necessarily mean they are deeper), get several quotes and decide what direction you wish to go. The yard folks can grind them and you can save by filling them, or take on the entire job yourself and always get help along the way.Having blisters on a vessel (more prevalent in freshwater by the way, due to density differences), seems commonplace these days. Opting for peeling the gel (major bucks), is your last option and it would take a zillion blisters before I would ever go down that road. Take your time, ask questions, read the literature and assess all the options. The key is patience. Best of luck Bob Catalina 30
