This article was originally published on SailNet in May, 2000.
Every sunset seen while underway, every school of dolphins spotted in the wake, and every cocktail enjoyed in the cockpit with friends, all are dependent upon the one trip that shivers timbers and checkbooks alike for boat owners everywhere—the haulout. And no matter your status in life, every boat owner is subject to at least one or more of the side effects associated with hauling out: physical, emotional, or fiscal pain.
Within the context of hauling out, it's the infamous bottom job that is most likely to prompt a bit of heel dragging, especially if your boat needs more than just some sanding and a new coat of bottom paint. And if you don't have the deep pockets required to pay someone else to do this time-consuming and less-than-glamorous work, that usually makes you even less enthusiastic. For us and our 1969-vinatage vessel, years of procrastinating had come to an end. We knew it was time to grapple with the worst of the worst—the dreaded blister-repair job.
For those uninformed about osmotic blistering in fiberglass hulls, some explanation may be required. Water seeks to get into boats any way it can, and over time it can manage to seep through the paint, into the layers of gelcoat, and into the hull of the boat itself, compromising the hull structure in worst-case scenarios. The water creates a chemical reaction with the various resins and solvents used in fabricating the boat, and this produces an acidic mixture that collects in cavities under the gelcoat. The bulge of the dreaded blister results from a caustic mixture that is under surprising pressure. When punctured, it can send a jet of noxious fluids one's way, making eye protection, respirators, surgical gloves, and a tyvex suit mandatory gear for properly effecting blister repairs.
Since paying a crew of workers for days of work wasn't an option—especially because they would be using grinders, sanders, putty knives, and other tools that we already owned—there wasn't much decision-making involved in whether we'd do it ourselves. (Though we thought about sandblasting, the boats that we saw that had been blasted for blister repairs didn't have all the blisters opened, which was probably due to poor quality control on the part of the operator rather than the machine's capability. This strategy was even less desirable due to the $90-per-hour price tag and prohibitive minimum hourly requirements.) So we arranged to get hauled out at a nearby boatyard and do the work ourselves.
After the pressure washer had blasted into oblivion the numerous species of marine life that had made their home on the bottom of the boat—sea grass, barnacles, tiny crabs, and squirting polyps worthy of a nature documentary—the picture became clearer. Thousands of silver-dollar-sized bumps stretched up and down the hull. My better half and I soon became a two-grinder family in order to tackle the job most efficiently. Wearing the proper safety equipment (which also included ear plugs since the sound of a Dewalt grinder at 13,700 rpm is deafening), we began a tortuous series of long days grinding blisters, sending an acidic mixture and plumes of fiberglass dust in every direction. The end result was that the hull looked more like a giant, scuffed-up golfball than a sailboat.
That we were doing the work ourselves prompted a steady stream of advice from boatyard workers and passers-by. But we found that we were lucky because the gelcoat on the boat proved exceptionally thick, close to a quarter-inch. It was the thickest that several meandering surveyors, who were attracted to our experiment, had ever seen. And fortunately, except for an isolated few blisters where glass would have to be added, the water had not made its way into the hull.
After opening and exposing all the blisters, the next step was the long process of removing all the bottom paint with twin orbital sanders and 80-grit paper. A that point, the tide slowly began to turn. We had reached the point where we could begin to add to the boat, rather than remove material from it, and that gave us a bit of a psychological boost, which we believe is critical to the undertaking.
Of particular concern for boat owners who face osmotic blistering is how and how long to dry out the hull, since any remaining moisture can nullify your repair
efforts. We found that when we were done grinding each blister, a reddish yellow, sticky liquid weeped from the craters in the hull. The boat yard's personnel encouraged us to hose off the boat with freshwater as much as possible, following the theory that this aids the drying process. But we figured that we should also bring out the big guns, so we bought a 100,000-BTU kerosene/diesel heater, affectionately known as The Blaster, and erected what I referred to as the ET tent around the hull—a plastic tarp that acted like a hothouse when the heater was going.
Here too we encountered a bit of disagreement among the peanut gallery. The yard's fiberglass repairman said we were doing it right, but the yard owner said he had read that heaters introduce moisture into the equation. But we were convinced that our strategy was worth pursuing to accelerate the drying time. We left the heater going night after night in an attempt to dry the hull out, with temperatures inside the tent hovering in the mid-90s. Though we could have achieved the same temperatures naturally had we waited a few short months, neither of us relished the idea of spending time in the boat yard during a South Carolina summer.
|"By the time we were ready to fill and fair the pockmarked sections of the hull, I was confident that our drying-out strategy had worked."|
While the hull dried out, we moved on to tackle the other things on our list: installing new thru-hulls, repainting the topsides, rebuilding the rudder, and installing a dripless shaft. By the time we were ready to fill and fair the pockmarked sections of the hull, I was confident our drying-out strategy would put us within acceptable amounts of moisture content. This proved a little overly optimistic. Although the blisters had stopped weeping, a surveyor with a moisture meter gave us a bit of a reality check. The hull still had moisture in it—though seeing the meter register in the yellow range and not the red was good news.
The surveyor told us that he too lived on a boat that had blisters, but that did little to assuage our concern. In his very useful book, This Old Boat, Don Casey states that after opening the blisters, the time required to dry out the hull offers a good opportunity for you to go to Paris for six to eight months, before coming back to work on the boat. I'd be the first to agree with that strategy, however, at $25.00 a lay day in the only do-it-yourself yard in town, I wasn't quite fiscally prepared to tack that expense on to our mounting costs.
For every haulout, there's a point where momentum takes over, the breeze glides across the water, and it becomes evident that it's time to get on with the program and get back to sailing. That point had come for us. Armed with beer, Powerbars, Gatorade, a gallon of acetone, a gallon of denatured alcohol, nine containers of West System 406, several putty knives, two gallons of epoxy with both slow and fast hardeners, and one garbage bag full of 410 fairing compound, we set forth on filling the ravages left by the grinders. That endeavor required 200 pairs of surgical gloves, hundreds of pieces of sand paper, and left plenty of aches and pains with which to contend after successive days of filling and sanding. Time seemed endless at this point.
Before and after. The left side of the boat in this shot is ready for a final fairing, while the right still needs several rounds of filling and fairing.
Before we started filling the holes, we washed the hull in freshwater one last time before cleaning it with acetone. We shallow-filled each blister (which our crude census told us was around 2,600) with epoxy
thickened with West System 406 Colloidal Silica, a high-density filler. Working in batches and taking care to be as neat as possible to save on the amount of extra sanding needed later, we continued the process using a 50-50 mix of 406 and 410. When this had been done, we moved on to the epoxy
with straight 410 Microlight, which sands much more easily. One last pass with the 410 and a final sanding left us with results we thought we could live with. After working until sundown, we parked the car and aimed the high beams at the hull. There were some fairing anomalies, especially in the hard-to-reach section between the twin keels, but the boat isn't an IACC racer, in fact it's not any kind of racer, and the results overall pleased us.
With the filling and fairing finished, we were ready for the painting portion of the program. We first used two gallons of Interlux 2000 epoxy barrier coat applied in three coats, before moving on to two coats of Pettit Trinidad, waiting the allotted four hours between coats and hoping we had confined a minimum amount of moisture within. Three weeks and a blizzard of receipts later, we were back in the water, heading out with the tide.
Many boat owners will tell you that owning a sailboat is not a logical, economic, or moneymaking endeavor. The ever-present project list is just one of the prices we must pay for the luxury of being able to cast aside the fetters of shoreside life when we please. Of course there will always be those owners who get their work finished and get out of the boat yard before you, but there will an equal number that linger on long after you're gone. For each, the payoff looms in the future. Will it be the coast of Nova Scotia? The Caribbean isles? Or the hot spots of the Mediterranean? As certain as boats need periodic work, something beautiful is just over the horizon, and at some point, you'll make it there—hopefully on a clean, blister-free bottom.
The Boatyard Blues by John Kretschmer
Repairing Gelcoat Cracks and Chips by Don Casey
New Shine for an Old Hull by Don Casey
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