7 commonly asked questions
7 commonly asked questions
During my 11 years at West Marine (where I work when I’m not writing this column) I’ve been asked many questions. My reply to questions I don’t know the answer to is, “Beats the heck out of me.” Then we try to find the answer. There are, of course, many I can answer, so here are some of the more common questions.
1. I have to make a repair with epoxy and want to gelcoat afterward, but I’ve been told you can’t gelcoat over epoxy. What can I do?
A: You can apply gelcoat over epoxy, but you first must remove the amine blush that’s produced as epoxy cures. Amine blush, if you can see it, is pale pink or tan. Whether you see it or not, thoroughly wash the surface that you plan to gelcoat with water and a sponge or rag to remove the blush. When dry, you can sand, wipe and apply gelcoat.
2. What’s a quick and easy way to get rid of cracks around stanchion bases?
A: Unfortunately, there’s no “quick and easy” solution. Those cracks likely are the result of the deck flexing. This may be because the deck layup wasn’t strong enough, the core sandwich below the fiberglass (balsa, foam or plywood) has been compromised, or the stanchion was subjected to excessive stress. The right thing to do is first restore the integrity of the sandwich, then stiffen the area under the stanchions and install backing plates beneath the bases.
3. How can I stiffen local areas of my deck, cabin top or hull?
A: Introduce a “hat box” section of fiberglass as a stringer or frame. You can buy lightweight foam forms, or use a cardboard carpet core cut in half lengthwise and tabbed to the underside or inside of whatever you’re stiffening. Apply a fillet, from the half-core to the boat, of catalyzed epoxy thickened with filleting filler. This will ensure that fiberglass laminated over the half-core will have a strong surface contact. If you use the purpose-built foam forms you bypass a lot cutting and filleting. Next, lay up two or three layers of fiberglass cloth, not mat. The cloth should span the half-core or foam form and extend a least 4 inches, if possible, onto the boat structure on both sides. The next layer should be an inch shorter, the last another inch shorter. Remember to first prep the area with solvent, roughen it with about 36 grit sandpaper, and wipe away the residue with solvent. The resulting repair will be similar to an I-beam.
4. I have a small powerboat and don’t go very far offshore. What GPS do you recommend?
A: I recommend a GPS/chart plotter. A powerboat moving at 15 mph covers more than 1,300 feet per minute. If there is a rock along your projected track it likely will find you before you find it on a chart. I recommend choosing a color plotter; it will be much easier to interpret under all conditions. I believe you’re better off with a smaller color display than with a larger monochromatic.
5. What kind and length of dock lines do I need for my boat?
A: Prepackaged dock lines usually have recommendations as to size printed on the packaging. The size of the cleats on your boat also will provide some clue. I prefer three-strand laid line over double-braided line. While stronger for a given diameter, double braid provides less elasticity, so shock loads from wave action and the like are transmitted to the cleats rather than being absorbed by the line. At a minimum all boats should have two spring lines 2/3 to 3/4 the length of the boat, and two breast lines about half the length of the boat.
6. What type of battery should I consider for my boat?
A: Wet cell lead acid batteries are the least expensive and, so long as they’re not “maintenance free,” can be charged at relatively high voltages. High voltage can “cook” the electrolyte out of the battery, but it can be replaced. If you have an old-style battery charger and alternator without adjustable voltage regulation, a lead acid battery is a good choice. Gel cell and AGM batteries are sealed and require regulated voltage input. Some advantages of gel and AGMs are that they don’t leak, they self discharge at much slower rates than lead acid batteries, and they can tolerate remaining discharges for longer periods than a lead acid. If you have an older boat you may have to change to a charger and alternator with controlled voltage regulation.
7. How much anchor line do I need?
A: Consider that scopes of between 5-to-1 and 7-to-1 are considered optimum for non-storm conditions, then do the math. In sheltered water, anchoring in 10 feet requires 70 feet of rode plus the distance from the water surface to the roller at the bow. In an exposed location with high wind you may have to increase scope to 10-to-1.