Barnacle Bills

How do you prevent barnacles from growing on the stainless shaft and bronze prop? I have a mooring in Brunswick, Maine. When the boat was pulled last fall, the shaft and prop were completely covered and had to be scraped off.

Tom Neale: For more than 40 years I've been looking for a paint or anything else that will stop barnacles from growing on my strut, shaft, and props. I haven't found anything that works to my satisfaction as much as a regular program of diving and scraping. There are some rather expensive products available, and I've used some, but I prefer the manual method. I even painted on STP Oil Treatment one spring years ago when many of the local Chesapeake Bay watermen were swearing by it. Examples of products that some have found helpful are Propspeed and zinc paint such as Pettit's Barnacle Barrier, or generic "cold galvanizing" sprays. Copper-based paint on running gear can result in electrical interaction, doesn't stay on well, and can impair the gear.

Part of the problem is the constant abrasion you get on the prop from particulates in the water when the boat is running. Some people cover their prop(s) when they're not running the boat with a plastic garbage bag with a trip string so that they can easily pull it off before getting underway. But this is a hassle, probably involves diving at least to do the install, and you wouldn't want the bag to come loose and float away.

If your boat is in current with a lot of nutrients flowing by, this will greatly accelerate the growth. And warmer water also usually results in more rapid growth. I dive, either free diving or with a Brownie's Third Lung. If you keep up with it, the job isn't bad, but you must know what you're doing in and under the water and be in good health. If you don't want to dive, there are usually commercial divers around and the cost of hiring them may well be worth it when you consider the extra cost of fuel when your props, strut, and shaft are fouled.

If someone has a tried-and-true solution, meaning at least a full season with a lot of running and little or no fouling, and repeated success over more than one season, please email us and share the good news.

Which Way To Wrench?

I need to tighten the packing around the propeller shaft. It has a locking nut, and a nut to compress the packing. Looking toward the stern from the engine, does the lock nut turn clockwise or counter clockwise? Does it depend on the shaft rotation? My prop walk is to starboard.

Don Casey: The rotation of the shaft has no impact. Looking toward the stern from the engine, the lock nut is going to turn clockwise to loosen it. Conversely, the packing nut is going to tighten when turned clockwise, because clockwise moves both nuts toward the stern. Be sure to use two wrenches, one holding the packing nut when you release (or tighten) the lock nut. You might also need a pipe wrench to hold the box at the flange that sits on the stern hose to keep the box from spinning inside the hose if the packing nut is stiff. Except for access, this is usually a pretty easy job that goes off without a hitch.

Replace Or Not To Replace, That Is The Question

I read "Avoid Getting Hosed" in your February 2014 issue. I installed a new engine in my boat 11 years ago with SAE J1527 alcohol-resistant hoses. The local dealer says I should replace them after 10 years if I use ethanol fuel, which I do. Is it really time?

John Adey: If I owned a boatyard and was doing the service, without question I'd recommend replacement of 10-year-old hose. ABYC Standards (H-24 Gasoline Fuel Systems) recommend an annual fuel-system inspection, which I would perform. There's no magic destruct date on fuel hose. Remove one, and swab the inside with a Q-Tip. If black stuff comes off, the hose is deteriorating. Also check the outside for cracks or stiffness, both signs of deterioration. If all looks good, specifically around the hose barb where the hose is flexed and clamped, then you're probably OK for another year until your next inspection.

What's It Worth?

Is there a Kelly Blue Book or similar publication on boat prices like there is for cars?

Beth Leonard: There are several value references published for used boats, but it takes experience to know which, if any, to use for which boat types, and how to interpret the data. Such guides typically use data at least 18 months old by the publication date to which they apply some sort of algorithm, hoping to approximate current market values. Some are more successful than others.

One is completely free, Another is available for limited use free after registration, The others require subscription or purchase — not inexpensive, either way. BoatUS offers free, used-boat Value Checks to members, based primarily on the purchase histories of similar vessels as recorded in our marine-insurance department database, the detailed knowledge of our Value Check professionals, and other industry sources. Our estimates represent typical values for that manufacturer, model, and year, equipped to normal standards for the intended use. They're not vesselspecific appraisals, which can't be done sight unseen. But they'll provide objective guidance as to what a boat of a specific model and age is worth on the open market. Go to for your free estimate.

Two Cents ' Worth

I have a 42-foot Carver with the usual 340-hp Mercruisers. These are topped with Quadrajet carburetors and have logged about 1,000 hours. I'm planning on rebuilding or replacing the carbs in the interest of efficiency. Any advice?

Don Casey: I haven't had much to do with four-barrel carbs since my wasted youth trying to wring extra horsepower from big-block Chevys. That said, if you're easy on the throttles, I'd expect the Quadrajet to be as economical as any other carb, maybe better because the front barrels are smaller. A rebuild is also the cheapest and easiest option.

If you get info from a reliable source that you can make significant economy improvement with a different carb setup, my guess is that will be for Edelbrocks. There's a pretty standard relationship between energy in the fuel and engine output. When you're running these big engines at speed, they're going to burn a fixed amount of fuel no matter what carb is fitted, assuming the carbs are in good shape and tune. Run the numbers on potential economy improvement to see how many hours you'll have to operate to recover the cost of the different carbs. Without compelling evidence of really significant improvement, I'd stick with the Q-jets.

Let There Be Light! Or Not

I have a 1975 Tartan and would like more light below. Would it be allowable from a "best practices" perspective to remove and replace a section of the deck on either side of the mid-cabin hatch with Plexiglas?

John Adey: It sounds like you have a factory hatch in the cabin top. On either side you're proposing to cut large holes and cover them with Plexiglas? I strongly recommend you don't do this. Your cabin top is freely supported with a series of stringers and cored fiberglass that are buried beneath a headliner you cannot see. When a hatch is installed, there's even more support surrounding it (many times, the core is solid resin to add support) to compensate for the opening and the interruption of any continuous stringers. Once you start cutting through the deck, you never know what you will find. If you can remove the headliner and investigate, you might find some small places where you can add a new hatch. But knowledge of how the boat was built is critical before making that call.

Check owner's forums to see what others have successfully done. Also go with a glass pre-made hatch from Lewmar, Bomar, or similar. You'll end up with leaks, crazing, and cracking if you go the Plexiglas route. Please seek out a pro who can either tell you where to put the additional hatches or do the job for you.

Solar Charging

I'm looking for a solar maintainer to keep two deep-cycle batteries fully charged when the boat isn't in use. During the season I leave my boat in the water at a dock. The bilge pump is wired directly to one of the batteries, so it will work when the switch is turned off. What kind of solar charger should I buy and how would I go about hooking it up?

Don Casey: In a fairly sunny environment, you need a solar panel that putsout about 0.3 percent of the amp-hour (Ah) capacity of the battery to maintain a full charge. If you have one group 24 battery rated at 80 Ah, you need just 0.24 amps from a solar panel. But solar panels are rated in watts, not amps, so multiply this by 16 (the likely voltage of the panel). That gives you 3.84 watts, so you need around 4 watts of solar power for an 80-Ah battery, 5 watts if it is a 100-Ah battery, 10 watts if you have two 100-Ah batteries. The type of panel doesn't matter, only the output.

As long as the amp output of a solar panel doesn't exceed around one percent of the amp-hour rating of the battery bank, just connect it directly with no regulator needed. You need a fuse in the positive lead as close to the battery terminal as possible to protect against a short. One issue you face is keeping the two batteries independent. The easiest solution is to buy two 4- or 5-watt panels and wire one to each battery. An alternative is to splice two wires to the leads from a single (10-watt) solar panel, then insert a diode in one or both of the hot leads, paying attention to the polarity of the diodes. These act as one-way gates, allowing charging current to flow to each battery, but not allowing discharging current to flow in the opposite direction. Appropriate diodes should be available wherever you buy the panel. Be sure you fuse both hot leads right at the battery terminal. Fuse size will be 1 amp for 5- or 10-watt panels.

This all assumes you're leaving the batteries fully charged and that under normal conditions there are no electrical demands when the boat is idle. If your boat is open and you depend on the bilge pump to empty out rain, then you may need some additional capacity to accommodate that. You can upsize your panel choice, but not above one percent (1.6 amps or 25 watts of solar output for a pair of 80-Ah batteries) or you'll then need to put a regulator into the circuit.

At your library, bookstore, or, you will find my Sailboat Electrics Simplified that covers all of this in more detail, plus lots of additional electrical help for all boats, sail or other. Also keep an eye out for an article on solar panels scheduled for an upcoming issue of BoatUS Magazine.

Hanging & Swinging

I'd like to suspend my aluminum pontoon boat from davits. Is there a problem with hot-dipped galvanized shackles connected to the aluminum pontoon lifting eyes, or should I use stainless-steel shackles?

Tom Neale: I've used an aluminum dinghy for years, hanging from davits. I use heavy-nylon, braided-rope loops attached to the lifting eyes on the dinghy. I attach the nylon to stainless shackles. Either hot-dipped galvanized shackles or stainless shackles are going to wear into that soft aluminum as the boat moves, even slightly, over the years. And there's also the issue of galvanic reaction. Keep a sharp eye on the rope. It, too, will wear but that's much easier and cheaper to replace than your lifting eyes.

Hidden Hoses

I have a 1997 Trophy 2503 center console, and am concerned about my four cockpit drains that sit below the waterline. There's no access to inspect the hoses that connect them from the deck to the outside connectors. They're original hoses and if one pops, the boat will sink. Any ideas?

Beth Leonard: You're right to be concerned. If the thru-hulls for the cockpit drains are below the waterline, your boat is vulnerable, not just to sinking due to a failed hose, but to being overwhelmed by a heavy rain. If the hoses were not originally below the waterline, they might now be for a number of reasons including repowering with heavier engines, storing more weight in the back of the boat, or the boat stern or hull taking on water, perhaps around fittings that pass through the hull. If there's any way to get those outlets above the water, the boat would be significantly less vulnerable. If you can see no reason why the hull would be heavy but believe the outlets were originally above the waterline, hire a surveyor to check the hull to make sure it hasn't taken on water and become significantly heavier than when it was new.

As to the access problem, if you can get some idea of the layout of the cockpit hoses, you might be able to figure out access to them. I recommend talking to Bayliner to see if you can get a schematic, and to find out if they have a recommendation on how to gain access. It may be possible to cut an access hole somewhere and then cover it with a watertight hatch. Someday those hoses will need to be replaced, and based on their age, sooner rather than later. 

— Published: June/July 2014

Meet the Experts

Photo of Beth Leonard

Beth Leonard
BoatUS Magazine's technical editor, Beth Leonard, grew up powerboating, waterskiing, and fishing on Lake Ontario. Since 1992, she and her husband have completed two circumnavigations on two sailboats, doing all maintenance themselves. They also installed the systems on their 47-foot aluminum sloop. Beth has written The Voyager's Handbook, the how-to bible for offshore sailors, and hundreds of technical articles.

Photo of Tom Neale

Tom Neale
He's cruised long distance with his family for most of his adult life. He can take apart and fix almost every system aboard, has written two books, filmed a two-set DVD on East Coast cruising, written for top marine magazines, and has won nine first-place awards from Boating Writers International and many awards for his technical writing.

Photo of Don Casey

Don Casey
One of the most consulted experts on boat care and upgrades for 30 years. He and his wife cruise their 30-footer part of the year in the eastern Caribbean. His books include Don Casey's Complete Illustrated Sailboat Maintenance Manual, and the recently updated This Old Boat, the bible for do-it-yourself boaters.

Photo of John Adey

John Adey
The president of the American Boat & Yacht Council, John has been in the industry since 1990, with experience from a yacht brokerage and boatyard to owning a marine supply store. He and his family sail their classic 1976 Irwin ketch, a boat he completely restored.


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