Mailport June 2005 Issue

Mailport: 06/05

Power Inverters
[Re: "Installing DC Inverters," PS Advisor, April 14, '05] Your advice states that the chassis ground on the inverter should be connected to the DC ground of the vessel. My Xantrex manual states that it should be connected to the AC ground, thereby insuring a correct ground path when connected to shore power (assuming all other AC wiring is correct). Please advise your readers of this potentially hazardous error.

Robert Cole
Southport, NC

We had the electronics expert who authored that PS Advisor recheck this information for us. He consulted ABYC recommended standards as well as the folks at Xantrex. It turns out that the manual you have is incorrect. ABYC recommends connecting to the DC bus, and Xantrex concurs. Randy Johnson of Xantrex told us: "The chassis ground should be connected to your DC negative bus as recommended by ABYC. It seems our manual is wrong and is in need of correction."


As a retired electrical engineer, and someone who has installed a few inverter/chargers on boats, I would like to add a few thoughts regarding DIY installations to your PS Advisor "Installing DC Inverters."

Even running at 90% efficiency, these things generate a fair bit of heat. Running a microwave, which draws perhaps 6 to 8 amps at 120 VAC, will produce inverter heat equivalent to a 75-watt bulb, which must be dissipated. I put one in a locker under a dinette seat and had to install about 150 sq. in. of louvered ventilation in the face of the locker.

Electrical resistance is the enemy. Resistance produces heat, does no work, and wastes those precious house bank amp hours. Use the wire size chart in the West Marine catalog, remember that the run is round trip, i.e. double the distance between the devices, and when in doubt always go to the next larger size.

Rather than try to put more than a couple of big cable terminals under a bolt on a device (inverter, alternator, or battery switch, for example), use the big stand-alone brass terminal posts as intermediate junctions. You can put a lot of torque on these, and if the terminal faces are bright and clean, you will have a good low-resistance connection stack. Unless you want to make a substantial investment in the big crimping tool, use a tool at your local chandlery to make up your cables. It is fast (much faster with another pair of hands), and makes the best connection. I have seen high-resistance connections produce enough heat to do a little light welding.

Do not omit properly sized fuses right at the battery banks. These could save your equipment and batteries, or perhaps even your boat.

Some of the battery monitor and/or inverter control panels made by Xantrex produce a lot of RFI. If you mount these panels close to your VHF, AM/FM stereo, or TV, you may hear or see this interference in low-signal-strength situations. (I recall another reader writing about trouble with his chartplotter from this cause.) One meter away should be enough. I have often wondered if these devices are in compliance with FCC rules on spurious RF emissions.

Lastly, check and recheck before making the final connections to your batteries. It is not rocket science, but mistakes can be costly.

Also, it's all well and good to install a 2KW inverter, but you need a lot of battery, which adds a lot of space and a hell of a lot of weight, to power anything that large for more than a few minutes. You might want to point out the differences in usable capacity between the various battery types. Misunderstandings about batteries seems to be a common problem for first time inverter buyers. Also, recharging that big housebank is a major consideration. Unless you want to run your propulsion engine for several hours a day, serious inverter use will probably require a larger alternator and a new charge controller, and maybe a different belt and pulley set up to drive it. The proper installation of that $1500 inverter can easily wind up costing more than double that, even for the DIYer.

Dick Pell
Sarasota, FL


Bottom Paints
[Re: "Annual Bottom Paint Test," PS March, '05] I enjoyed your article on bottom paints. I have had great success with Awlgrip Awl Star by US Paint. I keep my 32-foot sailboat in Narragansett Bay, RI. Over the six years I have been sailing her—and painting the bottom with Awlgrip Awl Star—I have seen little if any growth at the end of the season. However, if I didn't sail her in the last two weeks before she is hauled out and placed on the hard, I will see a slight slime across all the non-leading edges of the hull. I am a firm believer in this brand of paint.

Thaddeus Kubis
Sheffield, MA


Reefing Considerations
[Re: "Reefing Preferences of the Pros," PS May 1, '05] Reefing sails is always an interesting topic. When I owned and sailed a Tayana 42, not delaying the reefing tactic was always vital whenever the winds increased beyond 25 to 30 knots. I always found that when I began thinking that it was time to reef, then it actually was the right time. So, don't delay this important maneuver, it only worsens the situation if you do.

Finally, knowing your reefing gear and how to use it in high winds is a must. And practice the tactic. You won't be sorry.

Don Watson
Pensacola, FL.


Caulks and Sealants
[Re: "Caulks and Sealant Test," PS April 1, '05] I'd like to correct a couple of inaccuracies in your article on caulks and sealants: Silicone is a synthetic polymer. Silicon is an element, the second most abundant element on the earth. Sand is a network of silicon dioxide (oxidized silicon), and silicone is not made from sand or silica.

David Walker
Marblehead, MA


It's an excellent idea to test caulks and sealants. I will be especially interested in the results regarding UV degradation.

I'd like to offer a couple of comments on that piece: Regarding cleanup, I found that 3M 101 and 5200, and West Marine MultiCaulk and Quick Cure all clean up easily with mineral spirits. Most sailors don't know, but West Marine MultiCaulk and Quick Cure are made by Starbrite. This I found out when dealing with them regarding a problem I had (see below).

The paintability of caulks is an important topic, and I wish you could include that in some future test. Certainly the claimed paintable properties might be true of some caulks, but equally certain is that they are not always so. When I painted over 200 linear feet of West Marine MultiCaulk using Interlux Toplac, the recommended primer went on OK, but when the finish coat was applied, things started to go wrong.

First, the Toplac took around three weeks to harden, plus the caulk underneath went very soft. I contacted the folks at Starbrite and worked with them on a solution with no positive final result. The company's reps initially claimed that I hadn't let the caulk cure before applying the paint, which was untrue. Fortunately, there was another area where I had used the MultiCaulk, and which had been down for well over a month and was not painted. I applied Toplac to part of this, cut out some unpainted and painted samples and sent them to Starbrite. I still haven't received definitive answer from them regarding what went wrong.

It may well be that the silicone additive in the Toplac was the culprit, who knows. My point is that users should be advised to try a test area before committing to the full job.

To rectify the above problem, I scraped out all the MultiCaulk, replaced it with West Marine Quick Cure, and had no problems with the Toplac.

Brian Cleverly
Sacramento, CA


Power Boosters
[Re: "12-Volt Power Boosters," PS April 1, ‘05] I was about to buy a second power booster for the boat, but I was curious about charging via the 12V cords supplied with some, but not all units. The previous unit I bought did not come with one, and when I asked a company tech about it he stated that this method of charging might damage the battery. He said that the included wall charger could not, in effect, overcharge the battery.

This time around I bought the big Walmart model you recommended and it comes with a 12V cord. I note that the unit has an AGM battery. I use flooded cells on my boat. Based on what I know (much of it from PS articles), it seems to me I should not use the 12V cord while the engine is running. It might be OK to top off the pack from charged house batteries just by letting them equalize the charge at rest. Can you enlighten me further?

Lenny Lipton
Via e-mail

We double-checked the instructions for the Xantrex, West/SeaVolt, and Walmart boosters. All three give the go-ahead for recharging your power pack via the 12-volt DC male/male connector while the engine is running. The Walmart instructions read: "Charging through the DC cigarette lighter plug is an alternative charging method. However, the amount of charging current from the DC cigarette lighter plug may vary in different makes of car, which may result in overcharge of the battery. Therefore, this method is recommended only for emergency or quick charge no longer than four hours."

"The two main cautions have to do with charging at too high a voltage and charging for too long, in case there's a regulation problem. It's true that either of those problems would stand to damage the battery. The SeaVolt instructions say not to exceed three to four hours of charging time. The Xantrex puts no maximum on charging time, but says not to leave the male/male cord permanently connected.

With the Walmart booster, if you want to go 12V to 12V, you should charge until the "High" light on the power pack is lit, then unplug and wait a half-hour to let the charge settle. If it settles below the High mark, give it a bit more to top it up.


Charting Inaccuracies
I purchased Raymarine's radar and their C120 display last year. As to the hardware, I am very pleased with the quality of the C120 screen. There are no problems with it, but I do have a complaint about the charting software.

The main problem—and it is one I'm sure no one addresses in reviews— is the charting program that goes with the C series plotters. The system uses Navionics charts, and for anyone cruising in the Bahamas, the charts are next to useless as an accurate navigation aid. I'm not sure how accurate they are for other areas.

I have had correspondence with West Marine (where I purchased the system), RayMarine, and Navionics. Guiseppe Carnavale, founder and president of Navionics, admitted that the charts are "very inaccurate" for the Bahamas. He holds that this is because they're based on the old British Admiralty charts, which were established using pre-GPS surveys and therefore aren't accurate.

The problem here is that hundreds of owners will buy the C series plotters from Raymarine, and a large percentage of those may eventually find their way to the Bahamas. They'll expect their very expensive chartplotter to work with some degree of accuracy and reliability, but these sailors will quickly find their hopes dashed.

When I bought the package at West Marine, the manager of the store knew that I was going to the Bahamas, but never did he mention that the Navionics charts were "very inacurate." Neither is there any mention of this in Raymarine's literature that accompanies the C120. If I had been informed of this as I read through the instructions prior to installation, the whole package—all $3,500 worth—would have gone right back in the box and been returned.

Through much correspondence, I know that West Marine and Raymarine executives are aware of this problem. Raymarine doesn't seem to be too concerned, but because no other system than Navionics can be used with the C-series plotters, it remains a serious issue. I realize that no sailor should ever rely solely on a chartplotter—and I never do—but the charts in a plotter should be the best available, and the Navionics charts for the Bahamas don't even come close.

The executives at West Marine have been helpful, and they've demonstrated that they're on top of this problem. I am not sure what Raymarine thinks about this problem or whether they're coordinating with Navionics, but I do know from corresponding with Navionics that they are working on the problem, and have promised the release of a new product by the end of 2005.

Alan Harries
Marsh Harbour, Bahamas

Mr. Harries highlights an important area of concern. PS regularly admonishes readers not to use electronic sources of navigation without paper charts as a back up. We too are interested in charting accuracy, and will soon be conducting a real-time comparison of various electronic charting programs and the actual geographic areas they're intended to represent. Look for that in a late summer issue.


... Where Credit Is Due
To Garmin: "We recently were able to go sailing again after repairs due to the two hurricanes that visited our area last fall, which left some of my neighbor’s roof aboard our sailboat. When I finally turned on my Garmin 48 (1998) it told me that the internal battery had died and all my waypoint information had been lost. (The four AA batteries I had left in it were still charged; I know I should have taken them out for long-term storage but we had other issues).

"Information on Garmin's website suggested I charge the GPS using the 12-volt adapter for three days to see if the internal battery would recharge. When this did not help, I e-mailed Garmin. Imagine my excitement when the company immediately sent a Return Authorization Number and said they would fix the unit for no charge!

"The package arrived with a repair summary saying the old unit was not able to be repaired so it had been replaced. This is why I still have a Garmin 45 as well as a newer Garmin 12." (

Joe Krivan
Fort Pierce, FL

To Mooring Products International: "I purchased my mooring whips from Mooring Products International two and a half years ago and during that time my Catalina 22 sat happily at her dock. At the end of January, we had a tremendous wind storm at Lake of the Ozarks—40 mph winds and gusts over 60. During that storm, a 20-slip dock broke loose from a marina upwind of my dock. I watched in horror as the 104,000-lb. behemoth came charging down the cove and smashed into my Catalina. The mooring whips were bent in half as the runaway dock hit the boat and tried to force her up on my dock. When the large dock finally cleared, I was utterly amazed to see those mooring whips push my boat back where she belonged.

"I e-mailed some photos of the crash to Mr. Gordon Swire at the company and complimented him on his firm's fine product. In passing, I mentioned that my snubbers had taken a beating. He replied that he'd get some in the mail. The snubbers arrived shortly thereafter, at no charge. In my book, you can't beat that for a great product and great service." (

Dennis Duffy
Camdenton, MO

To Edson: "Late last August, the six-year-old pedestal steering failed on my 38-foot sailboat just before the long Labor Day weekend. I was panicked. Friends were coming in from out of town to sail and Alacrity was out of commission. Will Keene from Edson parachuted in a team, including the designer (from Germany), who promptly fixed the problem, at no charge. And all of that took place before my first guest arrived. I love those guys." (

Kevin Clancy
Gloucester, MA

To Marinco: "I purchased a Nicro Day/Night Solar Vent in 2000, but didn't install it until a summer refit  in 2004. Water intruded into the solar panel and motor housing within two months, and I sent it to Marinco for repair. I was surprised to receive an e-mail from David Colclough saying that the seal failure should not have occurred. He offered a replacement for the out-of-warranty vent. What's the bottom line? Integrity, honesty, and excellent customer service prevails with David Colclough at Marinco." (

Jerry Webb
Fairfield, ME

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