Your recent article on solar panels [May 1] prompts me to suggest another criteria or two that may be important when selecting panels for use on a sailboat.
For catamarans in particular, weight is an important issue. Panels such as the amorphous flexible panels made by Uni-Solar generate far more power per pound than the "high efficiency" crystalline panels. Where weight is an issue, efficiency should be measured in watts per pound.
Also related to weight is windage. Again the amorphous flexible panels present a much lower profile than the crystalline alternatives. Fractions of an inch vs. inches.
By the way, your insights about the effects of shadows helped me considerably in choosing Uni-Solar panels for my catamaran where the huge bimini was the chosen mounting location for 4 of the largest flexible panels.
Your "Solar Panel Survey 2003" was informative and useful, but confirmed my experience that the easy part of adding solar power is the panels. In 1998 I added 400 watts of Siemens solar panels to my 47-foot sloop and sailed from San Diego to Honolulu without ever starting the engine.
One comment in the article may be misleading. You accurately note that panel power output drops with temperature, but for most of us this is meaningless because only the current from the panel matters. As panel temperature increases the maximum voltage drops, but the current remains constant. With either a direct connection to the battery (a bad idea) or a simple regulator, the panel voltage is set by the battery voltage. Don't bother to throw buckets of water on the panels.
Solar panels for simple installations are designed to provide enough voltage to fully charge a 12-volt lead acid battery even when the panels are hot. Most of us add a regulator to make sure that the battery is not over-charged and that the panel never discharges the battery. An ideal regulator would do much more.
On my boat, the panels cost about $2,000, the stainless arch cost about $2,000, and the regulator cost $20. If it had been available, I should have been willing to spend about $1,000 on a better regulator.
At 25° C the Shell Solar SP75 puts out 75 watts in full sun at 17 volts. If the panel is connected directly to a battery at 12 volts, the power delivered to the battery is less than 60 watts. A better regulator can reclaim the 25% additional power. It does this by running the panel at its peak power point, not the battery voltage. Also, because of shadows, a significant increase in efficiency can be achieved by using a regulator on each panel.
I wish I could tell you where to buy the ideal regulator.
Nitty gritty: the $20 solar charger regulator periodically put out so much EMI that the HF radio was useless. I had to put a switch on the solar so that I could get weather FAX or use SSB.
Of Hitches and Splices
I read your editorial, "Seized With Impatience," [May 1] with interest. Enclosed is a sample of a knot taught to me by Rod Stephens. We use it for snap shackles on halyards, spinnaker guys, and main sheets.
What's great about this knot is that it's stronger than a bowline, it slips to create a tight fit, it acts as a stopper knot, and if there's chafe on a halyard, you don't hesitate to cut it and tie a new one. The only disadvantages are that it's not as "shippy" as a splice, and that, once loaded, it jams and is very difficult to untie.
Its real name is the buntline hitch, but we call it the Rod Knot.
Keep up the good work.
President, Sparkman and Stephens
New York, NY
The buntline hitch and the rolling hitch are probably the two most useful and underused of all hitches and knots, and both are dirt-simple to tie. We've also heard the buntline hitch called a stuns'l tackbend, but that sounds a bit wooden in a day when few of us even know what a studding sail is, much less how to fasten its tack to the end of an extending spar. However, what goes around comes around: When we tested knots in high-tech rope a couple of years ago (see the September 2001 issue), we found the buntline hitch to be the most effective, by far, of all the knots used, including the bowline, constrictor knot, and anchor bend. This is because the buntline hitch locks its inside turn, digs in hard to the standing part of the line, and counteracts the tendency of the slippery core to creep. When those hitches finally broke, under heavy hydraulic pressure, they broke under the inside round turn of the hitch.
I made the lifelines for our 50' sailing catamaran with 5/16" Sta-Set X about a year ago and had no major problems, despite my inexperience splicing "high-tech" lines. Papillon's lifelines have thimbles at the gates and plastic balls (line stoppers) at the gate side of the stanchion. The balls and adjacent seizing keep the lifelines from being so tightly tensioned at the gate that it can't be opened. At the terminal end, the lines are led through padeyes on deck, double half-hitched, and tensioned by wrapping the upper and lower lines around each other like a noose.
After surveying as many instructions as I could get my hands on, I decided that Barbara Merry's Core-to-Core Splicing method in The Splicing Handbook (International Marine, 2000) was the easiest to follow. One trick is to be sure not to leave more than eight fid lengths between where you start the splice and the knot that keeps the cover from slipping too far down the line. If the cover can go "too far" you'll really have to work to pull it back over the eye splice. Also, follow Brian Toss' recommendations to massage the line near the splice while you're working the cover back over it.
Generally, if you ease the cover up twice, then stop and massage the core-to-core interface, you'll get more cover over it the next time.
When finishing the eye-splice, Merry suggests taping or seizing the splice and then cutting off the excess tail. This leaves a bit of a ragged endprotruding from the seizing. Instead, sew a couple of inches of empty cover to the standing end of the line, and cut it off. Wrap tightly with sail tape, then seize it.
The core-to-core splice may be confusing at first, but after you do a few you'll find them easier than the conventional double braid splice.
-Julia Parker, S/V Papillon
Ablative's Need for Speed
I missed the "Bottom Paint 2003" report in your April 1, 2003 edition until my customers began complaining about the "fair" rating that you gave our paint, Super Shipbottom. Then I remembered a prediction made by Dick Greenhaus, the former head of your testing program, that the newer style of testing might not give our hard-ablative, multi-season paint the same excellent results.
I know this might sound like sour grapes, but Practical Sailor and Powerboat Reports rated our paint good against slime and excellent against hard growth in the 1996 paint test. Using the same panel without repainting, you rated us excellent against slime and excellent against hard growth the next two years. We knew that the '96 good rating against slime was because the paint was fresh and a little rough, but it improved to excellent as the ablative surface smoothed itself over the next two seasons. We were ecstatic that Practical Sailor and Powerboat Reports proved Super Shipbottom would last three seasons with one coat. How much more practical can you get if boaters don't have to paint every year? But recently you stopped testing for multi-season performance?
Those multi-season tests were done on a barge that was towed around the bay several times during the year and that surely helped our results, because all ablatives need to move a little. I feel your new style of static testing is flawed because you're using panels mounted to stationary docks to test the paints. If you are trying to replicate a boat sitting idly in a slip with a fast tidal current going past, you have succeeded, but who wants to boat that way? Our paint doesn't have to move much, but it should be moved once or twice a season!
I understand tests aren't 100% accurate due to the difference in salinity, sunlight, and temperature. Initially I was convinced your results were flawed because of improper stirring of our product prior to application, but you have assured me that you take great pains in this department. I believe you. Still, there is almost 11 pounds of cuprous oxide in every gallon, and it settles to a hard, dry solid in the bottom of the can.
As you can tell, my customers and I are very disappointed in this year's results. I was especially disappointed by your comment about us "small guys mixing it up with the big guys." Yes, we have loyal followers, and we constantly search for new customers without multi-million dollar ad campaigns—but the little guy/big guy thing got my Irish up. I know you aren't biased, but it showed a little too much reverence for those multi-national corporations. If it wasn't for us "little guys," the price of bottom paint might double!
-Ed (I make the paint!) Donlin
Innovative Marine Coatings
Fort Myers, FL
There's no question that ablative paints fare better on surfaces that move through the water. As we said in the article, the Connecticut panels are exposed to a strong tidal current, and are shifted regularly to change their exposures. This, of course, is not the same as the strong waterflow caused by a boat moving regularly at high speed or through waves.
If our comment applauding the small paint makers for competing with the big companies sounded condescending, it was the exact opposite of our intention.
Centek Mycelx Bilge Cleaner
I have been a subscriber of Practical Sailor for nearly 20 years. You have a great publication, so keep up the good work.
Now for the real reason for the e-mail. In the December 2002 issue of the US Power Squadron Ensign magazine I read about bilge-cleaning products by Centek Industries. I talked with both Ken Harstel and Tom Watson, the product manager of Mycelx (the material that soaks up the bilge oil). I received from them a 12-oz bottle of the solvent and a couple of their Smartpads. I needed to clean up some years-old baked-on oil in the engine compartment and decided to try this product. While it did not turn my engine compartment into a dazzling white area, it did in fact dissolve much of the old baked-on oil. It also dissolved the diesel fuel on the outside of a fiberglass fuel tank in preparation of repairing a weeping fitting.
The solvent has a nice citrus smell, and according to the company is environmentally friendly. I have placed their Smartpad in my bilge, but since the bilge is presently clean I have no knowledge as to how this works compared to the other absorbent products on the market. What I can say is that it is certainly easier to work with than the 3M pads.
I suggest that you check this out for yourself. If nothing else you will have pleasant orange-smelling hands from the use of the solvent!
Now, in the interest of full disclosure, the solvent they sent me was a sample for me to try. So even though I did not pay for it, it still works great!See www.centekindustries.com.
Thank you for those tips. Centek's Smartpads were not among the bilge oil absorbers we tested and reported on in the March 2002 issue, but if they stack up well against the 3M pads, that's impressive.
Good Stuff at PS Online
Wow…I just found the section on your website on Tools & Techniques. What a wealth of information on hundreds of topics. Other Practical Sailor readers should take a look at this area and discover another facet of this great publication.
It's a handy trove, isn't it? Many of those articles are from Better Boat magazine, which was acquired some time ago by Practical Sailor's owners, Belvoir Publications, and originally edited by Nick Nicholson, The company decided to repurpose that content, the core of which is as valuable today as it was when first published ("evergreen," as we say in the trade), although a certain number of the original contact names and numbers will need to be looked up again.
These articles are in PDF format, and are available free of charge. Click on "Tools & Techniques" among the red buttons to the left, and take 'em as they are. While you're on-site, feel free to add your voice to the surveys we have online—in particular the new one covering sails and sailmakers.
For those who missed the PS Advisor headline, "No Steel Wool on Stainless," in the June issue, it was in response to a quick inrush of notes from readers pointing out a careless error of ours in the May 1 issue. Best not to use plain steel wool on stainless. Stainless steel wool and bronze wool are OK. And here are a few other ideas:
I have found the best product for this job was under the kitchen sink. Go to the supermarket and get "Bar Keeper's Friend" (comes in a container like Comet or Bon Ami). This stuff is amazing for cleaning up rust spots on boat stainless. No clean-up mess or harsh chemicals to deal with.
It's also safe to use on fiberglass and it washes off with water. I have to thank my Matie for turning me on to this product! Visit the web site for more info and a free sample: www.barkeepersfriend.com.
-Francis S. Capsan, S/V Caribe Time
We've seen pretty good results cleaning rust on stainless with Wichard's Wichinox paste. We were told about it by one of the many BMTs (Boat Maintenance Technicians) who frequent our store. Definitely knowledgeable folks! There's also super-efficient metal cleaner/polish called Met All.
Hathaway, Reiser, and Raymond
Today I replaced a kitchen sink faucet on a stainless sink which had been installed over 20 years ago. A backing plate under the chrome cover was completely rusted away, and had made major rust marks on the stainless sink under the old faucet cover plate. Since the replacement faucet in stainless had a somewhat smaller footprint, it was necessary to remove all the rust areas.
I found that MaryKate On & Off Hull & Bottom Cleaner, used without dilution, really did the job. Most of the rust was removed by rubbing with an old toothbrush and the On & Off cleaner.
I was surprised you did not mention Wichinox when A. J. Beland asked for advice on removing rust from stainless steel stanchions, etc. I've been using the product since reading about it in PS years ago in one of Nick Nicholson's Offshore Logs. It's pretty amazing stuff.
Remember to follow the directions: Protect skin and eyes from contact, wash all the Wichinox off the area after the rust is gone using lots of water, and apply a coat of protecting wax right away.
For light surface rust streaks, just wipe the Wichinox on, wait for it to dry, and wash it off. For heavier rust, use a toothbrush, some Scotchbrite pads, or a stainless steel or bronze wire toothbrush.
For really heavy stuff, second and third applications may be needed to penetrate to the bottom of the rust scale.
The best thing about the product is that it passivates the stainless steel, making future rust less likely. It is non-abrasive and does not leave scratch marks.
I've also found the laundry product Oxi-Clean useful. Mix up a strong solution and soak the rusty part. Oshpo and Rust Arrest, both industrial treatments primarily used to prepare rusty mild steel for paint are useful in dissolving rust on stainless steel. Both are available in good hardware or paint stores.