A cracked keel, VHF usage, “powering” up your mainsail
I am the owner of a 1985 Cal 22 sailboat that is moored during the season in Lake Tahoe, Nevada. The boat is in very good condition; however, when I pulled it out of the water at the end of the season in early October this year I noticed a slight crack in the keel that extends around the entire keel, about one third down from the hull. A friend looked at this condition and called it the “Catalina Smile,” explaining the crack occurs on older boats where the hull meets the bolted on keel. I am wondering if this condition requires immediate repair, and if so, what type of repairs are needed. Bill Jonkey, Minden, NV DON CASEY REPLIES Your friend is right, although Catalina has no special claim to keel smile. Well, maybe some claim because the company unwisely used plywood in its keel stubs up until around 1987 or 1988, which has tended to make the “Catalina smile” somewhat broader than some others. The crack exhibited in your photo is more or less normal for a 30-year-old boat with a bolt-on keel. Plastic boats flex; metal keels don’t. I doubt that your smile requires any action, but before you repaint the bottom, you would not be wrong to reef out the crack a bit with a wire brush and give it three or four coats of an epoxy primer (Interlux Epoxy Primecote or something similar). If you still have a gap, fill it with a troweled application of polyurethane sealant, like 3M 5200, and then let the sealant cure for a week before painting. Moving forward, just watch the area every year. If the smile doesn’t return, or even if it does but not any wider, deal with it cosmetically. However, if it shows any signs of widening, you may need to re-torque the keel bolts. The definitive repair is to drop the keel, check the bolts, perfect the mating surface and reattach on a fresh sealant bed. However, the current condition of your boat doesn’t suggest anything this drastic.
VHF PORTABLES ON LAND Q:
Our dockmaster tells me that portable marine VHF radios are now permitted for use on land. Does this mean I can use my hand-held on the ski slopes, or talk from the office with boats for weather reports? Don Hull, New York, NY
GORDON WEST REPLIES
Yes, and no. The Federal Communications Commission (FCC) in its August 2016 Report and Order amended the rule 80.115 (a)(1)-(4) to allow portable VHF radios to be used on shore “adjacent to a waterway” to talk with your own ship about ship’s business. With this in mind, for pleasure craft you would use non-commercial channels and keep transmissions to a minimum practical time. However, this rule change does NOT allow ski slope operation. Nor does it allow you to gab with any and all ship stations—just shore to your own ship station, like calling from the dock for the kids to pick you up, or calling your ship from a shore-side marine hardware store to see if there are any other parts you need to bring back aboard.
The FCC also makes it clear that this should not be interpreted as a free-for-all on using marine hand-helds ashore between each other. Again, the only permitted shore-to-ship calls will be to your “associated ship station,” and not anyone or everyone to just “yak, yak, yak.” DSC calling on channel 70 is also permitted to minimize Channel 16 traffic.
OUTBOARD SAFE FOR CHARGER? Q:
I have a Yamaha 9.9 outboard on my F-27 trimaran. I have heard that it is not uncommon when running the alternator on the 9.9s for many hours to see the charging voltage go over 15 volts and fry the batteries. (This apparently happened to a couple of guys writing into the F-boat forum.)
Since I will be cruising my boat starting later this month with the possibility of having to motor for 10 hours or more at some point, I would like to know whether disconnecting the 12V power to the alternator would stop the alternator from charging if the charging voltage went over 14.5V. In other words, if I could find the 12V lead to the alternator circuit that allows it to work, could I install a switch so that in case this happens after, say, five hours of motoring I could simply switch off the alternator?
Beyond that, can you help me understand what to do if the charge voltage goes too high and wants to fry my batteries? In the F-boat forum the guys that had this happen to them installed a solar panel regulator and bypassed the Yamaha regulator. Hank Stein, Largo, FL
NIGEL CALDER REPLIES The output of an alternator is controlled by something called the field current. To shut the alternator down you need to disconnect the field wire, but in your case this wire will almost certainly be internal to the alternator and inaccessible. Fundamentally, you need to fix the alternator problem! The one thing you can’t do is disconnect the alternator from the battery when the outboard is running, because this is likely to irreversibly damage essential components, called diodes, in the back of the alternator. However, there is an interim fix that can get you out of trouble. Most diodes create a voltage drop of between 0.5 and 1.0 volts. If you buy a diode with an amp rating at least as high as the rated output of your alternator and wire this into the alternator’s output cable (be sure to insulate it after you are done) it will drop the voltage at the battery by the amount of the loss through the diode. Be aware, that you need to make sure the diode is the right way around, or it will shut down the charging circuit altogether. (The diode will have an arrowhead symbol with a straight line across it; you want the arrow pointing toward the battery.) Unfortunately, you should also be aware that this diode will now slow down your battery charging at all times. If you feel you will be able to manage the charging process manually, you could put the diode in a switched bypass cable and simply switch over to this circuit once the battery voltage starts to climb above 14.5 volts.
POWERING UP A MAIN Q:
My friends tell me that I need to “power up” my mainsail in light winds, but I am not really sure what that means. Can you explain? I race a Pearson 37, mostly beer-can races. Joseph O’Brian, sailmail@sailmagazine.com
BRIAN HANCOCK REPLIES
Powering up your main is very important in light winds. Equally important is being able to “depower” the sail when the wind comes up. Powering up your main means adding depth to the sail. Mainsails are designed with a specific chord depth (draft, or curvature depth) for general sailing purposes. In light winds you want to increase the chord depth, and there are a number of ways you can accomplish this. The first and easiest thing you should do is ease the outhaul. This immediately adds depth to the sail because you are effectively bringing the leech closer to the luff. Also ease the halyard or cunningham. This, in turn, relaxes the fabric along the luff allowing the draft to increase. Another important thing you can do is to ease the backstay, effectively straightening the mast. The reason for this is that part of the sail’s overall shape is induced by the amount of luff curve the sail designer has specified for the sail. When the mast is bent, the luff curve matches the mast and the sail has a flatter shape. When the mast is straightened (by loosening the backstay) that luff curve shape is pushed into the body of the sail and increases overall depth. To depower a sail, simply do the reverse to reduce the amount of draft, or curvature, thereby producing a flatter sail. s