Telltales, fiberglass repairs and GPS dilemmas

UNSTICKING TELLTALES Q:

All my life I’ve been vexed by jib telltales, both yarn and nylon, that stick to the stitching or material of whatever headsail I may be carrying, especially in lighter air. Any thoughts on how to remedy this problem, other than climbing up onto the bow pulpit and whacking the heck out of the luff of the sail?

BRIAN HANCOCK REPLIES

In the past, I have tried spraying my telltales with McLube Sailkote or something similar, and that seems to work. Be sure you only use a little, so that the telltales don’t get too heavy. Come to think of it, I bet if you sprayed some McLube on the sail itself and not the telltales it would work just as well, maybe even better.

REPAIRING HOLES IN FIBERGLASS Q:

I have read two conflicting strategies to repair a hole in a boat. Your book states you should start with a piece of fabric slightly larger than the original hole and increase the fabric size until the outside of the sanded area is covered. However, epoxy suppliers, like West System and Sea Hawk, recommend starting with a larger piece against the hole that is the size of the sanded area, then placing smaller pieces until the last piece is the size of the hole. Which method is correct? DON CASEY REPLIES I have been offering repair advice for quite a long time, so my “stated” position on this question can depend on the age of the book you are consulting. Allow me to quote from the latest edition of This Old Boat. “When filling a depression or doing reconstruction, the intuitive order is small to large, but the problem here is that we are trying to replace cutaway or grind-away fabric, and the new fabric, except for the bottom piece, will only attach to the original material at the perimeter—in effect, a butt joint. So the largest piece should go into the cavity first to maximize the surface area of the secondary bond. After that all subsequent laminates bond to this first piece and each other on a molecular level, but applying them in a large-to-small order still maximizes the mating surfaces.” Bottom line: laminate the largest piece first to maximize the secondary bond. After that, it really doesn’t matter, except that small-to-large tends to create voids at the overlap that can result in drain-through with thin epoxy resin. Large-to-small avoids that.

GPS SABOTAGE?

Q:A very strange GPS event in our harbor! Some large

motoryachts heading south for the winter recently pulled into our harbor, and several of us immediately lost GPS capabilities. After they pulled out a couple of days later, all our GPS receivers began to work again. Powerboats versus sailboats?

GORDON WEST REPLIES

Wow! One of those powerboats likely had its own GPS on the fritz too and didn’t have GPS capabilities until the crew turned off its amplified omni-directional TV antenna for over-the-air reception. A while ago a marine TV antenna importer discovered that the internal pre-amplifier in some antennas can go into oscillation, causing broad-band interference on the GPS 1275 MHz band, locking up GPS receivers up to a half-mile away. Of course, well out to sea there are no TV signals from land to receive, so the powerboater in question would shut down these antennas, until they got to the next harbor, where they undoubtedly turned it on again, wiping out GPS reception all around them, including on their own yacht!

Only the military has added GPS channel bands (secret) to prevent interference like this, but for those of us trying to get a fix in the harbor, the culprit would be an amplified over-the-air (not satellite TV) antenna system going into oscillation like this. I am told the problem of the circuits has long been resolved with a recall.

When I am sailing I have a tricolor mast light that is also an allaround white anchor light. When I am motoring can I use the masthead “anchor light” as a stern/steam light and use a bow pulpit red/ green light, or do I have to install a separate stern and steaming light?

NIGEL CALDER REPLIES

You cannot use the anchor light as a stern light! A stern light has a defined arc, as opposed to the all-around arc of an anchor light. When you are motoring, you should have a white steaming light above your red/green pulpit lights as well as the stern light. In other words, you have two modes: the masthead tricolor, which combines the red and green lights with a white stern light in a single fixture when sailing, and the red/green bow pulpit lights with a separate white steaming light (facing forward) and stern light (facing aft) when under power. s