Tell­tales, fiber­glass re­pairs and GPS dilem­mas

SAIL - - Contents - Bart Jack­son, San Diego, CA Brad Hunter, sail­mail@sail­magazine.com

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

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