Good evening all.....A few months ago,I bought and installed those PVC tubes that are split and go on the shroud lines as chafe protection for the Genoa.They really look good .However,I just read an article in this months "Practical Sailor" that quotes, Bill Seifert former Tartan project engineer,"When stainless steel is deprived of oxygen,it is subject to crevice corrosion. This is the reason why the International Sailing Federation {ISAF}now requires that lifelines NOT be PVC coated." So ,off they come. I guess the replacement mod is going to be a small wheel type of thing on the shroud to keep the genny from dragging on the shroud. Just giving everyone a "Heads-Up". Happy Sailing.....Don
Don _ I dont think you need worry about the PVC tubes keeping oxygen from the rigging... I think they are talking about a sort of a dip treatment of standing rigging with plastic that was in vogue for a bit...
I just put the Davis tubes on my rigging - got 4 for $6 at WM on special table.
Catigale.......Thanks for the reply! I hadn't taken them off yet, and I think that I have the Davis brand also. So I guess they will still "breath" o.k. because of the split? Sorry for the scare,no alarm.Again thanks.....Don
Yeah, that rust scare is horsehockey, Don. I've had'em on my 1970's Boston Whaler Harpoon for *many* years.. so long, in fact, that recently those white plastic covers have started to get brittle, crack and crumble, so I removed them.. and underneath, my old stainless rigging looks just like new. I'm gonna put another set on.
To deprive oxygen you'd have to I would think ,"Encapsulate" it in something, I would imagine you would need to coat it or sealed it somehow, and the coating would have to be a non-porous product.
I could see causing corrosion with the use of a : Paint, Liquid tape, a Vinyl or PVC coating. self-fusing tape (riggers tape ) and then somehow the moisture became trapped between coating or covering and the SS? Maybe in some rare case with a lifeline cover ,where it held saltwater for long periods of time repeatedly unable to evaporate, and when it did dry out it left a salt residue behind? But I cannot imagine a 3/4 " hollow PVC tube a foot or so long that is constantly moving and open on the bottom and the top causing a problem . Lastly if there was a problem I cannot imagine someone here not discussing it in the past. IMHO very little seems to get by most of these fellows .
Exactly....I just read that article on my flight from LAX to CLE.....the BIG No-No is the rigging tape around the turnbuckles, but the PVC covers will allow air in...so they are fine and I will be putting them on my boat!
If you haven't yet made the purchase, consider this:
choose the covers sized for 3/16ths shrouds. They're still amply tight over our 5/32nds shrouds, but they're also loose enough to be easier to install, plus they can spin. I haven't yet tried to drop the mast with them on the shrouds ... not sure what will happen.
Frank C wrote:If you haven't yet made the purchase, consider this:
choose the covers sized for 3/16ths shrouds. They're still amply tight over our 5/32nds shrouds, but they're also loose enough to be easier to install, plus they can spin. I haven't yet tried to drop the mast with them on the shrouds ... not sure what will happen.
Hmm.. well, I had the more loose ones on my Harpoon way-back-when and took'em off... made a 'rattly' sound in the wind and just seemed untidy... went with the snug fit and they seemed to almost become part of the shrouds. In fact, I never noticed them again until only recently when the plastic started to degrade and they began to crack (*many* years after installation). As I stripped them off, the plastic shattered into little bits and the clean-up was a bit of a mess with tiny pieces of plastic all over the boat, but then as I say, I got at least 20 years of use out of them. I'll replace them, for sure - they prevent marring the boat when the mast is down and the shrouds are slapping the deck, and they also protect the sails... not to mention, if you've got one tiny broken strand in the bunch that always acts like a razor and slices your hand! (don't ask)
I think the plastic shroud covers make it much easier to "corral" all the shrouds for boat travel. They also eliminate the possibility of a shroud getting loose and marking up the deck while you're trailering. If you use the covers that go over the chainplates also,make sure you take a peak at the ringdings on the clevis' every once in a while
I use shroud covers and like them on the backstay too. Keeps clothes and sails cleaner on contact, prevents wear on gel coat or side windows when rigged for traveling, makes gathering and tieing up for traveling easier, and looks nice. I've never found any deterioration of wire in fresh or salt water from using shroud covers.
I'm a bit confused with this thread, seems like some folks are talking about the tight fitting cable covers (which cut down on line chafe) and others are talking about the bigger covers which are designed to go over the turnbuckles themselves (in our case, slot adjuster thingees). My Genny sheets are always getting caught on those adjusters and today, I added another set of spin sheets so yet another line to get caught. My old keelboat had the turnbuckle covers but they seemed like a rip-off (price wise) when I looked into buying them for the Mac.
Does 3/4 PVC fit over the slot adjusters/ring dings? Wouldn't look as good without the little cap on top but maybe something could be fabricated with a plug. Anyone done this?
Yes, we've bought a heck of a lot of diapers over the last decade I must have been thinking of something else that is a rip-off at WM (fancy that).
Thinking back on how those things work though, will they really cover up the chainplate to the point of preventing sheet snags? With both slot adjusters side by side like that on a chainplate, seems like you may not get the same kind of benefit you would on a different boat. Ie, the tube needs to come right down to the deck so lines can't get under it.
My experience has been that the warm Gulf waters will corrode fast, but with routine examinations, you simply keep-up with preventative measures. I've never seen the type of corrosion we're discussing here. It does, however, make sense that if the metal cannot be rinsed off, the electrolyte will continue to move those electrons.
I have the Davis covers on the shrouds, the plate covers, as well as the covered lifelines and have not experienced problems. Agree with using the next size up on the David covers, they are much easier to get on and they also fit better. Almost like they're sized incorrectly. Like what happens with our waist size. The 'right' size seems somehow a little tight.
.However,I just read an article in this months "Practical Sailor" that quotes, Bill Seifert former Tartan project engineer,"When stainless steel is deprived of oxygen,it is subject to crevice corrosion. This is the reason why the International Sailing Federation {ISAF}now requires that lifelines NOT be PVC coated." 
So ,off they come. I guess the replacement mod is going to be a small wheel type of thing on the shroud to keep the genny from dragging on the shroud. Just giving everyone a "Heads-Up". Happy Sailing.....Don
I must have been thinking of something else that is a rip-off at WM (fancy that).