Before I Go Up the Mast ... In Situ Sheave Lubrication?

[rardiH36]

Maybe because I wasn't able to sail for a 7-8 month period last winter, and my masthead sheaves sat unused, my main halyard now isn't running as freely as before. I can tell by pulling the halyard up/down by hand that sheave is still free and is not catching. Just protesting a bit. The "exit" sheaves at the mast base are rotating fine.

My hope is that going up the mast to lubricate the main halyard sheave will get things right again. The sheaves I am guessing have been in place on the Kenyon mast since the boat was built in 1980. So I would expect that trying to remove the SS axle center pin do a more proper cleaning and removal of scale would be a challenge sitting in a Bosun's chair.

Before I go up the mast, suggestions? PB Plaster only? Aerosol propelled grease? Any other considerations?

Thank you.

 

[rgranger]

Graphite? Or a marine based silicone lubricant? I have this water proof stuff (green in color) that I first purchased for my bicycle chain. It seems to really hold up well and not attract gunk...I suspect it is the same stuff you see advertised as marine/water proof etc... I've used it on my winches with great success.

I'd worry that using a petroleum based lubricant would invite dust bunnies and gum up he works after a short while. (?)

 

[Parsons]

Out of an abundance of caution, how old are the halyards on your boat? Considering that your boat has a 50-foot mast height, and that falling from such a height would leave a serious dent in your cabin top, not to mention the impact to your friend / partner who is winching you up there, perhaps this is a job that should wait until the mast comes out. Seriously, I have seen halyards part and shackles fail on much less stress than a grown man swinging in the breeze! How much does pulling the mast really cost in SF - $200? If you don't know that the system will definitely hold at least ten times your weight, I suggest doing this on the ground.

 

[dlochner]

When's the last time the mast and standing rigging has been throughly inspected? How is the wiring? The more work that can be done on the mast while it is down reduces the cost per job of the unstepping and stepping. Not to mention significantly increasing the safety factor.

A lot of masthead sheaves ride on the axle with maybe a thin aluminum bearing. Over time the bearing begins to wear and with a little corrosion, it chews away at the SS bolt that serves as an axle. This will weaken the axle and flatten the bearing making more oval than round. Lubrication helps, but the only solution is replacing the sheave, bearing, and axle. Depending on the mast head, this may not be possible while the stick is up.

For a short term solution, if you go up the mast, try using a dry lubricant, such as McLube or a dry teflon lube. These won't gum up the works.

 

[rardiH36]

Out of an abundance of caution, how old are the halyards on your boat? Considering that your boat has a 50-foot mast height, and that falling from such a height would leave a serious dent in your cabin top, not to mention the impact to your friend / partner who is winching you up there, perhaps this is a job that should wait until the mast comes out. Seriously, I have seen halyards part and shackles fail on much less stress than a grown man swinging in the breeze! How much does pulling the mast really cost in SF - $200? If you don't know that the system will definitely hold at least ten times your weight, I suggest doing this on the ground.

Parsons:

Thanks for the reminder. Also on my mind always. The halyard I will be climbing up is only five years on. Still in good condition. Not chafed. Is a premium line, not the standard "yacht braid" or Sta-set". I use a "mast climber" ascender. As further safety, I rig a second halyard next to the primary climbing line. And wrap a prusik knot around that which I connect by a short line direct to my climbing harness (which I don in addition to the bosun's chair harness). After each "hoist" or "release" with the ascender, I move the prusik knot up or down, then take out slack and re-tension the knot. So if the primary ascender fails, or the climbing halyward, I have a safety backup. I might find myself stuck and need to be rescued. But I shouldn't be able to tumble to the deck. That said, going up the mast never has been my favorite sailing task!

With your question about getting the mast down, afraid the cost is a lot. With our boats remaining in the water year round, masts aren't routinely dropped. The nearby yard charges $480/hour for the crane. +$119/hour for general labor. So looking at a $500 - $1000 expense to hire it out. I probably will be dropping the mast in about two years at my next haulout. Time to replace the standing rigging by a professional rigger. And at the same time have the professional thoroughly inspect/repair everything suspect.

 

[rardiH36]

When's the last time the mast and standing rigging has been throughly inspected? How is the wiring? The more work that can be done on the mast while it is down reduces the cost per job of the unstepping and stepping. Not to mention significantly increasing the safety factor. ...

Standing rigging was all renewed in 2007. And I had a professional rig inspection 4 years ago. Got a "pass" report. I've been up the mast a couple of times since then and each time made a point to look carefully at all the swages, fittings, SSwire, visual suggestion of stress cracks, etc. I will be renewing the standing rigging again along with the next haul-out in about 18-24 months.

A lot of masthead sheaves ride on the axle with maybe a thin aluminum bearing. Over time the bearing begins to wear and with a little corrosion, it chews away at the SS bolt that serves as an axle. This will weaken the axle and flatten the bearing making more oval than round. Lubrication helps, but the only solution is replacing the sheave, bearing, and axle. Depending on the mast head, this may not be possible while the stick is up.

Many thanks for a description of sheave anatomy. Will help me make the interim repair determination.

For a short term solution, if you go up the mast, try using a dry lubricant, such as McLube or a dry teflon lube. These won't gum up the works.

 

[RobG]

Rardi,

I did the same repair on my Kenyon rig but it was down. I have the shaft pin with the tear drop tab. First problem is the SS screw holding the tab threaded into the alum mast. That may be a bear to break free so have PB with you. Next risk is, as you can imagine, removing the pin and preventing the sheave from dropping down inside the mast. Not much room to get something under it and leave room to get it out the exit at the mainsail side. My sheave was anodized aluminum throughout. No other bearing material that I recall. Since it is dragging the old lube has hardened and needs to be cleaned from the sheave and the shaft. Mineral spirits is excellent for this and stays wet longer than other solvents. I re-lubed with Lewmar winch lube, very appropriate for the task. Water resistant, doesn't attract dirt and good for dissimilar metals. Rigrite has all the replacement parts with some sheaves in more modern design.
Good luck. Rob