Masthead sheaves

[Cat 310 #1 in GA]

My masthead sheaves appear to be frozen as it is extremely difficult to use the spare halyard to hoist anything especially a person! I have never had the mast off this boat and am wondering if it is possible to access the sheaves by going aloft with a mast climber and then lubricating the sheaves and moving them with channel locks? Have seen numerous pictures here of the masthead and the one attached make me think it might be possible. Of course we would have to relieve all pressure on the jib halyard and then the spare halyard as we try to loosen the sheave. Do those of you who have seen the top of the mast think this can be done? Not replacing the sheaves but just accessing them with channel locks and lubricant to free them.

 

[east coaster]

My mast head is welded to the mast and when I changed out the hard plastic sheaves it was a frustrating but it got done. I also have inmast furling. From your photo it certainly looks like you can remove the masthead bolt and
lift off the masthead fixture making the sheave changeout easier than what
I went through . TThere are different diameter sheaves so it best to contact the mast manufacturer for the relevant info and replacement , they are not cheap.

 

[marchem]

My rigger was able to lubricate the sheaves on our C310. He also says there’s no way to replace the sheaves with the mast in the boat, because the mast head needs to be removed, including fore and back stays.

 

[Cat 310 #1 in GA]

My rigger was able to lubricate the sheaves on our C310. He also says there’s no way to replace the sheaves with the mast in the boat, because the mast head needs to be removed, including fore and back stays.

My rigger was able to lubricate the sheaves on our C310. He also says there’s no way to replace the sheaves with the mast in the boat, because the mast head needs to be removed, including fore and back stays.

That is good to know but I doubt we could actually access the sheaves with channel lock because the forestay is in the way based on this other picture attached. Might be worth trying to lubricate and see if that works.

 

[marchem]

That is good to know but I doubt we could actually access the sheaves with channel lock because the forestay is in the way based on this other picture attached. Might be worth trying to lubricate and see if that works.View attachment 224490

Sorry, didn’t read your post all the way. I'm in the middle of rerigging our 310, so more tired than normal this morning, even though he’s doing all the work going up and down the mast.

If your spare halyard hasn’t been used much simply lubing the sheave may make a difference, since there shouldn’t be any wear on it.

 

[jssailem]

Two thoughts.
1 Yes it is often possible to lubricate the sheaves. I’d suggest a dry product that does not attract dirt. I find McLube Sailkote to be my product of choice.

MCLUBE™
Sailkote™ is an easy-to-apply, fast-drying lubricant that instantly bonds to clean, dry surfaces, repelling dirt, salt, and reducing drag from air and water. Sailkote lasts significantly longer than PTFE additives, oil, or wax-based lubricants and is environmentally friendly, with no chlorofluorocarbons (CFCs), petroleum, or poison-emitting toxins. Use on mainsail tracks, hatches, sliding doors, sails, battens, telltales, slider cars and tracks.

2. When you get up there check the size the line and the width of the sheaves. Previous owners may have oversized the line. This can cause friction at the sheave making it difficult to raise and lower everything. Some older lines leave chafed threads the bind in the sheaves.

 

[PlaneTom]

My mast head is welded to the mast and when I changed out the hard plastic sheaves it was a frustrating but it got done. I also have inmast furling. From your photo it certainly looks like you can remove the masthead bolt and
lift off the masthead fixture making the sheave changeout easier than what
I went through . TThere are different diameter sheaves so it best to contact the mast manufacturer for the relevant info and replacement , they are not cheap.

A few years back our main halyard on our 310 was getting quite hard to move as the sail neared the top. I had replaced the sheaves on our old Catalina 27 for the same reason, a 5 minute job once you were at the top.
Looking at the masthead fitting on the 310 from deck level, I could see there was no access to change the sheaves with the fitting on the mast, which means dropping the mast to change them.
I called Catalina and asked for sheave part numbers, and was told to contact the manufacturer of the mast, but it could be one of three used at the time. I eventually figured out which one it probably was, and tried to contact them. Repeated phone messages and emails were unanswered.
I cleaned all the blocks at deck level, lubed where appropriate, sprayed the sail slides with SailKote every time I raised the main, and it's much better, but not what I'd call good yet. But it did improve enough that now I wonder if it's really worth going through the hassle/expense of pulling the mast to change the sheaves at this time.
Our local boatyard got a new manager who was somewhat reluctant to do it with the equipment they had, there is a launching crane near our yacht club, but I'd have to enlist someone who is authorized to run the crane and get permission to store the mast somewhere while I pull the upper fitting and figure out what sheave I need.
I'm not quite annoyed enough with it to dive in at this time.

 

[marchem]

A few years back our main halyard on our 310 was getting quite hard to move as the sail neared the top. I had replaced the sheaves on our old Catalina 27 for the same reason, a 5 minute job once you were at the top.
Looking at the masthead fitting on the 310 from deck level, I could see there was no access to change the sheaves with the fitting on the mast, which means dropping the mast to change them.
I called Catalina and asked for sheave part numbers, and was told to contact the manufacturer of the mast, but it could be one of three used at the time. I eventually figured out which one it probably was, and tried to contact them. Repeated phone messages and emails were unanswered.
I cleaned all the blocks at deck level, lubed where appropriate, sprayed the sail slides with SailKote every time I raised the main, and it's much better, but not what I'd call good yet. But it did improve enough that now I wonder if it's really worth going through the hassle/expense of pulling the mast to change the sheaves at this time.
Our local boatyard got a new manager who was somewhat reluctant to do it with the equipment they had, there is a launching crane near our yacht club, but I'd have to enlist someone who is authorized to run the crane and get permission to store the mast somewhere while I pull the upper fitting and figure out what sheave I need.
I'm not quite annoyed enough with it to dive in at this time.

We had good luck with lubricating the sheave in place. It does require a trip to the top of the mast, likely on a different halyard, but a lot easier than pulling the mast.

Ws considered switching the main halyard to the (now) unused topping lift, but decided to wait until the main halyard got worse.

 

[PlaneTom]

We had good luck with lubricating the sheave in place. It does require a trip to the top of the mast, likely on a different halyard, but a lot easier than pulling the mast.

Ws considered switching the main halyard to the (now) unused topping lift, but decided to wait until the main halyard got worse.

I may have to borrow or buy a climbing setup to get up there. Or bribe some young'un to go up for me.
For the smaller boat I had a Mast Mate climber, but it was too short for this mast by several feet so I passed it on.
I haven't looked at any of the halyards to see if they could be routed to a jib winch for hoisting a person without passing over things that would add friction.
I don't think that my wife could generate enough steam to lift me, and she isn't going up there.
In addition to lubing it, I'd like to know what condition the sheave is in. It's buried in there to the point I doubt there is UV damage, but it could be broken or stuck.
I think someone going up to inspect is the next move. With luck it's just lubed and freed, if not I start planning to pull the stick. I'm guessing the wiring disconnects are tucked inside the mast, I can't find them down below.

Thanks for the input.

 

[east coaster]

In my case the mast was made by spar craft and I got the drawings for same from the Catalina 320 website. You can also go to spar craft and search for 802055 sparcraft-mastheadcover.zip. it's a large file as it has lots of photos and information that will help you in your sheave replacement. Also nice to have manual anyway.