SailNet Community banner
1 - 20 of 33 Posts

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #1 · (Edited)
Hey all! Any help on this one would be much appreciated and it really is a two part sort of thing where one answer may solve both issues.

We have the mast down on our M25 1981 and are doing some mantainance and additions. We want to add a topping lift and were looking at the mast head (right name?) where the lines, in this case just a main halyard, come up run through sheaves and back down. Here is ours.
Aft


Forward


First off, I think the sheaves that are already there need replacing. Can these just be purchased somewhere like Mcmaster Carr? How do you pull it apart to replace them? Sorry for the green question but I have never seen a connection quite like these. Look like giant rivets.

Also, if I want to add a topping lift, can I add additional ones or do I need to change out the whole top to add a space. How do folks handle that one? Could you just hang a block for the purpose? Where would you hang it that wouldn't mess with the sail. Sorry. I am gabby.

Any suggestions? Gotta add an outhaul too for our new fancy sail sitting in the box while my lakes are still frozen. But the work can really begin. Keel cable and bolts inspected today, battery back in and charged, connected back to solar, everything removed for an internal scrubbing, etc.

Here to show you we are in this for real, this is what is behind me right now. Two down, 5 to go plus the cockpit if we are inspired after the interior.


Thanks for any help. This is my first real project that I can talk about on here. I promise to take pics :D
 

·
Registered
Joined
·
7,864 Posts
I can't tell from the pics how the sheave pins are attached. Pics from each side would help.

You don't need a block at the masthead for a topping lift. You can dead-end it at the top and put a block above the end of the boom. A line runs from the boom end through the block and back down to the boom, through a small cheek block and to a clamcleat if you want. The clamcleat can be anywhere on the boom - near the mast or at the aft end.
 

·
Registered
Joined
·
32 Posts
Hi AlaskaMc
Just took a quick run outside to check my mast head and as I thought it is the same as yours. (I too have a Mac 25) My sheave blocks are just through bolted so just undo them and replace the sheaves and bolt them back in.
As for a topping , just forward of the backstay I have another bolt that goes through the masthead to which I added a block, ran a line through the block and down to the mast. After lifting the mast up I run one end of the line to the boom and the other end down the mast to a turning block to a deck organiser and then to a cleat on the cabin top. This works for me as I can raise or lower the boom from the cockpit. Hope this helps.
Anthony
 

·
Asleep at the wheel
Joined
·
3,016 Posts
Yes, absolutely replace those sheaves. Measure them, then look around for replacement sources. We replaced the sheaves from our Catalina 25 using the sheaves sold by Catalina Direct:. Their sheaves may work for you, too.

Regarding Brian's suggestion for the topping lift, if his description didn't make sense, check out the description and drawing here:
Topping Lift Kits from Sailcare
 

·
no longer reading SailNet
Joined
·
2,309 Posts
You can make a topping lift kit for well under $100. Use dyneema (Amsteel) instead of wire for the fixed portion of the topping lift, it is much lighter and will blow out of the way of the sail when sailing. Even the smallest dyneema will be plenty strong.

A basic topping lift on a 25' boat is about 30' of 7/64" dyneema ($10) with a brummel splice on each end, a Harken 2698 T18 block at the bottom splice ($17), and 10' of 1/4" double braid running from the end of the boom ($7), up to the block, and back to a cleat on the boom. If you don't already have a cheek block and cleat on the boom you'll need to add them, but you can still do the whole project for well under $100. It makes a much better topping lift then the kit from Sailcare.

This is what I mean by the dyneema topping lift flies out of the way of the sail:


That photo was taken in 6 or 7 knots of wind.
 

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #7 ·
I can't tell from the pics how the sheave pins are attached. Pics from each side would help.

You don't need a block at the masthead for a topping lift. You can dead-end it at the top and put a block above the end of the boom. A line runs from the boom end through the block and back down to the boom, through a small cheek block and to a clamcleat if you want. The clamcleat can be anywhere on the boom - near the mast or at the aft end.
I will grab some pics of the sheaves from the side today. It doesn't appear obvious how they were attached. Great idea on running it the other way and dead ending at the mast instead. That would be easy comparatively.

Hi AlaskaMc
Just took a quick run outside to check my mast head and as I thought it is the same as yours. (I too have a Mac 25) My sheave blocks are just through bolted so just undo them and replace the sheaves and bolt them back in.
As for a topping , just forward of the backstay I have another bolt that goes through the masthead to which I added a block, ran a line through the block and down to the mast. After lifting the mast up I run one end of the line to the boom and the other end down the mast to a turning block to a deck organiser and then to a cleat on the cabin top. This works for me as I can raise or lower the boom from the cockpit. Hope this helps.
Anthony
Thanks for going and taking a look. I will need to go and check that when I take my pics. I don't think these are bolted but I will look again. If so, then this was the silliest question ever and should be easy to fix! My plan for the lift was exactly as you describe though as we wanted to have it for an extra halyard should we lose it up the mast. Great description! You don't have pics online anywhere do you?

Yes, absolutely replace those sheaves. Measure them, then look around for replacement sources. We replaced the sheaves from our Catalina 25 using the sheaves sold by Catalina Direct:. Their sheaves may work for you, too.

Regarding Brian's suggestion for the topping lift, if his description didn't make sense, check out the description and drawing here:
Topping Lift Kits from Sailcare
Makes perfect sense and thanks for the link. Diagrams are nice to see and part lists are handy to say the least. Thanks! I will check with Catalina as well on the replacement sheaves. I was thinking of delrin sheaves from Mcmaster-Carr and thought those would work.

Al,

consider a Boomkicker instead of a topping lift. Works along with your vang and about the same price as a topping lift kit. We love ours and we trailer every sail.

Don
My wife likes the idea of the book kicker too but can it be used to lift the boom out of the cockpit when at anchor? Looks like you would still have the boom at face level when at anchor. We spend many nights out on the boat so that was one of the goals of the lift.

Thanks everyone! I knew I could count on sailnet.
 

·
no longer reading SailNet
Joined
·
2,309 Posts
When you are at anchor you can use the main halyard to lift the boom out of the cockpit. You should move the main halyard there anyway so that it doesn't slap against the mast and keep your neighbors awake at night.
 

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #9 ·
We secure our halyard so that it doesn't do such a thing. Never heard of moving it to the boom for neighbor annoyance avoidance. But then we are in Alaska and the odds of a "neighbor" doesn't come up often. But banging lines drive me good and nuts too. Good idea. Any thoughts on the jib halyard? We just usually clip both to deck fittings we have to keep them off the mast and out of the way. But if it can do something useful too that would be nice. Thanks.
 

·
no longer reading SailNet
Joined
·
2,309 Posts
When I had a hank-on boat I would bring the jib and spin halyards to the bow pulpit, but anywhere away from the mast is good.

Almost every boat that I sail on uses the main halyard to support the boom when docked. It's the best way to lift the boom high off of the cockpit if you want to hang out in there. Most topping lifts (like the design that I described above) allow you to lift the boom up to a foot to support it while raising sail and to provide sail shape in extremely light air. They aren't meant to lift it farther.
 

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #12 · (Edited)
When I had a hank-on boat I would bring the jib and spin halyards to the bow pulpit, but anywhere away from the mast is good.

Almost every boat that I sail on uses the main halyard to support the boom when docked. It's the best way to lift the boom high off of the cockpit if you want to hang out in there. Most topping lifts (like the design that I described above) allow you to lift the boom up to a foot to support it while raising sail and to provide sail shape in extremely light air. They aren't meant to lift it farther.
Ok, this sounds easy (your plan for the topping lift and how to put it together) but I have a devil's advocate question; why not run it up the mast through a block and down to the top of the boom. This is how it is on the boats we have run in the past (newer/larger) so that it can act as an emergency halyard if needed. Why not just do this with dynema line. I am sure there is a good reason I just am new and not getting it.

EDIT: And one more question, if you are on a run downwind and want to adjust, isn't it a pain if the line is cleated on the boom vs in an organizer/clutch on the cabin top? Again, asking as I have never had one on my boat.
 

·
no longer reading SailNet
Joined
·
2,309 Posts
Ok, this sounds easy (your plan for the topping lift and how to put it together) but I have a devil's advocate question; why not run it up the mast through a block and down to the top of the boom. This is how it is on the boats we have run in the past (newer/larger) so that it can act as an emergency halyard if needed. Why not just do this with dynema line. I am sure there is a good reason I just am new and not getting it.
On your boat there isn't space for a second sheave to run a second main halyard. Adding one is a lot more work.

You also need to splice something to the dyneema that will work in a cleat. Dyneema is extremely slippery and doesn't work in cleats, clutches, or knots without a cover.

EDIT: And one more question, if you are on a run downwind and want to adjust, isn't it a pain if the line is cleated on the boom vs in an organizer/clutch on the cabin top? Again, asking as I have never had one on my boat.
I only adjust the topping lift about one out of every ten sails on my boat. It normally stays adjusted just longer than the leech of my sail so that it flies out of the way when sailing, but keeps the boom off of the dodger when the sail is down. It's not worth the cost and expense to run it back to the cabin top in my opinion. In general I'm not a believer of running all lines aft.

It is easy enough to go forward to the boom if I need to adjust this line, since I'd only do so in light wind.
 

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #14 ·
On your boat there isn't space for a second sheave to run a second main halyard. Adding one is a lot more work.

You also need to splice something to the dyneema that will work in a cleat. Dyneema is extremely slippery and doesn't work in cleats, clutches, or knots without a cover.

I only adjust the topping lift about one out of every ten sails on my boat. It normally stays adjusted just longer than the leech of my sail so that it flies out of the way when sailing, but keeps the boom off of the dodger when the sail is down. It's not worth the cost and expense to run it back to the cabin top in my opinion. In general I'm not a believer of running all lines aft.

It is easy enough to go forward to the boom if I need to adjust this line, since I'd only do so in light wind.
That makes perfect sense. I would have fun full into the dyneema and cleat issue since I don't have any yet on the boat. Woulda been a head slapper, thanks. On the adjusting, same thing, thanks. Makes perfect sense. We are moving some things aft and adjusting some things to mimic the larger boat we use much more rarely, but only where it makes sense.

Thanks!
 

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #17 ·
Ok, finally back to this one after diversions onto many projects that caused the masthead to be 28 feet above my head. But she is back down now and I need some help.

What the heck are these? Sorry if this is a total newbie kinda question but it doesn't look like any rivet I have ever used.


I have an exact match to this fitting on a destroyed old block and have tried drilling it out and punching out. Can these be removed so the sheaves can be replaced? Or do I have to replace the head piece.

What do you all think?
 

·
Registered
Joined
·
661 Posts
Drill out the end, punch out the pin and replace the sheave with a stainless bolt and locknut

Easy peasy lemonsqueazy

(Actually, it is a PIA but if you get sheave from a consignment shop it sure beats the big $$$ you would throw for a new masthead)
 
  • Like
Reactions: AlaskaMC

·
Frozen Member
Joined
·
565 Posts
Discussion Starter · #19 ·
So that head in the first pic is just a rivet head? Drill out and tap out as you would a typical rivet? That is easy if so. Is that just a washer under the head?

Thanks! Then I would just replace with a SS bolt and locknut and a new sheave? That does sound easy!
 

·
Tartan 27' owner
Joined
·
5,238 Posts
I have used those delrin sheaves from McMaster to replace a sheave in my boom.
One nice thing about the delrin is I was able to easily adjust the shape of the sheave a bit by sanding the sides to make it "thinner" and a drill bit made the pivot hole slightly larger to fit my application.
So you don't need an exact fit but as close as possible given the sizes of delrin sheaves McMaster Carr sells.
 
1 - 20 of 33 Posts
Top