ATTACHING SHEET CLUTCHES

[twodzusfittings]

I have two Spinlock rope clutches which I've designated for the main and spinnaker halyards. The intent is to mount them on the mast above the winches. As I'm thinking this through, I am concerned about the strength of the machine screws into the aluminum mast. My plan is to pilot hole and then drill the correct size to be able to cut threads for a 5/16 fine thread flat head bolts. Will this suffice to hold the load of the sails, in absence of any backing plates or nuts. Any suggestions on how to attack this project.

 

[Davidasailor26]

I’ve used machine screws on the mast but only for lower load items. I believe rivets are preferred for higher loads, and halyards would probably qualify.

 

[Don S/V ILLusion]

how are the mast mounted winches secured?

 

[twodzusfittings]

how are the mast mounted winches secured?

I'll have to check when I get back down to the boat. So it's on hold till then.

 

[Don S/V ILLusion]

I'll have to check when I get back down to the boat. So it's on hold till then.

I think you are better served by seeing:
1. What works now for the winches and
2. What has survived the load previously

than to rely on opinions here.

 

[kloudie1]

Check out “Rivnuts”. A rivet with a threaded insert.
You may be able to rent the tool to install the inserts.

 

[jssailem]

I have installed Cleats on the mast with screws, Cam Cleats too. I suspect that clutches will work. Kind of depends on the thickness of the aluminum mast extrusion. You might reach out to the mast maker and ask for a recommendation

 

[twodzusfittings]

Just to circle back to all who participated in this thread and anyone reading. I looked up various options. Due to the nature of how these clutches fasten to a surface, its not possible to rivet it, at least not with the tools available to me. I looked into making holes and tapping them out, but even using a 24 thread, there would not be enough meat to hold the weight/pull, that would make me feel comfortable. So I looked into rivnuts and inserts. I don't think helicoils would be good and the other inserts, the tools to insert them are super expensive. I watched a few videos and decided a rivnut method would work. I bought a simple tool from amazon which came with five of the four needed 5/16x 18 rivnuts. I bought the stainless versions, although only 304 grade, I believe this will be sufficient. I drilled the holes, inserted and spread the rivnuts using the tool and then mounted the clutches. lt went well. I used some lanocote between the rivnuts and the mast and some thread locker when the 1" coned, flat head bolts were inserted. I believe this will work. You will all be the first to know if it doesn't.

(Sorry about the picture. I never understand why its one way in my files and then turned when I attach it to this site.)

 

[Timm R Oday25]

I believe the reason your photos turn out like this ,is because you took them with an I Phone and weren't aware of the orientation is saved . Try taking the same photo and turning the turning the phone 90 degrees, 180 degrees and so on.

 

[jssailem]

YOU can also inport the photo to a desktop. Using image software rotate it to the proper orientation. Save the image. Then Export the image and it will retain it's proper orientation.

Here you Go

 

[smokey73]

Can't say as I have ever seen a rope clutch on a mast (cleats, yes). Looks like a great idea for a the right application. BZ (Well Done for those of you not in the Navy).

Do you have a picture of the special tools needed.

 

[twodzusfittings]

For $27 or you can go real expensive

 

[jssailem]

The halyard clutches in the image above serve to grip the line when the halyard is wrapped around a winch, but they inhibit the best part of having your halyards at the mast. The ability to pull your sail up quickly. On my 35ft boat I can hoist a sail to the masthead manually. That is because I can "Jump" the sail. The exit box for the internal halyards is well above my head and arm reach. This allows me to reach up full extension and use my weight (all 205) to pull the sail up the track. The clutch would get in the way of this sailors effort.

Winching a sail up the mast with "Lazy Jacks" is always an issue. With the sail flapping as you head into the wind, the batten can often get caught in the lines and then stretch or tear if the crew are not observant. So you either have to slack the lazy jacks or back the sail down and try again. Standing at the mast, I watch the sail as it is blown by the wind and pull/jump the sail past the lazy jacks when the time is right.

I know many are not comfortable moving about the boat let alone attending sails at the mast. Just saying there are some advantages to having such seamanship skills. Using a tether and having bars/handholds at the mast makes the evolution a quick and efficient solution. When the problems occur ducked behind the dodger and you have to go forward, to the mast, it is good that this is not just an occasional experience. The trouble always seem to happen when the seas are unruly.

 

[twodzusfittings]

@jssailem I hear what your saying. I can still do that. There is much space between the clutch and the winch. The cleats shown in the picture are not the cleats I use for tying off the line. they are below the winch. I prefer to use the winch to haul the sail up and as the winch is not of the self tailing type, I am fighting the weight of the sail. I don't have lazy Jacks, so there is no issue there for me. So far my experience has been all positive with my new install.

 

[jssailem]

That is great. There are several ways to accomplish raising the sail.

I learned old school. With the halyard outside of the mast, it is easy to jump the sail, pulling with your weight not your arms. With internal halyards, if the exit box is higher than your reach as I had mine installed you can still jump the sail.
When the sail is at or near the top and you want controlled leverage, I was taught to run the halyard down around a cleat and to hold on to the running end. Then you can grab the halyard with one hand and pull it like pulling a guitar string. As you release the halyard you pull up the slack with the tail in your other hand. Do that a couple of times and your sail is all the way up.

Now with the self tailing winches I installed on my mast, I can haul (jump) the sail up nearly to the top of the mast and wrap the line around the winch to finish the hoist. I am not happy just leaving the halyard in the winch so I wrap the tail from the winch around a cleat to secure the line when sailing. Stops line creep on my halyards.

 

[jssailem]

If your halyard exits the base of your mast, you are forced to pull up on the halyard to raise the sail. This means your pull strength is limited to your arm strength. My arm strength is less than my ability to grab the halyard and let my body weight pull the sail up.