Adding Rope Clutch to Mast

[S/V Antares]

You might consider "Nutserts" which aree like rivits but threaded. Much stronger than tapped thinwall mast and easy and you can remove the clutches if needed.

NUTSERTS from Aircraft Spruce

[Geoduck]

I find my rope clutches to be a pain in the ass every now and then. It seems like every time I'm in a hurry to get the jib down, the damn line gets a twist in it and jams up at the clutch. I wish there was a quick way to open the clutch and free the line. I'm not sure theyre worth the trouble as they are. It's fine when I've got 2 people on the fordeck but I sail alone most of the time it seems.
Anyone else had this trouble?

[cal40john]

Originally Posted by Geoduck

I find my rope clutches to be a pain in the ass every now and then. It seems like every time I'm in a hurry to get the jib down, the damn line gets a twist in it and jams up at the clutch. I wish there was a quick way to open the clutch and free the line. I'm not sure theyre worth the trouble as they are. It's fine when I've got 2 people on the fordeck but I sail alone most of the time it seems.
Anyone else had this trouble?

Only when new crew coils my braided line instead of doing whatever the proper term for rabbit ears coiling is.

John

[Geoduck]

Originally Posted by cal40john

Only when new crew coils my braided line instead of doing whatever the proper term for rabbit ears coiling is.

John

Yeah!
good point - I should know that - old fisherman that I am - we'll see if that works!
Muchas Gracias

[DeepFrz]

Those nutserts look nice but you need a compressor and special pneumatic tools. A lot of expense for a couple of clutches.

[hpeer]

Those nutserts look nice but you need a compressor and special pneumatic tools. A lot of expense for a couple of clutches.

try a marsen tool, under $200 - manual and worked well for me.

325-RN Thread Setting Tool / 34604

Blind Rivet Guns and Blind Rivet Kits

[osirissail]

Originally Posted by S/V Antares

You might consider "Nutserts" which aree like rivits but threaded. Much stronger than tapped thinwall mast and easy and you can remove the clutches if needed.

NUTSERTS from Aircraft Spruce

Okay, what is the metal they are made of? If it is not marine stainless steel they will rust out rather quickly. Something you don't need when they are holding the halyard that is holding up the mainsail or headsail.
- - You have to be very careful when trying to use land or aviation fittings on a salt water vessel.

[hpeer]

I used Marson klik rivit nuts. They don't say what kind of aluminum they are, but I doubt that they will rust. Don't know why you would use SS in this application.

[osirissail]

Originally Posted by hpeer

. . . Don't know why you would use SS in this application.

If you are using stainless steel machine screws to hold the line clutch to the mast then using SS "rivet nuts" would make sense in order to reduce the bi-metallic interaction between aluminum and stainless steel. A problem that usually results in the machine screw corrosion welding to aluminum. Not to mention the huge increase in strength of a ss "rivet nut" versus an aluminum one with aluminum threads.
- - If such an animal - ss "rivet nuts" are not available then the discussion is moot as you can only use what you can get.
- - Strength is a major problem with stainless steel screwed into aluminum. Which is why I prefer to use aluminum pop rivets whenever possible. They fill the hole and expand out behind the mast wall. To remove the item I just use a drill bit to remove the head of the rivet and slide the item off the mast.
- - This might be where mounting an aluminum or stainless steel bracket onto the mast with rivets and then attaching the line clutch with ss machine screws and nuts might be a better solution especially if the mast is not very large.

[sabray]

I used to use these to repair aluminum doors. Attaching the panic bars. Last about a year before they deform. Not sure what grade aluminum it was but it was soft. They would last about a year.granted the loads are very different. The threads would strip out and the aluminum sleeve compressed into itself. These were impact loads being on a door not sheer loads. But wouldn't use them on my boat.

[hpeer]

I'm gonna try to remember to take a photo of what I did and share it.

Not that I am to be copied, but done is done, right or wrong.

I tend to think I came up with a pretty good solution.

I'm sure there will be something to be learned from the criticism, good or bad.

[S/V Antares]

"Rivnuts", or "Rivit nuts", or "Nutserts" are available in several series Aluminium as well as stainless. The ones I quoted are aluminum. I also use "Pop" rivits for the same application. You can easily dtill them out if you need to change something.

Another link for other types: McMaster-Carr

[sabray]

Mt concern using a nut insert. Not saying it won't work it's a clever piece. First is the process the aluminum is compressed and folded upon itself to complete the backing. With a blind rivet the metal is stretched and fatigued with a Knut sert it is folded and stretched compressed tortured if you will. the thread machining is loose. Maybe because the threads have already been subject to a large force creating the backer. Given what I have seen I would tap straight into the mast rather then Rely on this in the marine environment. Could be wrong no metallurgist. Just a gut thing

[CarlF]

The reason to use stainless screws here is that steel is much stronger than aluminum. The clutch is designed so that the rope exits close to the mast. This causes the force to be almost entirely sheer force that is perpendicular to the screw. The "pull out" force on the threads isn't really significant.

For a given diameter, stainless steel has a much higher sheer strength than aluminum and solid screws have a much higher sheer strength than hollow rivets.

Stainless can suffer galvanic corrosion with aluminum but Tef-gel works great.

Carl

[hpeer]

Here are a couple of pics of what I did to mount rope clutches.