Why Not Monel

[Paul Seamons]

Re: pop rivets into aluminum masts. Aluminum rivets are weak. SS rivets strong but lead to galv. corrosion. How about Monel?.. Yes a little costlier but would they avoid the corrosion problem but give better strength than aluminum?

[Brion Toss]

Hello,
If strength is really adequate with them, use aluminum rivets; if max strength is needed, use stainless, but isolate it (Tef-Gel, plastic washers); if you want to spend extra money, and still get galvanic action, use Monel. It is easier to drill out, though.
Fair leads,
Brion Toss

[Brian Duff]

Why use rivits at all ? Drill and Tap !
Also some blind rivits are sold as Stainless Steel or Monel but have steel mandrils, dont use those as the old rivit maindrils often end up trapped inside the spar to rust away, adding even more galvanic variety in the bildge.

[TomP]

Brian,

I have been reading and listening to your posts at length, and though some are with merit, most are not. By your own admission you have stated that you are new to the art of rigging.

So, with that statement alone, lets tap. Yes, lets tap a .158 mast wall with, say, a 10-24 screw. Why even tap, lets use a sheet metal screw. Simple enough. 13/64 bit and a #10 screw...why even tap!? Now, lets fasten a halyard restrainer. Any make you like. Shaeffer, Harken, a good old fashioned ring and plate. Okay now, lets add for corrosion effects that will, invariably take hold. Even better, lets look at the angularity of the loads of a simple halyard restrainer...Bah.

One must take care in the material of the mast before pre disposing on a method for fastening...

Courses in Materials Science and Strength and a few in Physics, then throw in some Numerical Methods and you might begin to see. In some cases one is warranted over another. In either case.

Originally Posted by Brian Duff

Why use rivits at all ? Drill and Tap !
Also some blind rivits are sold as Stainless Steel or Monel but have steel mandrils, dont use those as the old rivit maindrils often end up trapped inside the spar to rust away, adding even more galvanic variety in the bildge.

[Paul Seamons]

Tom, Tom, Tom,

Chill, man. We're trying to have a conversation here. We're trying to increase the sum of our collective knowledge. Speaking for myself, and based on the substance of your remarks, which are well taken, I look forward to your continued participation. If that participation is contigent upon it, I'm glad to stipulate that you are the smartest SOB I've ever encountered.

Fair leads, Brother.

[TomP]

My apologies to all concerned. I, obviously, was not in a good frame of mind and my frustrations with other things were clouding me.

Originally Posted by Paul Seamons

Tom, Tom, Tom,

Chill, man. We're trying to have a conversation here. We're trying to increase the sum of our collective knowledge. Speaking for myself, and based on the substance of your remarks, which are well taken, I look forward to your continued participation. If that participation is contigent upon it, I'm glad to stipulate that you are the smartest SOB I've ever encountered.

Fair leads, Brother.

[Brian Duff]

Tom,
I did not mean to ever imply that I am new to rigging. I have been working as a yacht rigger for 7 years now, and have been involved with yacht rigging, sailing, cruising and boatbuilding my whole life. I am however aware that there are many who have been rigging much longer that me and I just always try to make it clear that "I" do not yet know everything, hence am always learning.
I prefer to stay away from rivits as a rule becasue I so often find them not doing the job they were intended to correctly, I even had a step pull out from under my foot the other day (more like two months ago actually) because somebody somehow didn't rivit it on correctly. I see it all the time, more often that lousy machine screw fastenings. This is perhaps a result of rivits being very popular in fierecly price competitive production enviroments, where quality control can be more difficult. oh, and they are a mess to remove and re install, drilling and tapping only makes a mess once, if you protect the threads with lanacote of tef gel or lifeseal when installing them.

You are quite right that the wall thickness should be considered, as one wants to get as many threads engaged as possible, so why would you use a self tapping screw. I was under the impression that these were the weakest fastner commonly used in rigging. I did take your advice and just ordered a couple of 'Design Assistance Corporations' Instruction/Training Manuals , specifically p/n 540-MAN Industrial Fastner Manual
http://www.dac-3d.com/DACTRNG/PRODBOOK/540BOOK.HTM and for curiosity and further information p/n 550-MAN Crane and Rigging Manual
http://www.dac-3d.com/DACTRNG/PRODBOOK/550BOOK.HTM

I however for now will continue to avoid rivits if at all possible, and rather use the correct thead count and diameter for the job.

"13/64 bit and a #10 screw...why even tap!? " ...wouldn't that screw just slide through the hole ? I suppose that was your point, but I just didn't want anybody drilling a 13/64 hole expecting a #10 fastner to work in it.... : )


Constructivly Participating,


Brian

[Champion1]

if max strength is needed, use stainless, but isolate it (Tef-Gel, plastic washers); if you want to spend extra money, and still get galvanic action, use Monel. It is easier to drill out, though.????

[allene]

.156 wall thickness. 5 threads give almost full strength so use a 10-32 screw. But personally, when I want to attach something to my mast I use a wood screw.