What's better for installing aluminum mast steps: rivets or tapped threads?

[a64pilot]

I consider rivnuts the work of the devil, reason is often it loses friction with what it is shot into and spins freely, then you have a screw that spins freely but cannot be removed and since it spins freely, you can't even drill it out, it just spins, so you slip a flat screwdriver between the two to try to hold the rivnuts to get the screw out, works as long as the screw is loose and threads clean, good luck with that in salt water environment.
Nut serts are a little better as they have teeth on the shank to bite into what you shoot them into, rivnuts are very often used in aircraft in non structural things as they are cheap and easy.

Maybe a mast is thick enough so that the rivnut won't spin, but I'd want to put red Loctite on the outside of it to try to keep it from spinning.

Maybe more work than you want, but pull the mast out, put it on sawhorses and helicoil the holes

[Deltasailor]

Originally Posted by estarzinger

Not what you want to hear . . . but the mast steps . . . better off without, and learning how to do the various excellent rock climbing techniques for going up the mast.

The rivet nut suggestion is excellent.

However, this is not really a high load application. Bog generic aluminum pop rivets have a shear strength of 310lbs. Put three of those in and you have a decent safety factor and dont have corrosion. And you can get 'extra strength' aluminum rivets.

I think the only reason to have mast steps is to climb up to disentangle a halyard that has wrapped round them!
I do think two steps a metre or so from the masthead would help when working above the masthead. Rivets with lanolin.

[Scotty Kiwi]

Previous owner had installed mast steps during a full re-rig for the purpose of finding breaks in the reefs around Fiji. Riveted. 25 meter mast. Maybe 40 steps. Mast aluminium, not sure of rivet material.

In my typical region, where we don't have many shallow reefs and what we do have it well charted, their use was limited for checking the masthead gear once a year and even better for parties, giving the young and dangerous an activity -
jumping from the spreaders.

Halyard entanglement was a nuisance, but can be reduced with good technique. But in flukey conditions, or with novice crew, or etc etc it still happened. And when is happens, not hard to swing it to disentangle. Takes time though.

In 15 years three steps torn off, I guess initially loosened due to pressure as a halyard wrapped around them unnoticed whilst being winched.

Never noticed any chaffing inside the mast (ssteel halyards), but on reading this I can see how it could become a problem if the steps weren't fixed properly inside the mast.

Based on my cruising grounds I wouldn't install them at all.

[blueazimuth]

For mast step installation use appropriately sized Al rivets with Al mandrels.
Use 6 rivets per step. Insulate each hole, rivet and area between mast and stainless steel with Tuf-Gel: it has no equal. It's not inexpensive but one small tub will last half a lifetime. Apply with a toothpick.
While rivets are versatile, they are NOT suitable fasteners for items such as winches, cleats, turning blocks.

[Scotty Kiwi]

Originally Posted by blueazimuth

For mast step installation use appropriately sized Al rivets with Al mandrels.
Use 6 rivets per step. Insulate each hole, rivet and area between mast and stainless steel with Tuf-Gel: it has no equal. It's not inexpensive but one small tub will last half a lifetime. Apply with a toothpick.
While rivets are versatile, they are NOT suitable fasteners for items such as winches, cleats, turning blocks.

That explains why I lost some steps over 15 years ... I only had two rivets per step!

[Jim Cate]

On our previous boat, I put folding steps up to the first spreaders, solely for the purpose of easily going aloft for conning through coral areas. Spent a lot of time up there, and it was a huge benefit amongst the reefs. Because they were folding, there were no halyard issues.

For this usage, steps are far better than all the climbing gear efforts... they are there, ready to go at a moments notice. And yes, I went up without harness, safety line, or other gear. Probably goes against all kinds of rules, but in protected waters I felt quite confident and in fact managed to never fall off. Worked for me, YMMV, and I do not recommend this practice to others (Mandated disclaimer!).

I see little advantage to steps further up the mast. For working aloft, a chair or harness is required, even if you have the steps. With the benefit of some form of powered winch (Milwaukee drill, proper electric winch, windlass etc) no particular effort is needed to go aloft for work higher up. And the cost of a Milwaukee drill isn't much different than the cost of 20+ steps and the installation of same... and it has heaps of other uses as well.

Oh... on that boat, I drilled and tapped for machine screws, 4x 10-32 IIRC. Held them in place for the 10 or so years I kept the boat, and are still there last time I saw her.

Don't have steps on our current boat. I'm nearly 80 and the prospect of the climbing is less attractive these days! When I need to go aloft, the chair or the harness and the drill in Ann's capable hands winds me up quickly. The view from up there is still great!

Jim

[estarzinger]

Originally Posted by Jim Cate

On our previous boat, I put folding steps up to the first spreaders, solely for the purpose of easily going aloft for conning through coral areas. Spent a lot of time up there, and it was a huge benefit amongst the reefs. Because they were folding, there were no halyard issues.

For this usage, steps are far better than all the climbing gear efforts...

On Hawk, we mostly stood on top of the hard dodger to see coral. But I could get up to the first spreader pretty quick if I needed to - just a matter of familiarity - if you use the climbing gear reasonably frequently it is like 30 secs to clip on and get going up.

[W3GAC]

I added mizzen masts steps on our CAL 46 ketch 20 yrs ago. I used SS ribbits. No issues. I'm up & down a lot because of my experimentation with various amateur radio, v/uhf 2-way radio, marine tv antennas. Still as solid as day I put them on. I did install while mast up... but usually only 3-4 in morning and 3-4 more in afternoon until done. (Climbing belt and harness required!)

FYI- I have drilled/ tapped and used SS screws for other mountings on the mast. When I went to remove them/ change what I had install 20 yrs ago... they came out powdery. Became concerned about their strength and over time removed all SS mounting screws and when re-installing used ribits.

[rocco lombardi]

In the rigging biz we say " if you have mast steps you will need mast steps to untangle all the lines from your mast steps." Leave them off, get a chair, block & falls, and all is good...

[Jesse]

A big "THUMBS UP" for the RIV-NUTs. They are perfect for that project.

[David B]

Originally Posted by Captsteve53

Rivets! Rivets! Rivets! in the following preference

1) Monel
2) Aluminium
3) Stainless Steel

Regardless of which MATERIAL you decide on I would put them with DURALAC DURALAC DURALAC available at fishing supply companies and some chandler stores, Trying to educate all yachties they should have a tube in their tool box!!-No I dont work for Duralac it's just a dam good product!!

Duralac is an anti-corrosive jointing compound for use between joints of dissimilar metals. It is in the form of a tough, flexible, yellow paste with low moisture permeability, and contains barium chromate in an inert filler matrix. The barium chromate is only very slightly soluble in water, so it remains in the joint, even in the presence of a considerable flow of water. It has a long useful life because it only becomes active in the presence of conditions which promote corrosion.
• Indispensable for the effective sealing of joints between dissimilar metals --- even very active magnesium alloys
• Effective at preventing corrosion at stress contact points in similar metals, such as rivets in masts
• Protects metals in contact with non-metallic materials such as wood, resins, rubber, etc.
• Especially useful in saltwater environments which exacerbate corrosive processes
• Conforms to specification DTD 369B

https://www.fisheriessupply.com/sadd...nting-compound.



Cheers Steve

How about Tefgel Steve? Understand many are going over to that as it is non-toxic. Just wondering if you have tried it and gone back to Duralac, or have yet to try it.

David

[out42]

Tefgel is definitely the current hot stuff, but it is very slippery. Duralac isn't, and sets seemingly almost as hard as loctite thereby doing two good things in one........

[thinwater]

Originally Posted by Steve OBrien

I'd use self tapping aluminum screws

Not if you have loose halyards or wires in the mast. The points and threads will eat them in a few weeks. The halyards may jam.

I've tested rivets and machine screws for an up-coming magazine article. There is not practical difference in strength. Think of all the beach cats that have enjoyed many decades in the sand. Yes, coat with duralac or similar, but they will last. Also, the smooth inside can't be beat. This is the only important factor, in the end.

Mast-up? the rivets wouldn't be too bad, but the drilling would suck. I also don't see the point; if you are that comfortable in the harness, what in the h_ll do you need steps for?

[mikedefieslife]

Originally Posted by estarzinger

Not what you want to hear . . . but the mast steps . . . better off without, and learning how to do the various excellent rock climbing techniques for going up the mast.

The rivet nut suggestion is excellent.

However, this is not really a high load application. Bog generic aluminum pop rivets have a shear strength of 310lbs. Put three of those in and you have a decent safety factor and dont have corrosion. And you can get 'extra strength' aluminum rivets.

What techniques are those that allow you to easily climb the mast without help and take the necessary tools along to complete a job. Steps sure sound easy. Climb up wearing a harness and clip/unclip every so often.

I'm a boulder so only have limited rock climbing knowledge when it comes to ropework. I'm guessing using ascenders, but won't they wear the lines pretty quickly?

[estarzinger]

^^ re mast climbing . . . . Allen on the l-36 website has a couple good articles and papers on one decent way to do it. I personally think he over complicates things, and my technique and gear is simpler. But yes ascenders and Grigri (I personally use the Petzl RIG, which is the industrial version of the grigri) are the basics. I had a 23m stick and don't like heights, but this solution allowed me to efficiently get up the mast when I needed to (twice on my last solo to greenland for instance - B&G wand failures)

Re Duralac vs tufgel, I have used both. They are a bit different, but in the end (after say 5 years) my results have been quite similar between them. Personally I prefer and have had better long term success with more "adhesive" solutions. When you drill a mast you break the paint (or anodizing) and expose raw aluminum. My sense is that it is preferable to use something that will solidly bond/adhere/seal that edge - loctite works, but I have also dipped fasteners in 2 part Awlgrip primer which also worked.

The best long term solution works to avoid/minimize mixed metals, and avoid breaking (or permanently reseals) the paint/anodizing film. It is much better to use a good solution, than to try to goop up a poor solution.