Fittings on a carbon mast of a high performance catamaran (18ft Whisper) are coming loose and need new rivets. It's all 3/16, small rivets.
Googling around, I can find stainless steel pop rivets, or I can get aluminium tri-fold rivets. I've tried both; with limited success. I want -- and the mfg in the UK recommends -- tri-fold SS rivets. Does anyone know where I could find them? Hopefully order online in the USA.
Help!?
Finding trifold stainless steel pop rivets
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I had not heard of tri-fold rivets, but the aluminum version looks like a great solution to the rivets on my tramp that are pulling loose at the rear. The exploding head or trifold design would be like adding a washer and distribute the load into the glass. This would be a lot easier than pulling the deck to reinforce a conventional rivet.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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If your rivets are loose already, are you sure the manufacture is the most qualified to provide the best advice? Plenty of boats much older than your's do not suffer these issues. Its true that there are far superior rivets to the ones mostly see on beach cats, but the reason is that they are not necessary
There are monel/ss rivets here.
http://rivetsinstock.bmob…b-tite-blind-rivets.html
Edited by bacho on Apr 19, 2017 - 11:01 PM.
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Offering sails and other go fast parts for A-class catamarans
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That Bulb Tite rivet is interesting for its load sharing back. Curious to know what the special tool is. Is it just a special nose for a standard rivet tool or something more? I would also want to know about shear strength compared to SS and Monel rivets. Many of the rivets on a mast are in high shear applications, so it would be important to know the differences before committing. For sure we know that standard aluminum rivets are not up to many of the applications in a mast.
I think Tom is on to something for using these folding rivets in tramp tracks.
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dg
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For the tramp I ended up buying aDP Exploding Pop Rivets ABS610XPeel. These are a longer 3/16 diameter aluminum rivet that uses the nail to cut a curling peel from the end of the rivet body, resulting in 4 strong curls that support the rivet against the inner surface. These are supposed to have a 1000 lb holding strength, and will fill over-size holes like my worn fiberglass has. It is a very strong attachment and the main disadvantage is the rivet leaves a sharp edge on the blind side. Not a problem for the boat, but could be an issue in body work and other applications.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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Peel / exploding rivets just "unpeel" under pressure when pulled. Not my fave.
The folding/trifold/monel style rivets fold right against the surface, increasing the contact surface... so they work much better with carbon/fiberglass, etc. In a sense they form their own washer. For affixing things to carbon spars, where the fasteners will be pulled -- I wouldn't use peel rivets.
For the trampoline -- which I don't know your boat but seems likely that _shear_ loads on the rivets will dominate -- it's probably ok. -
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I'll let you know if I get wet. Seemed perfect for the tramp application. FWIW, the force it would take to "unpeel" one of these rivets is far beyond any original load design anticipation. They would first crush,and that would be well beyond any load anticipated for a conventional rivet.
Edited by tominpa on Apr 21, 2017 - 11:09 PM.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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Speaking of wet, those rivets have an "easy out nail" feature to make drilling out later easy. However, this means you will have to inspect them often to see if you need to seal them against water leaks.
Personally, I dislike adding more work to my boat.
My $0.02
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When the rivets pull, they leave a hole in the center. The nail that cuts the rivet body falls right out. So some clear acrylic caulk plug will solve any water issues quickly and permanently. The rivet head is very strong, and the way the back curls and rests against the blind side is extremely strong.
With regard to more work, the alternative is cutting access or removing decks. I could tell you which is more work, but I think you can guess.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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