Stanchion base bolts

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Nicholas Koligiannis
Posts: 22
Joined: Wed Sep 25, 2013 12:51 pm

Stanchion base bolts

Post by Nicholas Koligiannis »

Hi to all:

One of my boat's previous owners had replaced the original bolts on several of the stanchion bases. I don't know why, but what I DO know is that he chose inferior grade, stainless steel bolts (304, also known as A2) for the replacements. Furthermore, the bolts were all thread, rather than having a solid body for most of their length. The result was that, at some point, when someone from a neighboring boat pushed one of my stanchions a little too enthusiastically, the whole thing just came off. I'm in the process of re-bedding the stanchion bases and have been replacing these A2 bolts with solid-bodied 316 (or A4) bolts (incidentally, the original bolts from Albin Marin are in great condition). If your bolts are the original items, then I think all's well. But if some have been replaced, pull one out and take a close look.

Nicholas
Moments of Clarity, hull# 334
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Last edited by Nicholas Koligiannis on Fri Oct 24, 2014 10:42 am, edited 2 times in total.
Bob McGovern
Posts: 283
Joined: Fri Oct 26, 2012 3:08 am
Location: Wyoming, USA

Re: Stanchion base bolts

Post by Bob McGovern »

Eek! Invitation to crevice corrosion, those all-thread fasteners. What are you using for bedding sealant under your stanchion bases, Nicholas? When we re-do ours, I'm unsure whether to use butyl tape for flexibility & easy service, or 3M 5200 for its adhesive properties. Few items see as much abuse as lifeline stanchions.
Nicholas Koligiannis
Posts: 22
Joined: Wed Sep 25, 2013 12:51 pm

Re: Stanchion base bolts

Post by Nicholas Koligiannis »

Hi Bob:

I use Sikaflex 291 which is similar to 3M 3200. 3M 5200 is a structural compound (some boat builders use it to join hulls to decks without further fastening) so I would stay away from that, just in case you want to remove the bases at some point in the future. Sikaflex 291--especially in its recent 291i formulation--gives excellent service, has medium adhesive properties and remains flexible for a long, long time. I've heard that 3M 3200 is similar. Incidentally, I have enormous respect for 3M products. I use their masking tapes and sanding pads and discs exclusively; in fact if there're not in stock, I just don't paint.

Nicholas
Bob McGovern
Posts: 283
Joined: Fri Oct 26, 2012 3:08 am
Location: Wyoming, USA

Re: Stanchion base bolts

Post by Bob McGovern »

Yeah, if we used 5200 it would be on the assumption that the stanchion bases were never, ever coming off. So perhaps a medium-strength polyurethane is the better choice. Our bases also have slot-head machine screws rather than hex bolts. I might replace those, simply because the slots have been mangled over the years and it will be hard to get proper torque on the nuts.

There's also quite a bit of play between the stanchion itself and the base socket. Enuf that the lifelines cause the stanchions to lean inward. Do you think we should insert a shim (mylar? thin stainless steel?) to make the fit tighter, or would that be inviting corrosion?
Nicholas Koligiannis
Posts: 22
Joined: Wed Sep 25, 2013 12:51 pm

Re: Stanchion base bolts

Post by Nicholas Koligiannis »

Hi Bob:

I'd probably leave them as is, i.e. without any inserts. Mine lean inboard too, but I think that's actually a good idea as the most likely force to be imposed on them is outboard, from someone about to fall overboard. Mind you, my guard wires are bar-taught, which actually places less strain on the stanchions bases in the event of a mishap. The slot-head machine screws are probably the original ones and the quality of the stainless steel is great. So replace them only if really necessary.
At some point, I was thinking of replacing the stanchions with higher ones (around 75cm) which are more effective at keeping someone from falling overboard. But that would have put even more strain on the bases and I'd have to figure out a way of strengthening them. And then you start saying to yourself "well, maybe what I want isn't a Ballad but a Colin Archer". Anyway, it's nice to keep one's mind working but, then again, one has to draw a line somewhere.

Nicholas
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prjacobs
Posts: 235
Joined: Fri Oct 12, 2012 4:06 pm

Re: Stanchion base bolts

Post by prjacobs »

I'm also a fan of Sikaflex 291. When you don't use the whole tube, I've found that regular 291 will harden over time in the tube, but fast cure lasts a lot longer. I use an old 1/4" (6mm) drill bit in my drill to get the short hardened piece out, and voilà ... it flows again. I usually get the full amount out.
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