Attaching accesories with bolt snaps

[UnixSage]

Also, take a look here for some more info:
http://www.diveriteexpress.com/library/boltsnap.shtml

How long does this last? It would seem to me that it would wear very quickly given the enviroment. Also would you attach a SPG like http://www.diveriteexpress.com/regs/img/rg2759nhlg.jpg
the same way?

 

[Meng_Tze]

How long does this last? It would seem to me that it would wear very quickly given the enviroment. Also would you attach a SPG like http://www.diveriteexpress.com/regs/img/rg2759nhlg.jpg
the same way?

I tie all bolt snaps this way (also the spg, which is tied off at the hose not the metal neck). These knots last almost forever. The key is the line quality and the knots being secure (glue and burning)

 

[mer]

I find myself re-doing my long hose snap and primary light snap about 1x a year (150+ dives), SPG, backup lights, and stuff in pockets seem to last forever.

 

[UnixSage]

I tie all bolt snaps this way (also the spg, which is tied off at the hose not the metal neck).

Does the hose slip? What is the reasoning to not tieing to the metal neck?

 

[Meng_Tze]

Does the hose slip? What is the reasoning to not tieing to the metal neck?

If you tie it off tight enough, the hose is not slippery (three time around the hose and snap, then go into the square knot scenario). I have the connection on the hose for two reasons:

1: the spg hose is nice and straight coming from the first stage, the snap is exactly where my left D-ring is. Snapping on is just a matter of pulling the snap towards my D-ring, the position is spot on. This also makes the wholew thing, in my opinion, neater

2: metal to metal connection: If the snap would be on top of the spg neck, this would be a metal to metal connection that under certain circumstances cause chemical reactions at the point where the two metals connect. This could lead to fusing of the metals, or there could be corrosion of the spg neck, which could lead to a leak. I suppose a loose connection at the neck could do, but then I would not achieve my reason 1 above.


I suggest to try out either/both and pick what suits you and with resepct to any cons to them.

 

[Charlie99]

2: metal to metal connection: If the snap would be on top of the spg neck, this would be a metal to metal connection that under certain circumstances cause chemical reactions at the point where the two metals connect. This could lead to fusing of the metals, or there could be corrosion of the spg neck, which could lead to a leak.

Is there a DIR prohibition on dissimilar metal-to-metal contact, or is the prohibition on metal to metal connections simply a mechanical restriction on things like stage bottle boltsnaps on rings captured by the valve, where that wouldn't leave you with a way to cut it free if entangled?

 

[RTodd]

Is there a DIR prohibition on dissimilar metal-to-metal contact, or is the prohibition on metal to metal connections simply a mechanical restriction on things like stage bottle boltsnaps on rings captured by the valve, where that wouldn't leave you with a way to cut it free if entangled?

I would have to look to see if mine are tied on the hose or directly to the metal. I probably have some of each. There may be an "official" position on what the right location is. I would not know it or care too much. The important part is it not hang down too far. So, if on the hose it generally needs to be right by the connection anyway.

The DIR problem is metal to metal connections. If you have a dissimilar metal problem before the hose has to be replaced anyway, I will personally send you a new one.

 

[Randy43068]

the more I read about the "DIR" way of doing things the more I like 'em. Even if I'm not a tech diver, these ideas make sense to me.

 

[mstudley]

How long does this last? It would seem to me that it would wear very quickly given the enviroment. Also would you attach a SPG like http://www.diveriteexpress.com/regs/img/rg2759nhlg.jpg
the same way?

I use it to attach a small boltsnap to my backup light and it's been there for about a year without any signs of wear. It's easy enough to replace it when necessary though.

As for an SPG, I use an o-ring folded in half through the loop of the bolt snap and then attach it to the high pressure hose using a zip-tie. It's easy, it stretches when needed and is a breakaway connection. I also use this method for the small boltsnap on my long hose.

 

[WJL]

I use an o-ring folded in half through the loop of the bolt snap and then attach it to the high pressure hose using a zip-tie. It's easy, it stretches when needed and is a breakaway connection. I also use this method for the small boltsnap on my long hose.

I think this used to be a fairly common attachment method, but more recently people have pointed out that there's no real need for a breakaway connection on the spg or second stage. If either of these get caught in some way that requires you to get rid of the bolt snap, then you can just cut the cave line. The o-rings wear out and break more rapidly than cave line and if that happens during a dive it can be inconvenient.