Lifejacket gas cylinders -corrosion

[concentrik]

Encouraged by a previous thread we're doing our own LJ servicing this year. Three of the 33g cylinders have surface corrosion and will be replaced, though they are still intact and with gas.

The cylinder material appears to be some sort of passivated metal (?), not particularly corrosion resistant it seems. Is it worth treating the new cylinders somehow to improve their corrosion resistance?

I can see that paint might not be a good idea (concealing corrosion) but would something else suit?

Or is this a design safety feature?

 

[Aeolus]

Your post reminded me that I should check my LJs too.

Which then gave rise to the thought that if I replace any gas cylinders, I might try activating the life jacket (a) to check that it inflates and (b) to get a sense of what it feels like to be wearing a life jacket when it inflates. Of course, it may be that there will be a small phut as the cylinder demonstrates that it was indeed due for replacement.

 

[Tidewaiter2]

Encouraged by a previous thread we're doing our own LJ servicing this year. Three of the 33g cylinders have surface corrosion and will be replaced, though they are still intact and with gas.

The cylinder material appears to be some sort of passivated metal (?), not particularly corrosion resistant it seems. Is it worth treating the new cylinders somehow to improve their corrosion resistance?

I can see that paint might not be a good idea (concealing corrosion) but would something else suit?

Or is this a design safety feature?

We paint clear nail varnish on the cylinders, then renew coating as needed. Do the same on our brass work.

 

[vyv_cox]

I think they have a very light electroplated finish, maybe zinc? Perhaps a clear lacquer would help to reduce corrosion whilst allowing the surface to be inspected. Otherwise wax polish would give some corrosion benefits.

 

[prv]

I'd be wary about applying any coating, as it will interfere with the weight test.

I suppose you could weigh each cylinder immediately before painting, then afterwards, and if there's a noticeable difference mark with the new weight for the next test?

I haven't seen any corrosion on ours, but they are Hammar Crewsavers which mount the bottle inside the bladder where it's (hopefully) dry.

Pete

 

[AntarcticPilot]

We simply varnished ours.

 

[Tidewaiter2]

For test purposes, it's best to inflate them with a dinghy pump, not the cylinder- stress issues, or by mouth-mould issues.
Leave for 24hrs-thats about max survival time in Northern waters- and check to see if still firm.