Am I going to die? BCD repair

[neevo]

I have an old AP Diving Buddy Commando BCD that I love. It's only got a few hundred dives on it. And it shows, because it is in fantastic condition. I've had it recently serviced, to make sure its safe to dive and the service centre did the regulator/inflator service as well as doing a pressure test.

The BCD is fine although it didn't pass their strict pressure tests as it lost 50% pressure in 24 hours (I think I remember that correctly). But they mentioned it would be fine to dive until it's time to replace it (plan on going BP/W at some stage anyway).

The one thing the service centre weren't able to fix was a seam that had split slightly. It annoyed me and so tonight I thought I would have a crack at sewing it back up, as I'd just learnt to use the missus' sewing machine making some soft weights so why not use my new skill twice

Luckily for me anyway as I took the BCD apart as much as I could by taking the dump valves off the outer BCD material and found some big salt crystals in the bladder which I duly flushed with warm water to completely clean it out.

I managed to sew it up nicely and put it all back together. I've inflated the BCD and cannot hear any leaks and it appears to be holding pressure, however want to make sure I'm not forgetting anything before I dive it as I don't want to find out I have a problem at 30m down (although will use a drysuit on local dives which offers another level of protection if anything goes wrong).

What's the thoughts from those that do their own maintenance?

Some obligatory pics.

 

[The Chairman]

As long as you didn't use cotton thread, you might be good. Don't rely on hearing leaks: let it sit overnight. You might even want to dunk it in a tub of water and carefully examine it for bubbles. This is how we find punctures in tires.

 

[industrious95]

If there's a bad gasket or worn spot losing 50% in 24 hrs, how do you know it's not going to fail when you're at 80 feet and you try to add some air to the BCD?

I know it's a common argument on ScubaBoard, but there are plenty of dry suit divers that use the dry suit for buoyancy and the BCD for backup. In other words, unless there was another factor like a dry suit leak, I wouldn't abort a dive if I suddenly saw a tiny stream of bubbles from my BCD inflator, but I wouldn't step onto a boat for a trip knowing my equipment wasn't in the proper condition to make my dive safe.

 

[neevo]

As long as you didn't use cotton thread, you might be good. Don't rely on hearing leaks: let it sit overnight. You might even want to dunk it in a tub of water and carefully examine it for bubbles. This is how we find punctures in tires.

I've left it inflated in the garage and will see how it fairs in the morning. I used polyester thread to repair the seam which should be fine for salt water.

 

[neevo]

If there's a bad gasket or worn spot losing 50% in 24 hrs, how do you know it's not going to fail when you're at 80 feet and you try to add some air to the BCD?

The service centre does a lot of military equipment and their test are apparently required for their stuff. That's what I was told with the pressure test they do. They mentioned it was perfectly fine to dive however wasn't going to pass muster for the sort of industry they service.

They also struggled to service the air dumps which I suspect is where the BCD was losing pressure so I'm looking into some rebuild it's for those too if they're economical.

The BCD hold pressure fine for a few hours and will take full pressure with the blow off valves working fine too. I was just worried I could have done something wrong or it was a risky strategy. If that were the case I'd probably take it back to the service centre and get them to give it the ok once again.

 

[neevo]

Pumped the BCD up this morning and left it in the garage with slightly less air than full as to not put too much pressure on the bladder. Went back to it 6 hours later and it's not quite as tight when I feel the bladder but is still holding most of its air.

No idea if this is a legitimate test but if left for 24 hours I could see that I would lose some pressure.

Will proceed with a leak test to see if I can identify the cause of the leaks (highly suspect the dump valves) and look to address as required.

 

[Couv]

The first thing you need to do is get your money back from the dive shop if you found salt crystals in your BC after paying them to service it. Next, do as Doc says. Fill it with air and submerge it in water in different sections at a time to find where the leak(s) is(are.) I don't think the leak you have is that bad, but why not find and fix it?

The most common places to find leaks-in no particular order:
Corrugated hose at the elbow or power inflator.
Power inflator dump valve not holding.
Dump/OPV valve not holding pressure.
Dump/OPV or elbow bladder seal.
Bladder with pinch flat holes.
Bladder with other pin hole.
Bladder just too damn old to hold it in.

Yes you will die-but most likely not from a leaky BC.

 

[neevo]

Thanks couv. I'll take it in the bath with me this week and try some stuff. Pretty sure it's the dump valves but a dunking will sure help to find out where.

 

[halocline]

Pumped the BCD up this morning and left it in the garage with slightly less air than full as to not put too much pressure on the bladder. Went back to it 6 hours later and it's not quite as tight when I feel the bladder but is still holding most of its air.

No idea if this is a legitimate test but if left for 24 hours I could see that I would lose some pressure.

Will proceed with a leak test to see if I can identify the cause of the leaks (highly suspect the dump valves) and look to address as required.

If you put air in it orally, some of the pressure loss could just be from the air cooling. If there's any sort of significant leak, it would be essentially empty (ambient pressure) after 6 hours, so I wouldn't be too worried. Looking for a leak is still a good idea, I just would not stress too much about it.

Assuming you are diving correctly weighted, a leaky BC should not be dangerous. It might not be enjoyable, but you should be able to swim to the surface without any air in your BC and then drop weights if necessary to get positive on the surface. Its usually only technical divers with a lot of extra gear that can't swim their rigs to the surface, or possibly someone who is grossly overweighted.

 

[Wayward Son]

my wing failed on me during a dive last month. I didn't even know it until after I was back on the boat. warm water diving with no suit crush to change buoyancy it didn't matter, it was like diving when I was a kid & had never heard of BC's