BCD Questions

[BlueTrin]

Removing the valves or the inflator hose is one way to get the water out but it can cause more trouble than it's worth. I have many people bringing in BCs with missing valve o-rings/gaskets, stripped threads on valves, missing dump valves etc. If you forget to replace the dump valve and leave it behind, the BC is useless.

I worked at one shop (large chain) where an employee decided to remove the dump valves on all the rental BCs during cleaning ... then another employee started renting those BCs

I can imagine for a shop it can be trouble.

For myself, I make sure I always put it in my save-a-dive box immediately.

 

[TMHeimer]

Removing the valves or the inflator hose is one way to get the water out but it can cause more trouble than it's worth. I have many people bringing in BCs with missing valve o-rings/gaskets, stripped threads on valves, missing dump valves etc. If you forget to replace the dump valve and leave it behind, the BC is useless.

I worked at one shop (large chain) where an employee decided to remove the dump valves on all the rental BCs during cleaning ... then another employee started renting those BCs

That's funny.
Removing valves/hose never entered my mind when I bought it 15 years ago. I am NOT mechanically inclined. I suppose that led to my question about how the insides ever truly gets dry. I didn't think others would even consider taking stuff apart after every dive outing.

 

[Boston Breakwater]

Yep.

I finally decided that diving a few (but only a few) pounds heavier than ideal on a recreational dive has its advantages.

Hey, John. The say New England divers "Dive Heavy." I'm not sure if that's fact, or fiction. I was taught to dive heavy, and always have. I would think its advantageous....What do you think?
Cheers.

 

[Ayisha]

Any thoughts as to why? Makes sense that overweighted divers use more air, but not properly weighted divers regardless of how much weight makes them "proper".

When someone is underweighted and they're shallow and maybe having difficulty holding a stop, they may keep trying to release gas from their BCD. If there isn't any gas or it's not at the highest point, pressing the inflator will allow water in instead.

Along the same vein, if someone is horizontal or head down and uses their inflator hose to release gas, water will go in instead. If they use the rear dump, which is at the highest point of their body at the moment, then gas will be released instead.

Hope that helps.

 

[BlueTrin]

That's funny.
Removing valves/hose never entered my mind when I bought it 15 years ago. I am NOT mechanically inclined. I suppose that led to my question about how the insides ever truly gets dry. I didn't think others would even consider taking stuff apart after every dive outing.

On my wing it’s not hard to remove them, you just rotate the corrugated hose or the dump valve, the top part can be removed just by rotating it, it is simply screwed onto the attachment on the wing.

To detach it, I literally rotate it 5 turns ?

It is actually designed to be removed or replaced easily. Their dump valves are interchangeable with the ones on their DSMBs.

Ill take a pic tomorrow.

 

[JamesBon92007]

I rinse my backwing after a dive trip, but rarely between dives while on a trip. I have not worried about there being water in it since everything except the SS dump valve spring is some kind of plastic or other. I do keep air in it while it's waiting for the next dive trip because I've heard about bladders getting stuck together. OTOH I remove the inflator after each dive trip and thoroughly clean and lubricate and check the o-rings it because, in my experience, that's what is going to fail. Another reason to rinse thoroughly is just in case there's any loose debris floating around inside. I once had a dump valve get stuck open because some sealant had come loose so now I remove my dump valve when rinsing.

 

[boulderjohn]

Hey, John. The say New England divers "Dive Heavy." I'm not sure if that's fact, or fiction. I was taught to dive heavy, and always have. I would think its advantageous....What do you think?
Cheers.

I dive a few pounds heavy with recreational (single tank) dives, but not really more than that. In my earliest diving days, I tried to get as close to ideal as I could, sort of as a challenge, but I eventually got away from it. The first reason was mentioned above--fighting to get a few burps of air out of the BCD at the end of the dive. It does not take too much, though. A pound of extra lead needs about a pint of air in the BCD to be neutral. Put a whole lot of extra lead on, and you've got a whole lot of unneeded air in that BCD.

The more air in the BCD, the harder it is to dive. You control buoyancy through that air and through your lungs. As long as the air volume in the BCD brings you within a reasonable range of neutral, you can maintain control through breathing alone. Get out of that range (by ascending or descending), and you have to adjust the BCD. The more air in the BCD, the more it controls your buoyancy rather than the lungs because it makes the range where you can control with the lungs much smaller. I do a demonstration for OW students in which I go from the bottom of a 12 foot pool to the top and then back to the bottom using only my lungs, and I can do that even 6-8 pounds overweighted. When I am practicing tech diving with my steel doubles in the same pool, my range is limited to a few feet.

There is a second reason to be a little overweighted, which I discovered on a dive trip in Mexico more than a decade ago. I was using a ScubaPro Nighthawk with shoulder trim pockets. I had learned that with a 3mm suit in salt water, I needed 8 pounds divided among the 2 waist pockets and 2 shoulder pockets to be nicely weighted and in good trim. The boat I was on only had 4 pound weights, so I had a choice of being nicely weighted but out of trm or nicely trimmed but overweighted. I was then a fairly new tech diver, so I had been getting accustomed to being overweighted, so I decided to go that route. It worked out very nicely; I was quite comfortable in the water. So, I have decided that if I have to have a bit more weight than I like in order to be in trim, that's what I am going to do.

 

[Rickk]

I have my weight pretty much dialed in so I inflate my BCD a little once I reach depth to counteract the mass of air in the tank.Over the course of the dive I gradually release air to compensate for the loss of air in the tank and the fact that I gradually decrease depth as the dive progresses. Buoyancy control is mainly by my lungs. By the time I get to around 100 bar, the BCD is empty and I have no problem holding the safety stop. I dive without neoprene in warm water so never need to compensate for that.

I only put air in once and release perhaps 3 or 4 times in a dive. Some dives I have a litre or more in the BCD some dives I come up empty. I think that the difference is if I release by the infiltrator, dump valve and my orientation in the water at the time.

Once on the boat or shore, I use the power inflation and the bottom dump valve to blow a lot of air through the BCD. This forces out al the water in the BCD. At the end of the day I will take off the top dump valve, put the hose in the BCD and put in a few litres, swish around and dump out the bottom valve. I replace the top valve and oral inflate the BCD and dump the air out a couple times.

I finish by hanging to dry with some air in the BC, if not diving for a longer time I will remove the dump valves to let the bladder dry fully, Storage is with some air in the BCD so that the bladder cannot stick together inside.

 

[TMHeimer]

I dive once weekly in summer and once bi-weekly winter (about 6 months of each). So (particularly in summer) I guess my BC insides is never completely dry. Maybe even in winter. I would assume this has no ill effect since the BC is over 15 years old. Wonder what's in there.....Maybe that's really why I rinse with baby oil?

 

[BlueTrin]

Here’s the hose and dump valve attachment on my BCD, it’s made to be easy to remove