Problem with one side of BC inflating more than the other

[DukeAMO]

Maybe we can try a little armchair diagnosis for my DH.

His BC is a Zeagle Ranger. He likes the fact that it can be adapted to so many uses, but it's messing with him right now. It has a very high lift capacity (44lb), so the bladder is big. For comparison, my Zena has a 30lb lift capacity, which is still big. And he doesn't need to wear a lot of weight to sink.

He has a problem where one side of the bladder ends up bigger than the other. I think the left side is the bigger one. When that happens, it pulls him out of alignment, so he ends up wasting energy finning just to stay level. Here's a video showing him fighting it:
AOW 1205 PPB2 Hover 1.MOV - YouTube

Our instructor tried to push the air back around at one point, but it ended up mostly on one side again before long. You can actually see that in the video. We talked about it a little after class, but haven't figured out a fix yet.

So... any ideas on how to correct the issue? (Buying another BC is obviously not our first choice.)

 

[g1138]

Has he tried forcing himself to tip all the way to his left to get the air to start traveling to the right side of the wing?

I had this problem at times with my 23lbs BC, a Sherwood Axis. There was a small channel running between the right and left side of the bladder.
If I was ever rolled slightly on my right, the air I added would of course enter from the left as usual but rise to the highest point which was also my left. A quick forceful roll to my left allowed air to travel back the other way, and I just re-centered my self when I felt that everything was even.

 

[herman]

A smaller bladder is not going to make much if any difference. If you are neutral, you will have the same amount of air in a 20 lb bladder as you will a 45 lb bladder. I am assuming he had a fair amount of wetsuit on, otherwise there would not have been any reason to have that much air in the bladder to start with unless he was overweighed. Considering the class, I don't think that is the case but is still worth checking. What he needs to do is to learn to manage the air bubble, which is all about body position. If he happens to be one shoulder up when inflating (or deflating for that matter), the air will tend to collect in one side of the bladder. To balance it out, he needs go heads up vertical for a few seconds, it is important that he stays straight up (left/right, f/b is not critical). This causes the air to migrate the top of the bladder. Then he needs to move back into a horizontal position staying level as he does. This will cause the air to migrate down both sides of the bladder more or less equally. Most of us tend to roll to one side when going from vertical to horizontal, doing so will cause a good bit of air to shift to the upward side and end up in one side of the bladder. A little practice and he can get the balance close. As the dive progresses he may need to do this a few times because as he adds or releases air to the bladder, the odds are it will only change in one side. During the dive, you can tweak the air balance by going slightly heads up and rolling the side you need air in up slightly upwards. This takes practice. If you don't go up far enough or roll enough, not enough air will migrate, too much and too much air will migrated. Also, if he happens to go sideways for some reason- to look at something for example, odds are the bubble will migrate to the high side which will require the balance to be reestablished.
If this does not make sense, I will at the quarry this weekend with a class, drop by and maybe I can explain it better.

You just gave me an idea for a demonstration prop....bleep, another project.

 

[SnorkelLA]

That bladder looks pretty full. He must have been overweighted. I had a problem very similar to this when I was taking my OW, I got the bad apple in a batch of halfway decent BCDs. One side of it would stay inflated and not let any air out. With his problem, it could be anything from an excess of weights on one side to water filling the BCD and adding imbalance by rolling to one side. The water theory would certainly make sense to me because you can't just tip water like an air bubble to another side. It's going to go where it wants to go

 

[DukeAMO]

I don't think he's overweighted. I believe he had 14lbs of lead, but he was also wearing a 5mm Farmer John plus a 5mm long-sleeved shorty, gloves, boots, a hood, and AL 80 tank. The water was cold! We did weight checks more than once that weekend. I used 26lbs of weight in similar gear.

I like Herman's tips. Water in the bladder could be an issue too, I guess, because you completely empty the BC on descent, and water can get in when it's empty. To get the water out, can you just get vertical with air in the BC and pull the dump valves on each side?

I'm thinking he could also move a bit of weight up to the trim pockets (he doesn't have any in there yet). He swims pretty horizontally, but to me he looks kind of hips-down when staying still. What do you guys think about that?

 

[Hawkwood]

This may be obvious, but are both "wings" clipped in?

Bill

 

[SnorkelLA]

Try weaving some 1lb or 2lb into his shoulder straps, that might trim him down.

 

[DukeAMO]

This may be obvious, but are both "wings" clipped in?

Bill

I'm not sure what "clipped in" means. Are you referring to the string that goes around the outside and clips on each end, or something else?

 

[drbill]

This is why I almost always dive with a doughnut style wing for more even distribution of the air inside.

 

[Hawkwood]

I'm not sure what "clipped in" means. Are you referring to the string that goes around the outside and clips on each end, or something else?

No.

The wings on the Ranger can be "clipped" to the BCD using quick releases, thus keeping the wing tight against the BCD. The wing can also be "unclipped" allowing the wing to float freely. If one side is clipped and the other free, then you will get an imbalance. If both are free, then you can still have problems with balance. We use Rangers as our rental BCDs and it is a common problem if folks don't set the gear up correctly.

One side of the clip is on the edge of each wing, about the mid point. The other side of the clip is found by the weight pocket zipper. In fact, it goes over the zipper for the pocket. Folks often unclip the wing for access to the zippers and forget to clip it back up.

You can also try to wiggle/shrug your shoulders to get air to move from one side to the other. The two sides are only connected in the narrow band across the back of the shoulders.

You can see the clip in this picture: