Change in buoyancy from 12l to 15l cylinder

[Storker]

I use less lead with a 15L tank than with my 12L short and heavier tanks!!

So, the 15 weighs less than your 12 and has 3L more internal volume, and you use less lead? That just doesn't make sense to me.

From what I'm reading here, the 15 should be more than 3kp more positive than your 12. I could take some 4-5kg off my belt when I switched from a 15L to a 10L.

 

[BoltSnap]

So, the 15 weighs less than your 12 and has 3L more internal volume, and you use less lead? That just doesn't make sense to me.

From what I'm reading here, the 15 should be more than 3kp more positive than your 12. I could take some 4-5kg off my belt when I switched from a 15L to a 10L.

Sorry, I meant it the other way around, I use less lead with the 12L heavier than with the 15L one. I have to add more weight with the 15L tank.

 

[Storker]

Sorry, I meant it the other way around, I use less lead with the 12L heavier than with the 15L one. I have to add more weight with the 15L tank.

Thanks. That makes sense.

EDIT: Some 3-4kg less, amirite?

 

[BoltSnap]

Thanks. That makes sense.

EDIT: Some 3-4kg less, amirite?

Somewhere around that, I don't remember exactly how much now. I am traveling away from diving unfortunately

I normally use 15L and only use 12L when my 15L tanks weren't filled.

 

[CodeS]

I often use a 15L tank for a 2 hr dive (20-10m). This provides plenty of gas when diving a 32% mix (or more), it's nice not having to rush too much.

I have found with my tanks that I need to add around 1kg with the 15l. I think there is some variation between tanks as my buddy doesn't change his weighting. There isn't much in it, it'll be dive-able with the same amount of weight so hop in the water and see how you go.

 

[Diving Dubai]

My Faber 15's are stamped 16.5kg, my Faber 12's 13.5kg

I throw on an additional 1kg and I'm all good (even if I forget it's no drama)

 

[ljpm]

Not sure about your tanks over there but with our Australian tanks the 15lt is only .25kg more negative than our 12.2lt.

I'm in Canada so I tried to convert to metric for this thread. Seems I may not have gotten it quite right. There are so many conversions on line it is confusing.

Seems the conversions I was using were a bit off. I actually use a 133 cubic ft. tank. According to this chart it is a 17L tank. I'm not sure how that fits in with other previous chart. That chart lists an 18L as 150 cubic ft. and this one has it at 19L.

When I switched from an Al 80 (11L?) to the 133 I lost 7lbs of lead. That almost made up for the additional weight of the tank. The only real difference I have found using the 133 is I have to start the dive 2lbs heavier than I normally would or I wont be able to hold the safety stop. The Al 80 holds about 6.5 lbs of air and the 133 holds about 10.5 lbs.

 

[BlueTrin]

My Faber 15's are stamped 16.5kg, my Faber 12's 13.5kg

I throw on an additional 1kg and I'm all good (even if I forget it's no drama)

That’s what I did (using the same weight) and I was surprised that it was that straightforward and this is why I asked here, but I guess it makes sense as you only look at the buoyancy.

 

[Jcp2]

If there was only some buoyancy calculator on this site that could help...

Optimal Buoyancy Computer

 

[RyanT]

amirite?

Now, I'm suspicious @Storker. You say English isn't your first language but it sure seems like "southern US" english is in your command.