two different soda lime in the same canister

mapko

Hi everybody,
I know this is a stupid question but I have about 3kg of dragersorb, not enough to completely fill my canister (3.7Kg), I don’t plan to buy again dragersorb, but I don’t want to waste it.
The question is: can I fill my canister with the dragersorb I have, and complete the fill with softnolime??? Should I expect an explosive reaction????

thanks

decoweenie

I have done this simple little test on my Classic-KISS last year and reported to the KISS list. Can't remember off the top of my head about the exact reason at the moment...

I made multiple 1" thick of layers of different grade and brand of sorbs. The scrubber is axial so there were quite a number of layers. Again, can't remember the exact number of layers...

Memory is the first thing to go as you age, isn't it ? Can't remember...

Anyway, what I do remember is it made no difference from the diver (me) view-point as far as WOB and duration. The scrubber lasted about the same number of dives and hours as when I filled it homogenously with the sorb recommended by Jetsam.

Take it as a grain of salt since I am not very "sensitive" about the supposedly minute difference on the unit when the parameters are changed slightly...

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"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

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Padowan

I have mixed coarse and fine grade Sofnolime in a single canister once - it was in the Red Sea, the lime was old, but it was all that was available (hence using dribs and drabs of different containers) and I had a CO2 hit after less than 3 hours, whilst shallow, working hard in a current, but having obeyed the 3 "rules" of scrubber duration on the YBOD.

Read into that what you want.... could have been the mix or grades, could have been the age of the material, could have been a bad pack by me....

A coarse and fine mix Sofnolime is pretty much what you get if you buy Sefrasorb from mollecular products (which IIRC is just ungraded Sofnolime) so I doubt there is anything fundamentally wrong, it's just the expected duration, and whether it's been tested with that in...

If you decide to mix multiple grades the question then comes, do you layer it, or mix it all up?

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decoweenie

Which do you think will allow more movement (once "packed) when more vibration is introduced ?

1. multiple layers
2. 2 distinct layers
3. mixed outside, then pour in scrubber

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

Padowan

I would say that multiple layers coarse/fine/coarse etc would give the maximum potential for the pack to "turn bad". If you mix outside the can, you would expect a lot of the small spaces between the coarse grans to already be filled with fine particles.

So, I question why you decided to use layers, was is mainly to test for breakthrough/channeling (from a deteriorating pack), or WOB, which I would expect to be higher with a homogeneous mix, compared to a layered scenario?

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decoweenie

There was a specific reason for layering, but I can't remember at the moment. Sorry...

However, I used a specific protocol to minimize (if not eliminate) loose packing on the Classic-KISS (learned from a friend).

I pack tight as usual, but have enough sorb so that I have about ~1/4" gap where the scrubber is from the lid. Since I have to drive ~2.5-3 hour to the dive site, the vibration packs the sorb even more by the time I got there. I simply tighten the screw on the top of the lid. I don't think I will be able to tap the sorb down much tighter.

On the Sport-KISS, the procedure is to use a looser pack.

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

Sutty

I've used a mix of spherasorb and fine-grain sofnolime on my Classic Kiss on one occasion with no problems, it was mainly spherasorb with a couple of inches of sofnolime on top. I was aware there were bigger spaces around the spherasorb which the sofno particles might migrate into resulting in a loose pack so I added an inch and mixed them together then topped off. Had no problems and the pack was firm after use.

Dan

I did it the other way around - first Sofnolime 797 about 3/4 and then 1/4 Spherasorb on the top in my CK - with no problem.
I didn't ad any extra lime to compensate for the lime to migrate into each other. Maybe no problem in my case as I used the 797 first?

//Dan

buggeriamold

I have asked the same question, and got the same answers. So i layered my sorb and now my answer is, i couldnt pick any difference.

Mark

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Well, it is cheap stuff and it comes almost from the local gardening store, but it works fine and it's very solid. We tried to destroy one by hitting it with a hammer... we succeeded but we really had to hit it hard.

Philippe GERIN

Done that exactly on my CK (axial scrubber). Start the fill with the one sorb you have the most & finish with the other one. Don't push the scrubber to the extreme end.
Done that on my Azimuth too (radial scrubber), but I mixed the 2 sorbs before filling.
Either case, I didn't notice any differences from a scrubber filled with one kind of sorb.
Best
Philippe