Reading the Tea Leaves/Sodasorb Grains

jkaterenchuk · 1st August 2008, 21:00

The Meg is the first scrubber I have had that allows me to see the colour change in my CO2 absorbent immediately following a dive.

Now I am interested if what I am seeing is normal and why the colour change profile is uneven in height from bottom around the outside of the scrubber?

Any comments?

Is this the same type of profile others are seeing?

Is there an explantion for the uneven profile?

I am aware that I should not rely upon the absorbent material colour change as an indication of useful scrubber life.

Also, the scrubber in this case is what I consider as being on the high end of fully utilized.

Thanks, John

**sfldiver** · 1st August 2008, 21:17

John,

I've never packed a scrubber before, so I can't answer your question, however, I do have a comment...

That looks like Barney pee'd in your kitty litter!

Dsix36 · 1st August 2008, 22:35

If you would have just banged that canister against the wreck, it would have evened it out for ya.

**Gill Envy** · 1st August 2008, 22:40

I have gotten that coloration before. not sure what it means but would assume that for some reason the gas is flowing more readily to one side, for what reason I can only guess. I have not paid enough attention to see if it is always to the same side.

g

**wedivebc** · 2nd August 2008, 02:54

I sometimes get uneven colour change when using 4-8 scrubber. I find when using 8-12 which is what ISC recommends the colour change is more even.

jkaterenchuk · 2nd August 2008, 04:03

Quote: (Originally Posted by wedivebc)

I sometimes get uneven colour change when using 4-8 scrubber. I find when using 8-12 which is what ISC recommends the colour change is more even.

It is actually packed with Sodasorb 8-12. I have never used 4-8. I will be starting to use some Sofnolime 6-12 in the near future and I will see if that changes the pattern.

John

vincnt moore · 2nd August 2008, 23:06

Ha John
I cant tell what is happening in my scrubber due to the axle design and not being transparent but when packing it you have to tamp it down to get the lid on with no air space after it is on. I don't know if you have to tamp it or not but one side being more compressed would be a logical reason for the front migrating at different rates. Kinda like gunpowder in a shell when fired. Jim..

jkaterenchuk · 2nd August 2008, 23:27

Quote: (Originally Posted by vincnt moore)

Ha John
I cant tell what is happening in my scrubber due to the axle design and not being transparent but when packing it you have to tamp it down to get the lid on with no air space after it is on. I don't know if you have to tamp it or not but one side being more compressed would be a logical reason for the front migrating at different rates. Kinda like gunpowder in a shell when fired. Jim..

Jim

Thanks for the tip. My process for filling.

Fill halfway...tap tap tap turn tap tap tap turn (repeat several times)....fill to scored line on scrubber....tap tap tap turn tap tap tap turn (repeat several times)......fill alittle more back up to scored line on scrubber.....tap tap tap turn tap tap tap turn (repeat several times).....put in top scrubber compression disc....tap tap tap turn tap tap tap turn (repeat several times)....check to make sure level is still at scored line otherwise add more and repeat.

Usually takes about 10 minutes.

John

w ripley · 3rd August 2008, 00:43

Hey John:

From one view, it would seem that you're leaning towards Obama. From the other, McCain. Hard to tell, if you're breathing from the left or right?

Seriously, my MEG canister looked the same on some dives. Just more tapping... Or, you can pick up a small dental vibrating table and end all the confusion.

How are the wings?

Regards,

Bill

Underwaterbear · 3rd August 2008, 00:57

Not sure which absorbent you're using there but I think the uneven pattern is just a product of where the moisture is, rather than strictly where the scrubber is 100% spent.

My understanding is that the indicator dye (I think it's ethyl violet in Sodasorb but it could be phenolphthalein - I can't remember) is activated by the carbonic acid created when C02 dissolves into water produced in the CO2 fixation reaction.

So in your photos the "front " was somewhere just a bit lower down than the lightest pink shading. Of course some of the indicator has probably reverted to white or colorless now that you are not breathing on it.

When you were breathing on it, in the zone of spent and almost spent sorb, the moisture laden with H2CO3 was going where gravity took it, activating the indicator on the surface layers of each granule as it goes. If you were horizontal or thereabouts obviously the moisture tends to fall to the bottom half of the scrubber.

Bottom line I chalk* it up to gravity.

Cheers,
Andrew

* Sorry, couldn't help myself.

1st August 2008, 21:17	#2 (permalink)
sfldiver S.C.R.U.B.'S Photographer Current Rebreather/s: Optima Other Rebreather/s: Join Date: Jul 2007 Location: Pompano Beach, FL Posts: 819	Re: Reading the Tea Leaves/Sodasorb Grains John, I've never packed a scrubber before, so I can't answer your question, however, I do have a comment... That looks like Barney pee'd in your kitty litter! __________________ *Currently piloting & shooting...* Dive Rite O2ptima FX Rigged w/ a Dsix Custom Aluminum Frame, Nomad Wing, Transpac Harness and VR3 Computer w/ VPM-B/E & a 4th Cell Sensor Link.* Canon PowerShot G9 Digital Camera *Rigged in a Patima-PDCH 2008 G9 Aluminum Housing w/ an Inon UWL-100 Achromat Wide Conversion Lens, 2 Inon UCL-165M67 Close-Up Lenses and 2 Inon Z-240 Strobes.
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1st August 2008, 22:35	#3 (permalink)
Dsix36 Going Down? Current Rebreather/s: Optima Other Rebreather/s: Join Date: Aug 2007 Location: Deerfield Beach, Florida Posts: 1,154	Re: Reading the Tea Leaves/Sodasorb Grains If you would have just banged that canister against the wreck, it would have evened it out for ya. __________________ THE MORE THAT I LEARN, THE MORE THAT I STILL NEED TO LEARN!!!!!!
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1st August 2008, 22:40	#4 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,347	Re: Reading the Tea Leaves/Sodasorb Grains I have gotten that coloration before. not sure what it means but would assume that for some reason the gas is flowing more readily to one side, for what reason I can only guess. I have not paid enough attention to see if it is always to the same side. g __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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2nd August 2008, 02:54	#5 (permalink)
wedivebc Dave Tomblin Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,508	Re: Reading the Tea Leaves/Sodasorb Grains I sometimes get uneven colour change when using 4-8 scrubber. I find when using 8-12 which is what ISC recommends the colour change is more even. __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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2nd August 2008, 04:03	#6 (permalink)
jkaterenchuk . Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Lititz, PA Posts: 1,092	Re: Reading the Tea Leaves/Sodasorb Grains Quote: (Originally Posted by wedivebc) I sometimes get uneven colour change when using 4-8 scrubber. I find when using 8-12 which is what ISC recommends the colour change is more even. It is actually packed with Sodasorb 8-12. I have never used 4-8. I will be starting to use some Sofnolime 6-12 in the near future and I will see if that changes the pattern. John
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2nd August 2008, 23:06	#7 (permalink)
vincnt moore RBW Member Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Apr 2007 Location: Philadelphia Pa. Posts: 84	Re: Reading the Tea Leaves/Sodasorb Grains Ha John I cant tell what is happening in my scrubber due to the axle design and not being transparent but when packing it you have to tamp it down to get the lid on with no air space after it is on. I don't know if you have to tamp it or not but one side being more compressed would be a logical reason for the front migrating at different rates. Kinda like gunpowder in a shell when fired. Jim..
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2nd August 2008, 23:27	#8 (permalink)
jkaterenchuk . Current Rebreather/s: Inspiration Classic Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Lititz, PA Posts: 1,092	Re: Reading the Tea Leaves/Sodasorb Grains Quote: (Originally Posted by vincnt moore) Ha John I cant tell what is happening in my scrubber due to the axle design and not being transparent but when packing it you have to tamp it down to get the lid on with no air space after it is on. I don't know if you have to tamp it or not but one side being more compressed would be a logical reason for the front migrating at different rates. Kinda like gunpowder in a shell when fired. Jim.. Jim Thanks for the tip. My process for filling. Fill halfway...tap tap tap turn tap tap tap turn (repeat several times)....fill to scored line on scrubber....tap tap tap turn tap tap tap turn (repeat several times)......fill alittle more back up to scored line on scrubber.....tap tap tap turn tap tap tap turn (repeat several times).....put in top scrubber compression disc....tap tap tap turn tap tap tap turn (repeat several times)....check to make sure level is still at scored line otherwise add more and repeat. Usually takes about 10 minutes. John
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3rd August 2008, 00:43	#9 (permalink)
w ripley Customise Me! Current Rebreather/s: Other Rebreather/s: Megalodon Join Date: Mar 2007 Location: Norfolk VA USA Posts: 148	Re: Reading the Tea Leaves/Sodasorb Grains Hey John: From one view, it would seem that you're leaning towards Obama. From the other, McCain. Hard to tell, if you're breathing from the left or right? Seriously, my MEG canister looked the same on some dives. Just more tapping... Or, you can pick up a small dental vibrating table and end all the confusion. How are the wings? Regards, Bill
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3rd August 2008, 00:57	#10 (permalink)
Underwaterbear A Prismer in Megland Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: May 2005 Location: Seattle, WA Posts: 198	Re: Reading the Tea Leaves/Sodasorb Grains Not sure which absorbent you're using there but I think the uneven pattern is just a product of where the moisture is, rather than strictly where the scrubber is 100% spent. My understanding is that the indicator dye (I think it's ethyl violet in Sodasorb but it could be phenolphthalein - I can't remember) is activated by the carbonic acid created when C02 dissolves into water produced in the CO2 fixation reaction. So in your photos the "front " was somewhere just a bit lower down than the lightest pink shading. Of course some of the indicator has probably reverted to white or colorless now that you are not breathing on it. When you were breathing on it, in the zone of spent and almost spent sorb, the moisture laden with H2CO3 was going where gravity took it, activating the indicator on the surface layers of each granule as it goes. If you were horizontal or thereabouts obviously the moisture tends to fall to the bottom half of the scrubber. Bottom line I chalk* it up to gravity. Cheers, Andrew * Sorry, couldn't help myself.
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