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Spirit of Guernsey
13-05-2018, 06:47 PM
How long can used sorb stay in the unit before another dive? I dived with someone who had done two dives on it a week previously, is that normal?

Paulo
13-05-2018, 06:58 PM
Last week I did an hour. Wrapped it in a plastic bag to keep its humidity stable and I will get another hour this week and a shallow night dive for another hour towards the weekend.

If I didnt use it within say 3 weeks I would bin it as 2.5kg of lime is only around £8

JonG
13-05-2018, 07:02 PM
Think Simon Mitchell has a paper on this but can't find the link

JonG
13-05-2018, 07:13 PM
From memory a month is fine if sorb still in canister and sealed.

gobfish1
13-05-2018, 07:41 PM
Last week I did an hour. Wrapped it in a plastic bag to keep its humidity stable and I will get another hour this week and a shallow night dive for another hour towards the weekend.

If I didnt use it within say 3 weeks I would bin it as 2.5kg of lime is only around £8

closer to ten than eight . m8

Paulo
13-05-2018, 07:53 PM
closer to ten than eight . m8
You are correct


£75 for 8 fills = £9.375 a pop.

Barrygoss
13-05-2018, 07:55 PM
How long can used sorb stay in the unit before another dive? I dived with someone who had done two dives on it a week previously, is that normal?

With the KISS I stick a Narked at 90 lid on the can and leave it as long as Iíd leave it in the original container. As long as itís sealed from the atmosphere, then itís no different in the can than itís in the tub

B

JonG
13-05-2018, 08:01 PM
Do you do anything about any moisture or condensation in the water trap before you cap it Barry?

gobfish1
13-05-2018, 08:02 PM
You are correct


£75 for 8 fills = £9.375 a pop.

your also correct, as it still not a significant amout on money in the grand scheme of all things ccr, and not worth hanging on to part used lime for to long , as you alluded to in your post ,

if your not tossing your lime after a dive you may aswell go back to diving your 12l and pony :giggle:

Paulo
13-05-2018, 08:08 PM
if your not tossing your lime after a dive you may aswell go back to diving your 12l and pony :giggle:

Malta & Malin next month :)

Capt Morgan
13-05-2018, 08:10 PM
With the KISS I stick a Narked at 90 lid on the can and leave it as long as Iíd leave it in the original container. As long as itís sealed from the atmosphere, then itís no different in the can than itís in the tub

B

I use the same lid and have let it sit for quite some time between usage.





Do you do anything about any moisture or condensation in the water trap before you cap it Barry?

I have a large syringe with a length of thin hose on it to drain the water trap though I don't tend to get much water in it
on short dives, it seems to need to be 2.5 hours + to get any dampness and then it's normally time for a fresh fill anyway.

Barrygoss
13-05-2018, 08:19 PM
Do you do anything about any moisture or condensation in the water trap before you cap it Barry?

Same as Morgan, if itís being used on hour long dives in the local puddle, then either invert the can and leave it to stand for five minutes or not bother. Lime needs moisture to work and is antibacterial on its own.

Iíll do that for 3no 1 hour long dives and then bin it, so for winter diving in the puddle. Iíve got the can sealed up after last weekends dive on the Moidart with a 77min run time, itíll be fine for another couple of hour puddle splashes before the next coast trip next month.

B

notdeadyet
13-05-2018, 08:20 PM
I had a break over the winter. Lime had an hour on it when I put it away in December, then did three hours over a weekend on it in March before dumping it.

JonG
13-05-2018, 08:40 PM
Since I changed the BOV haven't really been getting much in there but when I did was gently removing base and wiping it dry before sticking it back together with the narked lid.

So far longest I have had between dives is about 3 weeks I think.

gobfish1
13-05-2018, 08:58 PM
I it seems to need 2.5 hours + to get any dampness,

id be thinking about getting a new girlfriend , i like to be fast a sleep in 20mins tops lol

Spirit of Guernsey
13-05-2018, 09:07 PM
id be thinking about getting a new girlfriend , i like to be fast a sleep in 20mins tops lol

You do it twice?

ColinIOM
13-05-2018, 10:01 PM
I take the canister out and put it in a ziplock bag, that way the head can dry out. I’ve had a couple of weeks between dives like this.

nigel hewitt
13-05-2018, 10:07 PM
I did a dive on a part used fill that was a couple of years old once on the IDA.
I monitor my breathing rate as I check my ppO2 and it was no different.
The chemistry of Sofnolime is too simple for it to go off unless seawater gets in.
I take no special precautions.

Capt Morgan
13-05-2018, 10:33 PM
id be thinking about getting a new girlfriend , i like to be fast a sleep in 20mins tops lol

I think it's just a build up of drool after a couple of hours :giggle:

cathal
14-05-2018, 08:16 AM
For Decompression dives, a new scrubber for each dive but for NDL dives or during the winter Iíve gone as far as 3 months with a scrubber, it had about 5 hours diving on it. It is stored in a dry bag.


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steelemonkey
14-05-2018, 08:52 AM
Speaking as a total numpty in this subject, and just for my own information.
I presume if the sonfalime stops working you get more co2 than is good for you. Does the unit tell you this is happening?

topper133
14-05-2018, 09:13 AM
For Decompression dives, a new scrubber for each dive but for NDL dives or during the winter Iíve gone as far as 3 months with a scrubber, it had about 5 hours diving on it. It is stored in a dry bag.

+1, depends on the next dive for me, will happily dive on 2month old scrubber, but depends on how much it was used and what the next dive is, I use the SubGravity cap to store it the unit but can still let the head dry etc.

topper133
14-05-2018, 09:15 AM
Speaking as a total numpty in this subject, and just for my own information.
I presume if the sonfalime stops working you get more co2 than is good for you. Does the unit tell you this is happening?

Correct its not good for you, the 2nd question will open a can of worms, some do (in various ways), some don't, but none are perfect or a substitute for common sense or training.

MadUKDiver
14-05-2018, 12:42 PM
I did a dive on a fill that was a couple of years old once on the IDA.
I monitor my breathing rate as I check my ppO2 and it was no different.
The chemistry of Sofnolime is too simple for it to go off unless seawater gets in.
I take no special precautions.

+1


Simon Mitchell's study conclusions:
Storing a scrubber between dives can influence CO2 absorbing capacity

Prolonged storage (28 days):
Sealing a scrubber from the atmoshpere [zip-lock bag] increases scrubber endurance

Brief storage (24 hours):
Unprotected scrubber performance is equivalent to a sealed scrubber after 28 day storage (implying that overnight unprotected storage is OK)

The study for 'unprotected scrubber' saw a 40 minute reduction in duration from approx 220 to approx 180 minutes at the 28 day point.

I think the myth that you need to replace scrubber if left overnight is truly busted but do think carefully about storage conditions - hot, dry, CO2 rich conditions are going to have a bigger impact. Sealing in a zip-lock bag will give you good protection in most cases for a month or so. Longer probably requires more caution.

The longest I've left one open on the bench and dived it is 180 days. Now I've seen the study results I've invested in a zip-lock bag ;)

steelemonkey
14-05-2018, 01:18 PM
https://www.amazon.co.uk/Andrew-James-Vacuum-Sealer-Reusable/dp/B001HBP7HW

I wonder if one of these would help.
I store large amounts of brewing grains in a roll type bag.

Spirit of Guernsey
14-05-2018, 03:46 PM
+1



The study for 'unprotected scrubber' saw a 40 minute reduction in duration from approx 220 to approx 180 minutes at the 28 day point.

I think the myth that you need to replace scrubber if left overnight is truly busted but do think carefully about storage conditions - hot, dry, CO2 rich conditions are going to have a bigger impact. Sealing in a zip-lock bag will give you good protection in most cases for a month or so. Longer probably requires more caution.

The longest I've left one open on the bench and dived it is 180 days. Now I've seen the study results I've invested in a zip-lock bag ;)

Thanks, I have a roll top dry bag which should be perfect for the job.

Hot Totty
14-05-2018, 07:05 PM
I just use a plastic bag to keep the moisture in, co2 in the atmosphere is tiny (not enough to use up your scrubber)

matt
15-05-2018, 01:19 PM
It's completely undefined and the safest is to chuck it out.

I leave mine stood in the bucket with the lid on in the bedroom and it "seems" fine.

I did a totally unscientific test to see if I could find any difference (using the tempstick, CO2 sensor and the "Pit Wanker" model). Here is the output (all the dives are ~60 mins to 35m dive 1 and 20m dive 2 where where was a dive 2):

https://s6.postimg.cc/5gzkn7y41/bedroom-scrubber_zps4hkscaa4.png

Mark Chase
15-05-2018, 04:47 PM
A year should be fine but in truth my sphincter demands about a week

At a cost of 10.00 my Sphincter wins very time


CCR diveing is all about confidence.

A fresh fill inspires confidence

No its absolutely not necessary and theres no scientific reasoning to it.

Its just nice to enjoy the dive without worrying


Welding grade o2 check no problem

Old cells Check i can manage that

Clumped lime errrrrrrrrrrrr sorry no

notdeadyet
15-05-2018, 08:16 PM
I'm not sure confidence is a particularly great asset. Both my co2 hits were on fresh lime. Being confident in the scrubber made me less likely to attribute what was happening to co2 and I ended up staying on the loop far longer than I should have. It's fresh lime, can't be co2...

Mark Chase
16-05-2018, 05:30 AM
I'm not sure confidence is a particularly great asset. Both my co2 hits were on fresh lime. Being confident in the scrubber made me less likely to attribute what was happening to co2 and I ended up staying on the loop far longer than I should have. It's fresh lime, can't be co2...

Good point, and one I often make for cells

But the fact remains Ill enjoy the dive less if I get in concerned

Bigger issue is, If I get in concerned enough times and get away with it, my concern will fade and ill become complacent

Its catch 22

As I said before, old cells are simply not a problem for me as i am confident i can manage that type of failure

But when it comes to C02, I know its a crap shoot and no amount of skill and experience can deal with C02 narcosis. So I try to minimise the risk.

Which in no way detracts from the valid point that you can still get a hit on a fresh fill,

Just IMHO its less likely.


The BIG thing for me is the number of times I have emptied my scrubber the day after a dive and found it to be a crusty solid lump on top or in clumps.

NOT conducive to confidance.

matt
16-05-2018, 09:30 AM
Each time you pack a scrubber there is some risk that you fuck it up.

How many people with CO2 issues (discounting retainers) had them because of assembly issues rather than over-use?

From my (tiny) experiments there is so much contingency at the CE level of testing it's almost unreal.

I didn't see anything in the OP that suggested keeping and reusing the scrubber was for economic reasons? Anyone diving CCR who is concerned about the cost of lime, cells or batteries needs to toss the unit onto eBay right away as CCR diving is not for them.

Matt.

matt
16-05-2018, 09:33 AM
The BIG thing for me is the number of times I have emptied my scrubber the day after a dive and found it to be a crusty solid lump on top or in clumps.

NOT conducive to confidance.

Over-packed? From what I have read when you over-pack you crush the lime and cause dust. Dust gets wet and causes "clumping". Under-pack gives channelling! Not sure clumping actually makes any difference to anything (I think Dave tested over-pack WOB and reported it was no problem).

Matt.

notdeadyet
16-05-2018, 10:36 AM
I used to get lumpy lime a lot on the KISS. I'm pretty sure it was due to a combo of over packing and water traps not being the greatest. Never really have it on the Mk15.

nigel hewitt
16-05-2018, 11:17 AM
I have always put my CO2 hit down to packing too loosely and then driving it down to Portland and it settling and becoming loose.
Hence I probably overpack these days.

Turbanator
16-05-2018, 12:29 PM
I used to get lumpy lime on my kiss too, and the shop fmcl Inspo classic that I crossed over on, that also used to get a tablespoon of water in the bottom of the scrubber.

My vision is dry, apart from condensation in the head and has yet to clump in the few (20ish) dives I've done with it.

Sent from my SM-G930F using Tapatalk

Paulo
16-05-2018, 12:40 PM
I tend to overpack to overcome settling in transport as I pack at home and drive the unit to the divesite assembled.

I do get clumping but have never noticed a change in WOB or had co2 issues .... yet

graham_hk
16-05-2018, 12:45 PM
Sorb is over rated - I have had some lovely dives without it (saves £10 too - bonus)

matt
16-05-2018, 01:35 PM
Sorb is over rated - I have had some lovely dives without it (saves £10 too - bonus)

All my OC diving was without sorb too.

iamyourgasman
17-05-2018, 05:46 AM
I get my assistant to change the scrubber when the inhaled CO2 goes above 0.4 KPa when using flows around 0.6-0.8 L/min (this is what you have in from your CMF or a total flow/min from your solenoid). By this time the change of colour is around halfway through the scrubber indicating the usage. In between uses days/weeks sometimes months pass, depending on which theatre we are working in...

In the rEvo I keep the partially used scrubbers packed in double insulation (ziplock bag plus other plastic cover) in the garage, longest time was 3 months.

I do have a friend who filled his scrubber ďfreshĒ but from a very old tub of lime (First opened 1 year+ before) and proceeded to have a CO2 hit. So watch out not just for old scrubbers, but also for long tim open tubs.

And please, please DO NOT ATTEMPT to use medical grade CO2 absorbents = suicide mission underwater!

Mark Chase
17-05-2018, 07:10 AM
Sorb is over rated - I have had some lovely dives without it (saves £10 too - bonus)

Me too, but my one and only C02 hit was on OC, so sadly I figured on many occasions, the CCR Scrubber its self has very little to do with C02 hits :(

On my DIRF (first one) course the GUE instructor Rich Walker told a good story about him getting a C02 hit in a cave on OC

simon mitchell
15-06-2018, 09:20 PM
Think Simon Mitchell has a paper on this but can't find the link

Hi Jon,

It is being published this month. The Eurotek fund is going to facilitate immediate release and will provide a link within the next couple of weeks.

Simon M

BluDL
03-03-2019, 09:03 PM
for me, if I am doing 60m or so - I will do it on a new fill. If shallow I will reuse a cannister that has done less than 2 hrs diving, although I do worry about channeling caused by the sorb clumping together when it is spent and subsequent vibrations of a long car journey. If it is30mins to a local pit to do 20m I am less concerned but it is a consideration. In between dives I put my cannister in a plastic bag (with the wire to temp stick leading outside the bag and then I knot the top. I will keep this 3 weeks max. I them put all of this in a big Tupperware style sealed container and put that well away from heat and varying temp.

simon mitchell
18-03-2019, 10:14 PM
Sorry team.

Forgot to do this. The sorb storage paper can be downloaded here:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6156827/

Simon

iamyourgasman
20-03-2019, 07:56 PM
Sorry team.

Forgot to do this. The sorb storage paper can be downloaded here:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6156827/

Simon

Thanks very much Simon!