Storing part-used scrubbers

[nickb]

At last year's Eurotek, Simon Mitchell gave a presentation on storing partially-used scrubbers.

Until then, I'd always been happy to leave mine on a shelf in my garage but he showed some convincing evidence that storing them in an air-tight container would keep the lime from deteriorating somewhat.

After that, I started keeping mine in a plastic bag when it wasn't in my unit. However, I recently bought a vacuum sealer for keeping food fresh for longer and preventing freezer burn.

Turns-out, the bags are just big enough to fit my JJ scrubbers. Here's my radial:

 

[Randy Thornton]

Nice Nick! I like it!

 

[Jeff Pack]

I have some tupperware containers that fit my meg scrubbers perfectly

 

[Ben Field]

How long are you storing it to make that worthwhile?

I give it a fortnight in the unit, no more diving- bin it and start again, its too cheap to worry about compared to charter fees, bailout fills, fuel to drive to coast, accommodation etc.

 

[daviesjez]

We've been doing exactly the same post EuroTek, 2 scrubbers fit in 1 vacuum seal bag a treat...

 

[Jeff Pack]

Stored airtight, I've left scrubbers for months

 

[nickb]

How long are you storing it to make that worthwhile?

I give it a fortnight in the unit, no more diving- bin it and start again, its too cheap to worry about compared to charter fees, bailout fills, fuel to drive to coast, accommodation etc.

Months. That radial was packed in October and hasn't been dived yet. The lime is probably better off in there than in a Sofnolime keg.

However, I've kept a part-used scrubber for many months and been happy to continue using it.

What's all the 'make that worthwhile' stuff about? Takes less than.5 minutes.

 

[MegDIR]

I use stretch wrap around my 8lb Meg radial, then place into a waterproof bag to seal, then place into my tall can with lid thus squeezing out any trapped air around the radial: no air circulation at all. Lasts for months.

 

[bazSXD]

Simple ... keep it in your fully assembled unit with the BOV closed - its airtight ! ..... regards Baz

 

[Captain Starfish]

I don't keep it in my unit because I want my unit wide open, in bits, with a chance to dry out between weekends.

I couldn't be arsed with the mucking around of the vacuum bagger. But I find a small dry bag (the type that you furl the end of to seal, then clip shut the corners with attached fastex clips to form a handle) is quick, simple and effective.

 

[nickb]

Simple ... keep it in your fully assembled unit with the BOV closed - its airtight ! ..... regards Baz

I have two scrubbers. There's only room for one in my unit

 

[Tim1]

I don't keep it in my unit because I want my unit wide open, in bits, with a chance to dry out between weekends.

I couldn't be arsed with the mucking around of the vacuum bagger. But I find a small dry bag (the type that you furl the end of to seal, then clip shut the corners with attached fastex clips to form a handle) is quick, simple and effective.

That's my approach too but I also put the scrubber into a pedal bin liner before slipping it in a dry bag. As I like to 'post-prep' my units as soon as possible after diving, a ready solution is important.

To add to the OP, I recall that Simon actually reported an extended service duration by a part used scrubber which had been sealed for one month, when compared with an unused scrubber...

As iQsub canisters can be sealed with a canister lid, rather than the head, I sometimes leave a part used scrubber in the canister as it serves to differentiate it from other unused scrubbers (I have eight scrubbers of various and similar sizes and six canisters). A scribbled note to myself popped in the canister serves to remind me of the degree of usage.

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[nickb]

To add to the OP, I recall that Simon actually reported an extended service duration by a part used scrubber which had been sealed for one month, when compared with an unused scrubber...

Yes, this was part of the presentation. The suggestion that a part-used scrubber, sealed and left on a shelf for a month seemed to offer a greater duration than a similarly part-used one stored overnight.

It's interesting but probably academic for most, aside from the few that are happy to let a tempstick dictate when their lime needs changing.

 

[Tim1]

I stand corrected. It was not a comparison between unused and part used, but between part used in sealed and unsealed storeage

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[Vanny]

Is there a write up on Simons findings to have a read of somewhere ?

 

[Tim1]

You may find a paper on Rubicon

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[MadUKDiver]

I don't think the paper has been published in a widely available source yet.

If you didn't see the presentation then you need to be careful drawing conclusions without having heard Simon's caveats and cautions.

This is what I understood from Eurotek 2016...

Test conditions and results
Inspired CO2 "limit" chosen for the testing 1kPa (10 millibar), ventillation 44 L/min, CO2 production 2L/min (6 MET), test at Ambient Atmospheric Pressure. 797 Sofnolime. Inspiration Evo+ gave approx 200 min continuous duration under above conditions.

Storage environment - 20°C, 60%RH, 0.03% CO2

After 28 days stored open - 378l CO2 [~185 mins]
After 28 days stored in a sealed bag - 473l CO2 [~225 mins]

90 mins use followed by 24 hours stored open - 479l CO2 [~230 mins)

So an approx difference of 40 minutes between open and sealed scrubber after storage for 28 days.
And maybe 25 minutes "increase" in duration between continuous and interrupted operation

Simon's Outcomes
Storing a scrubber between dives can influence CO2 absorbing capacity

Prolonged storage (28 days)
* Sealing a scrubber from atmosphere increases scrubber endurance

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

An excellent piece of work by Simon et al. Addresses the fears of some and helps others adapt their behaviour ... whereas my longest storage of a part used scrubber (open) was 184 days I now store in a poly bag if I'm not going to be using the scrubber for more than a week.

There was some discussion at the end of the session regarding the observed potential "increase" with storage. Simon did not want people to overreact to this. I think it was Neil Pollock who suggested this may be due to the 3 reaction stages of sofnolime running at different speeds. Practically it is of little / no use to recreational divers so unlikely to be an active line of further research.

 

[Ben Field]

Months. That radial was packed in October and hasn't been dived yet. The lime is probably better off in there than in a Sofnolime keg.

Fair enough.

However, I've kept a part-used scrubber for many months and been happy to continue using it.

What's all the 'make that worthwhile' stuff about? Takes less than.5 minutes.

"Worthwhile" as in its a few £'s only, why even raise the question of whether its safe to store, as you say its moments to repack, why not just bin it if partially used and start from scratch?

I've moved to only packing my scrubber when the trip looks to be on- 12-24hrs before diving at most, once out of the can its "used" IMO


FWIW- I'm not saying this isn't safe at all, it would certainly seem it should be. I just like removing as much doubt as possible.

 

[Bobjr]

With a fill costing about the same as a pint or two ... I am left wondering why bother ... but then it is you Nick

 

[Wol]

My concern is more about channeling when leaving the scrubber stored. Also maybe it's just a peace of mind thing - but I have a concern leaving a prepacked scrubber left unattended for a period of time that someone may have knocked it/dropped it / tampered with it etc...

Be interested if the paper looked at channelling due to leaving a scrubber stored on its side...