Scubber sofnolime settlement

[Pierre Farrugia]

Hello all,

Today after a dive using my YBOD, now with 100min of scrubber used, removed scrubber to dry and noticed that some settlment has taken place. The sofnolime from one side (about 2 inches of circle) has settled down by about half an inch and other areas are ok. Has this ever happened to you, or your,or on your UK roads this does not happen, did I packed it wrong, not enough tapping? Or anything else? Should I scrap the whole lot?

[greekbird]

the advice from Mr. Greekbird is to scrap it...and pack it fresh. you have 2 choices either pack it loose and risk a Co2 breakthrough or pack it tight and suffer an alledged increase in 'work of breathing' (never noticed it btw), even if there was an increase in WoB thats certainly preferable to the former... particularly if you have to bail-out and havn't got a CC/OC mouthpiece.
HTH

[beanie]

um

I owuld bin it and work out what happened to it
got a picture of it by any chance?

dropping 1/2" is serious sounds like it was loose

[Decodiver]

Originally Posted by Pierre Farrugia

Hello all,

Today after a dive using my YBOD, now with 100min of scrubber used, removed scrubber to dry and noticed that some settlment has taken place. The sofnolime from one side (about 2 inches of circle) has settled down by about half an inch and other areas are ok. Has this ever happened to you, or your,or on your UK roads this does not happen, did I packed it wrong, not enough tapping? Or anything else? Should I scrap the whole lot?

Hi Pierre,

Bin it and pack the scrubber tighter.

I always fill my scrubber twice to make it tight, I'll explain.

I fill it and put the scrim and spider on and tap it down. When it is tight and has gone down about three quarters of an inch, I remove the spider and scrim and top it up and start over.

My rule is so that you can just preess the lime with your finger and it makes a slight indent, that's when it is tight enough.

As mentionned above, a bit more WOB is preferential to CO2 breakthrough from channelling.

Cheers

Dave Cooper

[nigelH]

Originally Posted by Decodiver

As mentionned above, a bit more WOB is preferential to CO2 breakthrough from channelling.

Definitly.
Some time ago there were people advocating a very loose pack (tip it in, quick shake, screw the spider on, fit it). This has (allegedly) been implicated in a recent channeling incident. As working it down well (pat pat turn pat pat turn, tighten spider - repeat for ever) just does not increase the work of breathing noticably and Cardon Dioxide is not your friend take your time an be assured it isn't going to move after you fit it.

If it sinks it was packed far too loosely. I'd throw it out rather than resettle it after breathing. It's one of those things that probably isn't a problem but I don't juggle with chainsaws either.

nigelH

[Pierre Farrugia]

Originally Posted by beanie

um

I owuld bin it and work out what happened to it
got a picture of it by any chance?

dropping 1/2" is serious sounds like it was loose

I will post a pic tomorrow, It dropped only in the red shaded areas

[Mark Chase]

I would say its not packed down enough. I half fill my one tap it down then fill and tap it down again. I turn tap and clamp down forever and if the spider goes more than 5mm below the lip I put some more in. I screw the thing down pretty tight and you can just depress the lime with a firm push of a finger. Then I pick up the scrubber and shake it to see if it rattles.

I don’t think I could pack it much tighter but I haven’t noticed a problem with WOB. I drive it to the dive site stood upright so the springs take the shock of any bumps.

Before I got a CCR loads of things scared me. Now I am only afraid of CO2.

ATB

Mark Chase

[Pierre Farrugia]

Hello,

Today I checked scrubber again, but this time turned it with spring facing up and tapped it and turn, now bottom is ok but if you try to tighten nut more down it cannot due to thread finish so I think I did the mistake not to fill it properly and needed more tapping. Now if I put in on spring it will take the space as there is about 5mm to 10mm loose, so I will have to scrap it what you guys think? Believe it or not this is after my 2nd rebreather dive during the course as everything happened from weather, buddy going abroad Xmas holidays Hopefully I will finish couse as I do it on Sundays!

[Padowan]

It certainly sounds like it was not packed properly. If you've bottomed out the thread on the nut, then there was definitely not enough lime in the can.

I use the half-fill-tap-tap-turn-tap, fill-tap-tap-turn-tap, top-up-tap-tap-turn-tap tecnique. And keep tapping and turning and tightening the nut until the bed is nice and firm both at the top and bottom, and also there is no sign on a rattle when you shake it.

Just a question, but if this is the 2nd dive on the course, are you using the lime fill that was in the unit when it was shipped? When I recieved my unit, the fill that was in the scrubber was terribly loosely packed.

[Pierre Farrugia]

The unit came empty and I filled it, altough not enough tapping