It finally happened - my CCR tried to kill me

[cathal]

To all of you that have taken the time to post in this thread, I thank you. Both for your contribution and for keeping things so civil.

I felt like I learned a lot from what happened. I feel like I have learned even more from this discussion. I will definitely be doing some things differently in the future.

Thank you very much for a well written incident report with exceptional detail for us all to benefit from and is searingly honest. It goes to show that you have a learning attitude to your CCR diving and are willing to acknowledge their mistakes.
As an aside, I also experienced difficulties with that damn battery box getting in the way of the lid when putting it on. I found that cutting away the cable tie for the LP hoses to the box, allowed me more room to move the battery box when putting the lid on as I could move the LP hoses, and that with this extra room to move the LP hoses, all I had to do was slide the battery box back in under the lid when the lid was on fully. I found that by doing this it helped getting the lid down far enough that the retaining bolt would screw through the retaining nut each and everytime. Just my 2c.

Safe diving

 

[stuartv]

Thank you very much for a well written incident report with exceptional detail for us all to benefit from and is searingly honest. It goes to show that you have a learning attitude to your CCR diving and are willing to acknowledge their mistakes.
As an aside, I also experienced difficulties with that damn battery box getting in the way of the lid when putting it on. I found that cutting away the cable tie for the LP hoses to the box, allowed me more room to move the battery box when putting the lid on as I could move the LP hoses, and that with this extra room to move the LP hoses, all I had to do was slide the battery box back in under the lid when the lid was on fully. I found that by doing this it helped getting the lid down far enough that the retaining bolt would screw through the retaining nut each and everytime. Just my 2c.

Safe diving

Thank you.

To be clear, the battery box was not causing any problem with getting my lid on. When I try to put the lid on and it doesn't go on all the way, that is the first thing I check and, of course, trivially easy to push into place to allow the scrubber cover to seat.

The problem with the lower shoulder of the O2 cylinder. The shoulder nearest the 1st stage reg. That is what the scrubber cover was hitting that prevented it from seating all the way.

I am familiar with the rubber band trick around the battery box and scrubber cover bolt, but I haven't done anything like that yet on my Micro. I think I will actually make a loop out of thin bungee cord to do the same thing. With the original battery box, it stayed in its spot easily when I had the cover and cylinders off. With the new battery box, I clearly have a very slight bit of twist in one of the cables going from the battery box into one of the CLs. That is making it want to lean a bit out of position when there is nothing to help it stay in place. I think a loop of bungee around it and the scrubber cover bolt will fix that right up.

 

[beldridg]

The problem with the lower shoulder of the O2 cylinder. The shoulder nearest the 1st stage reg. That is what the scrubber cover was hitting that prevented it from seating all the way.

Thanks for the incident report. I've learned a few things reading through the responses.

On this topic, I always put the cover on without any tanks on the unit. I think part of the reason that I just naturally do this is that I use the "travel" style tank brackets which makes it very easy to install and remove tanks and it does allow me to do a really good visual check to ensure the lid is on and the battery box isn't getting in the way (in addition to a pos/neg test). That is a lot tougher to do with tanks on the unit.

Based on other responses, I'm going to also investigate looking at cell mV readings during the pos/neg tests.

- brett

 

[stuartv]

Thanks for the incident report. I've learned a few things reading through the responses.

On this topic, I always put the cover on without any tanks on the unit. I think part of the reason that I just naturally do this is that I use the "travel" style tank brackets which makes it very easy to install and remove tanks and it does allow me to do a really good visual check to ensure the lid is on and the battery box isn't getting in the way (in addition to a pos/neg test). That is a lot tougher to do with tanks on the unit.

Based on other responses, I'm going to also investigate looking at cell mV readings during the pos/neg tests.

- brett

I have come to a SOP for myself of putting the cylinders on before the scrubber cover. I mostly dive dry, which means I need a little extra weight on my unit when diving. I use a 4# soft weight stuffed in between the dil cylinder, the scrubber, and the scrubber cover. It is MUCH easier to put that in place with the cylinder on and cover off than with the cover on and the cylinder off. With both on, I can't fit it in there. If I could, then I would have to worry about it falling out during a dive....

It is very easy for me to tell if the scrubber cover is on all the way, just from how far the scrubber cover nut screws onto the bolt. My problem this time (I believe - still not CONFIRMED) is not that the cover wasn't on all the way. It was (I believe) that the O2 cylinder was pressing against the side of it - not from underneath. It wasn't preventing it from seating all the way. I believe it was just pressing sideways against, which I think was enough to allow a very slow leak. If the lid wasn't seated all the way down, I think that would have been quite obvious during the negative test.

 

[beldridg]

Maybe try one of these:

http://www.dsix36.com/revo-scrubber-weight.html

All my diving since Covid has been dry as well and given the water temps here (52F @ bottom, 57F at 20'), I'm guessing that I'm wearing heavier undergarments.

Depending upon how much and what type of bailout I use, I tend to just put the weights on the tray on the top of the unit.


- brett

 

[stuartv]

Maybe try one of these:

http://www.dsix36.com/revo-scrubber-weight.html

All my diving since Covid has been dry as well and given the water temps here (52F @ bottom, 57F at 20'), I'm guessing that I'm wearing heavier undergarments.

Depending upon how much and what type of bailout I use, I tend to just put the weights on the tray on the top of the unit.


- brett

I have thought about ordering one of those weights from Don. But, since he was the one that suggested the 4# soft weight to me... and it was cheap.... and it works.... I haven't gotten around to ordering one.

You may indeed be wearing heavier undies that I do. I have plenty of bioprene to help keep me warm. But, I've gotten in over 100 dives in the last year and most of those have been in a local(-ish) quarry that was 50F last time or Lake Jocasee which has been as low as 49F. Usually, I wear a 150gsm Thinsulate 1-pc suit under my drysuit. Lately, with a 12V heated shirt as well...

I have the rEvo stand that came out last year on my Micro. That plus the 4# soft weight is generally all I need. If it's cold salt water, then I might add a little more in the trim weight pouches I have attached to my cylinders. I have never used any weight on the top tray. I don't have the standard pouch up there and I'm not sure if I even HAVE the standard pouch anywhere.

 

[Zebra 1]

My highest praise in opening up the way you have in this forum. Myself and I'm sure many others will learn from your experience and may very well save lives.

Much of the talk so far has been on the danger of a caustic cocktail if you had gone head down. I am purchasing an O2ptima which can use loose sorb or an Extend Air cartridge. I know the EAC will afford some benefit against a caustic cocktail but I would like to hear others more experienced opinions. Would the length of time resulted in a caustic mix anyway? I know there are reports that an EAC can be easier to over breathe, has this ever been actually tested?

 

[rjack321]

Would the length of time resulted in a caustic mix anyway? I know there are reports that an EAC can be easier to over breathe, has this ever been actually tested?

What do you mean length of time? the optima has an inhale counterlung which is vastly different than the revo inhale CL

There are numerous reports of overbreathing EACs. There is no empirical "over breathing" test, you are stuck with the anecdotal evidence which is not favorable.

 

[KenGordon]

Thank you.

To be clear, the battery box was not causing any problem with getting my lid on. When I try to put the lid on and it doesn't go on all the way, that is the first thing I check and, of course, trivially easy to push into place to allow the scrubber cover to seat.

The problem with the lower shoulder of the O2 cylinder. The shoulder nearest the 1st stage reg. That is what the scrubber cover was hitting that prevented it from seating all the way.

I am familiar with the rubber band trick around the battery box and scrubber cover bolt, but I haven't done anything like that yet on my Micro. I think I will actually make a loop out of thin bungee cord to do the same thing. With the original battery box, it stayed in its spot easily when I had the cover and cylinders off. With the new battery box, I clearly have a very slight bit of twist in one of the cables going from the battery box into one of the CLs. That is making it want to lean a bit out of position when there is nothing to help it stay in place. I think a loop of bungee around it and the scrubber cover bolt will fix that right up.

This all sounds very complicated.

 

[Zebra 1]

What do you mean length of time? the optima has an inhale counterlung which is vastly different than the revo inhale CL

By length of time I think the sorb in an EAC will also create a caustic cocktail if left soaking long enough.

How long it has to soak, and to how caustic vs loose sorb I have no idea(and would love to know).