mares mr12 as stage bottle reg

i just got a 40 cu ft stage bottle. I am slowly transitioning toward "tech" training. Would a mares MR12 work as a enrty level stage bottle reg. My primary is a Apeks DS4/TX50, I'd like another one of those, but don't have the cash for it, as I want a bp/w next. I can get the mr12 used, fairly cheap. I would plan to eventually add a O2 ready TX40 for the stage, once I have more of my kit assembled. I will be diving colder water 40 degrees and above in the great lakes, down to 130. For now, until I finish my training, the stage bottle, is just for weight/trim practice and as redundant air supply on NDL dives.

The MR12 works and routes quite nicely on a stage bottle, my brother uses those on his bottle(s). (I will try to get some pics for you)

For a stage reg, you do not anything super fancy. Just a simple bullet-proof reliable reg will do, after all you will most likely not be breathing it at major depths, so as long as the reg is a good breather go for it.

The MR12 is a very good balanced diaphragm reg. I would be curious to know the price you are looking at. You can currently get a brand new Scubapro MK2+ with R190 from Scubatoys.com for $179.95. This is about as bullet proof a reg as you can get and is used by a great many tech divers.

Last time I checked the MR12/Proton (the Proton is nice and small) goes for around $250. You can get it with the Rebel (bigger reg) for about $200. However, you can't really go wrong with Apeks, but I would pair it with the DS4 instead.

MR12 will work great. It's a workhorse reg. Easy to get parts for and easy to rebuild. I'd use on in a heartbeat.

I've been using MR12 Axis regs for stage/deco bottles during the past four years. They are very simple to oxygen clean, and the fact that there are relatively few O-rings is an added plus.

Just remember that a reg using high levels of oxygen blends should be initially pressurized very slowly. I press the purge button while slowly opening the valve. Rapid pressurization leads to a lot of generated heat, and the possibility of some serious problems. In fact, you should always use this procedure, as it lessens the wear on the high pressure seating mechanism.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine