is this a death wish?

[Colin]

What is a grease cap?
[/quote]

Matt,

A grease cap is something reg manufacturers did years ago before they thought of dry enviro kits with double diaphragms. It consisted of a rubber cap that went on the top of the first stage and was filled with silicone fluid or silicone grease to prevent cold water from contacting the main spring and piston in piston style regs. Some manufacturers called them "anti-freeze caps". The old Poseidons used the same system, and many folks would fill them not with silicone, but with vodka, hence sometimes they're also called "booze caps" because after a cold dive you could take a shot of vodka from the reg and warm up. Some old US Divers regs also used silicone fluid in their first stages...they were marketed with the first stage name plus the word "supreme" as I recall, as in Conshelf Supreme.

Colin.

[matt t.]

Thanks Colin. I've heard of the booze caps on the Poseidons, and heard that some manufacturers used to require liquid silicone in first stages. I never put it together that silicone would keep things from freezing up.

[systematic.entropy]

RE: ScubaPro MK25/S600

I have been using this setup for about three years now, 1)MK25/S600 + 1)MK25/S550. The only time I ever had a free flow problem was diving Bradford Beach in December about two years ago. I think the surface temp was about 13 degrees, and I don't even want to think what the wind chill was. Suffice to say, my wetsuit was frozen stiff before I was able to get it off in the parking lot. Even at that, it was controllable by just keeping the reg wet and out of the air. That was the only time it would start free flowing was bobbing at the surface. Once it got submerged (water was warmer than the air), the problem went away.

Yes, that's the only time I've had this reg. free flow, and it's been into Wazee and Lake Michigan well into October and November. So, I would say you're fine.

[settinggirl]

So do I have to check the IP often, i.e. does it have a tendency to fluctuate? 

[jeffberry]

I have mine checked twice a season.  Never really changes an it takes very little time to check.  Give me a bit more confidence in my gear.
  Jeff

[Vtach]

It shouldn't change greatly unless there is "tinkering" going on inside.  In that case you are likely to need a rebuild.

[oldtimer]

As long as your high pressure seat doesn't wear the IP won't fluctuate.  So, if you do six dives a year then have your reg serviced, non to worry.  If your like me and do 60 dives a year, you might want to check it once in a while.  It's easy to do.