Scubapro S620ti, "super-flow" hoses & swivels

[rsingler]

I love you, halo. You'll argue about anything, lol!

 

[rsingler]

But I'll agree with you on one thing: the D-series seats never freeflow after sitting around. That spring is so light!
Not like S600 or G250. Tune for 0.9", and let it sit for 3 months, and bingo: you've got a tiny freeflow.

 

[rsingler]

This stuff breaks my heart: dying regs, that are a lot younger than my Mk10, just because they aren't rinsed properly, or can't be environmentally sealed.

The left one, a Mk 20, is pitted where the piston o-ring sat against the land, probably with accumulated salt crystals.
The right one has vertical scratches in the piston land where flecks of sand or coral were trapped between the o-ring and the wall of the reg, and moved up and down a few millimeters every time the reg was pressurized, and up and down a little less than that with every breath.

So sad!

 

[Rusty Shackleford]

I do the same thing with my Atomic seconds - let them sit for hours in the sink. I just keep the first stage on the counter above it, and let the second stage dangle afterwards to drain any water out of the hose, due to the open valve of the seat saver feature.
You're a braver man than I, if you soak your first stages with just the seal that is screwed down between the yoke knob and the filter. I soak firsts that need it on a pony tank. But then my Atomic firsts don't need anything but an exterior rinse since they're sealed. It's why I won't use the Mk25: you can't seal it, and I go nuts when I service other guys pistons, and the o-ring land is all scratched from coral sand that has gotten stuck in the little space at the edge of the piston. I even seal my Mk10 with a DIY SPEC boot. It'll last forever!

Do you have to pack the chamber under the spec boot if you are not diving in cold or salt water?

 

[Rusty Shackleford]

This stuff breaks my heart: dying regs, that are a lot younger than my Mk10, just because they aren't rinsed properly, or can't be environmentally sealed.

View attachment 413144View attachment 413145
The left one, a Mk 20, is pitted where the piston o-ring sat against the land, probably with accumulated salt crystals.
The right one has vertical scratches in the piston land where flecks of sand or coral were trapped between the o-ring and the wall of the reg, and moved up and down a few millimeters every time the reg was pressurized, and up and down a little less than that with every breath.

So sad!

I have a used MK-20 that looks like the one on the left. Bought used. Still worked fine for years. I have the MK-25 replacement part for that one. I will upgrade it when the next service is due. Previous owner was a cave diver. I got chunks of limestone out of the chamber when I serviced it.

 

[rsingler]

Do you have to pack the chamber under the spec boot if you are not diving in cold or salt water?

I pack my chambers for warm water too. Just to keep the crap out of the environmental chamber. My piston lands are as smooth as the day I bought them.
In contrast, I've serviced a half dozen $1500 T2's with tiny scratches up and down the piston land. Not as bad as those pics above, but their regs won't last 25 years.
Shops hate doing it because it's messy. Costumers balk at the extra $20-60 for Christolube.
But I pack every piston that allows it, and as some other threads have discussed, even use a DIY SPEC boot on my Mk10.

Cheers!

 

[BoltSnap]

I pack my chambers for warm water too. Just to keep the crap out of the environmental chamber. My piston lands are as smooth as the day I bought them.
In contrast, I've serviced a half dozen $1500 T2's with tiny scratches up and down the piston land. Not as bad as those pics above, but their regs won't last 25 years.
Shops hate doing it because it's messy. Costumers balk at the extra $20-60 for Christolube.
But I pack every piston that allows it, and as some other threads have discussed, even use a DIY SPEC boot on my Mk10.

Cheers!

How do you insulate/seal the Mk25 first stage?

 

[halocline]

I have a used MK-20 that looks like the one on the left. Bought used. Still worked fine for years.

I've had a few MK5/10/15/20s that had a similar amount of corrosion in the ambient chamber and have worked fine as well. I can usually get rid of most it with micromesh or silicone carbide paper. But I have had a few that were bad enough to say goodbye to. In rsingler's case, I suspect he's working on a customer's regulator and is hesitant to let it out of the shop with any visible corrosion in the ambient chamber.

Recently I acquired a MK10 with corrosion in the piston head groove, and that one I couldn't get to stop leaking. Thankfully I have a stash of MK10 pistons.

 

[rsingler]

How do you insulate/seal the Mk25 first stage?

You can't.
It's why I still dive Mk 17's on the diaphragm side, but have switched to Atomic for pistons. Scubapro is just too unresponsive these days.

 

[rsingler]

As for the why, it's because there's no groove in the Mk25 to accept a SPEC boot.