Scubapro questions

[halocline]

Gee...I thought I started this thread to get some questions answered. I didn't realize I posted it on the classified section! LOL!
Anyway, what about the Mk20UL? Salt water & Al don't mix too well, so I'm curious if anyone knows if SP's "ceramic coating" on the Mk20UL works at all?

Sorry about hijacking your thread. I would not go for the UL. I have heard of some problems with corrosion on those, and honestly, I think it's a little gimmicky. It's not like you're carrying the thing up a mountain.

 

[wgmontgomery]

Not a problem...hope you guys work out a deal.
I thought the same thing. Metal & NaCl/H2O do not go well together, and Al does very poorly indeed. The "ceramic coating" would, in theory, help. I saw one for very little $$ but thought it best to pass as a close inspection of the pics shows corrosion.
Do you know if you can tell if a Mk20 has been upgraded to 25 specs?
Thanks!

 

[halocline]

The main differences between the MK20 and 25 are the external IP adjustment in the MK25 and the composite piston. I am now looking at a MK20TIS schematic I didn't know that I had that shows the composite piston and the upgraded parts for the externally adjustable seat retainer. Soooo.....it looks like there's essentially no difference between some late model MK20s and early MK25s. Go figure....

There's obviously no way to know what kind of piston is in the regulator until you take it apart. If you get a MK20 and it creeps, the composite piston is probably about $60. You can tell about the external IP adjustment by looking for a small hole in the middle of the seat retainer with a small hex set screw in it.

 

[wgmontgomery]

Do the older 20s have fins, too? The 20s that I've seen (& owned) were just a "barrel" w/o the heat sink fins.
THANKS

 

[Tbar]

The early MK25's didn't have fins