Eric Sedletzky
Contributor
A guy gave me a very old all metal Scubapro MK3/108 once (that was the model prior to the Mk2....yeah I know, weird numbering) Anyhow it was so corroded and green that I thought it was just going to be wall art. The body of the first stage and the metal second stage were so bad that almost all the chrome was rotted off and the brass underneath was totally pitted with verdigris all over it. One day I decided to take it apart piece by piece and see just how bad it really was. Mind you, this guy got it used in 1970, used it until 1990, never cleaned or soaked it once, and never had it serviced.
He finally hung it up on a nail in his garage where it lived until I got it in 2010.
The screws to the second stage cover were corroded/welded shut so I had to drill those out (the second stage was a chore), but the 1st stage actually came apart fairly easily. I was surprised to find that it actually wasn't as bad as I though it would be. It was completely dried out, no lubrication at all. But it came clean with a good vinegar soak. In those MK3-Mk2 unbalanced piston type regs there's only one moving part (the piston), a spring, a few shim washers, a high pressure seat, and 2 O-rings. The O-rings I found at a hardware store, the HP seat I flipped over, I lubed everything up then put it back together and it worked fine! I couldn't believe it.
It was easier than changing a tire on my truck.
Later I decided to sand off any of the chrome that was left and I polished out the brass so it looked like a piece of jewelry, like a gold anniversary reg.
So your 10 yo MK2 is probably like brand new compared to what I had.
I also have a MK2 and it's very similar inside to the MK3 - some newer different sizes of things, but same basic design.
In fact, those MK2's are so simple and so bulletproof that I wouldn't hesitate to use that reg for the rest of my life for the simple dives I do these days.
He finally hung it up on a nail in his garage where it lived until I got it in 2010.
The screws to the second stage cover were corroded/welded shut so I had to drill those out (the second stage was a chore), but the 1st stage actually came apart fairly easily. I was surprised to find that it actually wasn't as bad as I though it would be. It was completely dried out, no lubrication at all. But it came clean with a good vinegar soak. In those MK3-Mk2 unbalanced piston type regs there's only one moving part (the piston), a spring, a few shim washers, a high pressure seat, and 2 O-rings. The O-rings I found at a hardware store, the HP seat I flipped over, I lubed everything up then put it back together and it worked fine! I couldn't believe it.
It was easier than changing a tire on my truck.
Later I decided to sand off any of the chrome that was left and I polished out the brass so it looked like a piece of jewelry, like a gold anniversary reg.
So your 10 yo MK2 is probably like brand new compared to what I had.
I also have a MK2 and it's very similar inside to the MK3 - some newer different sizes of things, but same basic design.
In fact, those MK2's are so simple and so bulletproof that I wouldn't hesitate to use that reg for the rest of my life for the simple dives I do these days.
