I couldn't help myself and took the "worst" R109 apart tonight
As suspected the soft parts are toast; the diaphragm cover crumbled when I took it out (it was stuck pretty good); the exhaust T came off with some care, but has dry-rot all over; the exhaust valve was completely stiff and crumbled. Surprisingly the diaphragm - one of the old, black ones - is still supple. Go figure.
The front cover is a bit beat with lots of small scratches - most of them not through the chrome though. The back cover has a few scratches and some chrome wear where the soft parts were. The inside of the back cover has lost pretty much all of the chroming and is dark gray with some dark, bare brass patches.
The inner, small parts are all in fairly good condition; the orifice is old style chromed brass, and the adjustment knob is old style also with full diameter between the threads and the o-ring groove.
I gave all the bits a soak and wash in mild dishwashing solution and got much of the crud off. I then gave it all a bath in 50/50 vinegar solution - which didn't do too much of a difference, other than further expose/show off the bare brass inside the back case.
All in all, lots of fun, and I think with some fresh parts, this would end up a fully functioning regulator. I'm also pleasantly surprised at how simple the design is. I think that with some more reading (I bought both Vance Harlow's book and Regulator Savvy) and a some practice runs, I'd be comfortable rebuilding one of these myself.
Questions:
- is it possible to exchange the roll pin for the newer style D-clip?
- how about re-chroming the cases and the adjustment knob? I realize there are thickness issues in particular for threaded parts/sections.
Thanks all for getting me started in this, with all your excellent tech posts and advice.
Henrik
