Restoring Vintage Regs ?

[Vintagediver]

I just acquired my first DW Mistral to add to my two hose collection, and while working on it the other night I had a few questions come to mind. Do any of you have any suggestions on what to use to clean the sintered filter in the HP inlet. I have several NOS filters in my "Stash"; but was wondering if there are any chemicals that would properly and safely clean these filters. I am also wondering if there are any lubricants that any of you use on these reg parts when restoring and re-assembling these vintage regs. Any input that any of you might have would be greatly appreciated. This Mistral that I just acquired was in great shape; but as always I like to completely tear them down for inspection, cleaning & polishing, and re-assembly. I'm eagerly awaiting the arrival of one of Bryan's DW Mistral rebuild kits that I ordered a few days ago so I can beging the re-assembly and adjusting to get this "Diamond In The Rough" ready for some action this spring. Safe Diving To All of You! Terry Stevens

[duckbill]

Terry Stevens, Terry Graf here-
from a post of mine a ways back, with some editing/correcting:

Lever height on a Mistral is critical, as the diaphragm can act as a counterspring. Set too high, the seat spring may be overcome by diaphragm pressure at low tank pressures, causing a freeflow condition. Set too low and there will be excessive freeplay and vibrations, resulting in funny, groaning sounds on inhalation. At least, these have been my observations on my Mistral during adjustment. Trial and error is about the only way to adjust the Mistral with any degree of certainty. Once the levers are in place and pre-adjustment is complete (lever top flush with the rim of the box), just hold the boxes together tightly (with the diaphragm in, of course, and attached to a 300 psi air source) and check for freeflow. Then breathe off the inhalation port to check for resistance and noise. It should take very little effort to start airflow. Keep in mind that as you clamp the boxes together that the diaphragm probably will set a little lower still, so you may want to back the adjustment off just a tad. I set my Mistral at a tank pressure of about 300 psi until it just barely freeflows, then adjust the adjusting nut up (lever down) maybe an eighth of a turn more. Works for me. Finally, water test it. The regulator should not freeflow until the mouthpiece is a couple of inches above the regulator.

[Nemrod]

WARNING

Just one thing and it has been discussed before----do not--do not breath directly from the inhalation port. This could easily cause a lung over pressure and could actually be fatal. Very, very dangerous. Yeah, if you are careful you might get away with it. Put the hose on the port and a mouthpiece so that high pressure air is relieved by the exhaust cage valve--not a blow out in your lung!!!!! That is a high pressure venturi pointed right into your lungs when you put your mouth over it to inhale---No--NO!!! In a Mistral the other side of that valve is tank pressure. Even with a DA or RAM---still--it could kill you.
If you don't believe me then go ahead but please leave your vintage collection to me--Nemrod.

Nemrod

[duckbill]

Thanks James, I wasn't aware of the risk.

[1969ivan1]

Me either....I need not to do that again

[Nemrod]

Just for the sake of discussion, if you were to take a slow and gentle breath it would probably be OK, if you were to take a sharp, strong breath the venturi action would pull the diaphram down rapidly initiating a powerfull flow of air.
I would be exceedingly careful about applying any sort of high pressure air to your lungs or even your skin. Bad things can happen really fast. Compressed air is not a toy. When the regulator has the hoses attached they absorb the shock of the air flow and the exhaust valves allow a place for excess air to bypass your lungs as does the exhaust valve act in a single hose.
Wrapping your smackers around a Mistral inhalation port and taking a good breath could be your last breath with no place for the air to relieve to except through the lung wall and into the pleural cavity etc.

Imagine taking a compressed air nozzle and sticking it your mouth and pulling the trigger---Darwin award time!!!

James

[Vintagediver]

Thanks for your replies. The info regarding the adjusting of this reg will be very helpful since this is the first Mistral I've owned. I also found the warning about breathing off of the reg without a hose and mouthpiece very interesting. I never really gave this situation a thought but it sure makes a lot of sense, and you can bet I will take your advice. Thanks guys for your input and Safe Diving to you! Terry