Vintage Double Hose

Got a AMF/Voit MR12 and a Dacor Dart.

The MR12 seems to have a real fanclub here, so I'd like to try and bring it back to life. The mouthpiece is shot, and it's missing the exhaust tee. The mouthpiece I could probably replace with a generic one, but are there any options on the exhaust tee?

Also, I saw that there is an MR12 rebuild kit available here. Is that all I should need to bring her back, mechanically, (assuming the main diaphragm isn't torn)? If not, what is the availability of the other parts, (diaphragms, etc.)?

The other reg is a Dacor Dart. Don't know much about Dacors, but I doubt there's the aftermarket support there seems to be for the Voit/USD regs. Any chance of rebuild parts for it? All the parts seem to be there, even the rubber ones.

Pics, (right-click and "view image" to see full image. Board seems to be cropping them):

Bryan's MR12 kits are a great first step in the restoration process. The regulator will breathe significantly better if you install a Mares Abyss 2nd stage diaphragm. They are composed of a very supple black silicone, that will last for decades with proper care and storage.

The 1st stage can be rebuilt using a Mares Tri-Material HP valve, along with a custom made pin. Or, an Aqualung version can be used with the existing pin. The length of the pin is critical, as it needs to be within 0.003"+- to operate properly. The high pressure assembly must be removed with a spanner tool that fits the a recessessembly's recessed holes.

One of the trickiest parts of rebuilding the 1st stage is that of removing and replacing the -006 O-ring in the balancing chamber. It takes a lot of patience to install the new O-ring until you get the "knack" for doing it.

As far as an exhaust tee... The exhaust tees that are found on any Voit/Swimaster regulator manufactured from 1970-1980 will work properly. The only exceptions are the ones found on the tilt valve 2nd stages, such as the Little Gem, and the MR12 II.

Greg Barlow

Hi Greg,

I think we are going to have custom spanner wrench for this application available soon. I will let him post when they are available.

I have been looking at the balance chamber and the Aqua Lung balance chamber is going to work with very easy modification and the addition of a couple of washers. The washers that we need are available from McMaster-Carr (in 304 or 316 stainless steel, or even brass). Using the modified Aqua Lung balancing chamber will make it a lot easier to service.

I will post some pictures in a few days after I get the washers to show the assembly.

I tried the Mares balancing chamber, but it will not work. The diameter of the head is to big and will not allow the installation of the snap ring.

I will talk to you mare later.

50, I have a couple of the AMF/Voit seconds like that restored, they are great little regs. Nice to see you here, welcome. You will find this is a fairly close group that supports each other and dive together when we can. Too bad you missed Portage last weekend, there was a fair group of us there......plan on attending Sand Dog next spring.

Greg, Luis sent me a drawing of the plug and I got the material for the plug and J valve seats yesterday..now if I can aVoit the wife and get some shop time in, more tools and parts may soon be available........you started it Luis.

luis wrote:Hi Greg,

I think we are going to have custom spanner wrench for this application available soon. I will let him post when they are available.

I have been looking at the balance chamber and the Aqua Lung balance chamber is going to work with very easy modification and the addition of a couple of washers. The washers that we need are available from McMaster-Carr (in 304 or 316 stainless steel, or even brass). Using the modified Aqua Lung balancing chamber will make it a lot easier to service.

I will post some pictures in a few days after I get the washers to show the assembly.

I tried the Mares balancing chamber, but it will not work. The diameter of the head is to big and will not allow the installation of the snap ring.

I will talk to you mare later.

That is great news, Luis. It certainly will make replacement of the HP balancing chamber much easier. Please post some photos when you get a chance.

Greg

Here are my results of finding a replacement balancing chamber for a Voit regulator like the MR-12. This would also work on the Trieste or the Titan.

Below are pictures of three balancing chamber. On the right is the original Voit balancing chamber. On the left is the Mares Balancing chamber. Notice that the diameter of the top is very large. There is no way to insert the snap ring with that diameter head.



On the center is the Aqua Lung balancing chamber with the four little spacers. The spacers are too tall as compared to the Voit flange. So I first thought of just filling them down to the same height as the thickness of the Voit flange, but cutting them off and using shim washer will be easier and make it a perfect fit.



Notice the small opening size of the Voit balancing chamber on the right. Replacing the O-ring in this chamber is a hassle.



After cutting the tabs on the Aqua Lung balancing chamber I just stacked several shims to match the needed thickness.



Here is a picture of the original Voit chamber in the first stage assembly.
Notice on the left the modified Aqua Lung balancing chamber and the shim washers.



Here is the Aqua Lung balancing chamber installed in the Voit first stage with the required shims for a perfect fit.



The outside diameter of the shims is 0.498 since they are design for a perfect fit on a 0.5” bore. I will place one shim below the balancing chamber to provide perfect structural support to the balancing chamber and the rest will be on the back side (the ones visible in this view) to match the thickness of the original balancing chamber. The fit can be adjusted to perfectly match the space better than the original balancing chamber.

I bought two thicknesses of shim washers from McMaster Carr:
93574A713: 18-8 Stainless Steel Bearing Shim, .020" Thick, .378" Id, .498" Od
93574A707: 18-8 Stainless Steel Bearing Shim, .005" Thick, .378" Id, .498" Od

I may not end up using the 0.005” thick shims, but it can give more precise fit.
For the one in the picture, 4 of the 0.020 shims provided a perfect fit.

Interesting Luis. It would also be very easy to turn down the Mares one to fit. I realized the other day I got 5 or 6 NOS Voit balance chambers in a lot of old parts I bought so I have a few to experiment with. A MR12 that I am rebuilding was very corroded inside and since I had replacement parts, I decided to see if I could modify the origial Voit one. I turned the center washer out of the chamber but did not damage the crimp. It appears that it could be used that way but I have not yet tested it, the rest of the reg is in sad shape and I have had other projects...

So a question or two on the original Voit balance chamber. First, what's the trick to getting that o-ring in there? I squished one with a pair of non-serrated pliers & got it in the chamber, but it's still folded in half with the far end stuck down past the white spacer washer. I'm stumped. Second, I just thought of it now, what's the consensus on drilling out the brass retainer so that the ID is more in line with one from, say, a RAM crown block balance chamber? Just open it up & have a little more room to maneuver? I'm working on a unicorn/Pegasus. The Argonaut Kraken breathes too well, I need s challenge in my life!

Thanks.

Mark

Take your fingers and pinch the -006 o-ring together. Insert one end into the chamber as far as you can. Next, take a plastic or brass pick and push the remaining portion under the lip of the flat washer that is crimped into the housing. Insert a curved pick (plastic or brass) down into the housing, and carefully work the bottom section on the o-ring upward. Rotate the housing, and continue working it until it fully seats in the groove. Also, check the condition of the back-up ring. Only remove it if it has visible damage. I have replaced more than 50 of these O-rings over the years, and seldom needed to replace the back-up ring.

Greg

I have had some luck using Francie's small knitting needles to reach in and pull the oring up into place after getting it inserted as Greg described. The knitting needles come in lots of sizes and have a little hook on the end that you can file and modify as needed. She didn't like it when I modified one.

I have had some luck using one of Francie's small knitting needles to reach in and pull the oring up into place after getting it inserted as Greg described. The knitting needles come in lots of sizes and have a little hook on the end that you can file and modify as needed. She didn't like it when I modified one of hers, so I bought an assortment of my own.