Post by technidiver on May 28, 2019 10:27:14 GMT -8
Here's a quick disclaimer. This is just my opinion from my most recent dive and limited experience with double hose regs.
About a week ago I took my La Spirotechnique Royal Mistral into the water after disassembling, reassembling, and turning down the yoke nozzle by about 1mm. It isnt a perfect job, not as fine as the yoke nozzle on my Spiro Mistral from Phil, but it gets the job done. I also use a 12mm wrench to snug the yoke nozzle tight against the o ring in the valve. No leaks, no problems, no worries.
The Royal Mistral had an okay diaphragm, and a decent duckbill. Spiro Neoprene/Rubber doesn't degrade. Like never. Both Mistrals have a good duckbill, and that is interesting to note.
Now, onto the hoses. The reason for this post. I took the Royal Mistral into 10 feet of water in a pool at 60 degrees. Chilly, but I had my 7mm farmer john combo. I used my conshelf supreme/14 setup, no problems. To do a performance test, I tried clearing the reg. It cleared, well only partially. I wasnt pleased how it cleared the first time, so I rolled over on my left side and cleared again. Better but not perfect. Finally I took the reg out of my mouth and lifted it above my head. Small free flow, and then it was still partially flooded. I was confused as to why there was water still in the hoses after clearing it in 3 different ways, each unique and different.
Each breath was also slightly wet. Thats probably because some water got into the intake horn and stayed there for the dive. No check valves in this mouthpiece, so thats understandable. And the diaphragm is a bit funky, so when these factors add up, it turns into a wet and difficult inhalation.
I didn't experience any of these problems diving with my Mistral in 20 feet of water at the pool several months ago. In fact, I think it was easier to clear, and a better breather.
So it hit me, it has to be the mouthpiece and hose combination. I noticed after the dive that water would get trapped in the hoses and would stay there. When I took some photos for this post and disassembled the Royal Mistral, it was still wet in the hoses and the duckbill. Weird, because I had left it in the sun as an experiment to dry the hoses. The stretched grooves must trap water and hold it there until it is stretched again, and even then the water remains.
Moving to the mouthpiece. No check valves, so water can go up into the intake horn. Not a problem clearing it with the other Mistral, but those stretch hoses retain water and it all adds up.
As far as I know, the non-stretch hoses were standard until the late 70s. Here are some photos of the non-stretch hoses on double tanks used by the Cousteau Team.
And here are the two Mistrals I won. Notice the non-stretch hoses with the larger grooves. And the smaller grooved stretch hoses.
So after reading all this, you're probably asking: what are you going to do about the problem?
Well I intend to A. Get a new silicone diaphragm, B. Get a duckbill eliminator, and C. Throw a USD hose loop on the reg. These 3 upgrades should make it the finest single stage available, IMHO.
About a week ago I took my La Spirotechnique Royal Mistral into the water after disassembling, reassembling, and turning down the yoke nozzle by about 1mm. It isnt a perfect job, not as fine as the yoke nozzle on my Spiro Mistral from Phil, but it gets the job done. I also use a 12mm wrench to snug the yoke nozzle tight against the o ring in the valve. No leaks, no problems, no worries.
The Royal Mistral had an okay diaphragm, and a decent duckbill. Spiro Neoprene/Rubber doesn't degrade. Like never. Both Mistrals have a good duckbill, and that is interesting to note.
Now, onto the hoses. The reason for this post. I took the Royal Mistral into 10 feet of water in a pool at 60 degrees. Chilly, but I had my 7mm farmer john combo. I used my conshelf supreme/14 setup, no problems. To do a performance test, I tried clearing the reg. It cleared, well only partially. I wasnt pleased how it cleared the first time, so I rolled over on my left side and cleared again. Better but not perfect. Finally I took the reg out of my mouth and lifted it above my head. Small free flow, and then it was still partially flooded. I was confused as to why there was water still in the hoses after clearing it in 3 different ways, each unique and different.
Each breath was also slightly wet. Thats probably because some water got into the intake horn and stayed there for the dive. No check valves in this mouthpiece, so thats understandable. And the diaphragm is a bit funky, so when these factors add up, it turns into a wet and difficult inhalation.
I didn't experience any of these problems diving with my Mistral in 20 feet of water at the pool several months ago. In fact, I think it was easier to clear, and a better breather.
So it hit me, it has to be the mouthpiece and hose combination. I noticed after the dive that water would get trapped in the hoses and would stay there. When I took some photos for this post and disassembled the Royal Mistral, it was still wet in the hoses and the duckbill. Weird, because I had left it in the sun as an experiment to dry the hoses. The stretched grooves must trap water and hold it there until it is stretched again, and even then the water remains.
Moving to the mouthpiece. No check valves, so water can go up into the intake horn. Not a problem clearing it with the other Mistral, but those stretch hoses retain water and it all adds up.
As far as I know, the non-stretch hoses were standard until the late 70s. Here are some photos of the non-stretch hoses on double tanks used by the Cousteau Team.
And here are the two Mistrals I won. Notice the non-stretch hoses with the larger grooves. And the smaller grooved stretch hoses.
So after reading all this, you're probably asking: what are you going to do about the problem?
Well I intend to A. Get a new silicone diaphragm, B. Get a duckbill eliminator, and C. Throw a USD hose loop on the reg. These 3 upgrades should make it the finest single stage available, IMHO.
If you ever get a chance to see the movie, "The Monster that Challenged the World" you'll get to see them in action:
In the film they're just floppin' an' jigglin' around in the underwater scenes--yeee-haw!