Mares proton metal 2nd stage membrane replacement

[lucca brassi]

I'm diving with MR32 + CWD(oil kit) + 2 x proton metal 2'nd stage (long hose + short neck hose ) for 5-6 years.

I have a few times noticed that deep breath (independant from depth ) causing membrane in 2'nd stage HONKS , which made me unconfortable. Sometimes I even think I don't get enough air ( not real , but ... in mind)

I also have heard that same problem have scubapro A700 which is also designed by Mares engineer. Scubapro have made some improvement with membrane that can be replaced and succesfully remove that honking. Proton and A700 have same problem with very small 2'nd stage membrane which can resonate at deep breath (too low supply of air ? from 1'st stage ?)

After cleaning with fresh water and drying on land , membranes from both stages seals at inhalation breath prefect.

Question : have Mares do similar improvement-upgrade with 2'nd stage membrane ?

Regulator is regular serviced at authorized service in Slovenia (May 2010) , but I think in future I'll do this myself because I more confide myself into tehnicall stuff. IP is OK. Prime 2'nd stage opened submerged 10-15 cm , backup 2'nd stage opened submerged cca 1cm - in touch with water. At diving almost never go to free flow (sometimes buckup on neckle because of position)

My choice for Mares was first that Italy is very near to me (geographical ), and I 'll have secured spare parts supply . (not quite true btw.)

 

[Greg Barlow]

I'm diving with MR32 + CWD(oil kit) + 2 x proton metal 2'nd stage (long hose + short neck hose ) for 5-6 years.

I have a few times noticed that deep breath (independant from depth ) causing membrane in 2'nd stage HONKS , which made me unconfortable. Sometimes I even think I don't get enough air ( not real , but ... in mind)

I also have heard that same problem have scubapro A700 which is also designed by Mares engineer. Scubapro have made some improvement with membrane that can be replaced and succesfully remove that honking. Proton and A700 have same problem with very small 2'nd stage membrane which can resonate at deep breath (too low supply of air ? from 1'st stage ?)

After cleaning with fresh water and drying on land , membranes from both stages seals at inhalation breath prefect.

Question : have Mares do similar improvement-upgrade with 2'nd stage membrane ?

Regulator is regular serviced at authorized service in Slovenia (May 2010) , but I think in future I'll do this myself because I more confide myself into tehnicall stuff. IP is OK. Prime 2'nd stage opened submerged 10-15 cm , backup 2'nd stage opened submerged cca 1cm - in touch with water. At diving almost never go to free flow (sometimes buckup on neckle because of position)

My choice for Mares was first that Italy is very near to me (geographical ), and I 'll have secured spare parts supply . (not quite true btw.)

The second stage diaphragm is a standard part that is used in both the metal and polymer bodied Proton second stages. Unless there is a visible defect in the part, there should not be a problem that would result in an abnormal noise.

The cracking effort of the primary second stage should not be set below 2.5cm, and ideally should be set to 2.8-3.0cm. I believe that you meant 1.5cm, and not 15cm, as that would be far too high of an effort. I personally set the Proton primary to begin flowing gas at 2.8cm (28 mm). The back-up unit is normally set at 3.2-3.8cm.

I dive with Mares Proton Metal second stages in all types of conditions. My doubles use V16 first stages, and Proton Metal Limited Edition Metal Tech seond stages. The second stages are identical to the Proton Metal, except they are coated with titanium by the PVD process. I use a V42 first stage and two Proton Metal second stages when I dive with a single cylinder. My regs are regularly used in water as cold as 2 degrees Celsius.

Greg Barlow
Former Science Editor for Rodale's Scuba Diving Magazine

 

[lucca brassi]

Thanks for fast response !
I noticed :

I personally set the Proton primary to begin flowing gas at 2.8cm (28 mm). The back-up unit is normally set at 3.2-3.8cm.

I allways think that backup have to be tuned higher in that case 2.8cm (28 mm) because of high delivery of air in case of stress , high respire rate.... and primary lower in that case 3.2-3.8cm.

I'll check values again !

 

[gmanstan]

I have a Mares Limited. It started "honking" after about 5 or 6 months at about 40 dives. I took it to the shop I bought it at a few different times and had 3 different Techs look at it. Adjust it & test it.What was the general consensus was that it was the "DFC" .It breaths fine .I do notice it at 40ft or more and usually at 2000 lb.s or less. The shop assured me it was safe, just noisy. It breaths fine,but as I do a lot of solo Diving its not very confidence inspiring.

 

[tfsails]

I'm not an engineer, but my own PERSONAL opinion of honking regs is that it's a harmonic between the diaphragm, the poppet spring, and a demand lever that is adjusted loose. By "loose", I mean the demand lever is free to move (bounce) between the bottom of the diaphragm and the point where it starts to move the poppet. When there is looseness, it's possible for the poppet to vibrate at the natural frequency of the spring. If the natural frequency coincides with the amount of looseness in the lever, the reg will honk. Some manufacturers prescribe no looseness (i.e. it doesn't rattle when you shake the second stage), but Mares prescribes looseness for their second stages. One can usually get a reg to quit honking by varying the inhalation effort. It sometimes works, oftentimes it doesn't. By no means does Mares have a monopoly on honking regs. I've seen honkers from every manufacturer except maybe Poseidon.

If you have a honking reg underwater and it concerns you (as it would me), you might have your reg tech adjust the reg so that the demand lever is close enough to the bottom of the diaphragm that it gets out of the area where the spring's natural frequency enhances the problem.

I've never had this problem underwater with my octo, which is my only reg that ever honks on land. Usually the water is dense enough to damp any honking. Seems to me the diaphragm must be free to move enough to honk (vibrate loudly-- easy to do in air, but not so easy in water), because by definition of opening the poppet, the diaphragm, demand lever, and poppet must all be engaged to open the reg to air delivery. You're the first one I've heard of that has had it happen to them underwater. Hope this helps.

 

[Zak OHara]

All have very good input here. I will check again with our tech, but I believe if you reverse a spring in the 2nd stage it will often cure any harmonics occuring. The harmonics you are probably hearing are a natural phenomenon not unique to Mares and is not considered to be faulty or effect performance of the product. I'll get back with you tomorrow to see if we can come up with a quick fix.

Best,

 

[lucca brassi]

still no info from tech staff?

 

[Zak OHara]

Sorry I've been side tracked. Our Tech suggested turning the 2nd stage spring 180 degrees, upside down. This will often solve any harmonics.

Hope this helps.

Best,

Zak

 

[lucca brassi]

thanks - could post photo please ?

just to be sure !

Happy New Year !