Scubapro Mk-5 and 109 service kits.

[Luis H]

VDH is thinking about expanding a bit from double hose to some classic/ vintage single hose regulators.

Bryan at VintageDoubleHose.com is thinking about offering service kits for some Scubapro regulators. He has been asking me for information on what to offer (and in turn I have asked some of the DIY “usual suspects”).

He is planning on offering kits with all the O-rings (including the hard to find little metric O-ring for BA poppet). The kits will also have seats, the first stage filter, and the star filter retainer.


I think that there should be plenty of interest, what do you guys think?

Any suggestions?


I will post this on the DIY section also since many of the parts are the same for some of the newer Scubapro.

 

[halocline]

Regarding the o-rings for the MK5, I would include a polyurethane 90 duro 010 for the HP piston and a 70 duro polyurethane (022?) for the piston head. It would be great to have some IP shims available, especially if Bryan is planning on only one size HP seat.

I'd include o-rings for the turret, HP seat, seat retainer, and the yoke retainer. In short, all, not just dynamic, o-rings. I think it's only 3 extras.

For the 2nd stage, I think springs, for both unbalanced and balanced, could be a nice seller, and if Bryan can get his hands on duro poppets (or s-wing w/balance chamber) that would be great too.

There's a metric size (I think) for the 2nd stage side of the hose that's usually included in SP kits. I can fir up my computer to find the size, but I'm sure awap has it memorized.

 

[Eric Sedletzky]

I'm extremely new to the DIY scene but I think it's a fantastic idea since I now own 4 sets of old Scubapro regs (could it be condidered vintage?). Three MK5/ 109's and one MK3/108

Scubapro never did make any double hoses did they?

 

[Luis H]

I'm extremely new to the DIY scene but I think it's a fantastic idea since I now own 4 sets of old Scubapro regs (could it be condidered vintage?). Three MK5/ 109's and one MK3/108

Scubapro never did make any double hoses did they?

There was never a double hose sold under the Scubapro name, but since Scubapro was a spin off from Healthways, you could say that they are related.

The models Scubapro you have were design and introduced in the 60’s. They became very popular in the 60’s and early 70’s, so I don’t only consider them vintage, I personally think of them as all time classic designs.

 

[AfterDark]

As an owner of 3 MkV's I think it's an excellent idea. Please keep us posted.

 

[Luis H]

The kits will include the 90 durometer O-ring for the HP side of piston and 70 durometer for the other O-rings.

At this point I think that most of the O-rings are going to be Buna-N based on my recommendation. If there is a demand for other materials, that may change, but I have had excellent track record with Buna-N for over 40 years. Even with 100% O2 Buna-n seems to do fine.

Even with pure O2 in a deco regulator, the time exposure to O2 is much less than in other O2 systems that use Buna-N (aviation, medical, etc.).
This is just my opinion (based on observations), but if there is a demand for other materials I am sure Bryan will consider it.

 

[HenrikBP]

I'd certainly be interested in seats and shims, as well as some new style poppers and maybe levers.

If you guys could come up with a good DIN kit for the MK5 as well I'd be all set.

Henrik

 

[DA Aquamaster]

I agree with staying with Nitrile o-rings. I avpoid viton like the plauge, especially in dynamic applications. EPDm is fine, but offers little useful advanatge over Nitrile rubber.

I am assuming Bryan will be using flat nylon 66 seats for the full vintage effect and ease of production. If that is the case he may still want to consider multiple sizes or offer new main springs as an additional product as I have noted some of the Mk 10 springs have gotten stiffer with age, so a higher seat is needed to keep the IP in the specified range.

A Mk 5 kit will cover the Mk 1, Mk 5, Mk 6, the breathing side of the Mk 7 and the Mk 8. A Mk 10 kit will cover the Mk 9 and Mk 10. I use Mk 5s, 8s, 9s and 10s, for stage and deco bottles and when I put a kit together, I just add the larger Mk 5 piston head o-ring and the smaller swivel cap o-ring to the kit so it can do double duty.

It simplies the logistics for the cost of 2 additional o-rings and Bryan might want to do the same.

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Scubapro has changed poppets several times in both the 109 and 156. The latest S-wing poppet works fine with the A148 rivet style seat from Trident. Even though the seat is slightly thicker than the SP verison, the orifice adjustment, spring pressure and lever height all work out fine and the regs breathe great with that seat. I think the dealer cost on them is $1.60 but is no doubt cheaper in bulk.

The latest 109 Duro poppet uses a standard flat rubber seat so that is a non issue as long as the user has the latest poppet.

For users with the older or original poppets for the 109 and 156 with the molded on seat, they will either have to get newer poppets through Scubapro, or Bryan will have to make a new version of the old poppets or reverse engineer poppets similar to the modern ones. In either case, he will encounter customers with both second stages and poppets of both old and new styles in each.

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What I would love to see are parts for the now unsupported Air 1 as it is a superbly performing reg with both left and right inlet options. They use D400 service kits which are still available, but the critical parts are the diaphragm and the metal clip that secures the diaphragm.

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Historically speaking, Healthways went under in 1963 and in that same year Dick Bonin and the US rep for Beauchat (Gustav ____? ) bought the assets and put it back in business as Scubapro. Their initial second stage offering was a rebranded Beauchat design and that design and style influence persisted through all their metal cased second stages. Mehanically that early second stage is a straight downstream designs but is internally distinctly different than the later 108 design.

 

[simonbeans]

Luis call me and wanted me to add the following (he can't access SB from work, and he was running late this morning).


It is important to keep the O-ring material selection simple. We all know that the cost of an individual O-ring is not much (no matter what material), but stocking a large variety of O-rings and parts can get expensive fast.

I think it is important to keep for VDH to keep the kit simple and reliable, and not try to over extend into too many options.

 

[redacted]

The kits will include the 90 durometer O-ring for the HP side of piston and 70 durometer for the other O-rings.

At this point I think that most of the O-rings are going to be Buna-N

I agree with staying with Nitrile o-rings. I avpoid viton like the plauge, especially in dynamic applications. EPDm is fine, but offers little useful advanatge over Nitrile rubber.

I experienced some IP stability problems as a function of supply pressure with Mk10s that I finally attributed to extrusion of the HP 010 o-ring (not enough to cause any damage to the o-ring). I tried nitrile and viton with little difference. Finally, I went to urethane which was supposed to have better dynamic characteristics and that seemed to reduce the problem. It was not a problem that I saw in Mk5s. With no further investigation, I attributed the problem to friction between the piston stem and HP o-ring, coupled with the reduced operating forced in the Mk10 due to the much smaller piston head.

DA - why the concern with viton? Is it just in that application or do you have a problem with viton in general. I usually favor EPDM, but viton seemed to have better availability, particularly in duro 90.