Rust inside MK25/A700 after using with steel tank

[HamataBound]

The problem is that once the rust has gone past the filter (OP reported rust in second stage) then the iron oxide particles will act as an abrasive, causing premature wear of the plating on the inside of the piston cap. In my view a complete service is not a "waste" but a prudent step to take to help ensure the long-term performance of the gear.

I agree 100% I am a ScubaPro Tech as well as a longtime ScubaPro diver. If you brought this to me I would suggest a complete service on ALL stages. There are all sorts of places that the rust can get trapped and only a complete service and cleaning will ensure proper operation. Parts kits are not that expensive when you are talking about life support equipment.

 

[redacted]

I agree 100% I am a ScubaPro Tech as well as a longtime ScubaPro diver. If you brought this to me I would suggest a complete service on ALL stages. There are all sorts of places that the rust can get trapped and only a complete service and cleaning will ensure proper operation. Parts kits are not that expensive when you are talking about life support equipment.

An understandable recommendation. I would not expect a tech to make any other recommendation if only based on the fact that it will be less work and time for the tech to simply replace those parts than to clean and inspect them. The complete teardown and cleaning is appropriate in either case so not replacing parts is just more work and possible small added risk. It is possible to miss particles of iron oxide embedded in an o-ring or the seat that could lead to a small leak or performance problem later.

So, if the parts are not going to be provided under the PFL program, are you going to charge the customer your cost or the standard 100% markup on those kits?

 

[Zung]

I agree 100% I am a ScubaPro Tech as well as a longtime ScubaPro diver. If you brought this to me I would suggest a complete service on ALL stages. There are all sorts of places that the rust can get trapped and only a complete service and cleaning will ensure proper operation. Parts kits are not that expensive when you are talking about life support equipment.

I'm all for a complete and thorough cleaning of all parts.

And there's a remote but not impossible possibility of some tiny particles of rust getting stuck in some soft parts and escape cleaning; subsequently, these particles may travel with the air flow to places where friction will cause them to do some damage. How about that!

But even then, throwing blindly some services kits at the problem will not fix it, because there're only some soft parts in the kits, not all.

So if you really want to do a thorough job, you'll have to order and replace all o-rings, shims, hoses, and so forth.

Over kill? Yes, that's the point.

 

[sphillips3]

Almost all the current ScubaPro kits do in fact contain ALL the soft parts. Every O-ring, Every seat, Every shim. You get the entire setup. I'm not worried about non-wear parts such as a hose or second stage diaphragm, as I can clean those. In those rare cases where an o-ring is not included, I simply get what I need from shop stock.

As far as the discussion on a 1st stage failure leading to death, check the accident reports for Gilboa Quarry. Every single year one or two people die there after a 1st stage free-flow. Should it happen? No, but none of those fatalities are my students either. The fact remains, it is reasonable (from a liability standpoint) to act as if it can happen. Certainly, a "reasonable" layman (e.g. sitting on a jury) can much more easily draw a line from first stage failure to death then they will listen to boring philosophical discussions about CESA vs. feathering the valve vs air share etc etc. The hardware broke, the diver died - who is the last guy to work on the hardware?

I'm sorry, this is the USA and those of us that have professional responsibilities have to act in a manner that can be supported in a court of law. If you want to save a buck or two, buy a knock-off reg and a bunch of o-rings and service the stuff yourself. For that matter, teach yourself to dive too.

 

[redacted]

As far as the discussion on a 1st stage failure leading to death, check the accident reports for Gilboa Quarry. Every single year one or two people die there after a 1st stage free-flow. Should it happen? No, but none of those fatalities are my students either. The fact remains, it is reasonable (from a liability standpoint) to act as if it can happen. Certainly, a "reasonable" layman (e.g. sitting on a jury) can much more easily draw a line from first stage failure to death then they will listen to boring philosophical discussions about CESA vs. feathering the valve vs air share etc etc. The hardware broke, the diver died - who is the last guy to work on the hardware?.

I'm sorry, this is the USA and those of us that have professional responsibilities have to act in a manner that can be supported in a court of law.

When a regulator freeflows in cold water, the problem is rarely that the hardware "broke". Rather it is a problem of design limitations and/or poor technique. Could you point out the last time a scuba shop or tech were successfully sued due to faulty work (or does faulty work just never occur).

If you want to save a buck or two, buy a knock-off reg and a bunch of o-rings and service the stuff yourself. For that matter, teach yourself to dive too.

Good idea. Don't even need to go with knockoffs (not that there is necessarily anything wrong with that). There are some really great buys on older top of the line regs that can be had for $.10 to $.20 cents on the dollar in comparison to their overly expensive modern counterparts. Servicing is quite easy once you crack the nut on finding sources for some of the required parts. Would you like to try some of my home made LP seats (in your personal regulator of course)?

Ooh, I did teach myself to dive also. Really not all that different from learning to drive. Eventually had to get a couple cards but you know how that goes.

 

[HamataBound]

I'm all for a complete and thorough cleaning of all parts.

And there's a remote but not impossible possibility of some tiny particles of rust getting stuck in some soft parts and escape cleaning; subsequently, these particles may travel with the air flow to places where friction will cause them to do some damage. How about that!

But even then, throwing blindly some services kits at the problem will not fix it, because there're only some soft parts in the kits, not all.

So if you really want to do a thorough job, you'll have to order and replace all o-rings, shims, hoses, and so forth.

Over kill? Yes, that's the point.

MK 25 kit comes with every soft part minus one o-ring which is sealed under the piston and is not changed in the annual unless needed. So for the price of a parts kit and an additional dime every soft component would be changed. No, I would not sell the parts at my cost, why would I do that if it was not my tank that caused the problem? I would certainly call ScubaPro and ask if covered under warranty.

 

[redacted]

MK 25 kit comes with every soft part minus one o-ring which is sealed under the piston and is not changed in the annual unless needed. So for the price of a parts kit and an additional dime every soft component would be changed. No, I would not sell the parts at my cost, why would I do that if it was not my tank that caused the problem? I would certainly call ScubaPro and ask if covered under warranty.

Well, it does look like a generous supply of o-rings in that kit. The kit I opened included 16 o-rings which is what I count as the required number including the din to tank o-ring and the seat retainer o-ring. All the sizes look right so it is just a matter of picking out which of the -010s is the higher duro for use on the piston stem. (I wonder if that is why some folks are reporting a softer than expected o-ring on the piston stem.)

Has Scubapro issued instructions (TB) on replacing the o-ring sandwiched inside the composite piston?

As far as the cost of the kit(s), an '02 schematic shows the dealer cost of the Mk25 kit as $10. That is the older kit that only included about 4 o-rings so the newer one might be a bit more. In this particular case where rusty water entered the regulator, it seems to me that replacing all soft parts may provide little to no benefit to the owner. But it does make it easier on the tech who will simply remove and replace the soft parts and bypass the labor steps of cleaning and inspecting. So, it would seem that a price break on the kit would be appropriate unless, of course, the labor charges are reduced to reflect the labor savings.

I'm sure there are some shops that would figure they need to charge more for labor with this new kits since they now have to remove and replace all the o-rings rather than just 4. After all, how many service providers really remove, clean, and inspect all the static o-rings when they do that job? I don't on my own regs.

 

[Zung]

...it is just a matter of picking out which of the -010s is the higher duro...

Currently, the Duro 90 HP o-rings (1 x 010, 2 x 011, maybe the 013) have painted-on stripes to make sure the techs put the right one.

... After all, how many service providers really remove, clean, and inspect all the static o-rings when they do that job? I don't on my own regs.

Interesting point: I remove them, throw them in the ultrasonic, and put those that don't appear crushed in a bag just in case; sometimes they get recycled on hose ends. Inspecting them one by one is just too painful for a dollard's worth of possible saving.

 

[redacted]

Interesting point: I remove them, throw them in the ultrasonic, and put those that don't appear crushed in a bag just in case; sometimes they get recycled on hose ends. Inspecting them one by one is just too painful for a dollard's worth of possible saving.

If the reg is clean, I don't even bother running it through the US bath. Sometimes just the body of the 1st gets the US cleaner to clean the seating surface for the piston o-ring. Hose and port plug o-rings that were OK when I started, get inspected in place and reused. With the exception of the HP piston o-ring, I often even reuse dynamic o-rings after cleaning and inspection. Easily accessible o-ring are almost always reused. I would be very disappointed if a paid service provider did this but I have no problem doing this with my own gear and my wife's. My save-a-dive kit includes a complete, ready to go regulator, as well as a good supply of o-rings. In about 10 years, I used the spare reg once for me when an HP hose o-ring extruded (disassembled for travel and not tightened enough).

I was trying not to open that kit any more than I had to but.... Yes, one has a red line, is a bit duller than the others, and feels obviously harder. All 4 of the -011s have a yellow stripe.

 

[Zung]

... I was trying not to open that kit any more than I had to but.... Yes, one has a red line, is a bit duller than the others, and feels obviously harder. All 4 of the -011s have a yellow stripe.

I remove the staple and put a rubber band around the plastic tray for an easy inspection.

And yes, it's easy to tell the 90's from the 70's. And I miscounted the 011's: 1 for the retainer, 2 for the ports, and 1 for the seat.