Rust inside MK25/A700 after using with steel tank

[Scared Silly]

My first question is who's bloody damn cylinder were you using? If a rental cylinder I would be asking the shop to service my reg. I actually had that happen once - a rental cylinder was dumping rust into my reg. Fortunately, I caught it early enough that no there was no intrusion. Of course my shop offered to check my reg out for free. When the shop looked at the cylinder they were bummed cause the previous person somehow got a lot of water in it, enough that they condemned the cylinder due to the rust.

 

[Zung]

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.

Agreed, therefore, the OP should not dive this reg and take it to service immediately.

OTOH, a complete service means 2 things:

1. Cleaning of all the parts, including the o-rings and seats. That should deal with the rust
2. Replacement of some soft parts. Assuming step 1 is done properly, maybe with some extra time in the ultrasonic, this step doesn't add any value, apart from some 40-ish extra dollards on the bill for the kits

 

[Zung]

Did it happen on the Red Sea side? That side is a nightmare gear-wise: the salt content is so high that steel rusts instantly and everybody's using aluminum tanks. With a 7mm wetsuit, I carry 4 kg with a steel tank on the mediterranean side, and 10 kg with an AL tank on the Red Sea side.

 

[eponym]

Rebuild, definitely, if it were mine, especially if you're the original owner and have the SPro free service deal.

And I have a semi-hijack question . . .

Is this sort of thing most likely to be caused by an unattached/missing dip tube? Or can rust particles get up the tube when it's properly installed?

-Bryan

 

[redacted]

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.

If you are talking free parts provide3d under the parts for life program then why not. Scubapro can certainly afford the less than $5 worth of parts (their cost including packing & shipping).

But, if not, do you discuss this with the customer and let him make the decision or do you just add the $60 parts charge to his bill? I would not be too worried about the sealing surface in the cap. Afterall, that is exposed to any dirt and abrasives carried in to the ambient pressure chamber anyway. Sure, there are 2 o-rings there now but for 40 years, 1 o-ring did the job. Clean and inspect the o-ring and replace it for $.25 if needed. I'd be a bit more concerned about the HP seat which could result in IP stability problems and lower performance. I doubt if the SS piston is in any danger of damage. So, clean & inspect the parts and reuse them risking a possible leak from the ambient chamber if either of the piston o-rings is damaged or minor performance problems (slight freeflow) if the seat is damaged or pay the bill for service kits. What do you think the customer would choose?

 

[Zung]

I wonder if the part warranty would cover this case: it's not annual, and there's no malfunction... yet.

 

[redacted]

I wonder if the part warranty would cover this case: it's not annual, and there's no malfunction... yet.

In the USA, soft parts are not covered under the Scubapro warranty program. They are covered under the separate but linked part-for-life program. Unlike AL/Apeks, I don't believe SP puts any limits on how often you may exercise that ?BENEFIT?.

 

[aurax]

Did it happen on the Red Sea side? That side is a nightmare gear-wise: the salt content is so high that steel rusts instantly and everybody's using aluminum tanks. With a 7mm wetsuit, I carry 4 kg with a steel tank on the mediterranean side, and 10 kg with an AL tank on the Red Sea side.

It happened in the mediterranean sea.

 

[aurax]

Good question if the service policy covers such accident. free parts for sure, don't know about the service itself.

 

[halocline]

If you brought this to me it would get a full service, including complete disassembly, cleaning, full service kit (which always includes a filter) and reassembly and testing.

Complete cleaning, for sure. There's simply no reason to install a new kit, though, unless there's obvious damage, which is unlikely given the description. Now, if someone else is paying (namely the operation that gave you the bad tank), then sure, get every o-ring in the whole reg replaced. But if it were my reg I wouldn't pay the $75 for new kits, and I'm pretty picky about how my stuff works.

That is one dirty tank to push crap all the way to the 2nd stage. I've found some nasty crap in filters after a trip to Cozumel, but nothing like this.