Okay...I believe I know the answer to this one...but this is a discussion forum, so here goes:
Had my Mk10+ serviced recently...in April. Noticed at the end of a dive when I did some practice switching between my 2nd stage and the octo, that freeflow was an issue. I was in shallow water...maybe 4 ft deep at the time. Thought it was my fault as the mouthpieces were pointed up, but never had to be all that careful before. I had to turn up the adjustment on the R109 to stop the freeflow. So, I had one of those cheap, small IP gage's and decided to check things out. Here's what I got:
Tank: 2800 psi
IP gage hooked into the quick connect to the BC hose
2nd stages: R109 converted to a balanced adjustable; R190 octo
IP gage when I cycle the purge: drops 20 psi and returns to 128....then creeps to 158 before stopping. I did not have the second stages underwater to see if they are leaking air. Maybe the second stages are leaking when pressure hits 158.
The question: The Mk10+ needs to go back in the shop for a checkup. The tech at the shop thought I could dive it once more before going in. I'm not so sure. Maybe I'd better dive my backup Mk 2 and just send the Mk 10+ straight in for service. Bad seat? Bad o-ring. Bad orifice? Bad knife edge?
Yeah...ScubaPro...too bad I can't edit the title...oh wait, I can edit in advanced mode!
Fishpie
June 4th, 2012, 01:02 PM
Since you have a back-up you might as dive that, but you'd probably have no problem with the 10+.
The plus has a dull piston end and the same seat as the 20 and 25....problem is probably o ring related, corrosion where the big o ring seats or too slick piston shaft......does it bubble from the ambient holes?
Fine emery cloth the piston shaft can work wonders.
couv
June 4th, 2012, 03:17 PM
You are probably correct about the IP causing the freeflow. The second stage is acting as a relief valve.
Safe to dive? Probably, but if you have a backup reg may as well not. First off, the i.p. is way too high and the creep is unacceptable, so another shop visit is in order. Taking it back to the same shop that returned it to you this way, and advised you to dive it again, may be an error-unless you've had excellent service from them in the past and consider this a one off.
Both you and Fishpie have hit on a few possibilities, but unless you're willing to DIY about the only thing you can do at this point other than taking it in for service is:
A) Let it sit overnight pressured if no help go to B
B) Cycle it 30 or so times. Air on/air off purge = 1 cycle
To save air, disconnect an plug all hoses and ports except one second stage. After you've cycled it 30+ times check it again.
Keep us posted.
Zung
June 4th, 2012, 04:39 PM
I wouldn't dive that MK10+; I'd take it back.
If you're lucky, it's the seat: a brand new seat can develop a creep, because of some surface imperfections probably; I had a case like that with a brand new seat, and an easy fix: just replace the seat. Especially the 1st generation white seats are pretty bad; the current dark grey ones are very good.
If you're unlucky, it's the piston. I reported a pretty bad case here (http://www.scubaboard.com/forums/repairing-your-own-gear/330806-scubapro-piston-there-life-after-death.html). The edge of the piston can be scratched by some careless handling or, less likely, some debris that got inside. That requires a replacement of the piston if you're well off, or some polishing if you have a steady hand. And the 1st generation pistons are made of brass that scratches very easily: if you have it, the one with the yellowish stem, replace it anyway.
oncor23
June 5th, 2012, 12:43 PM
I wouldn't dive that MK10+; I'd take it back.
If you're lucky, it's the seat: a brand new seat can develop a creep, because of some surface imperfections probably; I had a case like that with a brand new seat, and an easy fix: just replace the seat. Especially the 1st generation white seats are pretty bad; the current dark grey ones are very good.
If you're unlucky, it's the piston. I reported a pretty bad case here (http://www.scubaboard.com/forums/repairing-your-own-gear/330806-scubapro-piston-there-life-after-death.html). The edge of the piston can be scratched by some careless handling or, less likely, some debris that got inside. That requires a replacement of the piston if you're well off, or some polishing if you have a steady hand. And the 1st generation pistons are made of brass that scratches very easily: if you have it, the one with the yellowish stem, replace it anyway.
I believe the original piston was replaced in a prior service, shortly after I got it. I'm not the original owner...I have no idea how much use the regulator had before I bought it. I suppose it could still be a brass piston, but probably not. I read your long thread about your Mk10 Plus #3. I don't believe my Mk 10+ had a serious issue with IP creep before the last service. I hope it's just a bad seat. I hope it's not sloppy handling and a damaged piston. I don't plan to take it apart and try to "micro-mesh" the piston edge back to health. If the shop tells me that the piston has gone bad...and I have to pay for a new one...it may be time for me to switch to another, less convenient shop. I haven't gone into all the details of my conversations with regard to this issue, but it would be safe to assume I'm not real happy. I've done maybe 5 dives since getting it serviced in April...all fresh water and not in conditions likely to leave large particles inside the regulator, thus causing damage since the service. One could well ask how it passed inspection?
---------- Post added ----------
I checked the old piston that came out of the Mk 10+ on a service about 2 yrs ago. That was steel, so I imagine the current piston should be steel. I can't believe the seating surface is already in this bad a shape. What about the orifice? Could that have somehow been damaged and causing the creep or does it have to be the HP seat or the piston seating surface?
Also, my balanced adjustable will free flow if I push the purge button and there is no counteracting pressure like holding it underwater facing down. Maybe when I tried it the IP pressure was above 140...but it free flowed. I tried turning the adjustment all the way in...still free flowing. Never did that before.
Zung
June 5th, 2012, 03:10 PM
I believe the original piston was replaced in a prior service, shortly after I got it...
Any idea why they did it in the first place?
...One could well ask how it passed inspection?...
There wasn't one for sure
... I checked the old piston that came out of the Mk 10+ on a service about 2 yrs ago. That was steel, so I imagine the current piston should be steel. I can't believe the seating surface is already in this bad a shape...
It takes only 1 bad service to mess things up. It was reported on another board that the creep had gone away after the tech stopped ultrasonic'ing the pistons. My view is that the edge might hit other metal parts in the tray. Or, more conviniently, the piston got dropped.
... What about the orifice? Could that have somehow been damaged and causing the creep or does it have to be the HP seat or the piston seating surface?...
No. The only way to develop a creep in the sealing between the piston and the seat: if it's not perfect, air leaks pass the seal into the IP chamber, raising the IP and pressing back again the piston/seal until it seals again... or not.
... Also, my balanced adjustable will free flow if I push the purge button and there is no counteracting pressure like holding it underwater facing down. Maybe when I tried it the IP pressure was above 140...but it free flowed. I tried turning the adjustment all the way in...still free flowing. Never did that before.
That's not good; don't dive it, take it back for a refund and look for another shop. But it can still be the seat.
halocline
June 7th, 2012, 03:04 PM
Depending on how long it takes to get from 128 to 158, I wouldn't dive it either. If its an hour, fine, dive it, but a few seconds (anything under a minute, I suppose) and that's very serious. As Zung correctly mentioned, the only thing that causes this is either a problem at the piston edge or the seat.
Mk10+ pistons can be notorious creepers, although the current seat (same as MK20/25) is really good. And if the shop you brought it to is a SP dealer, they'd have used a new seat, so my guess is there's a problem with the piston. Take it back, see what they say. They'll probably tell you it needs a new piston, at which point they'll say there are no new pistons available (I don't know if that's true or not) and then point to a nice shiny MK25. If you politely remind them that the problem didn't exist until they serviced it, it would be interesting to see what creative response they have to that.
As a last resort, I'm looking for a MK10+ to play with, so I'd be fine with trading you a MK10 (not plus) for yours provided the piston is not totally trashed. I'm perfectly comfortable resurfacing the piston edges. The difference is the MK10 has a knife edge piston and different seat that is less prone to creep. I have several of those. I could also try fixing your MK10+ for you, but I'm not a certified tech (like the guys in the shop, hehe) so you'd be taking your life into your hands.
I'm interested in knowing if there are generations of the MK10+ piston as there were for the MK20. I believe I've seen the brass tipped one and a dull stainless tip. The brass tipped MK20 piston was a spectacular creeper, so if the only MK10+ pistons are also brass tipped, my interest in them would take a nose dive. If, however, there's a newer style MK10+ piston similar to the MK25 composite piston, I'd get one of those. It could be a great performing first stage, something SP should consider re-issuing along with the G250V.
awap
June 7th, 2012, 03:43 PM
The IP creep problem needs to be corrected.
But the freeflow "problem' you describe may just be the first time you have gotten your 2nd stage tuned correctly. If you are going to get maximum performance, they should freeflow a little when you handle them badly. Use the adjustment knob to control it when not in your mouth, and enjoy.
oncor23
June 8th, 2012, 02:38 PM
Here is my recent test...again using my cheap IP gauge.
at purge....pops back to 130psi
after 45 sec = 140
after 60 sec = 142
after 2 min = 148
after 3 min = 152
after 5 min = 158
That was it...I do believe the R190 started to leak air slowly as the Mk10+ hit 158.
The old piston looks to be solid stainless. I talked to a shop tech at my LDS and he told me they didn't have any brass tipped pistons for replacement...and had not used any, at least for the Mk10 in a long time. So, I'm guessing the one that's in there is steel. The shop tech mentioned that the body of the Mk10 could be worn...or scored...and that would result in creep. Last year, last time I checked this Mk 10+ with my IP gauge, it was not creeping...or if some, just a little. Nothing like this. Frankly, I think they did something to it during the last service. Or the HP seat is bad.
So, my rig is going back to the shop and I will let you all know the verdict. Hey Halocline, if they declare it DOA, I will happily trade it for your Mk10. Yes, I will tell you exactly what they say is wrong. In any event, I could always send it to you and you can decide whether it is worth the trade. Since I don't do regulator repair, if the shop can't fix it, it becomes an expensive paperweight for my purposes. I suppose I could also take it to another shop where most of my relatives live. I visit there often enough that having the service done there would not be much of an imposition. Both my currant LDS and this other shop are ScubaPro certified.
halocline
June 8th, 2012, 03:23 PM
Okay, so they replaced the piston, but not on this service? Wear in the body and/or scoring won't cause creep. It might cause a leak; most frequently someone mangles the HP o-ring journal removing the old o-ring, and the result is HP air leaking into the ambient chamber. If there's scoring (usually due to corrosion or careless techs) in the ambient chamber where the piston head o-ring sits, IP air would leak into ambient. That would result in the IP dropping a bit until the piston gets pushed off the seat, which causes a rapid re-lock up, then slow IP drop again, etc...
There's only one place HP air leaks into the IP chamber, that's at the piston/seat interface. It's either a bad piston or bad seat. If the tech said "MK10" not MK10+, he should know that it's an entirely different piston and a MK10 piston will definitely NOT work with the MK10+ seat. They're not that dumb, are they? He must have meant MK10+.
Being SP certified means someone took a one-day course that nobody has ever failed. Not exactly 'rigorous' training....so the tech could be excellent or terrible at your store. There seem to be plenty of both at dive shops around the country!
couv
June 8th, 2012, 03:55 PM
Here is my recent test...again using my cheap IP gauge.
at purge....pops back to 130psi
after 45 sec = 140
after 60 sec = 142
after 2 min = 148
after 3 min = 152
after 5 min = 158
.....
Oncor23,
Certified or not, I'm not feeling warm and fuzzy with your shops knowledge of MK10/MK10+. I suggest you take Halocline up on his generous offer to trade. You'll be getting a known good regulator from someone who is meticulous about caring/rebuilding them.
oncor23
June 8th, 2012, 04:59 PM
Okay, so they replaced the piston, but not on this service? Wear in the body and/or scoring won't cause creep. It might cause a leak; most frequently someone mangles the HP o-ring journal removing the old o-ring, and the result is HP air leaking into the ambient chamber. If there's scoring (usually due to corrosion or careless techs) in the ambient chamber where the piston head o-ring sits, IP air would leak into ambient. That would result in the IP dropping a bit until the piston gets pushed off the seat, which causes a rapid re-lock up, then slow IP drop again, etc...
Yes, they replaced the piston about 2 yrs ago...not this service. It might be that was the previous service to this one. I'll have to check.
There's only one place HP air leaks into the IP chamber, that's at the piston/seat interface. It's either a bad piston or bad seat. If the tech said "MK10" not MK10+, he should know that it's an entirely different piston and a MK10 piston will definitely NOT work with the MK10+ seat. They're not that dumb, are they? He must have meant MK10+.
I'm sure the last tech I talked to was referring to my Mk10+. They do have several techs who work on the regulators...more than 2...I don't know how many.
Being SP certified means someone took a one-day course that nobody has ever failed. Not exactly 'rigorous' training....so the tech could be excellent or terrible at your store. There seem to be plenty of both at dive shops around the country!
Yeah, the guy who worked on my reg this time hadn't done any of my gear before. I don't know how new he is to working on regs, but he is the general salesmen, phone answer guy...so maybe that tells you something. I can't specify who does my gear. Maybe if I knew them better, I could.
---------- Post added ----------
couv,
As I've already told my LDS I would send it in for them to look at...I will do that. What happens if I don't like the result is totally open. At this point, I still need to have my gear serviced somewhere. That said, if they tell me the Mk10+ is DOA, and don't offer me any viable solutions to move forward...then I will be open and eager to work a deal with Halocline. Something that needs sorting out as part of the equation is where I get my gear serviced in the future. At this point, that is up in the air.
halocline
June 8th, 2012, 05:22 PM
Something that needs sorting out as part of the equation is where I get my gear serviced in the future. At this point, that is up in the air.
The best thing would be to learn how to do it yourself. Next best would be to find someone who you are certain does excellent work (I'm sure there are many, it's not that difficult) and make sure that person services your reg each time.
oncor23
June 13th, 2012, 12:06 PM
But the freeflow "problem' you describe may just be the first time you have gotten your 2nd stage tuned correctly. If you are going to get maximum performance, they should freeflow a little when you handle them badly. Use the adjustment knob to control it when not in your mouth, and enjoy.
Okay...talked to my LDS and here's their take on the freeflow. The regs are well tuned. What I found, again, is this: For the R190 octo, on a bungee around my neck...I believe it freeflows if the mouthpiece tilts up. Should I verify that, and if that's the case, have them increase the cracking pressure?
Balanced adjustable: Above water, hit the purge and it freeflows as it should. Release the purge and freeflow continues. I'm not holding it down for any real length of time...just push in a good amount and release. I guess that once it get's going...there's enough vacuum created that releasing the purge button won't stop it. Is this normal, for a finely tuned, easy breathing 2nd stage? Even when the adjustment knob is turned all the way in?
If you take a 2nd stage out of your mouth while underwater...do you expect it to freeflow? Not if mouth piece pointed down, yes if mouth piece pointed up? Do you have your octo set so it behaves differently?
As for the 1st stage creep, the LDS said they found a total of 20 or 20+ psi creep when left on for a long time. The creep over 45 secs was something like 6-8 psi, with an additional 1 psi in the next 15 secs, so it met Scubapro specs. My question is this...the additional creep should suggest that there is still a problem. It didn't lock up after 1 minute, but had a substantial creep afterwards. I'm still not clear on what, if anything, they did to rectify the creep. I will have to question them on this when I pick up the reg. They also said something about the IP pressure being a little high, so they adjusted that. I expect that they must know I will check for creep again when I get the regulator back! I need a list of questions to ask them when I pick it up...how much is the total IP creep now, for one.
Zung
June 13th, 2012, 01:21 PM
Okay...talked to my LDS and here's their take on the freeflow. The regs are well tuned...
I don't buy that.
... For the R190 octo, on a bungee around my neck...I believe it freeflows if the mouthpiece tilts up. Should I verify that, and if that's the case, have them increase the cracking pressure? ...
IMHO, an octo shouldn't free flow in any position. Do verify that, and if it's the case, tune it yourself: all it takes is to remove the hose, and screw the orifice clockwise 30° or 1 hour. Better still: juryrig a manometer and tune it to 1.4" or there about.
The reasoning is: if I need to use the octo, the dive is over and I don't care if it breathes a bit harder. OTOH, if the dive is NOT over, I want to enjoy it to the fullest and the last thing I want to have on my mind is to tend the gear.
... Balanced adjustable: Above water, hit the purge and it freeflows as it should. Release the purge and freeflow continues. I'm not holding it down for any real length of time...just push in a good amount and release. I guess that once it get's going...there's enough vacuum created that releasing the purge button won't stop it. Is this normal, for a finely tuned, easy breathing 2nd stage? Even when the adjustment knob is turned all the way in? ...
Not if the adjustment knob is all the way in; plus, the 109 doesn't have a lot Venturi, so it shouldn't free flow as much. Detune it a bit: 1" to 1.2" is good, with the knob all the way out.
... As for the 1st stage creep, the LDS said they found a total of 20 or 20+ psi creep when left on for a long time. The creep over 45 secs was something like 6-8 psi, with an additional 1 psi in the next 15 secs, so it met Scubapro specs. My question is this...the additional creep should suggest that there is still a problem. It didn't lock up after 1 minute, but had a substantial creep afterwards. I'm still not clear on what, if anything, they did to rectify the creep. I will have to question them on this when I pick up the reg. They also said something about the IP pressure being a little high, so they adjusted that. I expect that they must know I will check for creep again when I get the regulator back! I need a list of questions to ask them when I pick it up...how much is the total IP creep now, for one.
I'm sorry you have to deal with these guys. Perhaps you may respectfully suggest they learn to read: according to SP's EB242:
...
0 - 45 SECONDS: DRIFT OF LESS THAN 8 PSI
45 - 60 SECONDS: DRIFT OF LESS THAN 1 PSI AND TAPERING TO 0 PSI
...
What it means is: after 60 seconds, there should be no more drift. Else you could find yourself with the full 3000 PSI of your tank!
Edit
On second thought, the EB242 is from 1995; I think it refered to the early white seats that were terrible. With the current dark grey/black seats common to the MK10+/MK20/MK25, there should be no drift at all.
I just tested my #2 son's MK20 that has about 60 dives since last service, and it's snappy like new, recovering in under 1 second and no drift.
couv
June 13th, 2012, 01:54 PM
Again, I think you've been more than fair to the LDS clowns. Get your regulator back, either have Halo service it or trade it (that's what I would do, the MK10+ has too many issues.) I'll try to attach SB #248 so you can read it to the illiterates at the shop.
Zung
June 13th, 2012, 03:06 PM
And the EB 242 is here (http://www.scubaboard.com/forums/attachments/repairing-your-own-gear/75440d1272045420-scubapro-piston-there-life-after-death-242_mk20-mk10_info.pdf).
Charge them tuition and use it to fund SB. :)
oncor23
June 13th, 2012, 04:19 PM
I don't buy that.
Would you buy....well tuned to breath easy...really easy...with a little free flow thrown in?:D
IMHO, an octo shouldn't free flow in any position. Do verify that, and if it's the case, tune it yourself: all it takes is to remove the hose, and screw the orifice clockwise 30° or 1 hour. Better still: juryrig a manometer and tune it to 1.4" or there about.
The reasoning is: if I need to use the octo, the dive is over and I don't care if it breathes a bit harder. OTOH, if the dive is NOT over, I want to enjoy it to the fullest and the last thing I want to have on my mind is to tend the gear.
Hmmmm...gee...kind of what I was thinking about the Octo. Why would I want it to free flow if the mouthpiece points up?
Not if the adjustment knob is all the way in; plus, the 109 doesn't have a lot Venturi, so it shouldn't free flow as much. Detune it a bit: 1" to 1.2" is good, with the knob all the way out.
Actually, that's what I told them...cut it back some. They had bragged about using a 2nd stage set to 0.8". Maybe mine was set to 1"...if so, I can get them to cut that back to 1.2".
I'm sorry you have to deal with these guys. Perhaps you may respectfully suggest they learn to read: according to SP's EB242:
then:
...
0 - 45 SECONDS: DRIFT OF LESS THAN 8 PSI
45 - 60 SECONDS: DRIFT OF LESS THAN 1 PSI AND TAPERING TO 0 PSI
...
What it means is: after 60 seconds, there should be no more drift. Else you could find yourself with the full 3000 PSI of your tank!
Edit
On second thought, the EB242 is from 1995; I think it refered to the early white seats that were terrible. With the current dark grey/black seats common to the MK10+/MK20/MK25, there should be no drift at all.
I just tested my #2 son's MK20 that has about 60 dives since last service, and it's snappy like new, recovering in under 1 second and no drift.
:shocked2: Remember, we are dealing with a LDS here. I'll be reasonably happy if I get a lockup within 60 seconds and no more than 8 psi of creep. I'm still in doubt about what they did with my Mk 10+...they mentioned reducing the pressure...but maybe they did something else to reduce the creep, but didn't tell me? I really need to check the creep for myself to see what I come up with.
I'm getting the impression that they do not really want to discuss the details of what they do with the typical customer...or maybe just me. So...they fixed it...and since you the customer are not particularly knowledgeable about regulators, they don't see the need for going into details.
---------- Post added ----------
Again, I think you've been more than fair to the LDS clowns. Get your regulator back, either have Halo service it or trade it (that's what I would do, the MK10+ has too many issues.) I'll try to attach SB #248 so you can read it to the illiterates at the shop.
I have both of these ScubaPro bulletins...from Zung's other thread about his Mk10+ adventures. I do need to get my regulator back...and see how it performs. It may work fine...now. Once I see how it does...I'll go from there.
While we are on the topic...yeah, Halo was talking about trading for a Mk10...but would a Mk5 be a better choice?
halocline
June 13th, 2012, 05:26 PM
Would you buy....well tuned to breath easy...really easy...with a little free flow thrown in?:D
Hmmmm...gee...kind of what I was thinking about the Octo. Why would I want it to free flow if the mouthpiece points up?
While we are on the topic...yeah, Halo was talking about trading for a Mk10...but would a Mk5 be a better choice?
The B/A has a pretty aggressive purge, mine will keep flowing on land once they start with full purge. Just stop it with your thumb over the mouthpiece, it's normal with the adjustment knob out. I never tried it with the knob all the way in. You do need to have them set to at least 1" cracking pressure to avoid problems with case fault geometry...you could mention that to the tech at the shop, but it might not be worth it.
Almost any decent 2nd stage will start flowing if it enters the water mouthpiece up. For your octo, once it's flooded, it shouldn't flow in any position, but it's very common when entering the water. I like using the adjustable regs as octos because I can set them like normal 2nd stages and use the adjuster to control free flows.
With regards to getting a MK5 vs a MK10, I can't offer you a MK5, (I only have 2 or 3, I think) but I can give you my opinion...I would prefer a 5 port MK5 with the heavy yoke and a stainless steel turret retainer (I.E. the very last generation of the MK5s) to a MK10, but those late model MK5s are harder to find in excellent condition, and there are some practical advantages to MK10s, and the dive performance is indistinguishable. One is that you can use the universal DIN/yoke retainer on the MK10, where the MK5 has a unique retainer. The turret retainer on the MK10s never had problems, but all except the latest MK5s had brass turret retainers that were easily over-torqued and weakened. MK10 parts are a little easier to find, especially pistons. To be honest, I would try to get your MK10+ fixed by someone who knows what he's doing. This ain't rocket science.
Bottom line, late MK5 or any MK10 would be fine. I use them interchangeably all the time; my doubles set up is two late model (with spec boots) MK10s packed with tribolube. Most single tank diving I do with a MK5 and converted pilot 2nd stage.
oncor23
June 13th, 2012, 06:29 PM
The B/A has a pretty aggressive purge, mine will keep flowing on land once they start with full purge. Just stop it with your thumb over the mouthpiece, it's normal with the adjustment knob out. I never tried it with the knob all the way in. You do need to have them set to at least 1" cracking pressure to avoid problems with case fault geometry...you could mention that to the tech at the shop, but it might not be worth it.
Almost any decent 2nd stage will start flowing if it enters the water mouthpiece up. For your octo, once it's flooded, it shouldn't flow in any position, but it's very common when entering the water. I like using the adjustable regs as octos because I can set them like normal 2nd stages and use the adjuster to control free flows.
With regards to getting a MK5 vs a MK10, I can't offer you a MK5, (I only have 2 or 3, I think) but I can give you my opinion...I would prefer a 5 port MK5 with the heavy yoke and a stainless steel turret retainer (I.E. the very last generation of the MK5s) to a MK10, but those late model MK5s are harder to find in excellent condition, and there are some practical advantages to MK10s, and the dive performance is indistinguishable. One is that you can use the universal DIN/yoke retainer on the MK10, where the MK5 has a unique retainer. The turret retainer on the MK10s never had problems, but all except the latest MK5s had brass turret retainers that were easily over-torqued and weakened. MK10 parts are a little easier to find, especially pistons. To be honest, I would try to get your MK10+ fixed by someone who knows what he's doing. This ain't rocket science.
Bottom line, late MK5 or any MK10 would be fine. I use them interchangeably all the time; my doubles set up is two late model (with spec boots) MK10s packed with tribolube. Most single tank diving I do with a MK5 and converted pilot 2nd stage.
Thanks Halo. Yeah, I get that I shouldn't be surprised if a reg freeflows when it goes in the water mouthpiece up. Once it's under, it shouldn't freeflow on it's own just because the mouthpiece points up.
My comments about the Mk5 was not intended to strike some new bargain with you. It was really meant to question the value of a Mk10 vs Mk5. You answered it nicely. Thanks for that. As for my Mk10+, I do want to see how it performs after I retrieve it from the LDS. Hey, it worked well last year. If it works fine again...I'll give the LDS the benefit, but check it out more carefully after the next service. Or learn to service my own in the interim.
agilis
June 13th, 2012, 07:33 PM
First, my gratitude to couv, Zung, and halocline for all the invaluable information and fascinating comments over the years regarding my absolute favorite regulator combination, the Mk 5 and the 109/156. I still have my first Mk V (as we used to refer to them) and its 109 second stage. I've had them for more than 40 years, and have done all my own work on them since the 90s.
I have a second Mk 5 first stage that is more recent, with 5 lp ports and two of the larger diameter hp ports. I bought it a few years ago, almost unused in virtually new condition, clean as a whistle inside. I installed new o rings, a washer or two and the filter although everything seemed fine, though the o rings were a bit dry. IP locks at 135-137, no extra shims, solid as a rock. I've semi-retired my two port original mk 5, even though I replaced the light yoke long ago. I still use my 40 year old 109, upgraded to current standards with an s poppet, matching longer balance chamber, more recent lever and an appropriate adjustment spring. The chrome finish is still beautiful, almost flawless, despite many hundreds of dives and numerous plane trips carefully packed in my carry-on. All rubber parts have been replaced several times, of course.
I use the combination of the newer Mk5 and the updated 109/156(almost a 250V) on my tropical dive trips. They outperform most anything else, especially with the 109 tuned to utter perfection, and the impact they have on other divers and boat crews is interesting and amusing in the extreme. Compared to what's out there, they also are in another and much higher aesthetic category. "A thing of beauty is a joy forever."
I'm curious, halocline, about the Mk 5 brass turret retainer you mention. I think old Scubapro spec sheets call it a swivel retainer. Both my Mk 5s have brass retainers. I know about the overtorquing issue, and it's not a problem for me, since I (very carefully) do my own work. Still, I wonder if the stainless steel retainer is available as a new part, if it would fit properly, and if it it's worth doing a replacement the next time I service them, all things considered.
Many many thanks for the generosity, the expertise, and the sea of humor which obviously floats all of your boats.
halocline
June 14th, 2012, 02:47 PM
I'm curious, halocline, about the Mk 5 brass turret retainer you mention. I think old Scubapro spec sheets call it a swivel retainer. Both my Mk 5s have brass retainers. I know about the overtorquing issue, and it's not a problem for me, since I (very carefully) do my own work. Still, I wonder if the stainless steel retainer is available as a new part, if it would fit properly, and if it it's worth doing a replacement the next time I service them, all things considered.
If you're sure the swivel retainer has not been severely overtorqued, and you are the one doing the servicing, there's no immediate reason to replace it. A small of group went in on a run of reproduction SS retainers; Zung arranged that in Europe. I'm sure there are some of those available. I sent at least one to Bryan at vintage doublehose, so you could buy it there. Scubapro no longer has any.
I know at least one of my MK5s still has a brass retainer, next time I rebuild I'll replace it, but I'm not in any hurry. I ordered some mostly to support the effort.
The 109 upgraded and tuned well is a pretty jamming 2nd stage, no doubt about it. Probably about the most successful 2nd stage in history if you consider longevity, aesthetics from a design simplicity and elegance perspective, dive performance, and influence on subsequent regulators.
Zung
June 14th, 2012, 03:11 PM
I only kept 1 of those special order retainers for myself, because I only had 1 MK5 at that time. But due to the extreme bad influence of this board, I've got quite a handful now, and still only 1 ss retainer. :)
But since I also have a torque wrench I calibrated myself against the highly mission-critical scales of 2 local supermarkets, I don't loose any sleep over that one.
halocline
June 14th, 2012, 05:51 PM
I thought I had 5, but I only found 2 the other day going through some stuff. I didn't think I had installed any yet, and I thought I only sent one to Bryan. So I guess I'm unofficially missing 2 of them.....
agilis
June 14th, 2012, 07:44 PM
Brian tells me he had two, used both. Any other possible source? if any are available for sale or for installation, an email would be quickly answered. I'd like to have one to use on the late model Mk 5 that sees a lot of use. I suppose another production run is not likely.
couv
June 14th, 2012, 09:40 PM
I think those turret retainers were made from ether. I cannot recall how many we ordered; we don't remember using any-no one has any left. But a huge amount of effort (thanks Zung) went into procuring a run. :confused:
agilis
June 14th, 2012, 10:00 PM
I can only imagine the technical difficulties involved with machining substances ethereal.
mahjong
June 15th, 2012, 12:34 AM
You're in the Catskills. How far from Syracuse? Send your MK10+ to National Aquatic Service in Syracuse. Mike, the owner, at least used to dive only the MK10+, internally retrofitted to an MK10. He'll take care of you.
No one has mentioned the spring as a possible culprit. Certainly the piston and seat are the first places you want to look. If that doesn't work, shouldn't the spring be considered? An old spring, long sitting inside an MK10+ from the 1990s, might need to be replaced.
halocline
June 15th, 2012, 08:49 AM
I've never seen a mainspring cause a problem in a balanced piston 1st stage. It certainly wouldn't cause creep. I've had a few MK5s with low IP, like 120 with the shortest seat and no shims, I switched the spring, little effect. Someone sent me a NOS spring for a MK15, tried it at the next rebuild, no effect. These springs are pretty beefy and they're relaxed when the reg is not pressurized, so they last a really long time. I've read that sometimes they can stiffen up over time, resulting in high or drifting IP, but I've never personally experienced that. Drifting means they lock up at a slightly different IP every time you cycle them, and is not creep where the IP rises when the reg is closed.
There was an issue with mainsprings in some old US Divers doublehose regs; one of the vintage fans (maybe herman?) found some new springs that worked well. With those, the IP would drift down, usually you'd want to set it pretty high and it would hold for a while, but after a couple of dives it would be back down to under 125. I guess the springs were losing strength and causing IP to drop, which is more intuitive to me than a bad spring causing high IP.
This is a really simply problem, either the seat is bad or the piston edge (much more likely IMO) is bad.
elan
June 15th, 2012, 09:31 AM
Is it possible to refinish the edge if the damage not severe?
Zung
June 15th, 2012, 11:36 AM
Yes, with mattmagic (http://www.scubaboard.com/forums/repairing-your-own-gear/330806-scubapro-piston-there-life-after-death.html).
elan
June 15th, 2012, 02:04 PM
Thanks Zung, you guys are awesome
I cannot wait for my second MK5 to come in for rebuild, these things are addictive
I think I have enough regs now to assemble a DIR rig and piss my DIR buddies off:)
couv
June 15th, 2012, 11:51 PM
I can only imagine the technical difficulties involved with machining substances ethereal.
.....and metric on top of that!
I just crawled out of the "WABAC Machine" WABAC machine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/WABAC_machine) and located THE thread- http://www.scubaboard.com/forums/regulators/335230-mk-5-turret-retainer.html Can you believe we had approx 60 of them made yet there are none to be had‽
mahjong
June 16th, 2012, 12:19 AM
Thanks, Halocline. I'm certainly sold on your explanation. My understanding of regs is very basic. I couldn't help but think that proper spring tension mattered, but couldn't quite draw the distinction between IP drift and creep.
Just an added clarification question: Is there the possibility that an old spring that's lost proper tension could lead to piston action that could in turn lead to the seat going bad? So the bad seat is causing IP creep, while the bad spring was a contributing factor in the seat going bad?
I've never seen a mainspring cause a problem in a balanced piston 1st stage. It certainly wouldn't cause creep. I've had a few MK5s with low IP, like 120 with the shortest seat and no shims, I switched the spring, little effect. Someone sent me a NOS spring for a MK15, tried it at the next rebuild, no effect. These springs are pretty beefy and they're relaxed when the reg is not pressurized, so they last a really long time. I've read that sometimes they can stiffen up over time, resulting in high or drifting IP, but I've never personally experienced that. Drifting means they lock up at a slightly different IP every time you cycle them, and is not creep where the IP rises when the reg is closed.
There was an issue with mainsprings in some old US Divers doublehose regs; one of the vintage fans (maybe herman?) found some new springs that worked well. With those, the IP would drift down, usually you'd want to set it pretty high and it would hold for a while, but after a couple of dives it would be back down to under 125. I guess the springs were losing strength and causing IP to drop, which is more intuitive to me than a bad spring causing high IP.
This is a really simply problem, either the seat is bad or the piston edge (much more likely IMO) is bad.
oncor23
June 19th, 2012, 10:24 AM
Picked up my regulator. The head tech adjusted both 2nd stages with me there to okay everything. They both seem to be working the way I want...less likely to free flow. The 1st stage was "adjusted"; they told me they lowered the IP. I was told it is now locking up. So, I dove it...without issues. After I got home, I did check it with my IP gauge. Here's what I got:
Starting pressure after a purge or breathe: 122 psi
45 secs: 127
60 secs: 128
5 minutes: 137
I will continue to check it after every dive to see if the IP creep is stable or getting wider. Who knows what they actually did to the 1st stage. I doubt that the piston was changed. Maybe a new HP seat. Did they change the number of shims to get lower initial pressure?
So...it ain't perfect. It is considerably better than it was. We will see how it goes.
elan
June 19th, 2012, 10:39 AM
Picked up my regulator. The head tech adjusted both 2nd stages with me there to okay everything. They both seem to be working the way I want...less likely to free flow. The 1st stage was "adjusted"; they told me they lowered the IP. I was told it is now locking up. So, I dove it...without issues. After I got home, I did check it with my IP gauge. Here's what I got:
Starting pressure after a purge or breathe: 122 psi
45 secs: 127
60 secs: 128
5 minutes: 137
I will continue to check it after every dive to see if the IP creep is stable or getting wider. Who knows what they actually did to the 1st stage. I doubt that the piston was changed. Maybe a new HP seat. Did they change the number of shims to get lower initial pressure?
So...it ain't perfect. It is considerably better than it was. We will see how it goes.
I have a similar situation with one Mk5 that I have got recently, it stops at 125 after the purge and creeps to 135. Not ideal. Upon examining the piston I have found that the piston edge is a bit scratched. Careless handling by a tech I bet. So it takes more of the IP swing to make it lock.
In your case it likely is the same cause. But I might be wrong. They might have replaced the seat with a thicker one or removed a shim to reduce the IP. Its not really a fix but rather a bandaid. I guess the permanent solution would be replacing a piston or doing some polishing using the link provided by Monseur Zung.
In my case I have left the piston alone as it locks properly and I might try to do the procedure during th next service.
In your case watch it for a while, as the seat takes a set it might improve as it will greate the groove
couv
June 19th, 2012, 07:46 PM
Picked up my regulator. The head tech adjusted both 2nd stages with me there to okay everything. They both seem to be working the way I want...less likely to free flow. The 1st stage was "adjusted"; they told me they lowered the IP. I was told it is now locking up. So, I dove it...without issues. After I got home, I did check it with my IP gauge. Here's what I got:
Starting pressure after a purge or breathe: 122 psi
45 secs: 127
60 secs: 128
5 minutes: 137
I will continue to check it after every dive to see if the IP creep is stable or getting wider. Who knows what they actually did to the 1st stage. I doubt that the piston was changed. Maybe a new HP seat. Did they change the number of shims to get lower initial pressure?
So...it ain't perfect. It is considerably better than it was. We will see how it goes.
Personally, I think 10psi is too much creep. But if it definitely stops at 137 then probably no harm can come from it. However, it would be a PIA to tune the second stage, especially an unbalanced one.
With the MK10+ the intermediate pressure can be adjusted with shims under the hp seat cap or on either side of the spring. I don't know if the + has a series of hp seats (like a real MK10) that can be used to adjust IP. I do like the shim under the cap idea though.
Zung
June 20th, 2012, 01:23 AM
Bro, the MK10+ uses the same seats as the MK20/25 and there's only 1 single size. The IP has to be adjusted with shims, and they go only on 1 side of the spring opposite of the piston crown, and the seat retainer. That's because of the plastic piece built in the piston just below the crown.
halocline
June 20th, 2012, 08:31 PM
Starting pressure after a purge or breathe: 122 psi
45 secs: 127
60 secs: 128
5 minutes: 137
That's not even close to acceptable IP creep to me. Chances are it will get worse, too. You can try leaving it pressurized overnight, maybe that will help, but probably it won't do much. Assuming the guy changed the seat when you brought it back, meaning this piston has creeped with two different new seats, you need a new piston or possibly yours could be re-surfaced. What I don't understand is how a supposed professional tech would not know this, or let a regulator out of the shop with that much IP creep.
Zung
June 21st, 2012, 01:42 AM
"... they told me they lowered the IP..."
I think the only thing they did was to remove a shim. I can understand it from a business point of vue: they did something and collected some money against it; whatever extra they have to do is pure loss. If they had to throw in a new seat, that'd be another extra loss, worth at least $2. Whether or not this is ethical, or even professional, is usually not relevent.
OTOH, I know for sure SP would replace the piston under warranty: a LDS over here confirmed it. But since this can't be a warranty case, and the specs are nearly borderline, your LDS thought they could get away with it. That's sadly common: I have 1 MK20 and 1 MK25 that were freshly serviced before I bought them, and they had a similar case of creep.
halocline
June 21st, 2012, 09:28 AM
The older piston design, on the MK5, 10, and 15, had a sharp 'knife' edge that cut into the hard plastic seat and formed a very reliable seal. This is one reason that MK5s are so stable on lock up. At some point (well, with the MK10+) SP decided that they wanted increased flow, so they tried a rounded-edge piston that accomplished two things; better aerodynamics around the piston edge, for increased flow, and supposedly less seat wear because the piston simply sits against the seat instead of cutting into it. However, it took them a few tries to get the piston material and shaping, and I suppose the seat design, to the point where slow IP creep was not a common problem. That's where the latest piston that's on the MK25 really shines.
The irony of this was that the knife edge piston was not lacking in flow in any real-world sense, in fact the MK5 and 10 were considered very high performing regs (still are) but SP has long been trying to bump up the raw flow capacity of their piston regs. The MK25 is touted at 300 SCFM, this is the equivalent of emptying an AL80 in under 15 seconds. Since obviously the tank valve and a couple of high performance 2nd stages have nowhere near this type of capacity, one can only speculate about the practicality of that kind of flow.
oncor23
June 21st, 2012, 10:27 AM
"... they told me they lowered the IP..."
I think the only thing they did was to remove a shim. I can understand it from a business point of vue: they did something and collected some money against it; whatever extra they have to do is pure loss. If they had to throw in a new seat, that'd be another extra loss, worth at least $2. Whether or not this is ethical, or even professional, is usually not relevent.
OTOH, I know for sure SP would replace the piston under warranty: a LDS over here confirmed it. But since this can't be a warranty case, and the specs are nearly borderline, your LDS thought they could get away with it. That's sadly common: I have 1 MK20 and 1 MK25 that were freshly serviced before I bought them, and they had a similar case of creep.
It's a definite possibility that all they did was remove a shim. However, the IP creep has decreased, so maybe they put in a new seat, but obviously did not put in a new piston. It's hard to believe they would not question this amount of creep with a new piston and seat. OTOH, they did emphasize that it met factory specs. But factory specs are based on a lockup after 1 minute....right? I believe you are correct...they don't want to put in a new piston and not have the ability to charge for it. So, they did what they did and are hoping it doesn't get worse over the next few months. On my part, I have the capacity and the desire to keep testing if after every dive.
Of course, you are also correct that this is not a warranty case. It then becomes a question for them...what was the creep before they got it, after they returned it to me after service...and what is it now. That would tell the story on who is actually responsible for the creep...IOW, was the creep already high when I turned it in or did it get high after their service. I should have checked the IP & creep and wrote it down before I turned it in. And then checked the IP & creep after I got it back. That doesn't mean they would accept my numbers...but at least I would know.
elan
June 21st, 2012, 10:30 AM
Will not increased flow capacity improve the dynamic characteristics? That is faster flow will fill the lp hose faster when the inhale starts thus providing less IP drop?
Zung
June 21st, 2012, 02:21 PM
... It then becomes a question for them...what was the creep before they got it, after they returned it to me after service...and what is it now...
That's totally irrelevant.
A good definition of "service" should be some what similar to this: you hand in a piece of gear that's sort of malfunctioning (otherwise you wouldn't bring it back, right?), and they return it in perfect working order in exchange of your money.
Sadly in your case, there seems to be a gross misinterpertation of the term... Or is it because the term has evolved?
elan
June 21st, 2012, 02:24 PM
That's totally irrelevant.
A good definition of "service" should be some what similar to this: you hand in a piece of gear that's sort of malfunctioning (otherwise you wouldn't bring it back, right?), and they return it in perfect working order in exchange of your money.
Sadly in your case, there seems to be a gross misinterpertation of the term... Or is it because the term has evolved?
That was one of the reasons I started servicing the regs myself, there is only one tech I would trust and he would always be overloaded, even in off- peak times , most of the others will actually do more harm than good while servicing.
halocline
June 21st, 2012, 03:26 PM
Will not increased flow capacity improve the dynamic characteristics? That is faster flow will fill the lp hose faster when the inhale starts thus providing less IP drop?
The idea behind the rounded piston was to improve the aerodynamics so that overall flow would be increased, and I suppose more importantly, more quickly respond to IP demands, resulting in less drop as you mentioned. How much that translates into real-world performance is another story. Don't forget, the 2nd stage and the tank valve both have lower flow capacities than even the MK5. The flow capacity of SP first stages gets measured with a supply that has constant pressure and much higher flow than a scuba tank valve, and is measured with all the LP ports open at once. At least that's what Peter Wolfinger said.
Measuring IP drop with a consumer-level gauge mounted on the end of the LP inflator hose does not work well, as I described in a thread a while back.
I've never been able to tell the difference between the same high performance 2nd stage mounted on a MK5, 10, 15, or 20 with the same IP. Higher IP makes a difference IME, but I still like to set my own regs on the low side. There's plenty of flow and I just tune the 2nds to lower IP.
elan
June 21st, 2012, 05:26 PM
Me neither, running apeks scubapro and zeagle 2nd stages on MK5, 20, 25 and zeagle flathead I cannot see the difference. I guess marketing machine just needs fuel to run.
oncor23
June 21st, 2012, 09:16 PM
That's totally irrelevant.
A good definition of "service" should be some what similar to this: you hand in a piece of gear that's sort of malfunctioning (otherwise you wouldn't bring it back, right?), and they return it in perfect working order in exchange of your money.
Sadly in your case, there seems to be a gross misinterpertation of the term... Or is it because the term has evolved?
Follow the money. They were willing to look at the regs after I sent them back and "play" with them, because it didn't cost them anything but time. I suppose if they were busy enough, they wouldn't have done much of anything. But replacing the piston and not charging for it? That's money. They might be thinking...darn...we should have replaced the piston if it was creeping too much when we did the last service...but then they have to explain why the piston went bad since it was replaced in the prior service. Of course, I could be wrong about any reluctance. "Whoops, guess your piston is bad. Here's the bill."
elan
June 21st, 2012, 09:30 PM
Follow the money. They were willing to look at the regs after I sent them back and "play" with them, because it didn't cost them anything but time. I suppose if they were busy enough, they wouldn't have done much of anything. But replacing the piston and not charging for it? That's money. They might be thinking...darn...we should have replaced the piston if it was creeping too much when we did the last service...but then they have to explain why the piston went bad since it was replaced in the prior service. Of course, I could be wrong about any reluctance. "Whoops, guess your piston is bad. Here's the bill."
I think at least they could communicate that to you.
I spoke to my favorite tech many times and he said that he logs everything, how the reg comes in and how it goes out. All the metrics. So they could have communicate it to you and present you with a choice, even before disassembling the regs if it was having that creep, they could warn you , all it takes is one phone call of the secretary. Even if you have paid for the brand new piston you would have still saved your money because you would not waste your time and that would be even in the case when you were getting a minimum wage.
But I guess we are asking too much :)
That very tech once would not disassemble the reg before discussing the potential problems with me and getting an OK to go ahead and fix it. It turned out at the end that I did not have to pay anything extra...
oncor23
June 22nd, 2012, 09:24 AM
I think at least they could communicate that to you.
I spoke to my favorite tech many times and he said that he logs everything, how the reg comes in and how it goes out. All the metrics. So they could have communicate it to you and present you with a choice, even before disassembling the regs if it was having that creep, they could warn you , all it takes is one phone call of the secretary. Even if you have paid for the brand new piston you would have still saved your money because you would not waste your time and that would be even in the case when you were getting a minimum wage.
But I guess we are asking too much :)
That very tech once would not disassemble the reg before discussing the potential problems with me and getting an OK to go ahead and fix it. It turned out at the end that I did not have to pay anything extra...
Yeah...that sounds really great. I guess techs, and shops, range widely in the information they offer. From the full disclosure model that you report to the need to know version I am experiencing. They don't seem to believe that I need to know what is going on with my regs. I bring them in, they service them...the only input they want from me is whether I like how they breathe. And even then, they may disagree with my choice of breathing ease vs ease of freeflow.
Doc Ed
July 14th, 2012, 11:16 PM
Thanks for the links for the SP EBs. Now, because of all you guys, I've jumped in a swell with my 1st SP reg rebuild - an older MK10 without the groove for the spec boot. It has a sharp piston edge, and I managed to get one of the newer gray conical seats. Now, after reading EB 242, I'm not sure if I should change the piston, or will the original piston suffice?
