Sherwood SR-1 "Problems" - request for first-hand experience

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

rsingler

Scuba Instructor, Tinkerer in Brass
Staff member
ScubaBoard Sponsor
Messages
8,272
Reaction score
12,286
Location
Napa, California
# of dives
500 - 999
Sherwood can't get no love out here on the West Coast. Cramer Decker was uneven as a supplier for awhile, but Sherwood has one of the oldest histories out there. Sherwood was the first company I was certified on as a regulator tech, and their designs remain unique. The SR1/2 first stage, with its two-piece piston assembled by the service tech from both sides of the HP o-ring, has the largest flow of any piston on the market, Scubapro included. And it's dry sealed, in a fashion different from the Sherwood air bleed valve that raised questions of a "leak" in so many divers' minds.

Their second stage design is standard barrel design with a micro-adjust like the top of the line Scubaro G-260. Its orifice is uniquely adjustable without removing the hose, using its external sleeve (part #17 below). And it has a combined Venturi and cracking effort single knob adjust that predates Aqualung's "new" MBS by a full ten years!

If we can minimize the thread derailments, I'm looking for actual first-hand experience with problems involving the SR-1 reg set. I'd like to see what actual issues have arisen, beyond the usual leaks from faulty factory assembly and the like. I mean, I reported on my recent Scubapro problems with my Mk19 factory assembly and tuning, yet SP has a huge following. I'm not asking as an apologist for Sherwood; I'm asking because I'd like to know what the issue was!

At one factory seminar, the SR-1 had just been introduced. The rep mentioned that there had been "some issues" with second stage tuning, implying that the poppet spring was catching, and implied that the coming SR-2 would have an antifriction washer inserted at one end. But looking at the schematic, that never happened.

In fact, if you look below at the SR-2 schematic, virtually nothing but a few orings have been changed between models. The LP seat is new, and the ads promote some new anti-set capability probably due to a change in material, maybe like Atomic's. Yes, the case has a new logo, and the mouthpiece is different. The micro adjust went from a hex adjust to a slotted design, but the part number didn't change. Otherwise, I can't see anything significant.
20201101_114128.jpg

So what really was wrong with the SR-1? Who knows, first-hand? I love mine! It hasn't given me any problems at all. With a huge exhaust valve, the total WOB is very low, and the plastics are sturdy. The only Service Bulletin that I have is from 2009 and refers to a scattered number of loose first stage swivels on five undertorqued runs of regs.

Looking for some help here, to flesh out the rumors.
 
I had one come across my service bench with a destroyed HP seat. I'm not sure what caused it. It may not have been the fault of the reg at all, but it came in right after a new Magnum came in with a destroyed HP seat as well which put a bad taste in my mouth for their newer stuff.

I love the concepts behind the SR2. The diaphragm/piston marriage, the floating orifice in the 2nd stage, but their execution doesn't seem to be hitting very well.
 
A good friend bought one, it creeped 7 PSI out of the box. He brought it back, they couldn't fix it. They told him it would 'break in' and stop creeping after a few dives. Then the environmental seal diaphragm on the 1st stage popped off when he pressurized it. They fixed that, it still creeped. A year later they gave him a new reg, which I think was a SR-2. That also creeped, but a little less, like 5 psi, brand new. I sold him a nice MK20/G250 which breathed much better (IMO) than the sherwood. At least the 2nd stage was tuned well and it didn't creep.

Eventually sherwood gave him another new SR-2 and I haven't seen that one yet, but he's using it.
 
No experience diving these but in servicing them I have run into a few issues. The micro adjust (#28) is almost always stuck and you will strip it making the removal much more challenging. The external adjustment and floating orifice design seems to work well but in my opinion is a bit over complicated.

Another issue I ran into was when torquing the yoke retainer (to spec) all of the threads broke off (not stripped) with no damage to the 1st stage body. I also don’t love the two piece piston. Far too many opportunities for a careless tech to damage the sealing surface.

edit: after rereading the original post I realized you are asking specifically about the SR1 all of the issues I have come across have been on the SR2.
 
The micro adjust (#28) is almost always stuck and you will strip it
I guess that explains why they went from a hex to a slotted part even though they tried to hide it by keeping the same part number. Does the slotted version come loose any more easily? Plastic-to-plastic galling is as common as it is with stainless steel threaded items. I lightly lube a lot of plastic threads that the manuals never call for. Well, it's not really galling, but the frozen parts phenomenon is identical to the SS problem.

I also don’t love the two piece piston. Far too many opportunities for a careless tech to damage the sealing surface.
No argument about the risks of having to assemble the piston, but that was the only way they could overbalance it and have the more bulbous knife edge span the narrower HP shaft.

Thanks for all this info! It sobers my enthusiasm for this reg.
I'm sure their engineers won't take "over-engineered" as a criticism. :D
 
If the gummy/sticky material is like emergency radio rubberized coating originally, then it's the rubber breaking down. The gummy/stickiness can be removed with a rag and isopropyl alcohol. Look up something like "emergency radio sticky" to find videos.
 
Leprechauns resurrection, just picked up an SR 1, mostly interested in the first stage, it’s you fault Rob and George!
 
..... yep, I seem to have that itch too... haven't gotten mine yet...

and no interest in the second stage either....
 
https://www.shearwater.com/products/teric/

Back
Top Bottom