My *new* old Scubapro 109

[uncfnp]

I did it! I think. Cleaned, updated with a balanced adjustable upgrade kit from VDH and ran through the regulator check list by couv, et al. So far so good. Even managed to get the exhaust T back on!

Couple of questions...

Following the list, I submerged the pressurized regulator, mouthpiece up, in water. Started free flowing when the water hit the zip tie at the base of the mouthpiece. Does this sound about right?

There were a few small areas of rust that I cleaned. Is there anything that I can put on these areas to help prevent recurrence?

Thanks for all your help and encouragement. Next is an MK 10 that I hope to pair with the 109. Then the real test will be my upcoming dive trip when I'll try them on my pony.

View attachment 213684

 

[redacted]

You might be able to tune it a bit hotter than that , but you might not be able to notice it in use. I like to tune mine so there is a slight leak which I can control with the adjustment knob. Why don't you just loosen the orifice another 1/8 turn and see what you get. I would expect it would leak slightly but stop with about a half turn on the adj knob.

 

[raftingtigger]

I use a little chrome hobby paint on bare brass areas. I even emailed the manufacturer and asked about the paint, toxins, sea water, and breathing path - they said there was no issue after curing. Of course you can keep the paint to the outside only, or do nothing at all and just soak in fresh water after diving.

Congrats on joining the dark side.

---------- Post added July 29th, 2015 at 03:01 PM ----------

Then the real test will be my upcoming dive trip when I'll try them on my pony.

Put the GOOD and tested reg on the pony. You don't want a suspect reg on your emergency supply. Once you are satisfied then by all means use it on your pony. That combo is a solid and dependable set.

 

[uncfnp]

You might be able to tune it a bit hotter than that , but you might not be able to notice it in use. I like to tune mine so there is a slight leak which I can control with the adjustment knob. Why don't you just loosen the orifice another 1/8 turn and see what you get. I would expect it would leak slightly but stop with about a half turn on the adj knob.

Ended up adjusting a full quarter turn. Thanks.

 

[Nemrod]

It is really hard to tune regulators consistently without a Magnahelic. It seems that many people tune their adjustable regulators to the edge of free flow with the knob all the way to the stop. I prefer them a little tighter than that, but maybe to the edge of free flow on the primary.

I was not completely happy with my tuning skills on my best 109 set (which uses a clone MkV first with SP heavy yoke, why, because it is better and I have parts) so one of the "usual suspects" 109 gurus who had a look see and worked on them some. They were good before but even better now, I just wanted to make sure they were at their best. Of course, my biggest complaint then and now about the 109s are the smallish exhaust valve and not much can be done about that other than having a quality valve.

Congratulations on the new regulators.

James

 

[redacted]

It is really hard to tune regulators consistently without a Magnahelic. It seems that many people tune their adjustable regulators to the edge of free flow with the knob all the way to the stop. I prefer them a little tighter than that, but maybe to the edge of free flow on the primary.

I was not completely happy with my tuning skills on my best 109 set (which uses a clone MkV first with SP heavy yoke, why, because it is better and I have parts) so one of the "usual suspects" 109 gurus who had a look see and worked on them some. They were good before but even better now, I just wanted to make sure they were at their best. Of course, my biggest complaint then and now about the 109s are the smallish exhaust valve and not much can be done about that other than having a quality valve.

Congratulations on the new regulators.

James

Small exhaust valve is not a problem as long as you exhale slowly.

 

[halocline]

Following the list, I submerged the pressurized regulator, mouthpiece up, in water. Started free flowing when the water hit the zip tie at the base of the mouthpiece. Does this sound about right?

I basically tune them to the edge of free flow, then tighten 1/8 turn, or maybe a little less. You can get them to crack at a very low effort, maybe .5" of water, but they will not be stable underwater unless the cracking effort is at least equal to the difference in depth between the exhaust valve and the point where the diaphragm meets the lever. This is something called case geometry fault. There are posts about it on this forum and an explanation in the regulator savvy book, but the (sort-of) bumper sticker version is that the exhaust valve is a little shallower, and therefore subject to less pressure, when you are diving horizontally face down. Because it is the "out" valve, pressure in the case of the regulator will never exceed the pressure at which the exhaust valve opens. So, if the cracking pressure is less than the difference in pressure between exhaust and diaphragm, that small difference will cause the lever to move and open the inlet valve. Hello free-flow! This actually can get a bit worse at depth because the thicker air increases the venturi assist, lowering pressure in the case a bit more.

I guess that's a seriously long bumper sticker....just set your reg at a nice-and-easy-but-not-too-close-to-flow and you'll be okay. Or celebrate your new hobby by purchasing a magnehelic as a reward for yourself, then use it to set the reg to between .75 and 1" of water. Or set it hot, if and when it starts to flow, turn the adjuster in a bit.

 

[Eric Sedletzky]

I set mine right to where they stop hissing with the knob completely out. After the new seat settles in it may loosen up a bit to where you have to turn in the knob some. Congrats on the new hobby and welcome to the DIY brotherhood/sisterhood.

 

[uncfnp]

Update.

Went for my first dives since rebuilding my 109. Used the first dive to get in the scuba groove then switched my alternate to my 109 during the SI and splashed with my fingers crossed and the adjustment knob cranked way down. Giant stride, so far so good. Dropped to the bottom, got comfortable, switched over and opened it up all the way.

Wow! It actually worked. Perfectly. I can't see myself ever taking a second stage in for servicing again.

Next up, an MK 10.

 

[Keith.M]

Congratulations of the self service! I'll have to check it out next week!

Packing my gear...