Video Breakdown and Repair of ScubaPro 109. Convert to Balanced? What would you do differently?

[NYCDiverBlue]

This post/thread is a fork of another thread(below) that I started. This thread is to cover detailed questions about the ScubaPro 109, it's breakdown and repair and conversion to a Balanced reg.

Best used regulators? First stage? Second Stage? What exactly is Conshelf?

Based on the kind input of @couv and @buddhasummer , I found this video of a 109. I do not believe this is showing how to convert the 109 into a Balanced regulator but he does mention it.


And if you watch the 2nd video of his on poppets, he discusses the Balanced poppet assembly at 2:34 in the video.

Questions:

1. What would you do differently than he does with regard to breakdown and repair? Would this differ if you are an occasional rebuilder vs frequent.
2. To convert a 109 to a Balanced 109, does one have to simply change to the balanced poppet that is mentioned at 2:34 in the 2nd youtube video on poppets above? If so, I can see how the poppets function differently from the video. Could someone pls explain how the other poppets function differently from the balanced poppet.
3. What other questions would you ask or information that you think one should be aware of?

Thanks in advance.

 

[buddhasummer]

1) I would convent it to the S wing poppet ala BA. No different regarding frequency.
2) it's as simple as replacing the lever to a curly foot .141, a new S wing poppet, spring and balance chamber. As for functional differences (?) I'll leave that to one of the gurus.

Yes, It's as simple as it looks.

When I was converting them, as par for the course I'd replace, O rings obviously, the orifice, S wing poppet assy, curly feet lever, spring and balance chamber. I sell the kits for $55 plus shipping, all new stock OEM parts.

 

[Couv]

Servicing the BA vs. 109 is almost the same. There are a few more parts to the balanced poppet assembly. You don't need any special tools for the job. Cleaning can be done with elbow grease, toothbrush, pipe cleaners, gun cleaning kit, etc. A sink or bucket can replace a manometer for the occasional DIY guy. See the attached document that explains the SP poppet evolution and differences.

If you have an unbalanced 109 that is paired with a balanced first stage, there is little reason to convert it to balanced. However there are a few advantage each has over the other:
1.To convert an unbalanced to balanced is expensive. You need a poppet assembly, spring (the springs are not the same) and balance chamber.
2. Once you have a new Duro poppet (unbalanced) installed, service parts are easy to come by and inexpensive.*

The advantages of a balanced poppet (S-wing poppet):
1. Will better tolerate IP swings.
2. Holds tune a little longer due to less spring pressure when not in use.
3. If you have nothing better to do while diving, and lay on the bottom with a BA in one port and a 109 in the other, on a good day you may find the BA is a tiny bit smoother.

*I don't want to over exaggerate the price difference in the two service kits-its only a few dollars.

 

[herman]

I have been watching these threads from the sidelines, nice input guys. Buddha, if you are ever on this side of the planet, we 3 need to get together for some diving and have a beer, NYC you can join us too.
Let me add a little generic info to the conversation.
The purpose of balancing a reg is to keep the work of breathing (WOB) of the reg constant throughout the range of tank pressure, in other words, it breaths the same with a full tank as it does with an almost empty one. To accomplish this, EITHER the first OR second stage can be balanced. While most manuf balance both it is redundant and not necessary to accomplish the objective, besides except for the very low end regs, no unbalanced first stages are produced today. By balancing the first stage you keep the IP at (almost) constant pressure from a full tank to an almost empty one, there is typically a few PSI change but it's small enough that no diver can tell the difference when paired with an unbalanced second stage. Conversely, if you balance a second stage, it compensates for varying IP (within reason) as the tank pressure changes when paired with an unbalanced first stage. The change in IP of a modern unbalanced first stage is in the range of 15-20 psi. The major disadvantage to balancing the second stage is the increase in parts and complexity, it's not a lot but still there. In and of itself, balancing does not increase the performance of a second stage but typically balanced seconds are higher end models so the surrounding design features do increase performance. This is not the case when discussing the 109 vs 156 since both use the exact same case parts. Comparing 2 that were set up by the same tech, I doubt anyone could tell which is which. I will add that 99% of the performance of a reg is determined by the second stage which makes the argument of which first is better a mute point. As long as the first stage can deliver enough gas to supply the diver and keep IP within a reasonable range ( all modern first, including unbalanced flow by pistons -MK-2 for example ) when paired with a good second stage, the diver can not tell the difference, conversely, the best first stage available when paired with a poor second stage will perform poorly.

My choice....the Conshelf (or early Titan) first with a 109.

 

[Bryan@Vintage Double Hose]

3. If you have nothing better to do while diving, and lay on the bottom with a BA in one port and a 109 in the other, on a good day you may find the BA is a tiny bit smoother.
/QUOTE]

This

 

[NYCDiverBlue]

By balancing the first stage you keep the IP at (almost) constant pressure from a full tank to an almost empty one, there is typically a few PSI change but it's small enough that no diver can tell the difference when paired with an unbalanced second stage

@herman Thanks. I just watched this video by Alec Peirce the other day(only watched a couple of his videos but really like them). The difference between a $300 regulator and $1000 regulator. While he makes the point about how first stages are built today and that one wouldn't normally be able to tell the difference, you give some additional information. Anything you would add to his video?

Scuba Tech Tips: Do You Need A 'Balanced' Regulator? - S07E11

I will fork this thread to start a New thread: Best video channels to learn about scuba diving.
What are the best youtube channels that you recommend for learning about scuba diving. My favorite so far is
Alec Peirce Scuba
Alec Peirce Scuba

I was looking for a forum to post the above in Scuba Board but I didn't find a forum/sub-forum called Diving Education. Am I am missing something? What forum would you post this the above in? Do you think there should be a forum called Diving Education where the general subject and specifics of the teaching of diving should be discussed. There is the basic and advanced scuba forums. I sent an email to SB recommending a Diving Education Forum.

thanks

 

[buddhasummer]

I have been watching these threads from the sidelines, nice input guys. Buddha, if you are ever on this side of the planet, we 3 need to get together for some diving and have a beer, NYC you can join us too.
Let me add a little generic info to the conversation.
The purpose of balancing a reg is to keep the work of breathing (WOB) of the reg constant throughout the range of tank pressure, in other words, it breaths the same with a full tank as it does with an almost empty one. To accomplish this, EITHER the first OR second stage can be balanced. While most manuf balance both it is redundant and not necessary to accomplish the objective, besides except for the very low end regs, no unbalanced first stages are produced today. By balancing the first stage you keep the IP at (almost) constant pressure from a full tank to an almost empty one, there is typically a few PSI change but it's small enough that no diver can tell the difference when paired with an unbalanced second stage. Conversely, if you balance a second stage, it compensates for varying IP (within reason) as the tank pressure changes when paired with an unbalanced first stage. The change in IP of a modern unbalanced first stage is in the range of 15-20 psi. The major disadvantage to balancing the second stage is the increase in parts and complexity, it's not a lot but still there. In and of itself, balancing does not increase the performance of a second stage but typically balanced seconds are higher end models so the surrounding design features do increase performance. This is not the case when discussing the 109 vs 156 since both use the exact same case parts. Comparing 2 that were set up by the same tech, I doubt anyone could tell which is which. I will add that 99% of the performance of a reg is determined by the second stage which makes the argument of which first is better a mute point. As long as the first stage can deliver enough gas to supply the diver and keep IP within a reasonable range ( all modern first, including unbalanced flow by pistons -MK-2 for example ) when paired with a good second stage, the diver can not tell the difference, conversely, the best first stage available when paired with a poor second stage will perform poorly.

My choice....the Conshelf (or early Titan) first with a 109.

Herman, If I ever made it to your corner of the world I would most definitely like it if we could get together and with Robert do some diving and a beer or two. Just need one winning ticket and I'm there, take care.

 

[herman]

I agree with him but I do think he misses the boat a little by not distinguishing between the first and second stage. In the video, he is refers to the regs as a complete unit and while that is the way they are sold, this is a little misleading IMO. While they are sold that way, when buying used, you can mix and match as you like. Like I said earlier, 99% of the performance of the "reg"....complete unit...is determined by the second stage. Put a high end second stage on the cheapest first stage and you can't tell the difference, the reverse is not the case.....in other words, put your money where your mouth is.

Alex does some nice videos. I have had the pleasure of diving and spending time with him on several occasions (March this year).

 

[NYCDiverBlue]

I agree with him but I do think he misses the boat a little by not distinguishing between the first and second stage. In the video, he is refers to the regs as a complete unit and while that is the way they are sold, this is a little misleading IMO. .

@herman I think that he mentions it but makes this very clear in the earlier video which he references. $300 vs $800 regulator I recommend watching both because he covers different information.

In both videos he mentions his video on the venturi assist so I put it below.

I have been watching these threads from the sidelines, nice input guys. Buddha, if you are ever on this side of the planet, we 3 need to get together for some diving and have a beer, NYC you can join us too.

@herman thanks for the invitation, the invitation is returned in kind to you, @couv @buddhasummer and others kindly sharing their knowledge.

 

[Couv]

The videos by www.vintagedoublehose.com are all worth watching even if one does not own the exact same make/model. Alec Peirce's videos too-and I agree with Herman, Alec is a great guy, and an interesting person to talk with.

I'm sure there are other videos out there worth watching, but how about some good old fashion reading? Of course the two books often brought up here are worth reading and owning, "Regulator Savvy" and "Scuba Regulator Maintenance and Repair." I'll attach an article written by my friend @halocline, "A Beginner's Guide to Scuba Regulators."

If that ain't enough, do a search in the regulator and DIY forums for post by @herman, @Luis H, @DA Aquamaster, @captain, @rsingler, @halocline I'm sure there's others.

Still not enough? Go to www.vintagedoublehose.com and https://www.frogkick.dk/manuals/ download service manuals and read through them.