The pros and cons of rebuilding your own regulators...

[MikeFerrara]

Braunbehrens once bubbled...


The reason the tech courses don't use torque wrenches is most likely because they assume that most shops simply don't have them. I think that you can service most regs without a torque wrench, but using one it obviously better.

Some torque values are just plain wrong. The torque value on an Apeks DS4 DIN first stage, for the din connector is too low. You want that thing really tight, otherwise it will come loose. Should it come loose, you'll notice as soon as you charge the reg, so it's just a nuisance. However, take it to any dive shop, and they'll just tighten the heck out of it.

I guess with a torque wrench you could be certain of getting it wrong then. LOL But honest, the folks in the repair shop at (at least some of) the manufacturers aren't using torque wrenches. They are not the recommended or required tool listed in the repair manual. They also list torque specs for things like port plugs. Is there any one here who uses a torque wrench for these?

As for a magnahelic, no need to spend a lot of money. You can perform the same test by simply sticking the second stage in a sink filled with water. You want to see airflow at 2 inches, and you'll see that when the water level is near the top of the mouthpiece. If it's more than that, the reg isn't adjuste properly anyway.

But a magnahelic is better?

Genesis has said a lot of stuff I might say, so I'll shut up now, but I just want to point out that how long you've been diving has NOTHING to do with knowing how to service your regs. A novice diver might be great at it, and a seasoned veteran might not know the difference between a turret and a diaphragm.

He always has a lot to say. You're right, though diving experience has nothing to do with ones skill as a technician. One can be full of it no matter how much diving they have done.

Maybe I should have asked what his engineering background is. This might indicate his ability to read a technical specification intellegently. In manufacturing, we have specs for everything but we actually measure very few of those parameters. The decision to "measure" is based on the likelyhood that it will be wrong and the likelyhood of it effecting functionality and the severity of that effect all weighed against the cost and effectiveness of the measurement to manage the risk. The best place to fix such problems is always in the design. Notice we don't have dead divers all over because shops aren't using torque wrenches. Funny how that works huh?

considering how worried about liability every one in scuba is if the manufacturer determined that a torque wrench was required to service one correctly it would be stated as a requirement. It makes no sense to design reg repair training to the tools they expect technicians to have rather than the tools that are required to do the job correctly. To do so would be legal suicide. It would amount to intentionally training technicians wrong in the repair of life support equipment.

 

[otobmark]

I was going to stay out of this thread, really.... oh well. When I went away to college and had to occasionally cook for myself (and you think rebuilding your regs is dangerous), Lacking an instructor I would read the directions off of the package. So I see a "pinch" of salt; not an actual measurement in grams, mind you, but a pinch. What the *^& kind of spec is that? Well I muddled on nearly loosing all when I came to the step "FOLD in 4 eggs??!" Fold? Eggs? What the.....$%*.
Well here is where the torque wrench comes in. If I lack experience, and don't know what the right "feel" is for seating spark plugs then a 14ftlb setting on a torque wrench is a really good idea. It is certainly easier to give that spec than explain what it feels like when the washer begins to crush good but not quite bottom out. With experience you know when you are getting dangeously close to stipping out a bolt into aluminum. During a stint working on cars, expensive cars, I used quite a few "measuring" devices including torque wrenches. If something went wrong I could swear under oath (or lie detector) that I had put the part to spec. I slept better. On my own car I was much more likely to "feel" things into place. Same with parts, I used OEM. Sometimes there are forces at play that I don't know about. Brake caliphers are usually attached w/ relatively soft bolts--they are less sensitive to vibration and shattering. It would be easy for a person to assume that using a "higher" grade bolt would be better (in this case it wouldn't). Everybody with me?
I will never belittle anyone for using "objective" means to calibrate their work. A master tech w/ good hands may outperform his torque wrench (feels a little stickyness in the threads, overtorques a little to compensate etc.) but specs and the tools to measure them are certainly a very good and safe way to work. Germans measure, Italian feel, both make fine cars, but if my life depends on it I think maybe the Germans win out---but, those Ferrari's win a lot of races-IF they finish!

 

[ScoobieDooo]

PM me for the name of a UK source for Apek's....

 

[Braunbehrens]

Thanks for not publicly posting info on where to get parts. We want to make sure these shops don't get in trouble.

 

[diverbrian]

I have read the whole vitrolic line of posts. My conclusions are these:

1. I do not service my own equipment, I do not have the proper tools, training or parts. I didn't service anything that I wasn't trained on when I was an instrument tech and nuclear reactor operator on U.S. Navy submarines either. Why? I knew how easy it is for an untrained person to miss that important little sentence in a tech manual that could cause major problems. When you are trained (and even better yet after you have some experience), you learn what is critical to follow as it is human nature to skim some portion of a twenty page procedure, even if you are disciplined. In short, you learn what NOT TO SKIM AT ANY COST even though you will always strive for perfection.

2. I do trust my LDS technician to do it. The man's creditials are displayed. He uses an ultra-sonic cleaner and is obsessive-compulsive about how his work area is arranged. He dives the same types of equipment that I do and does his own maintanence. He hasn't lost a diver yet. He did show me how to put my tech gear together and set up my regs for tech to save him time (He doesn't do these things, I do now.). He also has been diving for many years (since the seventies) and has built his own submarine from stratch. If his maintenance was faulty, he would have been injured long before now. I will not put my inexperience up against his skills.

3. Basic things: I trust no one else to do them but myself. Not because I am better, but because if I screw it up I have only myself to blame. This list includes changing LP and HP hoses on regs, analyzing my own Nitrox, and setting up my own gear. In these cases, these are things that I know how and have been trained to do by the appropiate people along with some of the experience that I have in instrumentation.

4. Accidents and mistakes happen. The most likely time for them is after any type of service on any type of equipment as some sort of change has just been made. If you aren't doing the service frequently (rather once a year if it is just your own gear), how proficient are you at it? Does not that lack of proficiency increase the risk of a mistake? Think about it. As a soon to be DiveCon, I worry more about the diver that certified say, a year ago or more and hasn't gotten wet since their open water training than the diver that certified last week. We can't MAKE a diver take a refresher course. We can just recommend it. I am sure that many experienced divers have run into this situation. I test my gear before I go into the water by the book. If one piece fails, I have redundancy even in my recreational gear for my critical pieces and the training to use it. Mistakes by a maintenance person are a statisical fact. They will happen. I just ask that the person makes it right when they do.

If you are skilled enough to do your own work, I applaud you! But, for the rest of us that happen to have a good LDS and maintenance section, I would recommend that they stick with the professionals and use the time to dive!

 

[Genesis]

you will quickly see just how simple these things really are.

Quite seriously, all the hype about "complex" is a load of BS.

Finding a scrap reg you can disassemble shouldn't be too hard, and if you still feel, after having done so, that this is "hard" or "complicated", then I agree - you should have someone do it for you.

Frankly, its harder to change the oil in a car than to rebuild most regs.

 

[ScoobieDooo]

Genesis,
I have Vance Harlow's book and agree that it looks pretty simple - but what has me concerned is - am I setting the 2nd stage cracking pressure correctly? Is it too sensitive? Or not? If I don't have an inline adjuster - can I still do it correctly vs. a shop that has all the fancy gauges, tools, etc? Can I still do an adequate job with a homemade manometer or by using the bathroom sink trick for cracking pressure?

 

[Genesis]

It just takes longer.

A magnehelic gauge is just a water column pressure gauge. Water column is water column.

The inline tool just makes it FASTER (you don't have to depress and adjust, then repress and check, etc.) Besides, they aren't THAT expensive, and are pretty much universal.

 

[ScoobieDooo]

True, I have seen them for around $70.

From what I read, I needed a few simple tools such as a spanner wrench (Apek's), cover tool, snap ring pliers, IP gauge, torque wrench, few open end wrenches, crows feet wrenches, hex wrenches, 1st stage holder, Christo Lube, etc.

 

[Genesis]

Cover wrenches and spanners may be unique to a given line, and you want them because otherwise you'll damage things getting them apart.

The only real "required" special tool beyond that which the manufacturer sticks you with is an IP gauge, which is essential. You should own one anyway, even if you don't do your own rebuilds, as its a good "fast check" for the health of your 1st stage - if it will hold IP reliably, its probably all right, and if not, you really need to fix it one way or another.