Servicing my own gear

[wizbangdoodle]

Thanks again everyone. You may have saved me a big wad of cash. Now...what should I spend that money on?

Still interested in more opinions if there are any.

 

[bl6394]

My biggest concern is getting the parts needed to do this work. As far as I know, neither Atomic or Scubapro uses unique o-rings. I remember years ago when I was rebuilding a Beuchat for a customer and I had to use an off the shelf o-ring. I could not get that reg right until another tech told me it has to be a Beuchat o-ring.

They were referred to as proprietary in the service tech class. They are said to be EDPM. As there is uncertainty about the material and hardness, you should be able to find service kits on the grey market ( eBay, TDS, etc) - from time to time. Or you could make friends with a local shop that will supply you quietly.

I've never tried to cobble together a generic parts kit for scubapro. But as a shop employee - I've never had to.

 

[bl6394]

Something else you might find handy... I use a jeweler's loupe (10x) to inspect parts for damage: knife edges, etc. If everything is perfect - you can just put it back together. But if something is damaged - the loupe makes it easier to see.

 

[halocline]

You don't need the inline tool, you don't need the flow vane installation tool, you don't need a magnahelic, and I believe SP o-rings are EPDM (not "EDPM") duro 70 except for the HP piston (010) which is a duro 85. There's nothing special about SP o-rings, you can easily get high quality o-rings at a number of suppliers. Nitrile and viton o-rings are fine as well. In general, o-rings that are subject to high pressure gradients that could cause problems with extrusion should be a higher duro. I use duro 90 o-rings for the HP piston spot and the HP seat seal.

SP has used different materials for o-rings throughout the years; they were using polyurethane for the piston for several years and claimed it helped performance. But then they abandoned PU o-rings, I suspect due to concerns about shelf life, but that's a guess. The point is, the exact material is probably not that important as long as the o-rings are the correct size and an appropriate hardness.

There is a lot of good information on this forum if you search. You can look for posts from DA aquamaster, awap, couv for good info. There are others as well. I would start with the Vance Harlow book, then read reg savvy, and feel free to ask questions on this forum.

Before you spend any significant money, spend some time asking more questions on this forum and you will get some honest information based on experience.

 

[halocline]

Something else you might find handy... I use a jeweler's loupe (10x) to inspect parts for damage: knife edges, etc. If everything is perfect - you can just put it back together. But if something is damaged - the loupe makes it easier to see.

That's a good suggestion; I also use a jeweler's loupe to inspect parts.

 

[bl6394]

You don't need the inline tool, you don't need the flow vane installation tool, you don't need a magnahelic, and I believe SP o-rings are EPDM (not "EDPM") duro 70 except for the HP piston (010) which is a duro 85. ....

Ethylene Propylene Diene Monomer - EPDM... so Halocline doesn't have to correct me a third time. To his point - if you want to go through the trouble to verify the proper size / hardness / material off each o'ring - and source the HP seat and poppet seat separately - you could try to do that. I suspect you'll have an easier time finding Mk25 / G250 service kits on the grey market.

Each of the other tools has pros and cons. Generally time for money.

The inline adjustment tool permits you to dial the second stage cracking pressure in without unscrewing the hose for each adjustment. For $73 from scubatools.com - it was worth the money for me.
The flow vane tool is not used for installation - but for removal of the flow vane. They are hard to pop out without damaging the flow vane - and not easily accessible by an alternative tool. Again for $14 - it was worth my money. And occasionally, if the vane has been in there forever with a hardened o-ring - you'll break the vane anyway...
I qualified the magnahelic with (if you want to tune to factory specs). If a water test is good enough for you - the magnehelic is optional. Again - I found an ebay 4 inch guage to measure vacuum in inches of water - and built my own magnahelic for $70.

In fact - there is a similar one there now: Dwyer 2310 Magnehelic Differential Pressure Gauge (5-0-5"w.c.) | eBay

 

[redacted]

...
I qualified the magnahelic with (if you want to tune to factory specs). If a water test is good enough for you - the magnehelic is optional. Again - I found an ebay 4 inch guage to measure vacuum in inches of water - and built my own magnahelic for $70.

In fact - there is a similar one there now: Dwyer 2310 Magnehelic Differential Pressure Gauge (5-0-5"w.c.) | eBay

Resolution is a bit too coarse on that gauge. Other that provide better resolution in the 0 - 2 inch range are what you need if you are going to go that route.

Most o-ring applications provide plenty of leaway on hardness and material and even some on size. But other applications like the HP piston o-ring can be very touchy.

Many scuba tools afford simple work around so think twice on those high price tag items. Others like the bullet tool, which you do not need for your Mk25, will be very useful as your stable grows. A pair of divers really should carry a complete 3rd setup to the dive site for backup. And, when service cost are close to nothing, there is no reason to not add another......and another......and another......

Good luck.

 

[tbone1004]

also noted is that unless you are using very rich nitrox mixes, if you are spending considerably more for "nitrox compatible" parts kits you're throwing money away. It doesn't hurt and if it's only a few dollars more then fine, but most of the time the Nitrox kits are close to double.

also, same opinion on the flow meter. If you have the money to burn and want to burn it, they're nice to have, but they are a time saving measure more than a quality improvement imho. The biggest thing is to make sure you have two tanks available, one at ~500-600 ish psi, the other full. First to seat the regs and get initial IP, the other to finish it off. I will say the HF ultrasonic that I linked does work, but it takes a lot more time than the more expensive ones. I got it at 50% off sale and I can wait the 15-20 mins it takes to get some of the nastier stuff off when I'm doing a first service on regs that I have bought used. My regs are almost exclusively used in fresh water, so once the initial crap is gone, it doesn't come back which makes it impractical for me to justify a crest/branson/L&R at this point.

 

[redacted]

I don't know of any reg service kits that are not recreational nitrox compatible with the right lube. Those high $$$ kits are usually O2 compatible which is overkill for most divers.

 

[wizbangdoodle]

Again, this is really good information. I was told (many years ago) that standard o-rings would break down much quicker in a nitrox enviroment. This was just as nitrox was coming into it's own and becoming popular. It was also a dive shop, so maybe they just wanted to sell the higher priced kits. If standard 0-rings work fine, that is good news.