Learning to do maintenance on my own gear, Apeks

[Nemrod]

You pound it with your foot.. now I finally understand imperial units

At least he is not using stones, WTH!

Absolute accuracy to the nth degree is not really needed with regulator maintenance pressure instruments. Being consistent and thorough in procedures is more important.

 

[Mobulai]

At least he is not using stones, WTH!

That’s just a stoneage thing — I said what I said

 

[gratefulmjc]

Orifice adjustment tool, which one?

On my Apeks XTX50s (and XTX200s), the orifice takes a slotted tool (not hex, as noted in an earlier post).

While I use a 2021 Service Manual that covers XTX200/100/50s (but not also the XTX40s noted in your post), a 2013 version of the manual I have covers XTX200/100/50/40/20s with all models having the same part number for the orifice...so I would expect you'll need a slotted tool for XTX40s as well (I expect @buddhasummer could confirm/correct).

Here is a pic of a spare orifice (PSA, it's on a rubber mat) and the Sherwood tool I use for installation/initial positioning of the orifice:

I got the tool from Scuba Tools ((Sherwood Part#20-900-100) Brut Poppet Orifice Installation Tool) when putting together a tool set for the @rsingler reg class (as mentioned in an earlier post, an excellent way to kick start your DIY reg servicing).

If you would like a copy of the tool list I put together for the class, feel free to DM me.

FWIW, I use an inline adjusting tool attached to an inline shutoff valve for setting the final position of the orifice. While I haven't used the Sherwood tool to set the final orifice position...as an iterative process it would mean repeatedly removing/reattaching the hose as well as turning the tank valve off/on, I can only imagine the additional time and effort that approach would require...IMO, the inline adjusting tool is worth it.

Enjoy the DIYing!

 

[happy-diver]

Yep on the way to the happy-design room I grabbed a stumpy screwdriver and went hastily to the shaping shop

Immediate delivery!

Bootifull!

 

[Centrals]

Allen key for the older model or screw driver for the subsequent models up to XTX series.
Analogue IP gauge is dirt cheap and should be in every diver diagnostic kit.

 

[buddhasummer]

On my Apeks XTX50s (and XTX200s), the orifice takes a slotted tool (not hex, as noted in an earlier post).

While I use a 2021 Service Manual that covers XTX200/100/50s (but not also the XTX40s noted in your post), a 2013 version of the manual I have covers XTX200/100/50/40/20s with all models having the same part number for the orifice...so I would expect you'll need a slotted tool for XTX40s as well (I expect @buddhasummer could confirm/correct).

Here is a pic of a spare orifice (PSA, it's on a rubber mat) and the Sherwood tool I use for installation/initial positioning of the orifice:
View attachment 865515

I got the tool from Scuba Tools ((Sherwood Part#20-900-100) Brut Poppet Orifice Installation Tool) when putting together a tool set for the @rsingler reg class (as mentioned in an earlier post, an excellent way to kick start your DIY reg servicing).

If you would like a copy of the tool list I put together for the class, feel free to DM me.

FWIW, I use an inline adjusting tool attached to an inline shutoff valve for setting the final position of the orifice. While I haven't used the Sherwood tool to set the final orifice position...as an iterative process it would mean repeatedly removing/reattaching the hose as well as turning the tank valve off/on, I can only imagine the additional time and effort that approach would require...IMO, the inline adjusting tool is worth it.

Enjoy the DIYing!

You are correct.

 

[Walde]

I'll continue my own thread as I'm slowly getting there…
I'm planning to service my regs in about two weeks when I hopefully get my full mine course finished.
(my first dives after the service won't be in mines)

So far I have gathered all needed tools and service kits for servicing Apeks DST and MTX-R 1st stages and XTX40/50 and MTX-R second stages. For now I want to service my nitrox/trimix regs and oxygen clean is not necessary for 1st stages. Altough I would like to do everything so that it is oxygen clean, just for practice. My regs are in good condition and I mostly dive in fresh water.

For cleaning I would like to use chemicals that are and easy to dispose. Feels like most ready made ultrasonic cleaner solutions that are sold in Finland are some sort of toxic waste.

Cleaning process:
1. Clean my tools, I have used same o-ring picks with torch o-rings, maybe I'll get another set, but still make sure my tools are clean.
2. Disassemble regulators
3. Use powder free latex or nitril gloves for cleaning and assembly
4. Wash parts (including service kit parts) to get grease off:
- Use nylon brush
- Many use Simple Green, Joy, Dawn, … which are not available (or Really expensive) in Finland.
- Anyone have suggestion for similar product available in Finland/Europe?
5. Rinse with water to get all detergent off
6. Wash metal parts in ultrasonic cleaner:
- Use white vinegar with water 1:1
- 10% can be found on all stores here
- 1-3 minutes
7. Rinse with water to get rid of vinegar and everything that ultrasonic released
8. If parts are not clean, then repeat cleaning
9. If parts look clean then rinse with sterile water
- Cheap from pharmacy
10. Blow dry with (clean) air
11. Assemble and use Christo lube on all o-rings

Questions:
1. What to use instead of simple green that is available in Finland/Europe?
- Or what not to use? There are a lot of dish washing solutions for grease removal but which one to choose?
2. Apeks service kits has oxygen compatible parts, but do you use Viton o-rings for 1st stage if it's used with 100% oxygen? Or do you just clean oxygen compatible parts before use?
Quote from Harlows Oxygen hacker:
"While viton is less likely to combust, when it does, it produces fumes that are extremely toxic, even in trace amounts. For this reason, several SCUBA regulator manufacturers have specifically recommended against the use of viton!"
3. Has anyone read this TDI Equipment Service Technician Manual - International Training Online Store and Is it worth buying?

Thank you for all the comments.

 

[Mobulai]

1. What to use instead of simple green that is available in Finland/Europe?

Scent/perfume free dish soap — that’s what I go for

2. Apeks service kits has oxygen compatible parts, but do you use Viton o-rings for 1st stage if it's used with 100% oxygen? Or do you just clean oxygen compatible parts before use?

After reading abit on the boards here thoughts and discussions by other members , I adapted their preference towards EDPM as it has better shelf life, slower degradation towards hardness (in use) and still good enough oxygen fire saftey (I believe @Tanks A Lot and @rsingler have shared these thoughts in multiple threads before — and others too)
Scubapro for example doesn’t use viton and ships EDPM (regardless of o2 clean usage or not). I suspect for similar reasons as this

While viton is less likely to combust, when it does, it produces fumes that are extremely toxic, even in trace amounts. For this reason, several SCUBA regulator manufacturers have specifically recommended against the use of viton!"

Viton is commercial name of FKM; the F is fluoro-; so these funes will be containing hydrofluoric acid of some form — HF is toasty indeed

But… don’t overthink this; christolube is a respiratory irritant according to hazard labels so… it’s kinda impossible to comply this way or the other
I’d rather not have a hellfire underwater dealing with deco over off chance far ahead in life of having issues because some traces of a chemical has impacted my lungs minimally
And if your deco reg burns up — the toxicity is low prio on my concern list
You do your own risk assessment/mitigation strategy

Wash parts (including service kit parts)

you’ve mentioned this (twice)
What do you mean by washing service kit parts; they should be delivered grease free and already clean
Which parts do you mean specifically?
O hope you’re not washing orings

 

[Mobulai]

Clean my tools, I have used same o-ring picks with torch o-rings, maybe I'll get another set, but still make sure my tools are clean

And this is tip top — I do the same but not every cycle; I keep a pick for dirty stuff and another for reassembly
But cross contamination is very real — I agree having several of some specific tools makes it much easier, but if silicone isn’t explicitly needed for an application (I don’t know any sofar but I suspect something like a camera housing sometimes does ) I’ll stick with cristolube

 

[Tanks A Lot]

I try to clear up a few things, but also want to be crystal clear that this is a complex topic, one that can't be fully discussed within a short forum post. That being said, oxygen cleaning as it's done in the SCUBA industry isn't rocket science, as opposed to actual rocket science, like at NASA, where oxygen cleanliness is also very relevant.

Because the two industries differ so much, it's inevitable that our approach is much more basic, which also means it doesn't mitigate the risk as much as it could. This is what gets some very unlucky people into trouble from time to time.

For cleaning I would like to use chemicals that are and easy to dispose. Feels like most ready made ultrasonic cleaner solutions that are sold in Finland are some sort of toxic waste.

That shouldn't be the case. In Europe, I would go for 3M™ Novec™ 7100, Solstice® PF–HP, EnSolv®, Biox Oxygen (O₂), RXSOL Oxygen Cleaner, or EcoLink OOC, just to name a few. AS-BIOX-1 is another very popular alternative, but the truth is there is more choice than I can list here.

Not all of them are specifically aimed at ultrasonic cleaner use, but that's alright. While an ultrasonic cleaner is an excellent tool, for a hobbyist such as yourself it isn't strictly necessary.

Cleaning process:
1. Clean my tools, I have used same o-ring picks with torch o-rings, maybe I'll get another set, but still make sure my tools are clean.
2. Disassemble regulators
3. Use powder free latex or nitril gloves for cleaning and assembly

Excellent so far.

4. Wash parts (including service kit parts) to get grease off:
- Use nylon brush
- Many use Simple Green, Joy, Dawn, … which are not available (or Really expensive) in Finland.
- Anyone have suggestion for similar product available in Finland/Europe?

See above for suggestions for Simple Green replacements. I'm always a bit torn on whether one should wash the replaceable parts. If they come in a sealed bag from the manufacturer and are green-lit for oxygen service, I would not clean them.

5. Rinse with water to get all detergent off
6. Wash metal parts in ultrasonic cleaner:
- Use white vinegar with water 1:1
- 10% can be found on all stores here
- 1-3 minutes

Vinegar is an absolute no-go for me. It astonishes me to this day how it became so ubiquitous in the dive industry. There are many acids one finds around the household or hardware store, such as sulfuric, hydrochloric, oxalic, formic, citric, phosphoric, and acetic (which is vinegar), that do a good job at removing calcium carbonate (the white stuff on your gear). Most of them have severe drawbacks, such as toxicity or chromium(III) oxide removal, that make them unsuitable for us.

If one goes through the list and eliminates the unsuitable ones for various reasons, you end up with phosphoric, citric, and acetic acid. Of those three, acetic acid is just the absolute worst in every single metric I can come up with:

• Calcium carbonate dissolving? It's the slowest, which means the longest exposure time to the H⁺ ions.
• Chromium(III) oxide removal? It's the most aggressive and forms highly soluble chromium acetate, bad for us, as that means chrome removal.
• Dezincification? Acetic acid takes first place again, as it forms soluble zinc acetates, which again is undesirable.

Couple that with its horrendous smell, and I can't figure out for the life of me why people use it in SCUBA. Phosphoric acid is by far the superior choice by every metric I can conceive, and it's not difficult to obtain. Online retailers happily sell it at 85% concentration, which means a bottle will last you a long time. But even if ordering online is too cumbersome, the same shops that sell vinegar almost always sell citric acid, which is also leaps and bounds ahead of acetic acid in vinegar.

Apologies for the long rant, but it’s a topic dear to me, as acetic acid is such a weird choice for the intended job, calcium carbonate removal.

7. Rinse with water to get rid of vinegar and everything that ultrasonic released

Excellent as well. I would add a neutralisation bath to properly remove the H⁺ ions from all crevices, especially threads. A tablespoon of baking soda mixed into a couple of litres of water is an excellent and cheap choice.

8. If parts are not clean, then repeat cleaning
9. If parts look clean then rinse with sterile water
- Cheap from pharmacy

Best choice would be deionised water. Second best would be distilled water. The truth is, tap water is often perfectly fine, especially when parts are blow-dried. Tap water contains minerals, but blow drying prevents these from precipitating.

10. Blow dry with (clean) air

Often overlooked, but one of the crucial steps for me, as it very reliably removes lose particles.

11. Assemble and use Christo lube on all o-rings

Christolube is a great choice, although I'd argue not the best. In the US, Tribolube is very popular. In practice, any good PFPE grease will do a good job. A few that come to mind are Gleitmo 595, Gleitmo 599, Tribolube 66, Tribolube 71, Krytox 206, or Christo-Lube 111. But there are many more.

Products aimed squarely at the SCUBA market often come with the "SCUBA tax", so looking for another suitable PFPE grease may be a wise choice.

Questions:
1. What to use instead of simple green that is available in Finland/Europe?

See above.

- Or what not to use? There are a lot of dish washing solutions for grease removal but which one to choose?

For your very first cleaning step, removing gross debris and particulates, any dishwashing liquid will do. This is only to get to a somewhat clean state and preserve your subsequent washing solutions.

2. Apeks service kits has oxygen compatible parts, but do you use Viton o-rings for 1st stage if it's used with 100% oxygen? Or do you just clean oxygen compatible parts before use?
Quote from Harlows Oxygen hacker:
"While viton is less likely to combust, when it does, it produces fumes that are extremely toxic, even in trace amounts. For this reason, several SCUBA regulator manufacturers have specifically recommended against the use of viton!"

Harlow has written a great book, but he often simplifies certain things. FKM, of which Viton is a specific formulation and brand, is the most logical choice for oxygen suitability. The topic is too broad to fully explain here, but I do want to leave a few pointers.

EPDM is often suggested as being good for oxygen service, but it's horrendous. Of all the polymers you could possibly use, it would likely be my last choice, worse than NBR and certainly far worse than FKM. I believe the myth that it's suitable comes from the fact that Apeks switched to it at one stage, and Apeks is, for whatever reason, very popular with technical divers. Here’s why it’s a poor choice:

• Its heat of combustion clocks in at over 40,000 J/g, while NBR hovers around 35,000 J/g and FKM has a low 15,000 J/g. That means if a fire starts, the EPDM O-ring burns very hot, an excellent choice if our goal was to also set the metal ablaze.
• Its autoignition temperature at 103 bar in 100% oxygen is around 190 °C, while NBR comes in at 200 °C, and FKM leads the pack at 285 °C.

The above should make it clear that EPDM is a terrible choice from an engineering perspective, certainly worse than plain old NBR or the more expensive FKM.

And here’s why people often think it’s more suitable than NBR: EPDM has an oxygen index (OI) of 23.7%, while NBR has one of only 22.5%. People often confuse this to mean EPDM is better suited for oxygen. This is one of the things Harlow got somewhat wrong in his books. The oxygen index states how high the oxygen percentage of the gas must be to support continuous combustion of the polymer. And yes, EPDM needs just over 1% more oxygen than NBR to continuously burn without extinguishing.

But does that really matter if we’re using 50% or even 100% oxygen? The answer is a clear no, it does not.