MK10 Rebuilding Mods and Best Practices

[Timmyjane]

I have several MK10s to service.

I have come across a few comments here and there such as:

• Remove the polished surface from the piston stem o-ring.
• Micro-mesh the piston hard seat.

These comments were made as modifications to try. I don't know what they mean or what improvement these examples might make.

Does anyone have any servicing best practices and must do improvement mods?

 

[Mobulai]

the moment I see „micromesh“, I’d consult @rsingler ..
I know I have a few posts saved about this (not mk10 specifically — i think it was about an atomic); I’ll look in my dusty saved section and link them in a follwup reply

 

[Mobulai]

Found it, indeed it was an Atomic 1st, but I believe it’s easily extendable to the mk10
Mega thread
One simple thought I have about recommended mods is, if it has space for spec boot (groove over the env chamber) you might wanna reach out to/look up posts/comments by @James79 or @Angelo Farina and @rsingler about making these silicone rings; they have been working on diy revival of that „part“ for a few years now.

I wanna get my hands on some spec boots as well

 

[Mobulai]

Aand just saw this post as well, 2nd part discusses mk10 and micromeshing, but in context of cleaning and re-lubing

 

[Pressurehead]

OK, do you have one of these?

Piston Bullet for Scubapro First Stages

Since the knife-edge end of a flow-through piston is delicate and essential for the proper functioning of the regulator, this tool is used to guide the piston assembly though the first stage body while protecting the critical knife-edge and preventing damage to the piston stem o-ring. The tool...

scuba-clinic-tools.com

Please read why if you do not.

 

[Timmyjane]

OK, do you have one of these?

Piston Bullet for Scubapro First Stages

Since the knife-edge end of a flow-through piston is delicate and essential for the proper functioning of the regulator, this tool is used to guide the piston assembly though the first stage body while protecting the critical knife-edge and preventing damage to the piston stem o-ring. The tool...

scuba-clinic-tools.com

Yessir. I designed and printed one from ABS. I have shared the file here on ScubaBoard as well.

A repository of 3D print STL sources

Hello, Has anyone developed a compass holder with a mount for a light to illuminate the compass? https://www.emergencyuk.com/exhibitor-products/v3-led-flexi-light-sticks-8-lumens

scubaboard.com

 

[Timmyjane]

@Mobulai I have read on the SPEC boot DIY stuff. Seems it kind of fizzled out. One of the regs is able to accept a boot. It would be good to have that one ready for the dirty water I am hoping to dive in one day. I do have a MK25 and a MK18 that I believe I could use in the dirty water if I could get them rebuilt.

Thank you for all the links that you have found and posted.

 

[Pressurehead]

Yessir. I designed and printed one from ABS. I have shared the file here on ScubaBoard as well.

Well done, not having a 3D printer [or know how to use one] it is not an area I look at.
I will climb back into my analogue box with my old school brass one.

 

[rsingler]

@Mobulai I have read on the SPEC boot DIY stuff. Seems it kind of fizzled out. One of the regs is able to accept a boot. It would be good to have that one ready for the dirty water I am hoping to dive in one day. I do have a MK25 and a MK18 that I believe I could use in the dirty water if I could get them rebuilt.

Thank you for all the links that you have found and posted.

Having a SPEC Boot, DIY or original, requires a groove that allows the boot to serve as a reservoir for piston and lube movement. Though it's been done, a boot for the Mk25 or Mk18 has no accompanying groove, and hence no reservoir.
Though it's beyond the scope of this thread, I would strongly caution you against trying to seal a Mk18 or Mk25 unless you understand what makes the Mk10 SPEC boot work. It's kind of a matter of life and death below 60 feet.

 

[rsingler]

I have several MK10s to service.

I have come across a few comments here and there such as:

• Remove the polished surface from the piston stem o-ring.
• Micro-mesh the piston hard seat.

These comments were made as modifications to try. I don't know what they mean or what improvement these examples might make.

Does anyone have any servicing best practices and must do improvement mods?

The recommendation to remove the polished surface for the piston shaft oring is a crude solution to an old problem.
If you drive hard around a curve on a smooth asphalt road, you may roll your car. If you do the same thing on a cobblestone street, you'll just skid.
By decreasing the surface contact area by roughing the oring, you'll decrease friction. But at the same time, you'll increase wear. The better solution is to increase Durometer.

As for Micromeshing the HP seat, yes. You can polish an old flat seat and Micromesh out the groove and use it again. But the flat seats had far poorer gas flow than the newer cone seats that come in those expensive Mk10 service kits. The cone was adopted for both the Mk5 and Mk10 because the flow was so much better. You can't Micromesh a cone seat.

Tips for best performance out of a Mk10?

- Micromesh the knife edge to smooth and perfect
- Use Micromesh on a pencil or a Travers abrasive cone to work on the piston.
- Get a USB microscope to inspect your restoration
- Find a red spring

The regs are great! And yes - the Mk10's with a SPEC groove can be sealed for dirty water with a bicycle inner tube.