Which LOCKTITE product would you use on your regulator threads?

[Rred]

Intentional sabotage by whoever you didn't tip well enough seems as likely as anything else.

I seem to remember using Loctite "green" some years ago, instead of blue. In any case I would suggest calling Loctite to ask them about product choice, especially when it involves breathing air and possible oxygen-enriched air contact or leaks. Wet or dry, that's a concern. NASA got a nasty surprise when they were testing dummy space capsules lined with that great new Velcro stuff. And they found out that Velcro will self-combust in high oxygen atmospheres.

So, make a phone call. If no one calls for tech support, some guy at Loctite loses their job.

 

[inka]

I seem to remember using Loctite "green" some years ago, instead of blue. In any case I would suggest calling Loctite to ask them about product choice, especially when it involves breathing air and possible oxygen-enriched air contact or leaks. Wet or dry, that's a concern. NASA got a nasty surprise when they were testing dummy space capsules lined with that great new Velcro stuff. And they found out that Velcro will self-combust in high oxygen atmospheres.

So, make a phone call. If no one calls for tech support, some guy at Loctite loses their job.

Green Loctite is high strengh, blue is normal strengh, there are not made for that purpose. Loctite 565 is a liquid Teflon for steam, air, water, but not O2 approved. I once asked Loctite, and the only product O2 safe they had was the Teflon tape.

 

[Jonny Wishbone]

I think you Pi$$ed someone off and they messed with your gear. I believe that you know how to put your stuff together but I don't believe the wave action disassembled your gear. somebody did it....

 

[ams511]

The main question I have, which was asked and not answered was, Did others experience the same problems? One would think that if this was a common occurrence that the crew would have warned the divers to check all connections during the pre-dive.

 

[Caveeagle]

I use Loctite on *one* thread of my Abyss first stages, because they *will* loosen if I don't, from getting bumped (not hard) in relatively tight overhead environments. This is chromed brass, and excessive torque leads to eventual thread failure. The thread in question gets a very small droplet of Loctite 242 (IIRC) on the atmospheric pressure side of the fitting. No Loctite makes it into the inside of the O2-clean regs. (All my regs are O2 clean. It costs me nothing, basically, and makes them interchangeable at need without worrying about that particular detail.).

Thanks for this comment. I have also found a particular brand/model of first stage that seems to be very susceptible to working loose at the DIN to body threads. I has been reported to be an "improper torque" issue, but I have witnessed it with factory new regs, which you would assume to be torqued correctly. And, newest revision of their tech manual has a new higher torque spec. Problem seems to occur when DIN wheel is tight on tank/valve and not pressurized. Any rotational force to the first stage body can easily cause it to unscrew.

I have also considered a drop of loctite on the ambient (non sealed) side, just to help prevent this. So far, I have not tried this, just because reg manufacturer in question advised against it.

Just to repeat, I would never use any type of loctite or teflon tape on the internal, sealed, pressurized side of my regs.

 

[Kyle Musick]

I am fairly new to diving. However, I've been an automotive technician for over 20 years. Bottom line, LOCTITE is a terrible idea.
Green 290 has a low viscosity and is made to penetrate the threads of nuts and bolts that have already been assembled. So it will end up on both sides of the fitting. Also, it needs to be heated to loosen.
Red 271 is high strength and not made for regular disassembly.
Blue 242 is made for regular disassembly of steel fasteners. There is a very good chance it will damage the plating on the threads or the brass underneath. Even though it is made to be disassembled, it still takes quite a bit of torque to loosen.
None of the LOCTITE threadlocker products above is approved for O2 rich gasses.
Teflon tape or paste is used on NPT threads. On this type, the thread is what actually does the sealing. Teflon on a NPT thread is just a lubricant to tighten the fitting. However, teflon is not recommended to for use with O2 rich gasses (NITROX in our case, cutting torches in my profession). On the O2 tanks of cutting torches, we use a bit of beeswax on the threads to lubricate them since contact with O2 can cause teflon to combust.

 

[jd950]

I assume there were other rigs on the pangas and none of them had this issue or you would have mentioned it. Unless those rigs were "loctite-ed" and stayed functional for that reason, it seems unlikely that is the best solution. If your gear was somehow substandard and unable to take the pounding that other people's gear took, I wold replace what you are using with what worked well for others, Alternatively, the gear was not adequately setup or maintained , in which case I would change the maintenance and prep procedures. As others have said, anal retentive, nerdy or whatever does not really answer that issue; none of us are infallible.

Or, perhaps, as others suggested, you irritated someone who decided to mess with you by messing up your gear, in which case there is no solution. Well maybe a Dale Carnegie course or something.

 

[Endler's]

Vibra-TITE VC-3​

Underwater installation​

Unlike anaerobic threadlockers, VC-3 can be air dried and then installed into a mating part under both fresh and salt water. (Manufacturer Website)

'Fairly certain this is same used on Halcyon book screws...

 

[GF99/99]

Vibra-TITE VC-3​

Underwater installation​

Unlike anaerobic threadlockers, VC-3 can be air dried and then installed into a mating part under both fresh and salt water. (Manufacturer Website)

'Fairly certain this is same used on Halcyon book screws...
View attachment 710406

This product, locktite, or any other equivalent product should NEVER be used on regular connection threads. Do not put any of these products on them!

Backplate book screws is a completely different application.

 

[TrimixToo]

This product, locktite, or any other equivalent product should NEVER be used on regular connection threads. Do not put any of these products on them!

Backplate book screws is a completely different application.

Sorry about the Google link, but... https://www.google.com/url?sa=t&rct...-pdf.612092/&usg=AOvVaw34v6Ig7SujTrOHBN1CLCpJ