What do when din fittings are locked shut?

[Kharon]

I would try the proper size screw extractor because I have a full set. The Universal DIN retainer tool looks like it would work depending on how stuck it is. It might slip if it's extremely stuck. The screw extractor won't but will definitely bugger up the opening. Just my 2 cents.

 

[Jim Lapenta]

Someone's used too much loctite on the DIN post threads to hold it in the regulator body.

I had that issue on a DIN regulator recently. That DIN post is now a write off, so no need to be too delicate with it.

I used boiling water and ordinary dishwashing detergent in the ultrasonic cleaner for about an hour. Followed by using a vice grip pliers (see pic) on the end of the din post, alternating anti-clockwise (loosening) and clockwise (tightening) in quick vibration just to get some movement in the threads. Keep that going for a while … if no movement repeat in the ultrasonic bath with more boiling water and dishwashing liquid, then try again …

View attachment 450705

If someone used any kind of thread locker on a reg they should be slapped. Proper torque ensures things stay together. Loc-tite is never used on a reg.

 

[abnfrog]

I ve never had a reg I couldn't get apart , I like that tool (just ordered one ) as it MIGHT save the part but if your going to replace it almost anything will work to get it out ..some one who uses lock tight on a reg should be punched not slapped ..... but an ultra sonic that has heat works great in most cases just strip it down as far as you can

 

[Umuntu]

If someone used any kind of thread locker on a reg they should be slapped. Proper torque ensures things stay together. Loc-tite is never used on a reg.

The Mares manual (quote below) recommends a couple of "drops" of Loctite. But it's too easy to use too much. Or to use the wrong grade of Loctite -- which comes in numerous strengths.

"TO PREVENT THE BODY DIN CONNECTOR (24) FROM LOOSENING, APPLY ONE OR TWO DROPS OF THREAD LOCKING COMPOUND ONTO THE THREADS PRIOR TO INSTALLATION. REMOVE ANY RESIDUAL THREAD LOCKING COMPOUND PRIOR TO APPLYING ANY NEW COMPOUND (LOCTITE 415 OR SIMILAR). "
​

I've had ScubaPro MK11 DIN Regulators (in daily use) keep loosening at the DIN fitting until a drop or two of low hold loctite was used.

​

 

[Rred]

Option #1, take it to any machine shop. They have experience with getting things unstuck. Drilling them out, arc welding a handle to spin them out, all sorts of things you won't usually have at home.

Option #2, use heat--without any risk of melting things. Make a slush out of dry ice and alcohol. Immerse the fitting and give it 15 minutes to get really cold. Now hit it with a hair drier to get it really hot, without getting things "flame hot". Lather rinse and repeat 3x. The intense cold from the dry ice tends to contract things and break whatever is sticking them together, combined with the hair drier or heat gun, it should break out any loctite as well.

Dry ice can cause frostbite, alcohol easily gets set on fire, do take cautions with both.

 

[Joris Vd]

So yeah, i managed to disassemble the entire thing except the din-fittings. This thing is locked shut so much it's ridiculous. I ordered an extractor bit that first to force it out, it seems the only option at this point. The diaphragm, poppet etc all seems in very new condition, Probably someone use too much loctite on the reg I guess?

At this point I'm just gonna wreck it with an extractor and just buy a new din-fitting. Since I only paid 20 euro for the reg it's worth it to me. All the internals seems to be in perfect order, the diaphragm has no holes, poppets etc seems almost unused. ...

 

[TrimixToo]

I would try the proper size screw extractor because I have a full set. The Universal DIN retainer tool looks like it would work depending on how stuck it is. It might slip if it's extremely stuck. The screw extractor won't but will definitely bugger up the opening. Just my 2 cents.

Another 2 PSI...

I have a couple of sets of screw extractors in different styles. In my experience they rarely work particularly well* even in steel, and in softer brass they won't work any better. That clamping tool looks very promising, particularly if combined with heat. Loc-tite is designed to loosen with moderate heat. Don't use a torch. Put the reg in an oven at 325F-ish for long enough for it to reach that temperature internally (say, 20-25 minutes). If that's the problem, it should release the Loc-tite and the piece should unscrew without fanfare. You might even be able to reuse it! I don't think the O-rings will melt at 325F.

However, that's not the place Mares recommends Loc-tite. That screw just retains the filter; it's the thing it screws into that loosens in the regulator body and on which one uses (the correct grade of!) Loc-tite. I don't know why anyone would use it on the fastener that's stuck. It's a fine thread, though, and might just have been overtightened...or Loc-tited by someone who should have known better. Hopefully not with either the red or stud and bearing mount grades.

Machining it out is certainly an option. Drill to .025" or so the root of the thread, and then finish with a left hand drill .005-010" or so smaller than the thread root. It will probably take the remaining thin shell right out. (Don't do this with a hand drill or drill press. You need a vertical mill.) Or, just drill it out with whatever you've got to get access to the other hex socket and plan to replace both parts.

Good luck...

* Plus they're kind of a pain to remove when they break off inside the bolt that's frozen.

 

[tc]

Try this-
DIN Retainer Tool

 

[halocline]

I would try the alternating heat-cold-heat treatment. If you're patient, eventually it will come out. I've spent a few days freezing and boiling old regs to get them apart, and it's always worked eventually.

It wouldn't surprise me if the problem was that the threads are not protected by an o-ring, and so dried salt water is in there. The sealing o-ring is probably at the end of the fitting, inside the body of the regulator. At least that's how the SP fittings are.