Aluminum DIN dust cap is stuck...

[PriusDrIVER]

And I think its due to electrolysis. I bought this stupid <explitive> aluminum cap from the LDS that I had do my DIN conversion on the Mk2+. I had them do 2 of them, and I bought 2 DIN caps from them while I was there.

I asked if they had delrin caps, the guy at the shop clearly was an idiot and gave me aluminum ones. He looked at the sticker *they* had attached to the caps and said "no, these are delrin it says on the sticker". Well, I knew they were aluminum but didn't want to argue. I asked about it and got the response "even if they were aluminum, it would probably be better and you'd be paying less than we charge for the aluminum caps".

Of course, this is exactly the reason I didn't want aluminum caps. Funny how salt water and aluminum doesn't always get along, when another metal is right next to it. So, I'm curious how you are supposed to rinse any salt crystals that may be in the threads of your regulator when you aren't supposed to dunk the regulator without the cap on. sorta a catch 22 I guess. All of my regs are kept very clean, with a rinse as soon as fresh water is available and a good soak before being stored.

Well, anyway...to the problem at hand. I have both Mk2+ with these caps on them...I was able to get one off, the rest of the reg is clean as can be but clearly there must have been some salt in the threads of the cap/regulator as there was corrosion on the aluminum, thankfully the regulator/DIN fitting look fine.

The problem is the 2nd cap won't come off at all. These DIN kits have the delrin wheel on them, and my options are to strip all of the grips off of the wheel trying or to get more creative. I tried soaking the reg/cap in cold water and hot water to get it to losen up, no go. Not that I'd expect water to do much for corrosion on the aluminum threads.

So, what next? Take it and fight with the LDS that this regulator was purchased from and who installed the DIN? I know they aren't going to want to eat buying a new reg, and I'm not sure what the other options are.

Do I get the dremel cut-off wheel out and try to cut the end of the cap off so at least we can get the tool in to take the DIN fitting off and just have them replace that part?

Help?!?!?

 

[mkutyna]

Even if you screw up the Delrin wheel on the reg in the process of getting the cap off your dive shop should be able to replace it. I'd leave it up to the dive shop to get it off though. They probably have more tools at their disposal and if they damage the delrin wheel, there should be no argument about who needs to pay to replace it.

 

[cwkline]

Try some vinegar on the threads. Don't soak the whole thing, set the regulator so the threads and cap are down. Then either suspend or balance the reg in a dish of 50% white vinegar that just covers where the threads are exposed. If that doesn't work, channel locks are my next best idea.
Good Luck
Charlie
PS: I had the same problem, changed my caps to delrin.

 

[Packhorse]

Yeah, who is the dick head who came up with aluminium dust caps?

 

[h90]

I don't have a good idea to help you, but I want to say thank you, because I have a cheap plastic cap and already wanted to replace it with a metal one (aluminum). Most probably I would have ended with the same problem as you have now.
So thank you, I won't replace mine, and sorry that I can't help.

 

[redacted]

Aluminum has a higher expansion coefficient than brass so the correct application of hot and cold should do the trick with minimal damage. I'd soak the whole reg in ice water to get it good and cold (a couple minutes should do). Then just dip the aluminum cap into hot (just off a boil) water for a minute. I would expect it will take a number of cycles of this treatment to work things loose. You might want to also try a couple strap wrenched to get a better grip on the din wheel and the cap. If it does not work fairly quickly, just soak the whole thing in water while you take a break.

I would not let the shop try it until you are sure you can't. I suspect they will not take as much care as you can, they will see this as your fault for not cleaning (soaking) it adequately, and they will charge you for parts and labor.

Good luck.

 

[simcoediver]

Heres my din caps, works just as well and never gives me any problems!

 

[letterboy]

Sim that good ****... Lol
Posted via Mobile Device

 

[DA Aquamaster]

It is a catch 22 - actually 2 of them. Delrin caps won't corrode, but they "look" cheap, and DIN threads are stronger and are all the rage in techncial diving, but the connection has lots more potential corrosion issues that no one ever talks about.

The real problem is of course salt water left on the threads of the DIN connection. You can and should rinse them when you get home by carefully sealing the inlet on the end with your finger tip and then while holding it so that the inlet is facing down (so gravity will keep any water out if it gets past your finger tip) and then rinse the threads with warm water.

If there is lots of salt or any corrosion, do the same thing but scrub it with a tooth brush dipped in a solution of 50% water and 50% white vinegar, then rinse the threads again with water.

Obviously do the same with the DIN cap whether it is delrin or aluminum. (remember aluminum itself was not the cause of the problem.)

Less obviosuly, you also need to rinse the threads on the female DIN connection on the tank, and if needed scrub them out with a toothbrush and vinegar as well. Just be sure to crack the valve a few seconds to displace any water and dry the valve before you refill the tank.

 

[mkutyna]

Ah, vinegar. I didn't know that. Thanks!