Acetylene fitting leak

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I recently swapped out my acetylene tank.  I put the regulator on and soaped the connection from the tank to the regulator and no bubbles. Good to go. A bit later I thought I smelled acetylene and looked at the fitting where the regulator goes in to the bottle and there was the slightest amount of small bubbles (I had not wiped the soap off after the test). I got the spray bottle and soaped it again. Nothing. Watched it for about 2 minutes and finally the slightest amount of bubbles start to form. Obviously a very slow leak. Disassembled and inspected the fitting on the regulator, no nicks burrs etc. Tried to look into the valve body of the tank and thought the seat did not look smooth/shiny so tried to rub it with a cloth on the end of my finger and got some dirt on cloth. Reassembled and still a very slow leak that it is not immediately noticed. I turned off the valve and did not bleed the regulator and watched the bleed down. Lost 20 psi on the high gauge after 20 minutes so 1 psi/minute leak. Not a lot but too much.QuestionI could take back to LWS and say replace bottle; but that is time and distance I would like to avoid.Does anyone have any experience with smoothing the valve fitting seat with anything that might cause an adequate seal or do I not even want to consider anything other than replacement?
Reply:I'd take it back myself. That or just deal with it and remember to turn off the cylinder as soon as you finish what you are doing. I'd make sure it's snugly fitted with a big wrench and if it still leaked, I'd call the LWS and let then know there is a problem, and then look at taking it back as soon as possible for exchange.Reseating valves isn't something that the average person is equipped to do and do right. Most times when a valve seat is damaged, someone who had a damaged reg cranked the ever living pizz out of the connection and deformed the soft brass seat. You may get yours to seal better if you tighten it a bit more, but I wouldn't go crazy. Crank yours down too much and there's a chance you'll distort the fitting on your reg and then deal with this every time you get a new cylinder until you replace the reg fitting..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Same as above. Sometimes rotating the reg to different positions when tightening will find a sweet spot and seal. If not I would take it back as its the suppliers responsibility and obligation to provide a functional cylinder. My LWS will even give you a credit if you have to return a defective cylinder to help offset the travel costs.
Reply:Hypothetical case:  I'm on an island somewhere and far away from welding supply, I have the same problem you have, small leak.  What can I do to fix this?  I go to my garage and low and behold I see a can of Glover lapping compound.  Having done several valve jobs in my past I begin to think, would it be possible to lap the seat of this tank and fitting?  Just putting this out there, never tried it but I don't see why it could not be done.  Any thoughts?  Best  Bob
Reply:Originally Posted by rhuntHypothetical case:  I'm on an island somewhere and far away from welding supply, I have the same problem you have, small leak.  What can I do to fix this?  I go to my garage and low and behold I see a can of Glover lapping compound.  Having done several valve jobs in my past I begin to think, would it be possible to lap the seat of this tank and fitting?  Just putting this out there, never tried it but I don't see why it could not be done.  Any thoughts?  Best  Bob
Reply:Thanks for the comments.  I did not think there was any valid way to deal with it outer than return the tank.  I was just hoping to avoid the time and distance.  Safety always wins out.
Reply:Makoman, I had a laugh when you mentioned "sane man".  Thought most people think weldors must be nuts as their always working around sparks and flame!  Best Bob