Keggle Weld damaged Threads on inside

Hey everyone. I took the leap and decided to make a keggle. Everything has gone relatively well. A friend of mine knew a welder (with no keggle experience) but otherwise an exceptional welder (race car frames or something). Anyway, I just got the keggle back and the welds look great. He did the outside and the inside. The only problem is the weld on the inside has covered up the thread I can't get the drain tube screwed in. I have a plug that I can get to turn about an 1/8 of turn. Anybody have any thoughts as to what to do about this? A friend of mine mentioned a pipe tap but I'm not really sure how that works.

I used 1/2 ss npt. Everything is from Bargain Fittings.

Thanks for your help

If they are male threads you need a die, not a tap. It is basically a hardened nut with sharp threads and groves for "waste". You thread it on and off a few times and it will clean and straighten the damaged threads. You just need one in the correct size.

You may be able to use a 1/2" NPT Tap to clean up the threads in the coupling which is what your friend is suggesting. Stainless steel can be tough to work with and especially so if it has hardened some from the welding heat. It's at least worth a try.

Here's a link to the pipe tap so you can see what one looks like: http://www.ridgid.com/Tools/Pipe-Taps

You might have to go to a plumbing supply to get one. Home Depot probably won't have one and I'm not sure that Lowe's would either. Most local hardware stores do stock them, so you might try there first.

The taps should be used with a tap handle, but you might be better off using Vice Grips or a large adjustable wrench due to the thread being on the inside and more difficult to reach.

Start the tap carefully and when you are confident that the tap is chasing the threads and not cross threading, crank it in about 1/4 -1/2 of a turn. Back it out a little and advance another 1/4 turn. Use a lot of lubricating oil. Just about any oil will work for this, even some automotive motor oil. So, keep repeating this advance some and backing out a little then advancing more and so on. The coupling threads are tapered and so is the tap, so it will become increasing more difficult to proceed as you get deeper into the coupling. I would try to clean up at least five or six threads into the coupling if possible. This should allow you to thread the tube in at least three full turns and maybe a little more. If you have an unused coupling, you can thread the tap into it to see how it works and how far in it will go. You will probably have to use some fairly strong force to turn the tap. It might be a good idea to take the tap and the kettle back to the guy that did the welding. He will probably have some experience with taps and can help you with fixing the problem.

Sometimes people try to avoid what you are dealing with by putting a plug into the coupling when welding it. The problem with that technique is that often it will be very difficult to remove the plug after the welding has been completed. The threads on the plug and coupling can lock up almost as firmly as if they had been welded and it can be a major biotch to remove the plug.

They are female. I had couplers welded in

electrichead said:

If they are male threads you need a die, not a tap. It is basically a hardened nut with sharp threads and groves for "waste". You thread it on and off a few times and it will clean and straighten the damaged threads. You just need one in the correct size.

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He said he got a plug to start, so I am assuming he has a coupling welded into the kettle, not a pipe nipple. I sure hope it's a coupling as a nipple might be majorly messed up from the welding to the point it may be impossible to clean up with a die.

This is very helpful. Thanks for the info. I'll let you know how it goes.

Catt22 said:

He said he got a plug to start, so I am assuming he has a coupling welded into the kettle, not a pipe nipple. I sure hope it's a coupling as a nipple might be majorly messed up from the welding to the point it may be impossible to clean up with a die.

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7 pints + 2:30am = brain fried.

OP stick with what Catt22 said

Mine was like this when I had my first keg welded. I called the guy who welded it back and told them the inside threads were no longer good. He hadn't realized I needed the inside threads as well so he didn't take caution to protect them. He came, picked up the keg, fixed the threads and dropped it back off. Have you just tried calling the guy to did it? He may have the tools and might be willing (should) fix it for nothing.

I had some similar issues and happen to find the tap for it at ACE hardware. I was surprised but it worked. Mine was screwed up on the inside and my diptube sealed so all is good. I think that tap was right around $20

Hey guys,
I thought I would give you an update. I found a tap and wratchet at harbor freight and followed Catt22's instructions and everything worked fine. I think I was pretty fortunate in that there was enough thread exposed for the tap to get started. My dip tube is firmly sealed so thank you all for the responses. Furthermore, I can return the tap to harbor frieght.

I didn't take it back to the guy that did it because he did it for free. I guess that's what I get for free labor.

no you want to keep that tap and die set. Toools are tool and if you need them once you will need them again.

-=jason=-

SchulteMeister said:

Hey guys,
I thought I would give you an update. I found a tap and wratchet at harbor freight and followed Catt22's instructions and everything worked fine. I think I was pretty fortunate in that there was enough thread exposed for the tap to get started. My dip tube is firmly sealed so thank you all for the responses. Furthermore, I can return the tap to harbor frieght.

I didn't take it back to the guy that did it because he did it for free. I guess that's what I get for free labor.

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Sigh lesson not learned?