Would you TAP this?

[ahave]

Excuse the pun. I had a friend weld on a 1/2" nipple to my keggle. He did an excellent job on the weld, however some spatter managed to find its way into the threads of my nipple. I tried to grind it out with a dremel but that didn't seem to work too well. I now have a nipple with the first thread mostly mangled. I am not sure how to go about fixing it. I could buy a round file and try to grind it out that way or perhaps buy a 1/2" tap and attempt to reap the first thread. My concern with retapping is beginning the thread in the wrong spot and chewing them up even worse. Attached are some pics of the thread from various angles. It was kinda hard to portray the damage, I was using my phone and it is an awkward place to photograph.

Any thoughts on what the best method to repair this would be?

 

[kladue]

Use a 1/2" pipe tap, the tapered threads should engage below the damage and let you cleanup the threads again. Go forward about 1/4 - 1/2 turn and then backup to break cut material loose, repeat this step until threads are cut deep enough to remove discolored material. Use a cutting oil or tapping fluid like Tap-Magic, there is never too much used when tapping stainless steel. Clean up with hot water and liquid dish soap, a small brush for inside would be ideal but a piece of sponge will work to get oil out of the threads.

 

[sonex]

Look for a tap marked npt 1/2.

 

[Atl300zx]

what they said. i had to do clean mine out with a tap too b/c of weld splatter

 

[dmfa200]

I like to thread a nipple hand tight with a few wraps of teflon tape into my couplings to protect the threads while welding.

 

[seabass07]

Nipple spatter can be an issue while tapping...

 

[ahave]

Looks like the way to go is with a pipe tap. Any preference on material type? Would high carbon steel be ok to use or would it cause rusting issues?

 

[kladue]

A carbon steel tap is sufficient, in the future use "Solar flux" or milk of magnesia to pre coat the threads before welding, then run tap into fitting to remove coating. For milk of magnesia, heat item to drive out water as you apply and brush on to build up a coating of milk of magnesia (magnesium oxide) to protect from spatter.

 

[Islandboy85]

I'd retap it. You wouldn't believe what a mess my fittings were after I had an idiot weld them up for me. Yours look way better than mine ever did and I was able to fix mine.

 

[Niemer]

It's a tapered thread, it'll be fine.

 

[Marshall081]

Heh I was going through the same problem all morning. I can not get the tap to cut. I was using the 1/2 npt pipe tap but all I have to turn it with is a ratchet and air tool oil. I was not turning whatsoever after a certain point. I was pushing with alot of downforce also (I'm 400lbs and i bench 300lbs) so at that point I assumed it could not be done with the tap. I am going to try again using the suggested cutting oils but i am still very discouraged.

 

[Islandboy85]

Heh I was going through the same problem all morning. I can not get the tap to cut. I was using the 1/2 npt pipe tap but all I have to turn it with is a ratchet and air tool oil. I was not turning whatsoever after a certain point. I was pushing with alot of downforce also (I'm 400lbs and i bench 300lbs) so at that point I assumed it could not be done with the tap. I am going to try again using the suggested cutting oils but i am still very discouraged.

Mine was pretty tedious to fix. It took about an hour to fix all four fittings on my kegs. Sometimes you can only go a 1/4 turn and you have to back the tap out to clean the flutes out. Don't try to do it in one shot. Every turn or so just back it out a turn and then go deeper again. It makes it a lot smoother that way.

 

[Niemer]

Stainless is a terrible material to try and tap or drill, it'll be slow going. Make sure the tap you are using is sharp.

 

[Islandboy85]

We use rthis stuff at work when we have to tap out threads and any time we put in stainless hardware to protect the threads from galling. It's called BoeLube. It comes in solid, paste, and liquid form. Check it out at www.yardstore.com