Welder messed up threads. Is there a fix?

[ScottG58]

I paid a welder $60 to weld a coupler into my kettle. He welded it flush. The inside threads will not now take a male 1/2" fitting. Is there a fix?

 

[kh54s10]

You could run a tap through to clean up the threads but that might be more expensive than removing the coupler and taking it to someone else to weld a new one in.

 

[The542]

McMaster or fastenal will have a tap to chase those threads, no biggie

 

[ScottG58]

Doesn't sound like I'm brewing this weekend or anytime soon. I bought the coupler online.

Nothing like paying somebody to wreck a brew kettle.

 

[masteraviator]

Scott, try calling around to some of your auto parts stores, some have tools for rent or check out for auto repairs.

Maybe someone else could weigh in, but since that is likely a NPT (Tapered) fitting, you don't want to run the tap all the way in to chase the threads.

 

[The542]

Are the threads dicked on both sides of the coupling? If not, just start the tap on the good side & slowly work through. Pics? Am I not understanding the severity of the problem?

 

[ScottG58]

Are the threads dicked on both sides of the coupling? If not, just start the tap on the good side & slowly work through. Pics? Am I not understanding the severity of the problem?

Threads on outside are good. Probably the severity is compounded by my unhandiness. I hired a professional so I wouldn't mess it up.

 

[ScottG58]

These are cell photos

 

[The542]

Threads on outside are good. Probably the severity is compounded by my unhandiness. I hired a professional so I wouldn't mess it up.

Then get a tap, run it in where the threads are good and when it starts to bind, begin powering through a quarter turn at a time and backing out. Do this till your through. Napa, plumbing shops, fastenal, grainger, possibly other automotive stores, fastenal, lots of places online will have the tap necessary. I use taps for high temp fluid transfer on a weekly basis in the heavy trucking industry with no problems.
I sucks a person you trusted to finish a job warped/screwed your build, but since you are not making new threads, it should be pretty straight forward. If I were close, I'd be there for ya...

 

[ScottG58]

This is inside.

 

[ScottG58]

Then get a tap, run it in where the threads are good and when it starts to bind, begin powering through a quarter turn at a time and backing out. Do this till your through. Napa, plumbing shops, fastenal, grainger, possibly other automotive stores, fastenal, lots of places online will have the tap necessary. I use taps for high temp fluid transfer on a weekly basis in the heavy trucking industry with no problems.
I sucks a person you trusted to finish a job warped/screwed your build, but since you are not making new threads, it should be pretty straight forward. If I were close, I'd be there for ya...

Appreciate the offer. I'm in West Des Moines Iowa and in middle of a snow storm.

 

[ScottG58]

Then get a tap, run it in where the threads are good and when it starts to bind, begin powering through a quarter turn at a time and backing out. Do this till your through. Napa, plumbing shops, fastenal, grainger, possibly other automotive stores, fastenal, lots of places online will have the tap necessary. I use taps for high temp fluid transfer on a weekly basis in the heavy trucking industry with no problems.
I sucks a person you trusted to finish a job warped/screwed your build, but since you are not making new threads, it should be pretty straight forward. If I were close, I'd be there for ya...

I may not understand tapered fittings. Is the end of the fitting smaller in diameter than the outside?

 

[The542]

Taps are tapered to aid in starting threads. Below is an example of what you're after if 1/2", expensive example though...

http://www.mscdirect.com/product/64..._s4DaI4TfL_PLA__24478983664_t_S&026=-99&025=t

 

[TNugent]

Was that a full length coupler or a 1/2 coupler?

 

[2grit]

Why do you care if the inside threads are messed up? Aren't you just going to thread a fitting from the outside? You mention that the threads on the outside are good. I've welded hundreds of taps like this and probably would have done it the same way

 

[The542]

Probably wants to thread in a pickup

 

[LLBeanJ]

I may not understand tapered fittings. Is the end of the fitting smaller in diameter than the outside?

Yes, it is. You cannot run an NPT tap from one end through to the other. You have to start from the end you want to chase.

 

[Dog House Brew]

Had the same thing happen to me. My welds were terrible and I bought me a tap and it worked. Still have terrible sugared welds on my new Polarware kettle. Still makes me sick that I paid someone to screw mine up. Learned to weld my own after that. Get you a tap for 1/2" pipe thread.

 

[raouliii]

A NPT coupler's FPT threads are tapered from each end. If you run a tap from the outside all the way through, you will have cut straight threads through the entire fitting. You may then have trouble getting MPT fittings to tighten, and therefore, seal.

 

[Facinerous]

Just run a peanut grinder around the first 1/8" or so of the inside of your coupling. Your weld should be fine and you will make your threads usable.

Most of the time couplings are NPS threaded. Which means they are tapered. So if you run a tap all the way through the coupling you will be getting more than you bargained for. EG the tap will run in about 3/4 of the way and want to stop. You'll have to tap out the center 1/3 of the coupling to get it to run all the way through. From the looks of the weld if you try to run the tap from the inside of the kettle you will have a hell of a time getting the tap to start, and getting the tap to match the thread pattern would almost be an impossibility.

If you talked to the welder, and he gave you something you didn't want, I would take it back and ask the guy to grind it out and put it in the way you asked. (Most couplers like that are welded in the center of the coupling to the kettle) Good luck.

 

[pickles]

If that's a half coupler then you can only thread something into the outside. A full coupler will allow threading from both ends, but I would have expected it to be welded half in the kettle half out.

 

[Facinerous]

Well I can see why the welder did it the way he did. Most of the time people would not be interested in putting something inside a vessel. The guy most likely thought you were going to utilize a valve with that little coupling, and did it the way he did.

My experience is you have to be specific with what you want, or you get what you get. Its a pain. If my boss at work is not specific, and I do my job in a way that is different than what he/she envisioned, he/she has to deal with it. If my boss is specific on what they want me to do, and I do it otherwise, then its my own fault.

 

[SpikeBrewing]

Is the coupler full length or a half coupler? (If you don't know post up a closeup shot of the threads taken from the outside of the kettle looking in)

If the coupler is a half coupler then you won't be able to screw in from the back side. If it's a full coupler it should have been welded half in and half out. More than likely the coupler and threads warped during welding. We've had this happen on a few custom orders and I hate to say it but they became junk. It's not as simple as chasing threads to right the problem. The whole coupler is warped so a tap won't work.

The weld was not sanitary welded (back purged with Argon) and it was welded too hot. The backside of that weld needs to be ground down to remove the sugaring (black stuff on the backside of the weld) and then you should rub it down REAL good with Bar Keepers Friend to passivate it. Otherwise you'll have rusting issues going forward. And I hate to say this also but more than likely you'll still have rusting issues going forward even if all of that is done.

 

[T_Baggins]

If it is a HALF coupling (Detail B) it can be re threaded from the outside, the effect will be as in Detail C (these are GROSSLY out of proportion and scale etc, but you should get the idea of what it all means). If it is in fact a FULL coupling (Detail A) it should be threaded from the INSIDE regardless of difficulty.

Another note, I don't know who welded that for you, but it looks like SH!T and was done incorrectly I would get your money back or make them fix it!

 

[acidrain]

You paid for crap welding and a ruined coupler. If the guy told you he is experienced at welding stainless, he lied to you.
Go get your money back from that guy. If you paid with credit card, call the credit card company... they will reverse the chargers.
Seriously, that weld is horrible.

 

[T_Baggins]

not to mention no even mentioned repassivating!

 

[mattd2]

You paid for crap welding and a ruined coupler. If the guy told you he is experienced at welding stainless, he lied to you.
Go get your money back from that guy. If you paid with credit card, call the credit card company... they will reverse the chargers.
Seriously, that weld is horrible.

But there is a differnce between being able to weld stainless steel and being able to weld stainless process pipe (which this is more like).
For welding up SS fencing no one is bothered about the sugaring on the back side (it's hidden!) and a general welder would not consider it.

The big question to ask of your welder is "have you experience in SS welding for process pipework", then ask him how he will go about the welding.
If he doesn't mention anything about purge gas, etc. walk away. If you try and tell them how to do it they will most likely not listern to you as they are the "expert", after all you wouldn't teach your grandma how to suck eggs

 

[ScottG58]

You paid for crap welding and a ruined coupler. If the guy told you he is experienced at welding stainless, he lied to you.
Go get your money back from that guy. If you paid with credit card, call the credit card company... they will reverse the chargers.
Seriously, that weld is horrible.

Figured I paid $60 to ruin a $130 kettle. Guy said he welded for a lot of home brewers. Should have worried when he mentioned the pot was heavier gauge than he expected. He also described welding something that didn't make sense. The inside was important as I have fittings for a pickup tube. Full coupling.

 

[butterpants]

I have my couplers welded in that didn't use a sanitary weld. No issues with rusting.

I chased out the couplers because there was some carbon in them a 1/2 NPT tap from napa worked great. Just don't forget to lube them and go 1/4 turn counter clockwise to clean the tap once pressure builds.

My welds were free tho.... I'd be pissed off if I paid someone 60$ for a single sanitary weld and got that. Bad price and even worse work.

Sent from my Galaxy Nexus using Home Brew mobile app

 

[Bobby_M]

This is why I stopped being such a purist with a "weld it or nothing" attitude. Weldless fittings done right beat crappy welds all day long. You don't get that used and abused feeling afterwards.