Calling all stainless welders/experts

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jcaudill

jcaudill

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I need opinions from anyone well versed in stainless and particularly welding.

I had a local welder weld some fittings into new 100 quart update international pots. The first contact with water was when I was passivating them early October. I used about a 3% concentration of nitric/phosphoric acid. - Loeffler KMS-10 which is formulated for this. I noticed almost immediately after finishing the passivation and flushing that every weld, particularly where ground, was developing what appeared to be rust. When I got home I tried to scrub the heck out of all the areas with Barkeeper's Friend. At first this seemed to work. But I'd come back the next day, and the rust would be right back.

So after some reading, I found out the most likely scenario is that they introduced steel somewhere along the lines. Probably the grinding wheel - or maybe a brush. I also read the only way to fix this is chemically - that no amount of mechanical treatment will solve it. So I decided to run KMS-10 straight - which is basically around 40% phosphoric acid, and 15% nitric acid. All the reading suggested this combination should take care of removing the iron. So I decided to do a test soak - I soaked it for about 50 minutes. At first it was very promising - I saw no signs of rust. But after I got all the acid out and flushed it well, about 5 minutes and this is what I saw:



If my eyes aren't deceiving me, I see pitt corrosion. And not to mention it took almost no time for the rusting to start again. Anyone else agree with this? Any other comments on anything else I can try? At this point I'm close to throwing in the towel and calling the pots unusable. Just to reiterate - the pots have never been used!

Thanks in advance.
 
Is that the backside of the weld? If so, they didn't back gas which caused the sugaring you see. There may be some spots in there that didn't passivate. He didn't happen to clean the area with steel wool or a wire brush did he?

I wouldn't call them unusable.. Clean it up before a brew, brew, repeat.
 
Yes it is the backside of the weld.

I think it would be impossible for any of those spots to not have been passivated because I had the entire area soaking under acid for 50 minutes.

Honestly, I have no idea everything they did. The problem is - it takes an enormous amount of effort to make it go away. I can't just lightly scrub it, I have to scrub the hell out of it. And in a matter of minutes, it's back. I'm not so sure I am willing to go through that every brew - and I shouldn't have to.

Here's the before pic - I'm wondering if by tomorrow morning it'll look like this again.

 
What we need is for someone with experience in Stainless welding to write a spec for welding couplers onto kegs that we can all take to the local shop and say "Can you do exactly what is on this sheet and if you can't/don't I will not be paying you"
Looks like you are correct with they have contaminated by using a tool used with mild steel to grind back/clean up the welds. Chemical solutions can only clean up the free iron on the surface, if it has been embedded into the stainless you are in for a battle.
Have you spoken to the shop that did it? If they have used the wrong disc/flapper wheel on it they should take care of it, I would guess if it was a reasonable sized shop with an apprentance it would have been given to him and he might of messed up.
Did a quick search and found a bit of insight http://www.finishing.com/79/21.shtml
 
I have to admit, I'm pretty bummed! My luck with local welders has been, well, unlucky. What particularly pi**es me off about this one is I specifically asked for restaurant quality welding and they said that they've had experience with it. And they were even recommend by another welder for the same thing!
 
i must be lucky, never even knew there was anything special about welding stainless. my kegs have not had any of these problems after having couplers welded on.
 
Just my opinion, but that is a spectacularly poor weld just to start with. I'd go back to the shop and show them a "real" weld, and show them the rust, and ask them to make it right.
 
I can't say I disagree. But the thing is I need to be armed with both information on why it's a poor weld, and possible solutions. The thing is - I don't see any viable solutions right now. If chemicals can't fix it, ???. That's why I'm here. I need to hear from others with more experience.
 
Those welds are definately poor quality and lack fusion. The sugaring is caused by not having shielding gas on the back side of the weld. I would return it to where they attempted to weld it and demand they replace my brand new kettle. I would then take it to a real welder and tell him or her exactly what I want. There is a WPS (Welding Procedure Sheeet) for welding stainless and if followed you will never have a problem, if not you will have nothing but problems as long as you have that vessel. On that type of item the welds should look like a stack of dimes laid on edge and be of uniform depth and equally spaced. I'm not seeing anything like that in any of the pics you posted. I would have gotten fired for turning out some junk like that.. Oh, and I welded for a living for a good few days before I got disabled and had to medically retire.
Wheelchair Bob
 
If you have a disc grinder, I think you could clean this up fairly well with some flap discs and then some abrasive pads. You may have to finish by hand with some abrasive pads and then clean and passivate. I finished the back side of these welds that way after not getting a good back purge of argon on them.....

KettleInside08r.jpg.jpg
 
This sort of thing is why I say this on my website on welded vs. weldless:

It's not always a matter of choice. Welding is a niche skill and good, cheap labor is hard to find.

It is sometimes very difficult to find someone local that has the ability and time to take on your project at a price you'll be willing to pay. If the price seems too good to be true, you may want to ask some questions to be sure they know what they are doing. Welding stainless steel is a skill that a lot of professional welders THINK they have and it's either an ego problem or simply ignorance.

First, ask if they have any experience welding stainless. Ask what kind of TIG machine they have. Ask what they do to prevent sugaring on the back of the weld. If they say "nothing" or seem confused by the question, keep moving along. The only two ways to prevent the back of the weld from looking horrible and being a cleaning mess is to back purge the vessel with argon or use solar flux. With that said, a sugared weld area is not the end of the world on a hot side vessel but you'll be a lot happier if the welder prevents it. If you've gotten quotes from several places, make sure you know if they'll be accounting for the back gassing or not. At least you'll be able to compare apples to apples.

In many cases, the highly skilled welders that are aware of the various techniques would consider this "sanitary grade" welding and will have had experience working in pharmaceuticals, chemical processing, dairies, and other food processing plants. Here's the rub. Welders capable of this kind of work are busy doing that kind of work for top dollar. No one with a couple hundred feet of welding work over at Johnson and Johnson wants to put a couple doohickies on your kegs for $20. Some shops will offer to take the job and tell you to come back next week...only to find that some higher priced job took priority while you weren't looking. Worse yet, don't fall for a handshake deal with the welder in the back. You may come back to find that your 90 pounds of kegs and parts were sold to the scrapyard and the boss doesn't know who you are. Get something in writing showing what you dropped off, what work is to be done, when and for how much. This doesn't bode well for the stories of bartered welding labor for a couple six packs of homebrew (unless it's a friend of a friend).
Click to expand...
 
Wow ok so lot's of posts here. Some thoughts:

1) This was not a cheap welding job. It wasn't crazy expensive, but it wasn't cheap.

2) Here is what I need to know:

a) Are these repairable? If so, how? I'm going to preface this by saying: I just went out to my other pot which showed no signs of rust. I sprayed it with a bit of water. In 5 minutes or less, it started showing rust.

b) Do these just look bad, or are they actually unsanitary?

c) Do these show signs of being structurally poor? In terms of it being hazardous to use.

d) Is the pitting correctable, or is that permanent and will lead to failure?

I need to go in armed if I'm going to ask for replacement pots. And chances are, they're going to want to try and fix them. So I need to know when they tell me what they're going to do if they are actually giving me reasonable solutions or shots in the dark. I don't want to waste more time on this. I'm already pissed enough.

Much thanks to all.
 
If you have an angle grinder, get a 120 and a 80 grit sanding disc/ flap wheel. Grind the whole are down With the 80 first then the 120, then passivate. You should be fine after that and it will get rid of the sugaring. I don't think it's a big deal. I have seen worse.
 
JRems said:
If you have an angle grinder, get a 120 and a 80 grit sanding disc/ flap wheel. Grind the whole are down With the 80 first then the 120, then passivate. You should be fine after that and it will get rid of the sugaring. I don't think it's a big deal. I have seen worse.
Click to expand...

Are you suggesting this to cleanup the weld and sugaring? Or are you saying this will solve the rust issue as well?
 
Ok first off you shouldn't have to fix anything it should be ready to use as soon as they give it to you. It looks to me like the used a contaminated tiger wheel. If you want to try and fix it yourself you can go down to the local pool store and pick up some muriatic acid. That sh*t will eat the rust up in a heart beat. Be carful it will eat your hand off as well.

I would walk into that shop and throw the pots at them and demand they buy you new pots and pay for someone else to put the couplers on because they obviously can't do it the them selfs.

Do you mind me asking how much you paid?
 
One more thing. If they are a professional welding shop and they sugared that bad I bet the walls to the pot are pretty thin so I wouldn't try grinding on it for fear of grinding through the wall and making a big hole so when you throw the pots at them they say "well who's the idiot who polished a hole in this. It's not my fault. I'm not gonna replace sh*t".
 
I would not let them work on the pots anymore, but I would make sure they know that you're not happy with the job and that you'd like a refund on the labor just on principal. They should know not to mix abrasives between steel and stainless. They should back gas to keep the sugaring from happening at all rather than try to half ass the cleanup later.

I agree with JREMS that you can make that look much better by just taking it down a little further with a fresh sanding disc.

Edit.. sorry, I thought this was a keg. If the pot is thin, be very careful taking off any more material. The sugaring is ugly but not a major problem for performance. You can continue to apply passivating acids until all of the ferrous contamination is gone. After each treatment, you should notice a little less rust in between.
 
Bobby_M said:
I would not let them work on the pots anymore, but I would make sure they know that you're not happy with the job and that you'd like a refund on the labor just on principal. They should know not to mix abrasives between steel and stainless. They should back gas to keep the sugaring from happening at all rather than try to half ass the cleanup later.

I agree with JREMS that you can make that look much better by just taking it down a little further with a fresh sanding disc.

Edit.. sorry, I thought this was a keg. If the pot is thin, be very careful taking off any more material. The sugaring is ugly but not a major problem for performance. You can continue to apply passivating acids until all of the ferrous contamination is gone. After each treatment, you should notice a little less rust in between.
Click to expand...

It's the Update International Pots - aka Megapot aka Morebeer Premium Pots. 18 gauge 304 SS. So, yes it's not particularly thick gauge stainless.

So you're saying just to go ahead and keep applying KMS-10 and hopefully it'll eat the rust away?

The welds aren't pretty. As long as they are not unsafe, I can look past that.

Above all, my main concern is the rust. That is not something I want to keep dealing with. It'll be interesting to see what it looks like tomorrow morning.
 
SS Brewing is right the weld was ground on with a contaminated disk
Obviously the weld was not shielded either
Depending on the thickness your kettle may be fixable.
I have been welding for 23 years. 15 of them doing xray quality in chemical plants and lately doing work for two local breweries
Look at some of my posts to get an idea of my work
If you want to pm me I can explain in more detail a remedy for your problem.
 
SS_Brewing_Co said:
Ok first off you shouldn't have to fix anything it should be ready to use as soon as they give it to you. It looks to me like the used a contaminated tiger wheel. If you want to try and fix it yourself you can go down to the local pool store and pick up some muriatic acid. That sh*t will eat the rust up in a heart beat. Be carful it will eat your hand off as well.

I would walk into that shop and throw the pots at them and demand they buy you new pots and pay for someone else to put the couplers on because they obviously can't do it the them selfs.

Do you mind me asking how much you paid?
Click to expand...

SS_Brewing_Co said:
One more thing. If they are a professional welding shop and they sugared that bad I bet the walls to the pot are pretty thin so I wouldn't try grinding on it for fear of grinding through the wall and making a big hole so when you throw the pots at them they say "well who's the idiot who polished a hole in this. It's not my fault. I'm not gonna replace sh*t".
Click to expand...

I agree that I shouldn't have to fix it myself. But the options were, try and fix it myself with chemicals I know are while unpleasant to work with, have a shot at it and won't be harmful to brewing or their solution which was grind on it more, or use synthetic steel wool and light sandpaper. KMS-10 is about as much as I'm willing to try myself. I don't have the tools, nor the inclement to grind on it myself. And that I'm definitely sure I shouldn't need to do and will give them a chance to blame it on me. At this point, it's pretty clear this is all them and nothing I could possibly done.

As I mentioned above, 18 gauge 304 SS. So it's not particularly thick.
 
They didn't use shielding gas on the back and they cleaned the surrounding area with a flap disc used on something other than stainless. They did not follow any proper procedure for sanitary welding and didn't follow common practices for regular stainless welding. I don't know what restaurant quality welding is, but they didn't sanitary weld it. The weld isn't sanitary, but doesn't need to be on a kettle. I would try and clean The surrounding area lightly with a new flap disc then passivate. You won't cut through the metal with a flap disc.

I had a ****ty welder mess some things up too I feel for you.
 
fork said:
They didn't use shielding gas on the back and they cleaned the surrounding area with a flap disc used on something other than stainless. They did not follow any proper procedure for sanitary welding and didn't follow common practices for regular stainless welding. I don't know what restaurant quality welding is, but they didn't sanitary weld it. The weld isn't sanitary, but doesn't need to be on a kettle. I would try and clean The surrounding area lightly with a new flap disc then passivate. You won't cut through the metal with a flap disc.

I had a ****ty welder mess some things up too I feel for you.
Click to expand...

Same here. I can't tell you how many times I've seen this and it just makes me cringe every time. :(
 
Here's the latest:

I took it back to them today. They acknowledged the problem and they understood and agreed it could not be used for food service. I told them try whatever they want to try because at this point it's that or the pots have to be replaced. I also asked them to cleanup the sugaring. They said this is the 2nd time they've encountered this in 25 years of service.

I got a message later in the day saying he had used some 120-grit sandpaper and hit the areas of concern. He then watered them down and as of the end of the day no rust returned.

I am both optimistic, and worried. The optimistic side says maybe it just hadn't had the chance to go deeper. The worried side says what if it comes back later.

I think he's going to run the flap wheel on all the areas to clean them up.

Any thoughts on all of this?

Oh and one thing I should have mentioned because to some people there may be confusion: that was the backside of the weld not the front.
 
jcaudill said:
Here's the latest:

I took it back to them today. They acknowledged the problem and they understood and agreed it could not be used for food service. I told them try whatever they want to try because at this point it's that or the pots have to be replaced. I also asked them to cleanup the sugaring. They said this is the 2nd time they've encountered this in 25 years of service.

I got a message later in the day saying he had used some 120-grit sandpaper and hit the areas of concern. He then watered them down and as of the end of the day no rust returned.

I am both optimistic, and worried. The optimistic side says maybe it just hadn't had the chance to go deeper. The worried side says what if it comes back later.

I think he's going to run the flap wheel on all the areas to clean them up.

Any thoughts on all of this?

Oh and one thing I should have mentioned because to some people there may be confusion: that was the backside of the weld not the front.
Click to expand...

Sadly the alloy in the metal has been altered at this point. There really is no repairing it. Fact is he welded them incorrectly. These should have been TIG welded and back-gassed.
 
I disagree with statement that they are ruined
If the welds were made without over heating the metal than the sugaring may be ground off to clean metal.
If you could show me the outside weld I could determine if it was welded too hot
If it were me I would try to clean it up..
By the way how many welds look like that
And the statement the welding company made that that was.only the second time in 20 + plus years they have ever seen that happen tells me they are full of it. Hell I have seen it more times than I care to count.
Either they didnt even try to shield the back side or their shield failed before they even started to weld
If it was the later then the welder would have realized his.mistake and would have attempted to fix it
They are full of it.
 
I never took a picture of the outside of the pots and unfortunately they're both at the shop. I tried to search online, in terms of overall appearance this is the closest I've seen:

7875-outside-weld.jpg


Mine has that same ring. I would say the welding right around the fitting is a bit thicker and maybe a little darker. But overall, similar.

All the welds look similar except that some are ground a bit better than others. I'd say that's the worst.

Putting all that aside, I just need to have an idea if their sanding does seem to do the trick and they are able to clean up the sugaring a bit should I just roll with it for now.
 
I welded stainless steel for 15 years and after looking at your pictures I can tell you that the shop that welded your pot did not do a proper job of purging the back side of the weld. What needed to be done was the top of the pot should have been closed off except for a small vent hole then argon gas should have been slowly vented into the pot until all of the oxygen is displaced. The presince of oxygen on the back side of any stainless weld will cause thet sugaring you see. There secound problem is that after seeing the mistake they made they took a grinder to the sugaring to clean it up. That would have been fine if that tool was dedicated soley to stainless and the tool itself was either non metalic or stainless it's self. What they have done is impreginate the area with carbon steel that rusts after it is exposed to water. The good news is that if you can find someone that is experinced with working in stainless steel they should be able to grind it and polish it out to a proper finish. rember that whatever is ground away can be rewelded if needed. As far as the thickness of the metal it dosen't matter I have welded stainless as thin as two sheets of aluminum foil. I think the shop you took it to should be willing to cover the cost of you taking it somewhere else to fix. If they truly weld stainless steel they know the mistake they made and they should pay to have it fixed to protect there good name.
 
You can fix this yourself with a dremel and a brass wire wheel or a flap disc. As stated, they didn't backgas, or at least they didn't do it well. Then, they tried to fix the ugly weld with a grinder. Another thing I don't see mentioned is using too much heat. I'm not a professional welder by any means, but I'm pretty sure I read somewhere that too much heat can compromise the corrosion resistance and also make the base metal more brittle (basically alters the austenitic molecular structure through improper heating/cooling).

Keep in mind this is all on the hot side. Not a big deal, other than the frustration. Hit it with PBW at the end of each brew and wipe lightly with olive oil and you should be fine....at least until the next brew day.
 
I've been simultaneously posting on a pure welding forum about this same issue. The consensus is somewhat similar to yours except the majority think it is not fixable. There is real question as to the alloy having been compromised at this point. Apparently the right
way to get rid of this contamination is crazy expensive. The welders claim they've fixed it with sandpaper but my sneaking suspicion is with a little time the issue will be right back and possibly worse if they smeared
the contamination.

The weld quality is a whole 'nother thing. If
it was just that - I know that can be cleaned up enough to not
be uber-concerned about it.

In the end I'm not going to use them. They'll be up for sale
shortly. Maybe someone else has the time and
tools to play around and likely will get a
hell of a deal on big pots.
 
How bout a link to the welding forum. Im sure there is some useful info for ua in that thread as well.
 
I think you should ask them to replace the kettles for you, period!
You should not have to be out of pocket for a poor fab job on your kettles by someone who said they could do the job and clearly could not!

Totally bummed for you man.. I know exactly how you feel. Been there myself!

Jay
 
So you pick them up tomorrow? IN all honesty I would not be paying for the welds and demanding my $200 back. Did you pay by credit card, because if so if it comes down to it you could dispute the charge on the grounds they did not supply the service they orginally stated they would. You might get your $200 back but I would not think they would be willing to pay for new pots for you.
Once you have the pots back post some pics of their "repairs". If they look ok, I would atleast try them on a extract or AG brew (a very cheap one though), and then leave for a couple of weeks. Really time will only tell. As far as reducing the thickness to where it would brake due to the liquid load, I think this would need to be down to where you could poke through with your finger, i.e. tinfoil thin (ok maybe a bit thicker than tinfoil :D). If you are looking at lifting the pots with liquid in them this is a different story, but if you can lift a full 20 gallon pot of boiling liquid I would don't think we would be having this conversation after you kindly "talked" to the welders :D
 
Jaybird said:
I think you should ask them to replace the kettles for you, period!
You should not have to be out of pocket for a poor fab job on your kettles by someone who said they could do the job and clearly could not!

Totally bummed for you man.. I know exactly how you feel. Been there myself!

Jay
Click to expand...

I agree 100%.
 
tasq said:
I agree 100%.
Click to expand...

I agree that the should replace the pots. I don't agree that they will.

Really any fab shop I have been to that deals with SS are not really interested in some guy's pots. These jobs are a nuisence to them and they would prefer not to do them (read the welders forum OP posted to, he had a good welder at first but sounds like this is the case with that guy hence the reason for using these new "awesome" welders!)
These jobs would generally get left to the apprentices to do for their practical/tests. And that level of experience is a varied range!
I would bet money they gave it to their apprentice, when you are there ask them what they guy who did the welds is qualified to?
Any welder that does sanitary jobs will most likely have ASME IX tickets, and will need to upkeep them with detructive tests, etc. (6 monthly I think).
The chance you got one of these guys to do it is minimal, one of them might have told the apprentice what to do but some don't listern too well.

The shop is not going to take a hit of $200 plus the cost of new pots for some guy that they will never get any real sort of business out of. Plain and simple, how eger would you be to pay for someones car repairs if you braked hard (because you were not paying attention) and they swerved to miss you but then ended up in a ditch?

Not being hard on the OP and I feel for him, just being realistic.
 
mattd2 said:
I agree that the should replace the pots. I don't agree that they will.

Really any fab shop I have been to that deals with SS are not really interested in some guy's pots. These jobs are a nuisence to them and they would prefer not to do them (read the welders forum OP posted to, he had a good welder at first but sounds like this is the case with that guy hence the reason for using these new "awesome" welders!)
These jobs would generally get left to the apprentices to do for their practical/tests. And that level of experience is a varied range!
I would bet money they gave it to their apprentice, when you are there ask them what they guy who did the welds is qualified to?
Any welder that does sanitary jobs will most likely have ASME IX tickets, and will need to upkeep them with detructive tests, etc. (6 monthly I think).
The chance you got one of these guys to do it is minimal, one of them might have told the apprentice what to do but some don't listern too well.

The shop is not going to take a hit of $200 plus the cost of new pots for some guy that they will never get any real sort of business out of. Plain and simple, how eger would you be to pay for someones car repairs if you braked hard (because you were not paying attention) and they swerved to miss you but then ended up in a ditch?

Not being hard on the OP and I feel for him, just being realistic.
Click to expand...

:(

It's all good though! I understand my chances of getting anything out of this are slim to none. I hate being the guinea pig - but maybe this will be helpful to others out there. Don't take anyone's word for anything and know the right questions to ask
 
Well the guy I need to talk to wasn't there today so that will have to happen later. But I did take the pots back. So they definitely cleaned things up. Can you guys take another look and give me another assessment? I just got done spraying them with water to see what happens. I included a shot of the front side too as requested by a few people. Thanks again.



 

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