Another keggle rust thread.

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tasq

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Hi Gang,

Need some help here.

I recently had a buddy weld some couplings on my keggles. He used stainless wire, back gassed, and used 100% Argon. They are welded from the outside only.

I have scrubbed the welds 3 times, with barkeepers friend paste and a green scrubbie pad. Each time the rust returns.

Is it possible the metal just needs more time to passivate, or are these going to be a lost cause?

Any input will be greatly appreciated.

keg1.jpg

keg2.jpg

keg3.jpg
 
He used stainless wire,
this tells me it was mig and not tig, it also looks like mig (not the best but can ve made to work) the inside don not look like it was purged. the last photo on the right looks like a cold start.

to fix it i would grind the dark stuff from the inside, and try to passivate with bkf or if you have a plating house around you they will have nitric acid...
 
this tells me it was mig and not tig, it also looks like mig (not the best but can ve made to work) the inside don not look like it was purged. the last photo on the right looks like a cold start.

to fix it i would grind the dark stuff from the inside, and try to passivate with bkf or if you have a plating house around you they will have nitric acid...

Many thanks for your reply! I'll try your suggestions and post back if I am still having issues.
 
In my TIG welding days, a STAINLESS wire brush was the best to clean up the welds while they were still hot. Definitely stay away from a carbon wire brush. That will cause rust.
 
In my TIG welding days, a STAINLESS wire brush was the best to clean up the welds while they were still hot. Definitely stay away from a carbon wire brush. That will cause rust.

The guy who welded these for me is coming over tonight with a new stainless wire wheel. We are gonna hook it up to an air drill and go to town on them. I then plan to clean well with barkeepers friend.

Do you think a stronger solution of nitric acid might be necessary? WonderGel?
 
Following the keg polishing threads, I used gator grid pads to clean out the welds. "Bar Keeper's Friend" brand cleaner afterwards to clean & passivate.
 
Following the keg polishing threads, I used gator grid pads to clean out the welds. "Bar Keeper's Friend" brand cleaner afterwards to clean & passivate.

Thanks Sizz, I'll def try the gator pads if the SS wire wheel doesn't work out.
 
if you polish it up, passivate and it dose not rust your fine (for our use)

what the sugaring is telling you is that the base metal has been exposed to o2 while hot. Two bad things happen. First, chromium and other alloying agents are cooked out and second is carbides are formed and comes out of solution making the weld brittle.
 
if you polish it up, passivate and it dose not rust your fine (for our use)

what the sugaring is telling you is that the base metal has been exposed to o2 while hot. Two bad things happen. First, chromium and other alloying agents are cooked out and second is carbides are formed and comes out of solution making the weld brittle.

Got it. Thanks again for your explanations and help!
 
Little confused here. I get that the rust is a problem, but my keggle looks identical from the inside, and I've had no ill effects from it. Is this just a "I want my equip. to look pro" type thing, or are you really concerned that the sugaring will effect your beer?
 
Little confused here. I get that the rust is a problem, but my keggle looks identical from the inside, and I've had no ill effects from it. Is this just a "I want my equip. to look pro" type thing, or are you really concerned that the sugaring will effect your beer?

The goal here is to be able to fill my vessels with water the night before, and not come out to rust in the water on brew day. Cosmetically they are not perfect, which I'm fine with. I just want to make what I have the best it can be. :) It would also be nice to not have to scrub the rust off every time before I brew.
 
The goal here is to be able to fill my vessels with water the night before, and not come out to rust in the water on brew day. Cosmetically they are not perfect, which I'm fine with. I just want to make what I have the best it can be. :) It would also be nice to not have to scrub the rust off every time before I brew.

Gotcha. That would suck. My welds may be ugly, but no rust.
 
Go ahead and continue to clean up the welds. JMO. for a kettle or any "hot side" equipment, I think they will work great. Perhaps a "perfect world" weld is needed for a fermentor?
 
Welp, the wheel didn't take off all of the sugaring, but it sure helped a ton. I will sand the rest out with a flapper wheel this weekend and report back after some BKF love. :D
 
As long as you start out with the system sanitized you won't have a problem, pre boil fine,post boil would not be so good.

Pat
 
Make shure that anything you use has not been used on black iron. You can polish it to a mirror finish but if you use anything that has been used on black iron it will rust. I was a stainless fabricator and i had seporate wheels,brushes etc that were kept seporate other wise you will get the rust nomater how much you cleanit. Hope this helps have runinto this many times.Sometimes some muradic acid band a scotch brite pad will help if not too bad.
 
Make shure that anything you use has not been used on black iron. You can polish it to a mirror finish but if you use anything that has been used on black iron it will rust. I was a stainless fabricator and i had seporate wheels,brushes etc that were kept seporate other wise you will get the rust nomater how much you cleanit. Hope this helps have runinto this many times.Sometimes some muradic acid band a scotch brite pad will help if not too bad.

I don't know about the weld situation, but I have a bolt in water heater element in my HLT, and to keep it from rusting when I filled it the night before, I had to put a sacrificial anode in the keg. Mine is just an aluminum rod that I bolted in. Not as elegant, perhaps, but no rust on the element!

haze
 
Welp, I have tried everything. They continue to rust.

Is there any hope of having these fixed? (re-welded with new couplings) Or are they scrap now?

Anybody know a good welder that *could* fix them in Colorado? Where would be the best place to start a thread for that?.

:mad:
 
Welp, I have tried everything. They continue to rust.

Is there any hope of having these fixed? (re-welded with new couplings) Or are they scrap now?

Anybody know a good welder that *could* fix them in Colorado? Where would be the best place to start a thread for that?.

:mad:

I recommend you try the anode idea. here is a pic of mine:

anode.JPG


It corrodes so the steel doesn't have to. They put these in water heaters so that the steel tanks and elements don't rust out. Magnesium is the best, but AL will work. That is just a piece of aluminum rod bolted to the rim, and extending into the water. Any way you can get aluminum in the water and in contact with the tank will do it.

haze
 
I recommend you try the anode idea. here is a pic of mine:

anode.JPG


It corrodes so the steel doesn't have to. They put these in water heaters so that the steel tanks and elements don't rust out. Magnesium is the best, but AL will work. That is just a piece of aluminum rod bolted to the rim, and extending into the water. Any way you can get aluminum in the water and in contact with the tank will do it.

haze

Interesting, but I don't have the room for extra stuff in all 3 kegs. I'm in the process of either replacing these, or having them fixed.

Thank you for the info, at any rate. :mug:
 
Maybe I've got solder on the brain.

I keep thinking if you could clean the effected areas really well until they are rust free, use the correct flux and then "tin" them with a thin layer of silver solder, you could fix this.

Might be worth trying on one fitting / keg.
 
Maybe I've got solder on the brain.

I keep thinking if you could clean the effected areas really well until they are rust free, use the correct flux and then "tin" them with a thin layer of silver solder, you could fix this.

Might be worth trying on one fitting / keg.

Not a bad idea at all, but I'm not sure I'd be able to get to the bottom couplings very well on the inside.
 
try it!, you don't have much to loose, better than cutting out the whole mess and starting over again!

regarding the anode idea, i don't think that will help, the anode will fix corrosion due to dissimilar metals, (one could argue that the cooked sst is a different metal)

link
 
try it!, you don't have much to loose, better than cutting out the whole mess and starting over again!

regarding the anode idea, i don't think that will help, the anode will fix corrosion due to dissimilar metals, (one could argue that the cooked sst is a different metal)

link

I've already got 3 new virgin kegs. :D

I'm just deciding if I want to pay a welder, or go back to weldless for them. It would be nice if these were fixable though. Maybe I'll give it a go.
 
I've already got 3 new virgin kegs. :D

I'm just deciding if I want to pay a welder, or go back to weldless for them. It would be nice if these were fixable though. Maybe I'll give it a go.

You could grind it down to smooth and then fill with some 316 filler rod that might help just try not to over heat or have someone hold a purg linr from the outside and you should be fine.
 
You can repassivate with citric and ascorbic acid in hot water like we do for SS repassivation after welding or grinding and breaking the surface passivation. A 50-50 mix of 1 Lb acid blend in 4gallons of water, heated to 180 degrees, and left to cool for about 6-8 hours will extract the soluble iron and rebuild the oxides to protect the stainless steel where it has been heat affected. This is slower than the nitric acid method but safely do able by the homebrewer, and is the method of choice in the food and beverage handling industry these days. You will only need to cover the weld area, not fill entire keg as only weld or grinding/ polishing area needs attention.
 
You can repassivate with citric and ascorbic acid in hot water like we do for SS repassivation after welding or grinding and breaking the surface passivation. A 50-50 mix of 1 Lb acid blend in 4gallons of water, heated to 180 degrees, and left to cool for about 6-8 hours will extract the soluble iron and rebuild the oxides to protect the stainless steel where it has been heat affected. This is slower than the nitric acid method but safely do able by the homebrewer, and is the method of choice in the food and beverage handling industry these days. You will only need to cover the weld area, not fill entire keg as only weld or grinding/ polishing area needs attention.

Can the mix be moved to another keg afterwards and used again?
 
I think the acid mix is your best bet. It will actually repassivate the stainless. I don't thing BKF will actually repassivate it but instead just polish/clean it. Sounds like kludue has a lot of experience with it. I recommissioned a stainless 55 gallon drum once. I had to remove the top and bottom because they were folded over seams and re welded them. I searched in vain trying to find a way to repassivate the tank and welds. One day when I way in HD I was looking at some of the concrete etchers and cleaners when I found one that had nitric and citric acid blend. I ended up dilluting that with water and have never had a rust issue. I can't say it was FDA approved but I use the drum for a fermentation tank for wine and I am still normal (physically that is, mentally I've always had issues).
I work in the welding field so the last option is a product from a company called Harris Welco, every welding supply house will know who this is. It is a compound called 302. I could only find the MSDS sheet on their website. But this is nasty stuff that really works. Prob no one will stock this and the shipping is a pain because it is a corrosive, but this will do the trick.
Hope some of this helps.


http://www.harrisproductsgroup.com/pdf/MSDS/Compound_302.pdf
 
The acid blend should handle more than one keg application, the key to getting durations worked out would be get the solution hot (180 Max) and let it cool back to ambient temperature which will give the iron extraction time to complete. The common industry method used to determine when passivation is done is to monitor iron level in solution, when it plateaus the passivation is usually complete. Having worked with and tormented the folks from Astro Pak with questions about the process, it looks like the acid blend is the easiest and safest way for the home brewing community to repassivate the kegs and plumbing on their rigs.
 
The acid blend should handle more than one keg application, the key to getting durations worked out would be get the solution hot (180 Max) and let it cool back to ambient temperature which will give the iron extraction time to complete. The common industry method used to determine when passivation is done is to monitor iron level in solution, when it plateaus the passivation is usually complete. Having worked with and tormented the folks from Astro Pak with questions about the process, it looks like the acid blend is the easiest and safest way for the home brewing community to repassivate the kegs and plumbing on their rigs.

Where does one acquire the acids?

Thanks!
 
Where does one acquire the acids?

Thanks!

I looked for something at home improvement stores with nitric acid in it but never found anything. Ended up buying a squirt bottle of citric acid gel made for passivation from someone online. I need some more but I might just have to use the citric acid vitamin c recipe. Should be able to get it at health food stores. Seems like i remember the squirt bottle stuff was pretty expensive.
 
You can find both in powder form on Amazon, or in health food and craft stores, finding Nitric acid is going to be difficult if not impossible for the average person. Leave the Nitric acid to the professionals and go with the citric/ascorbic acid method, a bit slower but safe.
 
what stainless wire did he use? My guess he used the wrong wire, remember some stainless steels still rust, just not as fast, if it was migged then it needs to be a 308 wire with 98% argon and 2% co2. My guess is that judging by the picture, that was mig welded and he just spot welded around the fitting, if thats a tig weld it looks like it was his first time picking up a tig torch. Also, some people when tig welding lay down the weld with filler rod and then go back over the weld to "polish" it and make the weld look better which can cause the weld to rust

I cant believe so many people have problems with stainless rusting.... ive tig'd, mig'd, and stick welded stainless and have never had any weld rust, i think peoples main problems are poor welding/fabrication methods, improper materials, shielding gas, etc... and also contamination of the stainless from using the wrong grinding disks, wire brushes, etc, even drill bits can cause stainless to rust .
 
I would use 316 it dosent hurt to step up. We used 316 on any type of vessle repair and even when constructing them. I used to work for Delmonte. you can use Muratic acid "swimming pool acid" just be carefull with the fumes. we used it often to clean up welds. They wanted us to delute it but i would use it straight it works faster and it eats up contanimates "iron of carbon" Some times when welding the cheaper stainless the small amount of carbon would come to the top that is why we used the 316 we used it when mig and tig as well and some times when arc welding as well. Man they hated to buy the 316
Cheap A$$es but they wanted quality.we also used the muratic acid to clean the stainless where some one drug a piece of black iron over it because that would always rust. The other thing you can do is use a new grinding wheel or pad to take it off and then use the acid again. Hope this helps.:tank:
 
i was thinking that as well, some stianless's are poorly made, 316 has a much higher content of chromium which means it has even less iron in it. If any of you are buying stainless, get the heat number and manufacturer of the material and find out the parameters.....
 
Wow... bringing this thread back from the dead, eh?. I ended up replacing these kegs and had a REAL welder do the job. I'm much happier with my rig now.
 
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