Keggle Welding Questions

So, I've got a friend who has a couple of sankey kegs (legal ones, I checked) that he wants to get rid of. I will be taking them off of his hands and converting them to keggles. I looked at weldless conversion kits, but realized that I have access to (and skills for using) a TIG welder. I have a couple of questions for people who have welded fittings on to their kettles:

What kind of settings should I use on the TIG (including filler rod alloy, tungsten, etc)?

I can't backpurge, is this a problem?

Should I weld from the outside, or the inside?

Any post-weld clean-up steps required?

Can/should I repassivate (also, how)?

My welding experience is mostly 4130 thin-wall tubing (racecars you know), how much different is stainless (anything I should watch out for)?

Pics?

Thanks,

Mark

Check out Yuri Rage's how to's in his sig, Sorry I can't help any more than that.

wop31 said:

Check out Yuri Rage's how to's in his sig, Sorry I can't help any more than that.

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yeah, I was going to say the same.....


I have a buddy who welds a lot....made him some HB for my keggle conversions soon. I'll let him figure it out

I've never tried but I've had a few done and watched them being done.

I can't backpurge, is this a problem?
I've never seen it done without, I'd say try on a piece of scrap
Should I weld from the outside, or the inside?
I'd weld from outside, it's easier to dress if required
Any post-weld clean-up steps required?
Shouldn't be if the weld is adequate.
Can/should I repassivate (also, how)?
I've not needed to on the welds I've had done.
My welding experience is mostly 4130 thin-wall tubing (racecars you know), how much different is stainless (anything I should watch out for)?
dunno?
Pics?
no.
Thanks,
Your welcome

Here are some suggestions for tig welding kegs:
3/32" 2% thoriated tungsten, 3/32" 304 SS or 316 SS filler rod
60-70 amps to start out as stainless does not conduct heat and is easier to melt than carbon steel
you can use superior #9 or harris solar flux as a backup flux to prevent surgaring on the inside of the keg while welding the outside/outside when welding the inside
Chamfer the keg opening and bevel the end of the coupling so the inside edge of the coupling is 1/32" inside the keg, this lets you do a fusion weld as trying to add filler rod while back welding the inside is more difficult than you would ever want to try
put the backup flux inside the coupling before you back weld as a slip of the torch wont melt the threads
use a stainless steel wire wheel on a grinder to clean up the backup flux and welds, dont use a carbon steel wire wheel or use the stainless wire wheel on other than stainless steel unless you like the rusty weld look
the last item is the faster the weld is made the heat spread and weld area discoloration are reduced, weld should have red to straw colored tint after it cools

That is exactly what I was looking for. I hadn't thought of a flux, I'll have to pick some of that up when I go to get filler.

Thank you!

I have a guy that does all my stainless welding for me and they are always perfect. However, he is away for the entire summer and I wanted to get my old 7.5 gallon kettle outfitted with a half coupling and a full coupling. I took it to another local welder and asked him if he knew how to do a sanitary weld on stainless steel.

He swore up and down that he could, and in fact did them all the time. This is what I got back!!! I asked him if he backpurged while he was welding. I got no answer, just the deer in the headlights look on his face! So apparently he didn't!

He actually expected me to pay for this mess! I told him that not only was I not going to pay him, but he owed me $75 for ruining my kettle! Needless to say he wasn't going to do that, so we just had to agree to disagree.

Ouch......

orfy said:

Ouch......

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That's what I said Orfy! Can you imagine someone, with a straight face mind you, actually look you in the eye and ask to be paid for that crap? I asked him if all his work looked like that, and again with a straight face, he said yes, and until now nobody had complained! He must get some pretty stupid customers.

Is it just me, or does that look like a flux-cored weld? I say that because it's awfully globby, there doesn't look to be any penetration into the fitting, and there's definitely evidence of sparks on the surrounding metal. That sucks pretty bad, I'd call the BBB and file a complaint.

What the picture shows is what is called surgaring, this is where the back up flux works wonders preventing the ugly mess. For installing the couplings in thin wall pots it is easier to use 56% silver solder to attach the couplings. One can purchase the harris safety silv 56 solder and stay silv flux at a welding supply place. The only advice on the silver solder is it must be a cadmium free silver solder as the cadmium in the cheaper alloys is toxic.

What does the front look like? Do they leak? If they're holding water, I'd grind that mess the best I could and just go ahead and use it. Sanitary welds are required on a conical fermenter obviously, but a boil kettle is self sanitizing.

The front, while not as disgusting as the back, is still pretty pathetic for someone who claims to do this professionally. I don't know if they leak because I can't get a nipple to thread into them because of all the welding slag that he got in the threads! I know I can run a tap through them to clean up the threads, but I decided to just get another kettle.

The other deer in the headlights stare that I got from him was when I asked him if he used cadmium free filler rod. From the look on his face I'm assuming that he didn't.

I recently purchased a 10 gallon Megapot, with perfectly welded couplings from B3 to replace this POS. Without being sure that cadmium wasn't used, I'm hesitant to even give it away to someone.

Ok, that picture makes it look like the fittings are just sitting on a shelf of filler. Did the guy put any heat into the fittings at all? If that guy calls himself a professional welder than I think he needs to go back and take his certifications again, beads like that would get you fired from just about any welding job.

The guy knew he f'd it up. He looked embarrassed, which made me think that he knows how to do it, but had someone that worked for him do it. He still asked to be paid, but didn't put up much fuss when I told him to go bang his ankles!

Looks like the fellow was not experienced on thin SS pots, looks like he burnt through and struggled to fill the hole he created.
You could save the pot by putting a piece of wood dowel in the coupling and use a hole saw to cut the weld out, then use a SS washer bored to fit the 1/2" coupling and weld or solder it to the coupling and pot. Another method would be to use the washer with a female pipe by tubing bulkhead fitting for pickup tube and thermometer connections http://www.buyfittingsonline.com/Fittings/item6859.htm

Sorry! I've been on vacation for a week, so I've been offline. Kladue pretty much summed it up above.

If you're not brave enough to try welding from the inside of the keg/kettle, here's my method: I use Solar Flux and have done all of my welding from the outside. It turns out nice, but it's a pain to clean the flux off of the inside of the fitting.

For what it's worth, I think I'm going to try welding from the inside on future projects.

Here's my "free" weld. (no clean up)

I'm curious as to why nobody addressed the passivation issue. I didn't passivate my keggles, as I didn't think it was necessary given the application. I may be wrong, not sure.
If you decide to do so, a 10% citric acid solution (by weight) at room temperature for 24 hours should do the trick. A word of caution: While 10% citric acid is a relativley mild solution, it will etch the hell out of a concrete floor... be careful.

jpuf said:

I'm curious as to why nobody addressed the passivation issue.

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With proper techniques, passivation is not an issue.

If I do find the need to passivate stainless, I use Wonder Gel, a nitric acid based compound.

Yuri_Rage said:

With proper techniques, passivation is not an issue.

If I do find the need to passivate stainless, I use Wonder Gel, a nitric acid based compound.

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Where do you buy wonder gel??

You can also use Bar Keepers Friend to passivate stainless steel. It has oxalic acid in it and it works quite well for this purpose. Not to mention that is a great cleaner for any metal.

You can get Wonder Gel from McMaster Carr or a good metal supplier.

thebikingengineer said:

Is it just me, or does that look like a flux-cored weld? I say that because it's awfully globby, there doesn't look to be any penetration into the fitting, and there's definitely evidence of sparks on the surrounding metal. That sucks pretty bad, I'd call the BBB and file a complaint.

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Its not flux cored....he just burnt thru real bad and the metal sugared :rockin:

tigmaster - I appreciate your responses to all of the welding threads, but this one is 3 years old. The keg in question has likely been fixed or removed from service by now.