Soldering Stainless steel

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I got this one and it worked so far for my 2" hole. I also plan on using it for my 1.5" hole.

I got these two female couplers. When they arrived I thought I could have just used the first socket weld one but it wouldn't let me pull the reducer through enough. Glad I got the 2" coupler.

I dimpled out - but I am wondering how to solder it up tonight because I want to coil it around the T-C fitting on the inside, to fill the dimple. Will I have to heat it from the inside or can I heat the fitting from outside the keg (underneath) and and let the solder flow that way???

I wish I would have seen that fitting. I wanted one like that. It should work, I think those are inside measurements and OD should be around 2.375 based on this site, but hopefully someone else can chime in.
 
Last edited by a moderator:
cank said:
I dimpled out - but I am wondering how to solder it up tonight because I want to coil it around the T-C fitting on the inside, to fill the dimple. Will I have to heat it from the inside or can I heat the fitting from outside the keg (underneath) and and let the solder flow that way???

I wish I would have seen that fitting. I wanted one like that. It should work, I think those are inside measurements and OD should be around 2.375 based on this site, but hopefully someone else can chime in.
Click to expand...

You never want to heat the side your applying solder, youll burn off all the flux and you'll have a hell of a time getting the solder to "stick". flux and solder the inside and then heat the other side, focusing most of your heat on the ferrule rather then the keg. Check out the video posted on here if your still not sure.
 
Got it. Thanks.

Turned out pretty good. I'll do a leak test tonight.

image-1758958388.jpg


image-1220180591.jpg
 
Has anyone soldered the coupler so that it sticks out into the vessel? What I mean is currently I use the weldless valves and this setup as most of you know has the coupler on the inside and the valve wedged again the exterior wall of the vessel. I have no issue with this the way it is now and all my fittings for the inside are already measured etc for this length. Does any one see any reason why I would not keep this configuration? Negatives?
 
Daves69 said:
Has anyone soldered the coupler so that it sticks out into the vessel? What I mean is currently I use the weldless valves and this setup as most of you know has the coupler on the inside and the valve wedged again the exterior wall of the vessel. I have no issue with this the way it is now and all my fittings for the inside are already measured etc for this length. Does any one see any reason why I would not keep this configuration? Negatives?
Click to expand...

I have one like that on my kettle, works just fine.
 
wyzazz said:
I have one like that on my kettle, works just fine.
Click to expand...

Yeah, I kinda figured it was for cosmetic reasons, I can see for bottom draining etc why you would want it flush on the inside, but when you have a dip tube to pick up the wort it should not matter much.
 
Well I've been told regular paste flux won't cut it for soldering ss. I went with stay clean (harris products) and soldered my 1" nuts and valve easily
 
Yeah, I've tried that stuff before also and found that it didn't work. Save yourself the frustration and get the Harris stuff.

I got the kit from Airgas for $7.50 and it was enough to solder quite a few bulkheads in my kegs.
 
@SpartyParty in truth you are not supposed to rely on any kind of soldered electrical connection to stainless steel because the aggressive flux that you need will corrode the joint eventually. Can't you make a physical connection using a self tapping screw with a locknut and eye terminal, or something?

If you absolutely have to solder the connection, I would advise phosphoric acid (naval jelly) for the flux which is noncorrosive.
 
alien said:
@SpartyParty in truth you are not supposed to rely on any kind of soldered electrical connection to stainless steel because the aggressive flux that you need will corrode the joint eventually. Can't you make a physical connection using a self tapping screw with a locknut and eye terminal, or something?

If you absolutely have to solder the connection, I would advise phosphoric acid (naval jelly) for the flux which is noncorrosive.
Click to expand...

So a self tapping screw from the outside? Then just use a washer/gasket? That could work. I was hoping to be leak proof and not have to worry about another area to watch for leaks is all. Thanks
 
SpartyParty said:
So a self tapping screw from the outside? Then just use a washer/gasket? That could work. I was hoping to be leak proof and not have to worry about another area to watch for leaks is all. Thanks
Click to expand...

I don't think there's a problem with soldering the screw. You can then easily crimp a ring on the ground wire and use a nut to screw it down. This is what I did, but on the kettle itself. I think alien was thinking that you were going to solder the ground wire directly to the kettle based on his response.

BTW, how are you housing your elements?
 
alien said:
@SpartyParty in truth you are not supposed to rely on any kind of soldered electrical connection to stainless steel because the aggressive flux that you need will corrode the joint eventually. Can't you make a physical connection using a self tapping screw with a locknut and eye terminal, or something?

If you absolutely have to solder the connection, I would advise phosphoric acid (naval jelly) for the flux which is noncorrosive.
Click to expand...

Really? I've never heard of such a thing. How's come all of our houses aren't springing leaks over time?
 
I understand your concern, but the article refers to a reaction with lead. We're using lead free solder here; how does this apply?
 
alien said:
Huh? I never said anything about leaks.

The message is: Don't rely on electrical connections soldered with acid flux.

This basically precludes soldering stainless steel.

http://www.kester.com/Portals/0/Knowledge_Base_Articles/Soldering_to_Stainless_Steel.pdf
Click to expand...

The Kester article seems to indicate a reaction with the lead in solder as being the main problem. OK, so what about silver solders that contain no lead? Does the reaction occur with some other element in the alloy?

I also think the word "eventually" is key and necessary to define. Sure, in a piece of enclosed electric gear designed to work for 20 years is one thing but...
I silver soldered a copper grounding lug to a SS nipple over a year ago and my meter is still reading zero ohms between them. If there really is a problem, how many years will it take for some resistance to show up? 5? 10? How much resistance? How about just resoldering the lug on every few years?
 
OK, here is the information sheet for Kester 817 which is basically the same as Stay-Clean, and is what they recommend for soldering stainless.

The Inorganic Acid Fluxes were developed for non-electronic soldering applications... The corrosive nature of the residues precludes their use for electrical or electronic applications.
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Here is information from Harris. Emphasis added. Non corrosive flux required, not recommended.

Flux, tin-lead, and tin-antimony solders. Both Stay-Clean Paste and Liquid soldering flux is recommended except on electrical or electronic applications which require the use of a non-corrosive flux.
Click to expand...

Not too much wiggle room in those statements. It is kind of electronics 101 not to use acid flux. When active fluxes are necessary for cleaning really dirty or hard to solder parts it is advisable to clean up as far as possible with water, solvents etc.

The problem is not just electrical connections failing due to corrosion, but also conductivity as the flux residues absorb moisture which can create electrical paths between parts which are supposed to be insulated from each other!

Yes, it won't happen overnight, but since this is a critical application (grounding a power appliance) I think it's better take the advice of Kester, Harris, the guys that actually make the flux.

It looks like you can get rosin-core silver solder specially formulated for soldering stainless, but it's probably a complete ***** - rosin solder is generally pretty mild.
 
While building my E-Brewery last year, I made sure to test conductance between my Keggle walls and the ground post on my 50A/240V extension cord. It is all good!
 
There's also a difference between soldering a copper stranded wire directly to the stainless part and soldering on a grounding lug to which a wire is then attached using mechanical means. If you clean off the flux from the lug there shouldn't be any problems.
 
I've been trying to solder my welding spud for my temperature probe on my BK, but when I've leaked test it I have been finding leaks. I've tried re-soldering the welding spud a couple times now, but every time there's been a leak.

This time I decided to try soldering on the outside of keg, hoping this would clog up any holes. I haven't leak tested it yet, but hoping this did the job this time. You guys see any issues by doing it this way? I know usually your supposed to wrap some solder around the underside of the welding spud and place it on your hole and just heat around the area and just watch it drop in.

Here's an image to kind of give a better idea of what I did.

IMG_20130424_123703_845_zps27e5d902.jpg



Thanks.
 
either you are not using the right flux and/or you don't have it cleaned up enough. make sure you scrub the crap out of all the surface area being soldered with some fine sand paper or plumbers tape as they call it and use plenty of flux and keep the heat moving evenly. The joint looks like it is a cold solder joint with no wetting or flow of the solder.
 
Also, it's not necessary to build up solder on the outside of the joint. Clean it up properly and do like Bobby in the vid. ;)
 
Actually that's the one query I had about Bobby's spud video, he cleans up with a wire brush drill attachment and I wanted to know if it was a stainless one.

I just used emery paper and elbow grease. But first I wiped up excess solder with a flux soaked rag while the metal was still hot - just on the keg, I didn't want to dislodge the nut.
 
It was definately stainless wire brush. I believe he even mentions it in the video; but if you use a carbon steel brush it will rust.
 
I'm only about a quarter if he way through the thread, so ill just ask my question before doing all my research ;) I have a propane torch, but could a 1200 watt heat gun do the trick? I've seen mention of soldering irons, just wasn't sure if anyone had tried a heat gun out? I always cook my copper fittings. I'm getting better though.
 
Some have mentioned that a large Soldering Iron works (150watts) but I'm not sure a heat gun (I assume you mean something like a blow dryer on steroids.) would work. Well, I guess it might eventually work but I think you may get tired of holding it.
 
Heat gun? No. Soldering Iron? MAYBE...

Just use the propane torch. Make sure you heat up the area around the fitting for about a 12" diameter PRIOR to actually heating the fitting. A torch is the only way to go.
 
I am having one heck of a time getting my solder to stay in place. My ssurfaces are clean, and I am applying minimal flux, but it still runs and I lose all of my solder. I am using a water-based paste flux. Is that my problem? Will switching to stay-brite liquid flux fix the issue?
 
Abhitchc said:
I am having one heck of a time getting my solder to stay in place. My ssurfaces are clean, and I am applying minimal flux, but it still runs and I lose all of my solder. I am using a water-based paste flux. Is that my problem? Will switching to stay-brite liquid flux fix the issue?
Click to expand...

Stay-Clean Liquid Flux is critical when soldering stainless steel.
 
P-J said:
Stay-Clean Liquid Flux is critical when soldering stainless steel.
Click to expand...

Thanks. That is what I expected. I am going to try and find a supplier here in Jackson, MS.

ETA: Yup, you were right. The liquid flux did the trick!
 
If You Have a Friend That Has a T.I.G. Welder and The Peices Are Not The Same Material, Use Silver Solder, No Flux, Use T.I.G. For Heat Source.
Used This Before For Stainless Steel w/Copper & Bronse.
 
Has anyone used oatley safe flo silver solder instead of the harris? HD has that in my area in stock and it is cheaper than ordering the harris safe brite.
 

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