Soldering Stainless steel

[diS]

I think most people are using just propane or mapp gas. I picked up a oxy/Mapp gas setup that uses disposable tanks. When I'm done ill use the oxygen regulator to oxygenate my wort.

I assume that brazing with oxy/mapp was easier than with propane..?
Stay brite's silver solder is pretty pricey due to shipping to Croatia so I get flux coated rods (56% silver, no cadmium), they are 2 mm (0.08") thick and it is tough to braze them just with propane.

I am thinking to buy oxy/propane set with disposable tanks. Reached temperature is not for iron welding but it should be good for silver soldering, cutting and bending.. Actually, I've seen welding an iron with this setup, but weld was porous and unclean due to propane dirtiness.

 

[pickles]

Yeah it's much easier to braze with the addition if oxygen.


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[snowman_fs]

I used a yellow Bernzomatic MPS tank to braze the 56% silver solder, no O2. It was a carbonizing flame in air. I first applied general heating on the fitting for about a minute using the tip of the flame. This would "dry out" the flux with a ring of solder pre-placed in the joint. Then I made a 1/4" blue contact dot on the fitting with the inner cone of the flame. As the temperature climbs the flux would melt and form a bubbling puddle around the solder. Once the fitting started to glow red I would splash some heat out to the keg wall to ensure it also went red and the solder had a chance to bond to both sides as it formed a puddle.

I highly recommend the boron modified flux for silver brazing. It gave me enough time to make two or three trips around the fitting to ensure all of my solder would flow into the joint. After the first pass around it only took seconds to bring it back up to red hot on the second or third pass.

Total time with the flame on for a 1/2" Sch.40 fitting 2-3 minutes.

I used the two or three pass method because of observations I made while practicing on a scrap piece where I could watch the solder melt while heating from below. I noticed the silver 56 doesn't melt that fast even when the steel is red hot. If I moved away from the melt zone with the heat too fast I could leave the molten puddle behind. Then on the second pass I would catch it again and continue the puddle progression. When I was working on the keg with the fitting pointing down, I could not see the inside so I made the third pass for good measure.

Once the joint cooled for 3-5 minutes I poured a kettle of boiling water on the flux and it cleaned right up.

I also wanted to post the picture of my dimpling tool as it applies to either soldering or brazing. I used a 1/2" bolt so I didn't need to grind the inside of my reducing coupling and simply wrapped the bolt shank with some tape to help center the fitting. Then I made a second drawing pass for my heavy fittings with a modified 1/2" coupling where I beveled the leading edge on a bench grinder. To help ease the dimpling effort I also used a scotch bright pad on my grinder to polish the working surfaces of the tools.

 

[WeatherbyTom]

Moved question to new thread

 

[Chefboubou]

I decided to go that route too but couldn't find a reducer locally. So I found this steel hose barb at the hardware store. I simply cut the barbs away and used my large socket. Here is the result! Tomorrow I will be soldering this all together! Thanks for this nice thread! I just wish I haven't spent that much on three weldless bulkheads....


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[helibrewer]

Made "The Tool" and soldered two couplers onto my keg HLT, worked great!!! I love this hobby.

 

[ryanhope]

Just so you guys know. Harris Stay Brite is not the only acid flux for stainless. I just soldered at least 18 fittings onto 3 kettles using RubyFluid Stainless Steel Flux. It worked great. I never used Harris so I can't really make a comparison but I had no problems.

 

[Chefboubou]

I soldered 2 couplings. The first one was a success, the second one was another story. The tin was leaking at one precise spot around the coupling and this created a pin hole. Next time, I will visually inspect all around the coupling and hammer it if there is a void....

The third time I heated the things up and rotated the coupling 90 degrees. I also attached a SS wire around the coupling to act as a backup ring and prevent tin leakage. Somehow it worked.

Now I can relax and have an homebrew.

Cheers!


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[SouthernYankee]

WOW Im glad I came upon this thread. Having read thru most of the post I decided it was my turn.
I made my dipple jig... at a cost of $3 to 4 bucks...from there with my Mapp gas and Harris flux I went to town...
Solid as a rock and water tight!

I was going to go weldless, but now I don't have to.

 

[1fast636]

Any pics of your dimple jig I like the low cost I was thinking about turning a1inch rod down at an angle then drill out to gauge to 1inch

 

[SouthernYankee]

Any pics of your dimple jig I like the low cost I was thinking about turning a1inch rod down at an angle then drill out to gauge to 1inch

Simple parts, I tried the pvc part which I replaced with a steel sq tubing...worked much better. 5/8 5" bolt and nut. 3/4 to 1/2 copper reducer. For the top I used part of a bolt puller.

 

[sablesurfer]

THANK YOU to this thread! No really. I actually made it work for me.

I put my pics in a seperate thread as a "what not to do newbie" kinda thing.

https://www.homebrewtalk.com/f51/my-progress-silver-soldering-470149/#post6056055

But I want to thank this thread again and I want to say...SAND!!! Sand down your stainless before any attempt to solder with silver solder and flux...no seriously! Listen to this thread. LOL.

 

[doublehaul]

Dumb question - on a keggle, how do you know when the solder joint is done - when to stop applying heat? It seems like it would be tough to see down in the bottom of the keg and watch your torch on the outside at the same time.

 

[snowman_fs]

It seems like it would be tough to see down in the bottom of the keg and watch your torch on the outside at the same time.

Yup it is tricky. Practice first on a piece of scrap and get the feel for the time/temp required where you can see easily. It also helps if you have a friend with a flashlight watching the inside giving you feedback when working on a keggle. If I'm doing it blind at the bottom of a keggle I use a "three times around" technique but I also use a boron modified flux that can take the extra heat.

If you clean up a bad joint when its cool and re-apply flux you can reheat and fix up quite a bit. Again just practice and try cleaning a bad joint up. Its already a scrap piece and will let you know what you can fix should something go wrong on your keggle.

 

[doublehaul]

If I'm doing it blind at the bottom of a keggle I use a "three times around" technique but I also use a boron modified flux that can take the extra heat.

What's a three times around technique? I have the Harris #8 and staybrite kit but I've literally soldered one thing. Thanks.

 

[snowman_fs]

What's a three times around technique?

Sorry I described it earlier in this thread somewhere.

First I put a ring or two of wire solder in the dimpled area between the fitting and wall and cover it with flux, (both sides sanded first). Then I get the area and fitting nice and hot. I heat it to the point where if I hold the torch stationary on the joint for 2-3 seconds the solder will start to wet out in that spot. At that point I start a slow circular pass around the fitting, (maybe 10-15 seconds for the full 360 degrees) to "drag" the liquid solder puddle around and let it flow into place. Because the solder ring doesn't make perfect contact with the steel sometimes the solder puddle will get left behind if I move the torch too fast. So I make sure to do two extra passes around the fitting to catch any areas left with wire solder and continue to drag the puddle around.

I have attached a picture where you can see a small bit of the solder wire in the 4 O'Clock position that I "missed". After I noticed this I just re-applied some more flux and re-heated the joint to let it all melt and flow. You really just have to do it to get the hang of it.

 

[Charlieatthedisco]

This has probably already been gone over but what type of silver
Solder and flux are you guys using and has anyone heated the fitting with a torch rather than an iron? New to this so trying to figure it out
Thqbks


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[sablesurfer]

I used a torch. Staybrite solder is the brand most talked about, my roll cost me about $80 locally, but I hear online it is cheaper. My shop had no Staysilver flux, but since they were an HVAC warehouse supply store I took the flux they recommended, used it with no problems.

 

[wbarber69]

Harris stayclean flux and any silver bearing solder will work.

 

[Charlieatthedisco]

No doubt. I know thousands of brewers are happy with typically sold weldless solutions but I guess the idealist in me just wants to see it done better somehow. I will only sell sightglass kits where I can put the gasket between the compression fitting and the kettle wall with no other parts. The fact that I'm not trying to make a real busi

Hey bobby. Just watched all your vids on you tube for the soldering process (two six packs and a big bag of ice lol) good stuff by the way. I was wondering if the punch you were using would be good for soldering couplers in my keggle, and also would the harbor freight one work?!

Thanks man


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[Mirilis]

So I have read about 20 pages of this thread and cant seem to continue so im going to do the lazy thing and ask at the bottom... sorry.

I have free stainless compression fittings (1/2in thread to 5/16 compression) .. can I just solder that directly to my kettle. Its a Jarhill so the wall thickness is only like 0.95mm. Im thinking of doing the soldering from outside the kettle and eventually just put a dip tube in the compression side and a ball valve on the outside.

 

[wbarber69]

So I have read about 20 pages of this thread and cant seem to continue so im going to do the lazy thing and ask at the bottom... sorry.

I have free stainless compression fittings (1/2in thread to 5/16 compression) .. can I just solder that directly to my kettle. Its a Jarhill so the wall thickness is only like 0.95mm. Im thinking of doing the soldering from outside the kettle and eventually just put a dip tube in the compression side and a ball valve on the outside.

You can but personally I'd solder in a coupling so you can remove the whole compression fitting once you realize how terrible the flow will be out of 5/16.

 

[Mirilis]

Lol I meant 3/8 but I see your point.. I'll probably just do a 1/2 hex nipple

 

[iijakii]

Is there anything special about the Harris flux? I have some liquid acid flux and silver solder and it is just not binding at all. Maybe the acid content isnt high enough or something?

 

[Ravenshead]

It doesn't have to be Harris flux, Oatley makes one that works as well. It does have to be one that is specifically labeled for SS. There are some liquid fluxes out there that don't work for SS, Rubyfluid comes to mind.

 

[wbarber69]

All I know is that the Harris does work and has worked for everyone. So why not stick to that. Hell I found a bottle of the stuff in the shop of the house I bought a couple years back. I have no idea how old it is but it works just as good as the new stuff I bought from brewhardware.

 

[mendozer]

thought about this for putting on a triclamp to use Bobby's element holders. Can you silver solder a stainless clamp to an aluminum pot?

 

[wbarber69]

Probably

 

[SavageBrewer]

I was just wondering after reading the back of my bottle of Harris sta-clean flux. After the joint is soldered, what do you do to clean the joint? From reading the bottle, this stuff has some nasty stuff in it that I don't want touching my beer. I was going to solder a coupler in my keg using the dimple and solder from inside method.


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[wilserbrewer]

Bar keepers friend and elbow grease. Rinse well with hot water?


Wilserbrewer
Http://biabbags.webs.com/