Soldering Stainless steel

[Woodbrews]

I'd clamp that snug with a butterfly wall anchor setup like bobbym uses then reapply heat. It may nestle in tight as the solder begins to flow.


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Is this in one of his vids? I haven't run across it yet. I'm willing to give it a try - nothing to lose!




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[pickles]

It's in the video on the previous page of this thread . I think it's post. #1343


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[Docbruw]

One thing that needs to be stressed on soldering these bungs or 1.5" tri-clovers is to apply the heat slooooowww. If you watch Bobby's video when he is heating up the 1.5" tri-clover when the flux starts to boil he removes the heat for a few seconds tests for solder flow and then heats again if it doesn't. The trick is to get the flux to boil then turn to a light brown goo (technical term) which helps etch the SS so the solder will flow. You know you've applied the heat to fast if the flux boils and turns to a black char. You will still get some black char but it happens after the solder flows.

I watched Bobby's video 1 time and when out and attempted to solder on my first tri-clover after I had experience doing 9 nipples on the same kegs. The first attempt was BAD. My leak test failed 4 times before I got it sealed. I was not happy with the solder job so off it came. Watched the video again and paid much closer attention to how he applied the heat and solder, 2nd attempt turned out great. I did my other keg after that and it was even better.

I hope this doesn't scare anyone off of attempting the soldering. It is actually very easy to do if you take your time.

 

[Woodbrews]

One thing that needs to be stressed on soldering these bungs or 1.5" tri-clovers is to apply the heat slooooowww. If you watch Bobby's video when he is heating up the 1.5" tri-clover when the flux starts to boil he removes the heat for a few seconds tests for solder flow and then heats again if it doesn't. The trick is to get the flux to boil then turn to a light brown goo (technical term) which helps etch the SS so the solder will flow. You know you've applied the heat to fast if the flux boils and turns to a black char. You will still get some black char but it happens after the solder flows.

I watched Bobby's video 1 time and when out and attempted to solder on my first tri-clover after I had experience doing 9 nipples on the same kegs. The first attempt was BAD. My leak test failed 4 times before I got it sealed. I was not happy with the solder job so off it came. Watched the video again and paid much closer attention to how he applied the heat and solder, 2nd attempt turned out great. I did my other keg after that and it was even better.

I hope this doesn't scare anyone off of attempting the soldering. It is actually very easy to do if you take your time.

Great advice, all. I will work on fabricating a clamp, although it will have to be a little different than BobbyM's because the interior portion of the clamp will need to clear the flange in order to clamp against the pot wall. But I think it can be done, perhaps with toggle arms on both ends. I also will follow the advice from here and on the video about heating slowly until the solder flows. I'm using MAP gas, so it's easy to heat too quickly. I suspect that the technique takes some practice, and there's nothing wrong with that. After I'm done, I'll sure I'll be looking around for more stuff to solder!

 

[wbarber69]

I think the step most people scrimp on is the initial prep work. Grind/sand the hell out of the are to be soldered. And when it looks nice and clean sand it some more. Use acetone to clean all oil and sanding residue. If your joint is squeaky clean then it can't fail. Seriously. Is you look at your work and say that looks about good, your only half way there. Mor time spent prepping equals less time trying to get it to work. The soldering part should be the easiest and fastest part of the whole thing.

 

[snowman_fs]

Thanks guys.

I cut the top off my first keg today. On my way to a new BK. Also made my first dimple in the scrap and I'm impressed.

I used the dimpling tool pretty much as detailed on this post. The one exception is that I made it work with a sch40 1/2" bushing from McMaster. The fitting that is thicker than the original parts detailed here.

To do this I formed the dimple in two stages. First I used the typical reducing bushing and pulled all the way through. Then I made a second punch by grinding the leading edge of one of my thicker fittings to form a taper from the OD of the first punch to the final OD of the bushings I have.

I made sure to de-burr prior to any forming as well as using a light oil to lube the dimpling. Went really easy and formed a nice deep dimple that I think will give lots of strength to my keg fittings. I'll make the practice solder tomorrow night along with the holes I need in the keg. Fingers crossed it all goes well.

Oh, I also used the smaller diameter bolt to not worry about grinding out the fitting. To help center the punch I just wrapped the shank of the bolt with some tape to build up the thickness to a snug fit.

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[Bobby_M]

One thing that needs to be stressed on soldering these bungs or 1.5" tri-clovers is to apply the heat slooooowww. If you watch Bobby's video when he is heating up the 1.5" tri-clover when the flux starts to boil he removes the heat for a few seconds tests for solder flow and then heats again if it doesn't. The trick is to get the flux to boil then turn to a light brown goo (technical term) which helps etch the SS so the solder will flow. You know you've applied the heat to fast if the flux boils and turns to a black char. You will still get some black char but it happens after the solder flows.

I watched Bobby's video 1 time and when out and attempted to solder on my first tri-clover after I had experience doing 9 nipples on the same kegs. The first attempt was BAD. My leak test failed 4 times before I got it sealed. I was not happy with the solder job so off it came. Watched the video again and paid much closer attention to how he applied the heat and solder, 2nd attempt turned out great. I did my other keg after that and it was even better.

I hope this doesn't scare anyone off of attempting the soldering. It is actually very easy to do if you take your time.

This is a pretty good explanation of the nuances of doing it right. I can see it being really frustrating because I realize that some people want to just get the job done rather than learn a new skill. To really get it, to the point where you can repeat it on a few pots, is to maybe practice on some scrap copper and brass parts using cheaper flux and solder. The concept is the same, even though copper is a little more forgiving.


If you do happen to overheat and burn the hell out of the flux, reapplying some flux to those charred areas will freshen it up and flush the char away.
Keeping the flame away from the fluxed surfaces is also important because that will burn it before the metal is near hot enough to melt the solder. Finally, you do not want to hold the solder anywhere near your work at the same time as the flame is on it. Melt the solder with your work piece, not the flame.

 

[snowman_fs]

Here is the result. Pretty happy for boss #1. I didn't realize how much heat was needed for silver braze to flow. The larger mass fitting didn't help...

For those following along I used black silver flux paste, (superior flux 601b), Prince Izant Silver Braze 56 and MPS gas.

Nice and strong, threaded in the nipple and valve with no need to apply countering torque.

I'll leaked test next and then use some pbw but I don't expect problems. The braze is smoother than the center weld on my keg!

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[snowman_fs]

Sorry. I could only add one photo per post from my phone.

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[Bobby_M]

The result looks good, but just for everyone's clarification, the silver solder you used requires brazing temperatures of around 1200F. Everything in this thread is referring to soft soldering or silver bearing solders that flow at 430F. Pretty big difference.

 

[snowman_fs]

Haha good point. I got so involved with this I forgot what the thread title was!

The performance benefit of brazing vs soldering is higher strength and smaller capillary zones needed to achieve full strength. At the risk of carbide precipitation if the carbon content of the steel is high and the time above 1200F is held too long. If carbide precip happens to 304/316 SS it reduces the corrosion properties and overall strength of the base metal. For a critical application you would want to dig into this a little deeper and prevent it.

For me the small chance of any negatives are worth the benefit since the risks are nill. Well maybe some spilt beer or a BK that can't be passed onto my kids


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[cyberbackpacker]

Snowman I believe everyone would agree with you about brazing, but this thread exists for the overwhelming number of people without the materials or wherewithal to braze. That, and silver soldering has proven time and again to be great for our applications.

 

[ryanhope]

I finally got my 1.5" tri-clover flange soldered on!!! After many failed attempts (the pic below being one of them),


I finally though I should use my IR thermometer to see how hot the flange was actually getting. To my surprise I wasnt even in the 300's F Now that I realized that all I needed was patients and more time. I also changed my torch to the simple pencil style (I was using a HB torch before). This allowed me to get more focused heat on the flange and not as much near the flux. Anyway here is the final version product:

 

[Bobby_M]

Hey, leak free is the most important thing right? There's definitely more solder on there than you needed but it can't be pretty the first time. To be perfectly honest, my first try had extra blobs of solder too.

 

[Docbruw]

That's one of the best things about this, you can start over and try again if needed but i can't see that leaking.

 

[ryanhope]

How do you guys clean your stainless after you are done soldering? I have flux drip marks and other discoloring all over my pots after I am done. I've tried bar keepers friend but that doesn't completely remove the marks.

EDIT: 1500 then 2000 grid sand paper seems to do the trick

 

[Docbruw]

I use an angle grinder with a fine grit polishing pad. 10 seconds and it's shinny as new.

 

[diS]

What gas do you use for soldering, oxy/propane, oxy/acetylene or just propane?

I have small propane torch for copper soldering and flux coated rods, it is pretty tough to melt them, it can be done on small pieces but it is damn tough to do it on kettle.

 

[pickles]

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.

 

[Docbruw]

I used a small propane torch.

 

[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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