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MIG Braze 304 SS to copper


Fourlix

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I did it. I used my Miller 200 with a spoolgun and Silicon Bronze wire using a brush on paste flux intended for oxy acetylene use. The flux made the braze flow nicely. Without it the braze would just pile up. The set up that worked was 24 volts on the Miller and #4 on the gun. The SS was a scrap of 304 SS 14 gauge, and the copper was 16 gauge. I have a SS milk tank that I am going to build a copper top for. Copper to copper and ss to ss also works just fine. I used a zig zag motion and moved pretty fast. This is just my first attempt, but I was excited to share. I didn't have any Argon and just used CO2, I expect this to get a lot better with Argon and practice. I can tell you that it is easier than welding stainless.

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post-11117-0-63714300-1449850613_thumb.j

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Oh, and I think I will back off on the voltage a little, I think I was running a little hot, pretty flat weld. I expect the Argon to change things up. Who knows? Maybe I will end up liking the CO2 better? We'll see.

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I did it. I used my Miller 200 with a spoolgun and Silicon Bronze wire using a brush on paste flux intended for oxy acetylene use. The flux made the braze flow nicely. Without it the braze would just pile up. The set up that worked was 24 volts on the Miller and #4 on the gun. The SS was a scrap of 304 SS 14 gauge, and the copper was 16 gauge. I have a SS milk tank that I am going to build a copper top for. Copper to copper and ss to ss also works just fine. I used a zig zag motion and moved pretty fast. This is just my first attempt, but I was excited to share. I didn't have any Argon and just used CO2, I expect this to get a lot better with Argon and practice. I can tell you that it is easier than welding stainless.

I am very sorry but that weld looks like crap.

You will get good results if you TIG weld it. The silicon bronze does excellent when it is welded. Also, you can use de-oxidized copper TIG rod and it will look flawless. I will post some pics if I get time.

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http://forumbilder.se/ECSEF/img-3484

We are soon building distilling plants for full time here in Sweden!

legally and to match all laws like ATEX/EX and some more EU directive inside EU!

https://www.facebook.com/#!/FalbygdensBranneriAb/

Before we hard silver solder ss to copper but today we Tigweld it with Cusi3!

But am very interested to now more about “de-oxidized copper TIG rod” to Tigweld ss to copper!

Cheers from Sweden

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You can do a test using solid core copper electrical building wire before you go out and buy the deoxidized copper rod. Purity is not the same as the rods, as typical building wire does contain 0.04% oxygen (C110). I've only ever used this copper to copper - which works fine considering most copper sheet/tubing isn't pure either.

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I has to wait for my supplier to get the triple de-oxidized copper rods, so to get started with welds that could not be seen I used old electrical overhead cable after rubbing oxide off.

When the rods finally arrived I found they were not nearly as easy to get clean welds with. Many pin holes.

Went back to the electrical cable. (copper to copper welds)

I was expecting to see a difference in color especially as the copper surface aged but after 5 years the welds can't be seen.

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Hey Mr. Dehner Distillery.....WTF is your problem? This was an experiment, not a finished result, and a first attempt. This is NOT about TIG, it is about MIG brazing. It is not about stacked dimes. This is something new and different. It works. Making it pretty comes next, with practice and more experimenting. There are plenty of threads on here about TIG welding. If you can't appreciate this for what it is then just go away.

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Hey Mr. Dehner Distillery.....WTF is your problem? This was an experiment, not a finished result, and a first attempt. This is NOT about TIG, it is about MIG brazing. It is not about stacked dimes. This is something new and different. It works. Making it pretty comes next, with practice and more experimenting. There are plenty of threads on here about TIG welding. If you can't appreciate this for what it is then just go away.

Dude, settle down. I was just saying.... You have a long way to go to make it look good. Trust me, everyone was thinking it, I just said it.

So cool you jets.

You did not see me drop f- bombs.........

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If you use standard household electrical wire the arc and the way the weld looks will be totally different than if you use de-oxidize copper tig rod. It is also harder to weld with than De-oxidize copper tis rod.

Silicone bronze is good for joints that could flex because it is malleable. But a copper or even a stainless joint is far stronger.

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Something that I will try in the future is that I shall "test" Mig weld ss to copper with siliconbronze/Cusi3 but with a Mig welder that has pulsfuntion both single and double pulse and " only" just to see if this is possible and what the result look like, and if it is sealed and have No leaks... ... and with No flux.... only with single and dubble puls...

Merry Crismas and a Happy New year to you all from Sweden!

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"Copper and Stainless are used in manufacturing of food grade products, but silicon bronze is only used in water related components, like your water pump and spigots.

The silicon in the silicon bronze is there to replace lead that used to be used in bronze products.
Sounds like you need to Google some NSF and FDA standards on acceptable food grade metal materials and recommended joining practices. You will also find that the MIG process is not used in the US for the making of components and items that come into contact with food."

We sometimes use silicon bronze for our smaller columns, but only on the outside of the column and only on the upside of the vapor path and only with tig.

MIG welds lead to bacterial infections. You do not want a bacterial infection in your mash. Also MIG wire has flux, where as there is no need for flux with tig. If you are going to build sanitary equipment, even for yourself, you should do the necessary research to get it right. I am not attacking you, I am only trying to help you get things right. If you want to put that copper top on right, get yourself a tig machine and learn first how to tig copper to copper and then stainless to stainless and then copper to stainless. Out of my 15 employees only 5 of them can do sanitary tig and only 2 of them are good enough to sanitary tig copper to stainless. Getting a good strong sanitary copper to stainless weld without porosity is not easy. Only the the most talented, best tig welders can do it.

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Not sure why you'd put a copper top on a milk tank, unless you were trying to turn it into a still. We use a big bulk milk tank for mashing, and I wouldn't trade those big open tops for an itsy bitsy manway. Very easy to work with, clean, inspect, sanitize, etc. No sense mucking the whole thing up.

Turning a milk tank into a still though? Maybe one of the smaller round tanks, or a submarine style Zero tank - but most of those things are insulated and copper tube jacketed - so you have little leeway to fabricate. A steam jacketed pasteurizer might be an easier option, but it doesn't sound like that's what you've got.

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It is a round 100 gallon tank, double wall, but the bottom has been cut out so there is easy access to the underneath side. And yes, I want to make it into a still. As far as MIG goes, I have seen lots of SS wine tanks MIG welded, and it's what I have. I think this will make a very nice still. I plan on using the lid to make a new bottom for it, and adding a copper top. I see that there is a 0.02% lead content in the Harris Silicon Bronze wire...I am thinking there must be other brands, but that is a very tiny amount anyway. If you are TIG brazing with the same alloy, why not MIG? I expect to grind these welds smooth to avoid crevices that could harbor bacteria,,,,but it's a still, and none of the wine tanks I have seen had ground welds. Brazing is never going to get that pretty anyway, but it is a solid connection and there are no pits or bubbles.post-11117-0-50693300-1450979402_thumb.j

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And there are no pipes or insulation between walls. I am thinking that with the bottom back on I can heat it with a propane water boiler I have. I will put a manway in the copper top, which I plan on taking up a couple of feet.

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The picture below is of one of our copper to stainless welds after polishing. 308 stainless rod was used. The root pass fill pass technique was used. And the weld was purged with argon on the back side so that no sugaring occurred. If you want to do it right then that is the way that it should be done. The weld on the outside of the pipe looks exactly the same. If it were our copper to copper or stainless to stainless weld you would never see the weld bead after polishing.

post-3459-0-57544800-1450984485_thumb.jp

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Lincoln has a CuSi3 that has 0.1% Zinc and no lead.....There are some interesting U.K. alloys that are different as well. SIFMIG 968 and 985 look interesting.. There is more than one way to skin a cat!

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