Soldering Instead Of Welding?

[Thirsty Boy]

I know that welding is the gold plate option for metal joints - but considering that soldering is much easier and can be done with a handheld propane torch rather than a TIG or MIG... why dont homebrewers solder more of their fittings??

You can solder copper to copper (so easy its laughable) to brass, to stainless, to aluminium and each of those metals to itself.

Sure, a soft solder joint isn't as strong as welding - but its not exactly weak either. I have a few soldered copper fittings in my brewery, and I tried to pull one apart the other day to see how strong it was. The copper pipe got nicely bent into odd shapes, but the soldered joint held. OK, you wouldn't want to build your brewstand out of it (although I have seen a lovely brewstand for an electric system made from soldered copper pipe) but kettle fittings? If you aren't an "it must all be stainless" nut, you could do all your own fittings in easy to work with brass and solder them into your vessels, without tape and o'rings and without paying someone to weld them. I know about glavanic corrosion, but its not going to be worse than if you used brass weldless fittings and plenty of people do that. Or just buy stainless plumbing bits and solder them in yourself - all stainless.

So why not more soldering and/or brazing??

Thirsty

some research to prove I am not crazed - check out the soldering of the pepsi can, not even hot enough to make the paint burn

http://www.howtobrew.com/appendices/appendixB-3.html

http://www.durafix.com.au/index.php?conten...onstrations.htm

soldering stainless video - - he recommends an oxy torch but says you can get away with propane for small jobs.

and a lovely kettle fitting with brass soldered to stainless - http://forum.northernbrewer.com/viewtopic....hilit=soldering with links to other examples of brass to stainless and stainless to stainless soldering

And I've personally seen Spillsmostofit braze a bit of brass to a bit of stainless tube - so its more than internet research and might even be true

 

[Gavo]

So why not more soldering and/or brazing??

Maybe just because its a bit more old school? You can basically silver solder almost anything together. I have silver soldered cast iron to copper. There are actually less stresses caused in the metal. A old mate of mine races go-carts (his 80cc does 170km/h) and he builds the chassis of his own and has built many for others. His frames are joined with nickel/bronze brazing rods. Far stronger than welding as welding causes built in stresses in the metal and the welded frames crack around the welds in time.

You could very easily silver solder fittings into stainless kettles etc. You would have to watch out for warping on thin metal due to the heat fro the flame. The oxidized metal would have to also be cleaned with some fine abrasive to halt any possible corrosion.

Brazing a stand together would be quite strong. It would just take longer to do.
I just find it easier to grab the MIG and weld it together.


Cheers
Gavo.

 

[schooey]

Is Boilermaker, is welded....

 

[Ducatiboy stu]

Is Sparky...is soldered..

 

[Tony]

is fitter....... is hit with a hammer :lol:

 

[SpillsMostOfIt]

is manager... is given to some poor overworked ******* to do instead of eating lunch.

 

[Tony]

Is trade unionist....... is going to have lunch anyway!

Back on topic.......... i think soldering is a great option. Braising and silver soldering are strong as as said, less stress creating methods of joining steel.

But to be honest, A Tig, used corectly will give a better finnish once pickled on SS and a Mig is just so damn east to use for welding thin walled tube for frame building ect.

If its soft soldering your refering to, like lead/tin....... i wouldnt recomend it.

cheers

 

[schooey]

I found it pretty hard to get a decent soldered joint with one of those handheld butane torches and to silver solder properly, you really need a propane torch and a cylinder. Ok if you have one lying about I guess. I was considering silver soldering a lot of my fittings at one point, but the kettle drain fitting always had me a little nervous. The way the big ass burner licks up around the side of the kettle, I was a bit worried about it getting too warm.. sheer paranoia more than likely, but being TIG welded just gave me piece of mind

 

[white.grant]

I've been learning how to braze thin wall steel tubing for my bike frame building hobby. Compared to MIG, its quite hard to get right, you gotta be really careful with joint preparation, fit and cleanliness. You really need an Oxy set to get stainless hot enough, though you can do milder steel, brass and copper with MAPP or propane.

I think Schooey's right though, I wouldn't use a low temp soldered joint anywhere near a NASA, bound to end in tears sooner or later.

cheers

grant

 

[Batz]

What is solder?

Reels of solder
Photograph Rapid Electronics
Solder is an alloy (mixture) of tin and lead, typically 60% tin and 40% lead. It melts at a temperature of about 200C. Coating a surface with solder is called 'tinning' because of the tin content of solder. Lead is poisonous and you should always wash your hands after using solder.
Solder for electronics use contains tiny cores of flux, like the wires inside a mains flex. The flux is corrosive, like an acid, and it cleans the metal surfaces as the solder melts. This is why you must melt the solder actually on the joint, not on the iron tip. Without flux most joints would fail because metals quickly oxidise and the solder itself will not flow properly onto a dirty, oxidised, metal surface.

 

[chappo1970]

Do not solder what ever you do. I think your refering to brazing, I hope! But you have to have rocks in your head to solder. Remember the urban myth of American moonshiner's moonshine making people blind? It wasn't any myth. Apparently the bootlegger/moonshiner's would use the radiator out of car's and tin solder the stills together. Lead is dangerous stuff.

Back on topic.......... i think soldering is a great option. Braising and silver soldering are strong as as said, less stress creating methods of joining steel.

But to be honest, A Tig, used corectly will give a better finnish once pickled on SS and a Mig is just so damn east to use for welding thin walled tube for frame building ect.

If its soft soldering your refering to, like lead/tin....... i wouldnt recomend it.

cheers

Yep I agree with Tony and Batz. TIG (A+++), MIG (A++) even good old stick welding (A-) is within the novices grasp these days. A good starting rig can be picked up from evilbay for around $300 new less for second hand and stainless rods of good quality are pretty cheap these days.

Brazing with silver is not difficult but requires patience and lots of practice to master. A simple MAP gas rig will get you started. But it's alot like riding a bike, once mastered you have the skill for life.

Honestly I love the internet for the info but sometimes it can be full of a lot of miss information that is just out and out dangerous. I admit I didn't check out those linkies but being a forum member of a welding/metal arts forum we get alot noobs that have seen this or read that about welding/brazing that just is not true or correct. Like brewing a good beer there are a thousand variables that go into joining metals properly.

TB if I was in Melb I tell ya to bring what ever you wanted done to my place mate. I let ya nuts on my gear rather than see someone potentially hurt themselves. I twould also give you the knowledge of what you can do and what gear you would want. I have a TIG, MIG, OXY/ACE set, Plasma cutter and on and on.

 

[SpillsMostOfIt]

I agree with most of what has been said above, particularly about misinformation.

Electronic solder has traditionally been made of tin/lead and since the European RoHS legislation has filtered through, you will usually find electronic solder to be lead-free, but if you're not convinced you can also buy leadless silver solder all over the place, including the big green hardware sheds. It's harder to solder with it because you need higher temperatures than lead (which is why the electronics manufacturing companies resisted the change - they had to rework or replace all their soldering equipment), but it works and works well once you've got the hang of it. Brazing rods want hotter again, but they're still doable (harder if the thing you're heating up is a cheapie, paper-thin kettle). I think the key is a good clean surface and a good flux. For me, there's nothing like a good acid to get that job done...

Somebody gave me a propane gas torch, so I tend to use it as I have plenty of experience with solder and I cannot justify the expense of welding kit. It is 25 years since I did any welding at all...

 

[browndog]

I think TB when he was talking about solder was actually talking about silver solder, as Chappo stated is really more like brazing and nothing like lead solder. Jeez Chappo, I'd love to be given free reign in your garage mate, sounds like a HB Tinkerers heaven.

cheers

Browndog

edit: included (more like)

 

[rclemmett]

Seems like a good time to ask my question............ I know this isn't a welding forum but you guys seem to know what your talking about, and I know very little.

I was talking to a client at work ages ago and he informed me that they only tig weld stainless as when you use a mig it drives the "chronium" (can't quite remember if that was the element) out of the weld and then the weld will corrode. Is that true? If it is true, why doesn't a tig do the same and does the grade of stainless affect this?

 

[chappo1970]

I think TB when he was talking about solder was actually talking about silver solder, as Chappo stated is really more like brazing and nothing like lead solder. Jeez Chappo, I'd love to be given free reign in your garage mate, sounds like a HB Tinkerers heaven.

cheers

Browndog

edit: included (more like)

browndog you bring the beer mate and the shed is yours to play in! Anything is possible when there's beer involved!

 

[browndog]

browndog you bring the beer mate and the shed is yours to play in! Anything is possible when there's beer involved!

Woohoo....I think I've found a new best mate!

cheers

Browndog

 

[seravitae]

Silver solder for plumbing as far as i know must be food grade as it is used to connect plumbing designed for transferring water for human consumption. Silver soldering is very safe as long as you use the correct solder. In the big green shed in the tool shop next to the electronic solder they have plumbing silver solder. If you are worried call the company up and demand an MSDS - they have to supply one for you - it will list all the metals and fluxes used in the solder. Also next to the brass fittings they usually have 2% silver brazing rods which will do the same job. Generally the only difference between 'soldering' and 'brazing' are the temperature at which you are working at, brazing being higher.

Silver soldering uses the same principals as electronic soldering but it is safe.. Safe enough that it is regularly used on potable water supplies from what i know.

Blindness is not a common symptom of lead poisoning, in fact I could not even find blindness listed anywhere. However it may happen due to issues with CNS. It is way more likely that the reason moonshiners got blind was because a lot of them were diluting their products with methanol as it was tax free. Also because a lot of them (and even to this day still) derive their ethanol from products like antiseptics, causing toxicity because they didn't seperate the ethanol completely from the other nasties in there. Not from lead..

Hope this clears some stuff up.

 

[chappo1970]

Seems like a good time to ask my question............ I know this isn't a welding forum but you guys seem to know what your talking about, and I know very little.

I was talking to a client at work ages ago and he informed me that they only tig weld stainless as when you use a mig it drives the "chronium" (can't quite remember if that was the element) out of the weld and then the weld will corrode. Is that true? If it is true, why doesn't a tig do the same and does the grade of stainless affect this?

Wow Rob2 you know how to open up a can of worms here.

OK I am to assume that this is for the lay man as you have told me you have little experience in welding. TIG and MIG are a bit like chalk and cheese as in the way they form the arc and the frequency (temp) but they can essentially get the same results. I could go into a whole heap of hertz this and amps that but I think that would confuse the whole thing.

In short you are correct it is chromium, as well as few other elements which I won't go into here, and no you mate wasn't right about "drives" the elements out of the weld. That tells me the element is being vapourised which is not true. What happens however in alloys such as stainless steel is the individual elements melt/turn to a liquid state at different temperatures therefore you get "pooling" of different elements. Those elements can be very brittle and or very soft therefore making the weld fail. So therefore different grades of stainless like 304, 316 and so on need to be welded with differing techniques and temperatures with the same process. eg MIG and or TIG. IMO TIG is superior but MIG shouldn't be discounter either. Like where to place a tempmate probe on this forum everybody has a differing opinion on which is best in the welding world.

I hope that answers your question?

I need to lay down

 

[OLDS2006]

BOC has a range of food safe solder

 

[Tony]

The TIG is prefered as there is no spatter like you get from a MIG. Its like oxy welding where you form a molten pool with an electric ark under a cloud of argon gas and walk it along the join, adding filler rod as required.

The TIG will do the same to the stainless.

Its heat related. Once its temp is raised above "x" deg, it will rust again in the area where the temp was raised.

When its welded, you paint the affected area with a pickling paste which is some sort of acid and this restores the stainless surface to the metal.

cheers