This video is a class that was done at the Calo Services offices primarily for refrigeration pipefitters and so in this video we're going to talk about basic brazing techniques. This is the start of a series of short videos that we did together with my brother: Nathan Orr Matthew Taylor who is our Director of Refrigeration service and Roman Ball who is our Director of commercial. HVAC Big thanks to everybody who took the time to help us put on this class. Much appreciated.

Thank you Raising and Soldering! So this is just one of these things that I like to get out there real quick. A lot of times we'll call brazing Alloys What we use for brazing, we'll call it solder. When we say soldering, we're saying joining at a temperature below 840 degrees. When we say brazing, we're saying above 840 degrees.

Don't ask me why. It seems fairly arbitrary to me, but almost everything we do is brazing. There are some products out there like Stay Bright 8 where some folks do actually solder. In the refrigeration world, that's not standard at all, but a lot of times we'll hear folks say solder I use the word alloy because alloy is whatever joining material we're using and there are a lot of different Alloys that we can use.

We typically are using a silver a silver phosphorus brazing alloy when we're working copper or copper, but we're going to talk about some dissimilar Metals as well. Really key thing here. Really, really key. So number one thing you're going to take away is that we have to flow nitrogen.

Okay, I mean that's that's I'm giving away the lead here. But another thing that's really, really important when you're joining is that a lot of times we're doing repair type joining when we're supposed to be doing actual tube type joining and I'll explain the difference. The difference is when you are joining tube to tube when you have a coupling, or you have a Swedge or something like that, the goal is to draw the alloy into the joint, draw it into the connection using capillary action the same force that allows water to travel up through tree trunks right if small little capillary, and it's able to draw in what's required. In order for that to happen, you got to turn the alloy liquid.

If you don't turn the alloy liquid, you can't draw it in. Via capillary action: If you hand somebody who's brand new to brazing a torch, the first thing they want to do is seal the edge right that edge of the connection. That's not what we're trying to do when we're joining, we're trying to draw it in. Which means that you have to get the whole thing hot enough for it to join in.

A lot of times when people will see what we're talking about today, which is they'll see darkness in a joint or whatever they'll say, oh, you burned up the joint, you got it too hot, right? The goal is to get the joint hot enough that the alloy turns liquid. the reason that there's black inside the tube is because of cupric oxide buildup, and that's due to oxygen. That's not because you overheated. The Joint Those are two completely different things: Can you overheat a joint? Yes, What happens when you overheat a joint? It melts, right? So, a big hole, That's an overheated joint.

That's that's the main concern. Now can you get a joint unnecessarily hot? Yes. And why is that a problem? Well, because now you've got heat conducting down, you can damage. Parts There's lots of things that you don't want to do, but your average, uh, pipe fitter fails to get it hot enough.

Not the other way around because just getting that edge sealed is not the point. Now repairing is different. So if you show up for service tech for example, anybody here ever repair aluminum, it's a really good skill to have. There's a lot of really great Alloys Nowadays now you don't use silphos.

You don't use fast copper. It's a special alloy special fluxes that you use for this. But when you're repairing, for example, an aluminum coil and you can actually patch that surface channel on a micro Channel coil. but that's a patch.

do you want to draw solder in when you're trying to patch? Answer is absolutely not because that blocks the tubing. So different alloy, different technique. So when you see guys doing this like touchy thing, all right, that is a repairing technique. a joining technique is heat, heat, heat.

get it to the right color Pull It In move on. That's that's what we're trying to do. Get it to liquid so that you can have capillary action. So here we have an example and most of what we're doing.

What we're talking about today is joining. Which means get it hot enough if you're repairing. which is the skill I Want you all to have a little bit higher level skill? That's where you're worried about patching on the outside properties of Base Metals Not going to talk a whole lot about this, but the main thing you need to know is most of what we do is Copper to Copper when you're working Copper to Copper Life is simple. You notice we don't use flux right when we're doing Copper to Copper when you're doing pipe fitting.

Anybody here use flux when you're doing regular pipe fitting. Well, The reason why you don't is because we're using a phosphorus-based alloy Faz Copper or Fozz or Silphos, right? And if it's sofas, it can be silver and phosphorus. It can be silver, Copper phosphorus. It could be a wide range of things, but in that case, that Fozz part that phosphorus is what acts as the fluxing agent.

This is important to know because if you are ever working on a joint where there is another metal, another base material, then you cannot use fast copper Foss Copper or Fozz or Silphos that you guys use for joining every day. You don't use that if you're going to steel. I Wouldn't suggest using it if you're going to Brass You can get away with it sometimes, but the phosphorus isn't a good thing in that in that example. So what's the point? The point is, know what metal you're working on mostly copper.

Make sure that in In Copper melts at what is it around? yeah, 1900 2000 degrees? Something like that. And so usually the Alloys that we're using are around 12 to 1300 degrees that they melt. So you have that area to work with. You're working with some other materials like aluminum.

If those of you have done it much closer tolerances, you're just working and you don't see anything happen. and then the aluminum goes away on you and you've got a gigantic hole. So when we're working with copper, we have massive advantages compared to other types of work. As soon as it's you're going to something else.

Copper to Brass Braster Brass Steel Steel Copper Steel. Whatever. Stop what you're doing. Make sure you get a different alloy and a different flux.

All right. Well here we go. Base Materials: Um, Copper is great. It melts at 1950.

It has really high thermal conductivity, which means we can apply a torch over here and the heat moves on us, which is really nice. Um Roman's going to talk about this later, but that's why we can actually apply heat on the male side of the tube and that actually pulls that heat into the joint. When you're dealing with steel, it's not like that anybody here ever done significant amounts of work braising with steel. We don't see it a lot, but we see it on some valves.

A lot of times. have you ever burned through a stub on a compressor where because most compressor stubs aren't full Copper They're actually copper plated steel. and if you burn through that copper plating, good luck, right? it ain't gonna stick. Unless you switch your whole technique.

you got to clean it. Now you got to use a high Silver solder without phosphorus. All that stuff. Steel's a pain because the heat doesn't move, you heat it, and it creates this little hot spot and so you've got it.

You've got to move your torch a lot more. You've got to take a different technique, but with copper, we can kind of point it at it and that heat will move right down the right down the tube. Any of you ever grabbed anybody's ever grabbed a copper pipe a foot away after you just got done. Pipe fitting knows that heat moves really well in.

Copper When do you use flux? You use flux anytime you're working with dissimilar. Metals As soon as you're doing anything other than Copper to Copper That's when flux comes in and not all flux is the same. You don't use soldering flux, plumber's flux for anything that we do that kind of liquid or that, uh, you know, sort of rosin type flux. If anybody, if any of you've ever worked with electronics, you know a lot of times you'll have a rosin core solder or use separate rosin.

This totally different product. All of this stuff requires a very specific temperature range and very specific flux design. All right. Like we mentioned.

Alloys Usually we're getting it and getting it in sticks and sometimes we have round sticks. Sometimes none of that matters. It really matters. What is the what? is it made of? 15? uh, silphos is kind of the standard.

That's the really good stuff. now. anybody here. not like 15 percent.

So fast. Anybody here. Well, because you guys are all real pipefitters, right? residential guys. they gripe about 15 silphos and you know why.

Because it's too runny. it gets it gets so thin it doesn't It doesn't beat up the way I like I like to get this nice Gloppy gel that I can fill that edge I can create a cap with. It's because it's a misunderstanding of what it's supposed to be doing. We want it to flow.

We want it to get really thin. so that way it pulls into that joint via capillary action. Some folks get concerned that you're going to draw it in so much and you're actually going to create beads on the inside of the tube, right? It does not really happen in brazing. it happens in solder, so anybody has done.

Plumbing That's where you see that we're over applying it, draws in, and kind of keeps going in with silphos Rod as long as your gaps are correct. So and again, this isn't rocket science. It's not like we're taking a you know, a micrometer or something and measuring the tolerances when we're doing it. It's this stuff's designed to go together.

So as long as you didn't mess it up or it's not damaged in some way and you get it to the right temperature and you use a high quality alloy, it's going to make it in there and it's and it's going to be good. You just got to get it all hot enough. The point of flux. This is a really important point.

So this is like science. This is the basic science lesson that I want you to know. Okay, oxides. What does oxide sound like Sounds Like Oxygen right? Because it is right.

So it's a compound that's created a molecule that's created when combined with oxygen. and in Copper when we heat copper above about it's it's above about 900 Degrees A thousand degrees. In that range it starts to combine with oxygen and it creates something called cupric oxide. All right fancy word, it just means copper oxide.

So you know how like steel when you have it in your salt water and it's not painted. you know what happens. It turns to rust that's an oxide of Steel Same thing happens with copper when we apply heat and oxygen is present. Why don't we want Copper oxide? Two reasons: it makes it hard for us to create a good joint on the outside, but the bigger reason is is it creates that flaky black stuff on the inside.

All right. First time you ever heard about flowing nitrogen was probably 10 15 20 years ago, right? Old-Timers When you would bring it up to them they would say oh, come on, you're getting ridiculous on me right? Anybody have that experience I think this is almost Universal Now why why did Old-Timers not flow nitrogen and it wasn't a problem. Anybody who've done a gas conversion from A system that had mineral oil in it to a system that had Poe oil in it? A lot of you have right and it's so weird. you convert this old rack for mineral oil to Poe oil and all of a sudden all the screens plug.

Why is that? Well it's because back in the day nobody flowed. nitrogen and mineral oil didn't strip the cupric oxide out of the inside of the tubing, it just sat there. You could cut it open years later and you'd still just see the same cupric oxide build up. You go to systems that have Poe oil that Poe oil just strips that cupric oxide out and it does it fast.

Which is why if we start up a rack or start up a system or we didn't flow nitrogen, it has any large amount of tubing. We have issues so screens, plugging, and everything else. So whatever your grandpappy told you or the old dude you know who could smoke three cigarettes at a time told you when you were riding the truck. I'm not saying that guy's a bad guy.

We love that guy, right? Usually his jokes were a little a little rough, but uh, but you know we like that guy. But that guy, what he told you does not apply anymore. It does not apply. It doesn't apply to vacuum and it doesn't apply to flowing nitrogen.

So forget it. You got me. It's really important because Poe reacts to cupric oxide and strips it and it reacts to moisture left in the system and those are our enemies. Oxygen and moisture are our enemies and that's why we do.

What we do make sense. So when we choose a flux, a little back to flux which is what's on the screen. I Go on rant. sometimes.

Okay, it's my podcast voice when we choose a flux. We choose a flux because we're working with a similar similar metal and it needs to be designed for it. So here we have a soldering flux. We have Alloy Saw which is an aluminum flux that goes works with an aluminum alloy and we have a silver brazing paste flux which works with dissimilar Metals By the way.

Just a quick note, if you are ever working with steel to Copper or steel to Steel get a black paste flux. The black uh, braising paste flux is a high temperature Pace flux and it just gives you more room to work with less likely to burn it. All right? Safety practices: Um, we know what proper PPE is. Um, safety glasses are the main thing.

but also, be prepared for something to catch on fire. you know. So fire extinguisher, bucket of water Rags all that kind of stuff. Just be prepared.

it's not rocket science what you need to do in order to be safe while you're brazing. There are a couple things. One is that when you're doing a lot of pipe fitting, now again, this is. this is another difference.

If you guys came from residential, which a lot of folks do, that's where you start. And residential you can get away with a lot of nonsense because you're not doing as much fitting right. You've got maybe four joints in the whole system if that has a little Cooper guys because it gets caught in the filter dryer and it's no problem. When you're doing hundreds and hundreds and hundreds of feet of pipe fitting and tons and tons of joints on hard copper.

that makes a huge difference, but that also is a factor for your eyes too. So you're supposed to be using a three shade, at least when you're brazing. If any of you have done a lot of pipe fitting without wearing shaded glasses, you'll notice eventually you start to get some eye fatigue. It starts to not feel great so we don't want that.

Another thing is just basic. housekeeping is huge with pipe fitting because again, stuff tends to catch on fire when you're not paying attention to what's touching what. and you're not keeping the job site clean. So that's huge.

And finally, Do Not oil oxygen regulator threads. In fact, just don't oil oxygen or acetylene regulator threads. We don't want to have anything explode on us. All right.

So uh, with that, that's my. That's my quick science lesson. The takeaways are: copper oxide happens because of oxygen, so we keep oxygen away. That also comes down to how we set our flame, which we're going to talk about a little bit on the outside, but on the inside, we keep oxygen away.

How do we keep oxygen away? Nitrogen right? Nitrogen ain't nothing fancy. it's mostly what we have in our air right now. It's really simple stuff. It's really inexpensive stuff.

I'm happy if you waste nitrogen I Love it. If you waste nitrogen, waste a ton of nitrogen. flow the flow the crap out of it. Get plenty of extra tanks I Don't care, it's not a problem.

What is a problem is if we get oxygen inside the tubing and when you are piping a big store and you have that tubing open for a significant amount of time which we do, it's a perfect storm. The more oxygen in the inside, the more likely we are to have oxides when we go ahead and burn. bite.