All About Heating Tools: Soldering Irons, Heat Guns and Torches

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  • Transcript

    LESLIE: Sometimes all that a home improvement project needs to get done is a little heat or a lot of it in the way of a torch, a heat gun or a soldering iron.

    All About Heating Tools: Soldering Irons, Heat Guns and TorchesTOM: Yep. But finding the right temperature can be tricky. Too little heat and the job doesn’t get done. Too much and you can burn or melt materials, not to mention potentially cause a fire in the process. Here to tell us more about these favorite home improvement tools is a guy who’s used all of them and many, many more: Richard Trethewey, the plumbing-and-heating contractor on TV’s This Old House.

    RICHARD: I am hot stuff. Yes, it is.

    TOM: Well, we always thought so, Rich. So, listen, I think that folks that don’t do a lot of work around their house may be confused about the difference between these different types of heating tools. But they’re all designed for very specific types of projects, right?

    RICHARD: Right. I mean in my world, a plumber uses a torch and that torch is going to give you a really focused flame that you could put right onto a pipe and you could solder. They also make heat guns that you’ll want to use to soften paint and if you try to remove some surfaces or even if you’re trying to thaw a pipe or something.

    And then soldering irons are generally that smaller unit that you would use to bring two wires together, try to solder much more delicate works. So, they all provide heat but they have different functions and they have much more different sort of delivery methods.

    LESLIE: Delivery.

    RICHARD: Sure. Yes.

    TOM: Right. So perhaps with a soldering iron, you get a little more precise targeting.

    LESLIE: But it’s for detail work, really.

    TOM: It’s for really detail work.

    RICHARD: That’s right. You do not want me to come into that printed circuit board with my super-duper torch that could melt it into a hockey puck.

    TOM: With your torch?

    LESLIE: It’s interesting. My dad was so much into home improvement and construction and design but he was a hobbyist. He built model airplanes and he had all of these in his arsenal of tools for building the planes.

    RICHARD: Yeah, yeah.

    LESLIE: So, to hear about these being used in a plumbing standpoint, it’s so everyday.

    RICHARD: Yeah.

    LESLIE: And then to think about them in such a fine detail as model airplanes …

    RICHARD: You could smell Dad when he was working.

    LESLIE: Completely. I smell that flux from the soldering iron.

    RICHARD: That’s right.

    LESLIE: So heat guns are probably the weakest of all we’re talking about. Does it really make sense to have one of those? Because that seems more like, “Oh I’ve got a frozen pipe. Let me grab that.”

    RICHARD: Well, be careful. In my past, I almost lost a house by putting a heat gun into a wall and I just – it was hotter. You know, it was – and I …

    TOM: You were trying to warm up the wall cavity where there was …

    RICHARD: I tried. Yep. Trying to thaw something. It was a very historic home. I still lived in fear when I got the call that there was smoke coming inside the wall. And thankfully, we didn’t lose it but it was from a heat gun. I was surprised that it wasn’t from a torch. A torch is even worse, because it’s an open flame, but best thing is to have a variable output. These heat guns, they look like glorified hair dryers.

    LESLIE: But do not put it. Do not.

    TOM: It’d be a big mistake.

    RICHARD: Yeah, yeah. Yeah, look what happened to my hair.

    LESLIE: Yeah. You learn from Richard. Do not dry your hair with one.

    TOM: Now, what about torches? Do they all run on propane? Are there different gas sources for torches, depending on the project that you’re doing?

    RICHARD: The standard is propane and -but there’s also a thing called MAPP gas, which is a little hotter flame. It’s more a question of preference. Usually, the blue is for propane and the yellow is for MAPP. I’ve always just used LP propane.

    And the other thing I should talk about is some of these – there’s every kind of tip available for a torch. And you don’t want it to be too hot if you’re soldering. You don’t want it to be a killer-big torch tip if you’re trying to do a small, ½-inch solder connection. Because the solder will actually burn right out of it. You’ll almost braze when you don’t want to.

    TOM: Right.

    RICHARD: And this – and you really want to get – if you’re looking at a tip, if you’re looking at any flame, there are – there’s an inner cone and outer cone of any flame if you looked in gas burning. And the hottest place is right at the top of the inner tip. I don’t know if that’s easy to understand on radio. But just imagine there’s sort of a beautiful, little flame and then there’s a bigger yellow flame out through the – around …

    TOM: Well, just think of a burning candle. It pretty much looks the same way. You’ve got sort of an inside flame that’s the center flame.

    RICHARD: Yeah. That center of that inside flame is the hottest place and that’s where you want to place where you’re trying to get the work.

    TOM: Hottest point. Right.

    Now, Richard, if you’re totally freaked out by the idea of using a torch, are there non-flame-based alternatives to making plumbing connections that are reliable?

    RICHARD: Well, there’s a million of them. There’s solderless connections where you – it’s like a Dutch finger; you put it on, it sticks on. SharkBite is one of the brands that …

    LESLIE: Like a crimping tool, kind of?

    RICHARD: Well, it’s not – well, crimping, absolutely. There’s a million of them. That’s been the race all along about plumbing. How do I – the original connections we used to do was to pour lead joints and then you did solder joints, threaded joints. Now, there’s a whole world of crimp fittings and then special compression fittings, the ones that we can do now for – called SharkBites. You push the tubing in and it just stays right there.

    Now, in all those cases, I’m still – to me, nothing beats the solder connection on copper pipe because you know it works and people can hang clothes in the basement on the pipes and it doesn’t have – pull apart. And you’ve got to remember, also, that any pipe, when it changes its temperature, it wants to expand. And so I always worry about all of a sudden the pipe is 60 degrees in the basement and it goes to 140 degrees, because hot water goes through it, and it’s going to want to get longer. And if it got longer, it might actually pull out of those fittings. So, that’s what worries me a little bit.

    But there’s tons of choices out there and anybody – if you’re afraid of soldering, there’s always ways you can combine it without a torch.

    LESLIE: Are the heat tools very expensive to own as a do-it-yourselfer?

    RICHARD: The basic torch with a striker – a little match striker – is nothing. It’s 15 bucks. I will tell you if you’re ever – my favorite tool is – two of my – I have two favorite tools. But one of them is this torch that has – I just hit a button and it lights the torch tip from a little clicker – a little Piezo spark igniter. And for anybody – otherwise, you’re getting them a set of matches. Nobody has matches anymore.

    TOM: Right.

    RICHARD: The striker is always worn down and this thing is just fantastic as you can just – and the other tool that I love so much is this tiny, little cutter that allows me to cut copper pipe inside of a really tight, little space. Those are the two – anybody could be a plumber if that’s all you need. You just need those …

    TOM: Cutter and a torch and he’s a happy man.

    RICHARD: Yeah, yeah. That’s right. Simple man.

    TOM: Richard Trethewey, the plumbing-and-heating contractor on TV’s This Old House, thank you so much for stopping by The Money Pit.

    RICHARD: I’ll be here sharpening my cutter.

    LESLIE: Well, now you guys know what to get Rich for the next holiday season.

    TOM: A new cutter.

    LESLIE: Alright. You can catch the current season of This Old House and Ask This Old House on PBS. For local listings and step-by-step videos of many common home improvement projects, visit

    TOM: And This Old House and Ask This Old House are brought to you on PBS by GMC. GMC, we are professional grade.

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