I suck at sweating copper pipe.

Am running hot & cold copper water pipe for a wet bar in the basement.

I’ve tried. I really have. I’m using a wire brush, flux, applying the flame to the fitting (not the pipe), etc. and my joints *still *look like crap. Many times the joint won’t take solder, and I have to redo it. :mad:

I’ve watched some youtube videos and read some online tutorials, but they all lack details. I need ***details ***on how to do it properly. Do I, for example, keep the flame on the fitting while I am applying solder? Should I apply flux to the pipe and the fitting, or just one of them? Is it bad if the flux on the pipe extends past the fitting (so the flame is hitting flux)? Should I move the flame around the fitting, or keep it in one spot? What are the best tools to use?

The only advice I can offer is to use mapp gas and not propane. And apply flux where you want the solder to flow.

After I “helped” my brother-in-law solder some pipes, he had to call in a plumber (really it was his solder joint that failed). The plumber said mapp gas is hotter and hotter is better.

I forgot to add, I don’t have much experience with either. It was only what the plumber told my b-i-l

I’ll bet **raindog **can tell you what you want to know. IIRC, he’s an HVAC guy, but something tells me plumbing is in his wheelhouse.

Some folk have a habit of overcooking the copper, which then forms a thin oxide that will not readily take solder. Overheating causes other problems such as causing the solder to spread too much and too thin.

You need to get it hot over an area rather than locally hot, otherwise the joint will cool too rapidly. Don’t have your solder directly in the heat.

If there is a large gap, then wind some clean copper wire around the pipe to fill the gap, tin it whilst in place and then sweat the joint.

Ideally you don’t want to heat the soldering surface directly, heat next to it on both sides and allow it to spread inwards.This heat flow will also take your solder to the joint as it tends to move toward the hottest part.

What does “sweating” a pipe mean? And what’s a wet bar (is there a bar that doesn’t use water?)

A dry bar has no sink and running water. Just booze and glassware.

At elevation, I have to use MAPP. But what you may simply be missing is a wet rag an wipe the fitting when done.

It takes years of practice to be any good at it. Don’t get to frustrated. I’ve been sweating pipes for a few decades not and can’t compete with the plumbers I work with. While some are not neater all of them are faster. The soldering I do is limited to the immediate area of the pumps and pressure tanks.

Mapp is better in terms of speed. I would not recommend it for someone starting out. It can quickly burn pipe beyond usable. I still primarily use propane. I propane is better for other aspects of my job so I normally only keep a propane torch in the truck.

My method.

Clean both the male and female piece. I use wire brushes for the females but still do a quick ring with sandpaper too. The males I hold a piece of sand paper around the pipe and spin the pipe.

Flux both male and female. Thin layer on each just going around smoothly. The whole working area of the female. On the male preferable the whole working area as well but it is better to err on the side of further up then you need.

Press the pieces together. If you got the amount of flux right a very slight bead will form. If you used to much a larger bead will form just run your finger around it if there is too much.

Have the solder ready. For a single joint I roll about 8 inches straight out and bend a hook down with the approximate amount of solder I intend to use. Typically no more then twice the diameter of the pipe.

Heat the pipe. I always start on the bottom side and work the torch around the pipe. After I’ve warmed it a little I grab the solder so I can start testing if the pipe is hot enough. When I’m back to warming the bottom I touch the solder to the top. When the solder melts with contact your’ ready to go.

While soldering, I keep the heat on the far side of the female fitting. I am always applying the solder to the opposite side of the torches flame.

Once I’ve melted the solder in I put down the roll of solder and grab a rag. In that time the solder on the male end of the female has usually hardened a little and you can see the excess in the form of drips. I run the torch around those and smooth it out with the rag.
Hope that helps. It really is all practice. Most homeowners will never get the amount of practice needed to be really good at it. You simple never need to sweat that many joints. Not enough practice more often results in ugly looking joints then it does leaks. So If you require pretty joints you’re going to need a plumber.

Sweating pipe is a learned skill. It takes a certain “feel”. Unless you are a natural you will need to practice. If you have some extra pipe practice on getting the solder to flow on just a bare pipe. Then practice joining pipes by butting the ends together and connecting them with solder. Finally practice on fittings.
BTW I like to occasionally remove the flame and touch my solder to the part while I’m heating it. This way I can tell when the part is hot enough for the solder to flow. Good luck.

Thanks for the info so far. Especially boytyperanma.

The pipe? Some online tutorials say to heat the fitting, not the pipe. :confused:

Sorry misspoke there. Yes, you should be heating the female fitting.

I don’t have much to add, except once I started using sandpaper on the pipe, instead of just the wire brush, my success rate increased ten-fold.

Most of what above is good.

Heat the fitting by having the flame near the middle of the fitting. On pipe 1/2 inch or less propane is just as good as mapp gas and you do not have to worry about overheating. As you heat the fitting touch the pipe near the fitting with the sodder. When everything is hot enough the sodder will begin to melt. You do not need to keep the flame in contact with fitting while soddering. Just pass the flame over the fitting as you are soddering. If the fitting and pipe cool too much the sodder will not flow, it that happens just keep the flame on it a little longer. Do not use the flame to melt the sodder, that is a common mistake. Getting the copper cheery red is an other.

Do some testing first with spare parts. Use a “T” and sodder a short section of pipe into it. When you are done and the fitting has cooled, look to see if there is sodder all the way through the joint with some showing inside the “T”. Do it again with other side of “T”. If the looks good, now reheat the “T” until you can remove one section of pipe. After it cools look at the soddered end of the pipe, is it completely covered in sodder?

Now take a couplling and a short section of pipe sodder them together. When the cool using a saw cut the coupling along the lenght of the coupling. Using plyers try and pull the pipe and fitting apart. Take a look at the joint.

Also keep a rag with you whild soddering to clean up the drips.

I can’t help much with technique, as I struggle with these. What I find strange is here (In Canada) and I believe in the US, Yorkshire fittings are not available.

They are common in the UK, the cost a few pennies more but for DIY plumbers they make much better solder joints.

There are solderless fittings now available. I used one once when I needed to cap a pipe in an old house, the supply could not be shut off completely so the small trickle would prevent proper soldering. They are very easy to use and seem to work well.


Bread is your friend - take a chunk of plain old cheap white sandwich bread, ball it up and stuff it into the pipe. It’ll stop up the drip long enough to solder the fitting, then once the water is back on, it will dissolve.

Using this little Jedi Master trick costs a whole lot less than compression fittings.

I second this. as long as the connection is clean, the solder wants to get sucked right into the joint.

I would try using sandpaper. Get it nicely sanded, then put some flux on it. I’ve always done that and it has worked well. Try to heat the fitting evenly too.

I don’t have any advice for you but just wanted to let you know that my hubby feels your pain. We did okay for years with getting our plumber friend Mark to do it - he was an artist, I swear - but he passed away a couple of years ago. :frowning:

Good luck.

I had a TON of problems with this using the new “safe” flux. It doesn’t take heat as well as the older kind they used to use. So, I bought some of the older kind, and it doesn’t cook as fast, and I can sweat a fitting easily.