Sweating Pipes

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JnJ

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Alright, I've picked up copper tubing, joints, solder, and I have a butane torch. So how do I sweet joints without making a big mess?
Ive done a lot of metal fab work (welding, cutting, etc.) but I've never sweeted copper tubing.
 
Just keep in mind you have to heat the metal and the solder will flow easily when it reached the melting point. Cleanliness is IMPERATIVE and use the acid type flux. The copper surfaces need to shine and be dry. A good swipe of flux, heat, run a bead of solder, then let it cool briefly (a second or two) and without disturbing the joint, wipe with a dry cloth around in the direction of the seam.
 
Acid core flux? What exactly does flux do and is it a must? I'd hate to have to hit the store again.

Thanks for the replies.
 
I am no expert, but yes flux is required. It serves 2 purposes, it assures a good bond for the solder and aids in wicking in the solder into the joint. Plus the sizling of the flux lets you know when the metal is ready for the solder.
 
Roger, guess I'll make another stop at the box store on the way home from work.

Thanks again for all the replies.
 
You might want to pick up some steel wool if you don't have any works great on cleaning your connections.
 
zoebisch01 said:
Just keep in mind you have to heat the metal and the solder will flow easily when it reached the melting point. Cleanliness is IMPERATIVE and use the acid core flux. The copper surfaces need to shine and be dry. A good swipe of flux, heat, run a bead of solder, then let it cool briefly (a second or two) and without disturbing the joint, wipe with a dry cloth around in the direction of the seam.

Doing some research, I came across this http://www.acehardware.com/sm-working-with-copper-pipe--bg-1280921.html

In the instructions it says "Never use acid core solder for sweating copper pipe. ", but does not give a reason. Any idea?
 
Clean all soldered joints with sandpaper or steel wool to get nice and shiney.
Put soldering paste/flux on all surfaces to be soldered. Heat the female side of the join after the parts are joined and apply solder when the paste melts into the join. A little solder goes a long way. Wipe the excess solder from the join while still fluid while not disturbing the join itself.
 
I know you should never use it on electrical wiring because it is corrosive. I’ve never used it before so I don't know.
 
Bobby_M said:
I can tell you that the water based flux paste sucks ballz though. Just make sure the can of paste does NOT say water based.


Yeah that's what I was getting at. For electronics, I know you never use acid core...I realize I mistyped earlier, I said *core* there is no such thing as acid *core* flux, there is acid core solder, which contains the stuff in there iirc. What I needed to say was acid *type* flux and solid core solder. Sorry about the confusion all! You can use the water based stuff, but it's no where near as good (imo) as the regular stuff.
 
JnJ said:
Doing some research, I came across this http://www.acehardware.com/sm-working-with-copper-pipe--bg-1280921.html

In the instructions it says "Never use acid core solder for sweating copper pipe. ", but does not give a reason. Any idea?

The reason for this, I think is that with the acid core, you can't get it to penetrate deep enough in a joint (The flux is in the center of the solder). That is the job of the flux, hence the reason why you need to do it separately. Flux and solid type Solder, I don't think it matters if you use the acid flux or the water based...iirc that was what has been available for a long time before the water based hit the shelves.
 
I am not sure you can get anything but the water based flux's anymore actually. I haven't done any sweating since I migrated to PEX.
 
I use water based flux regularly and it works great. Acid based flux is easier to use for the beginning solderer, as it wicks the solder in more evenly over a wider temp range. it's very corrosive though, and that's why most who sweat copper regularly don't use it. It requires a good cleaning inside and out, which isn't always practical in the field. So as long as you clean your joints well, no problem.

Oh, and make sure to get Lead-free solder, you want 95/5, 95% tin, 5% Antimony.
 
JnJ, just remember...the absolute most important part is to make sure the parts that will be joined are shiny clean, and a thin even coat of Flux on both surfaces. Emery cloth is best. You can use one of those brushes but the tend to wear out rather quickly.
 
Good point about cleanliness and most newbies to soldering mistake what we mean by clean. Using 220 grit sandpaper and rubbing it on the end of the pipe in a shimmy shoe shine fashion for 30 seconds will show you what clean means. It's not about wiping it with a wet rag and calling it done.
 
Did you fire up the torch yet?

If not like the guys said before, just hit the pipe and the inside of what ever fitting you are using with some emery paper. doesnt take but a few swipes really. You'll see the difference. I've always used water soluable flux and never had a problem. They key is to heat the fitting on the outside up about halfway back, not just at the seam. Once the flux starts to bubble wait about 5 seconds and then lightly touch the solder to the seam. It should flow down the seam really quickly. If not just heat it up for 5 more seconds and try again. Some parts have alot of mass and take a while to get up to temp. If you get a blob on top where you are trying to solder dont add any more, just keep heating it until it runs.
 
I'll be off tomorrow, so I plan to solder it together then. I already cut and fit the pieces together.
Thanks all, this has turned into a good DIY thread for others that will want to do this in the future. And thanks to the mod who corrected my typo in the title. ;)
 
Virtuous said:
Did you fire up the torch yet?

If not like the guys said before, just hit the pipe and the inside of what ever fitting you are using with some emery paper. doesnt take but a few swipes really. You'll see the difference. I've always used water soluable flux and never had a problem. They key is to heat the fitting on the outside up about halfway back, not just at the seam. Once the flux starts to bubble wait about 5 seconds and then lightly touch the solder to the seam. It should flow down the seam really quickly. If not just heat it up for 5 more seconds and try again. Some parts have alot of mass and take a while to get up to temp. If you get a blob on top where you are trying to solder dont add any more, just keep heating it until it runs.

+1 on that. It is how I was taught and it worked for me when repiping half of the house I lived in before I moved to Minnesota.

If you mess it up, you can heat it up, take it apart, clean the crap out of it with the emory cloth, or use a little drum sander on a dremel tool to remove all of the solder from the outside/inside of the joint and then try again when it is clean enough. But, if you follow the advice from Virtuous you should be ok.

I've used propane torches with much success, but recently talked to a plummer who was making a repair on the rental house we live in in MN and he swears by map gas for 1/2" pipe. Hotter flame he said. I watched him make the repair, which was in a tight spot with many joints and the map gas worked in half the time I remembered it taking with propane.
 
Never use electrical solder or flux for piping, they contain lead.

For soldering pipes, I reccomend Taramet's Sterling solder, and Utility paste flux.

The purpose of flux is to prevent oxidation of the clean copper or brass while heating, oxidation prevents the phosphorus in the pipe and fittings from bonding, which is what makes soldering work.

Use steel wool or preferably sandcloth for cleaning the pipe before soldering, and invest the $2 for a fitting brush. You want to remove all traces of oxidation form where the solder is to flow.

I apply some heat to the pipe first, then heat the fitting. Once the flux stops bubbling, you should be hot enough for the solder to flow. If you overheat and burn the flux, the solder will not flow into the joint.

Let it air cool for a minute or to so the solder sets up, then wipe down with a wet rag. visually inspect the joint for any bubbles or gaps. If you need to resweat it, apply flux and heat again.

I'm a plumber, and I sweat a good 100 joints a week.
 
Anyone know if its possible to solder 1/2 od soft copper tubing to a small end of street fitting 1/2 elbow? I want to connect up arms of my herms coil without bending the soft copper up. THe street side of these elbows are alot bigger than the soft copper and i wasnt sure if i was supposed to get another fitting.
 
Hagen said:
Never use electrical solder or flux for piping, they contain lead.

with RoHS compliance that isnt true anymore unless you find a really old spool of solder. Im not sure if I wiould still use it for pipe sweating though
 
tbulger said:
Anyone know if its possible to solder 1/2 od soft copper tubing to a small end of street fitting 1/2 elbow? I want to connect up arms of my herms coil without bending the soft copper up. THe street side of these elbows are alot bigger than the soft copper and i wasnt sure if i was supposed to get another fitting.

1/2" soft copper requires a fitting labeled 3/8". You could use a 1/2" to 3/8" reducing coupling. There's such a thing as a reducing bushing, but not between such close sizes. I do know that the soft copper fits a little loose inside a street and you might be able to get a seal with solder.
 
Well it went together with no problems other than a few drips. So now my HLT is done. Thanks again to every one who gave advice.
Next I'll use this when I build my keggle.
 
Sea said:
I use water based flux regularly and it works great. Acid based flux is easier to use for the beginning solderer, as it wicks the solder in more evenly over a wider temp range. it's very corrosive though, and that's why most who sweat copper regularly don't use it. It requires a good cleaning inside and out, which isn't always practical in the field. So as long as you clean your joints well, no problem.

Oh, and make sure to get Lead-free solder, you want 95/5, 95% tin, 5% Antimony.

Your right that it is corrosive, but only on the surface. And that is part of it's value. It tends to etch better and that will give a better bond. It will cause exposed surfaces to patina (green) early. Which is a restoration trick to make new cooper look old.

I am not sure why you need to solder anything. There is no pressure here, your just making a collector. You could just use a pair of pliers or vise-grips to crimp the joints. Or leave them loose and it will be MUCH easier to clean as it can be completely torn down after use. This is the method I am going to try.
 
tbulger said:
What did you put together? just curious.

A pickup tube for my HLT (former keg).

CEMaine said:
I am not sure why you need to solder anything. There is no pressure here, your just making a collector. You could just use a pair of pliers or vise-grips to crimp the joints. Or leave them loose and it will be MUCH easier to clean as it can be completely torn down after use. This is the method I am going to try.

Actually, the valve is above the pickup tube so I have to rely on vacuum to get all the water out which requires the pipe joints be sealed.
 
JnJ said:
Actually, the valve is above the pickup tube so I have to rely on vacuum to get all the water out which requires the pipe joints be sealed.

Hmmm. That kind of makes sense.

Still it seems to me that if the whole rig is under the mash bed there should not be a problem. Also, as it is suction and not pressure, the need for soldering still seems pretty slim to me.
 
CEMaine said:
Hmmm. That kind of makes sense.

Still it seems to me that if the whole rig is under the mash bed there should not be a problem. Also, as it is suction and not pressure, the need for soldering still seems pretty slim to me.

This is a Hot Liquid Tank, not a Mash Tun. There is no mash bed.
 
Bobby_M said:
It's not really that slim. As the wort/water level drops below the topmost slip joint, the tendency to pull air is high due to the siphon being created by the outflow.
Exactly, again, there is no mash, just water, so a leak at the first joint would allow the pump to pull air which is easier than water.
 
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