How to solder copper pipe upside down

Sweating Copper pipe

              Soldering  copper pipe is usually done easily if proper techniques are known. It can be done by you easily by following the simple steps. Soldering is the process which has two or more items and usually it contains metal. The two items are to be joined with the melting and also the filter metal in the joint. Soldering is quite different from welding as it does not involve the melting of the work pieces. There are 3 simple steps in how to sweat copper pipe. The first step is to take some time and start with the small flame and it should be large enough to reach most of the place of the copper.

 

Sweating copper pipe

              Once the pipe heats up, torch the end of the solder plumbing  joint at about  90 degrees, from the flame source. keep the solder away from the melting point of the flame. The large sized pipes will require you to move the solder along the joint face. You should be able to withdraw the flame and then feed the solder in the hot plumbing joint on smaller pipes.

Let it cool down

              You should not wipe the joint until it cools down. You can see it if you watch that the solder goes from the silvery color to the bright color. In such case you should allow it to cool down, clean it and then try again. The dulling gets off once the soldering starts setting down. If the fitting shows too much of rainbows or turn blue then it means that you have used too much heat. Home repair projects are becoming very popular in the current times. People love their home and take interest in it and also feel the enjoyment and satisfaction in maintaining the home. Sweating copper pipe is an easy task which needs a procedure to be followed properly.

              If  followed, soldering upside down is no different than other positions because if you solder properly the solder sucks into the joint and follows the heat.

How to solder pipe upside down

The main concern is safety. Do not ever place yourself under the work. As you solder, both the hot flux and the hot solder will drip down and burn, main, or lose eyesight….its not worth it! Figure out how to position yourself in a way other than under the work, even if this means you have to dig, remove floorboards ect. This explains to the question how to solder copper pipe upside down. See the main page for more safety and skill tips.

What’s the difference between copper soldering, brazing and welding?

The basic concept is temperature.

Most good copper solders melt under 500 F degrees.

Brazing occurs over 840 degrees.

Welding occurs at around the melting point of copper, over 1900 degrees.

Sweating copper pipe

 

 

 

 

 

 

 

 

 

Soldering: The goal of sweating copper pipe is to heat the pipe/fitting enough to melt the solder but not so much as to anneal and soften the pipe….also over 800 degrees you can burn off all your flux. When the solder melts it seeps into the space between the copper pipe and the fitting cup creating a very strong joint. Strength of the silver solder is Tensile Strength – 5,000 PSI (at 250°), higher than the hard pipe (1250psi) and higher than the 95/5 solder (1000 psi). The solder must fill at over 70% of the void space between the pipe and fitting to meet piping code standards.  Silver solder ‘flows’ much better and should be used. The extra cost will be covered by not having failed fittings. It sucks having to take the system all apart just for one failed joint…so the extra cost of the solver solder pays for itself pretty quickly.

 

Figure 2 Brazing Copper Pipe

Brazing: usually occurs between soldering and the copper melting temperatures. An interesting thing happens when copper is brazed or welded. Copper anneals at around 700 degrees and loses strength when this happens…up to half its strength. So the act of brazing produces a system where the pipe is the weak point and the joints the strongest. However, this system is tougher and better fit for vibration like a mechanical system(refrigeration). That’s why most refrigeration systems are brazed. However, be sure to use the annealed copper charts when looking to meet the system strength requirements, not the hardened copper. Brazing has some conditions: there should be a fillet buildup as well as penetrating the brazing material into the pipe fitting Joint(minimum penetration is three times the heaver wall thickness)….vs a soldered joint does not need the fillet but the penetration is about 10x the wall thickness. Brazing is done with MAPP gas or oxygen/acetylene.

Welding Copper Pipe

 

Welding occurs at higher temperatures. For example most of the filler metals melt between 1100-1600 degrees depending on composition. Using rods containing silver yield great results. There is no penetration into the socket, the pipe and fitting are actually fused and heated together along with the filler metal. The oxygen/acetylene torch or welder create a copper puddle and then the rod is fed into it in a swirling pattern to mix the two parts. Copper is tricky though, heat it too much and it separates and beads like water on a waxed surface…poking a nice big hole in your work. Practice on scraps before welding copper pipes.

Brazing copper pipe – the mystery of Rosebud

Brazing copper pipe – the mystery of Rosebud.

What is Rosebud?

              For you movie fans, Rosebud is not a mythological childhood sled from a strange childhood! It’s a type of torch tip that looks like a rosebud, which is great for the kind of rapid broad heating that’s great for brazing copper.

Rosebud flame – brazing copper

Soldering is the process which has two items to be joined by melting  the filter metal in the joint. Soldering is quite different from welding copper pipe  as it does not involve the melting of the work pieces(welding copper pipe actually melts the metal pipe). Brazing is in between welding and soldering heat wise. You can easily learn to braze successfully at your home. The first tip for is that you need to use the proper flame for the project. The flame which is perfect for the brazing copper pipe is known as the rosebud flame. Be sure to use a  carburizing or neutral flame.

Brazing copper pipe

 

 

There are 3 simple steps. The first step is to take some time and start with the small flame and it should be large enough to reach most of the place of the copper. Once the pipe heats up, touch the end of the silver brazing alloy to joint at almost 90 degrees, from the flame source. It allows keeping the alloy away from the melting point of the flame. If you have done this process properly then the braze will go around the joint and it will meet the other part of the joint where the flame was. You need to follow the plumbing joint all around with the brazing wire because at the end of the project there should be a fillet weld at the joint. The large sized pipes will require you to move the braze along the joint face.

Heating

              Heat the pipe not the silver-brazing wire ! Use flux ! It is always preferable to under heat rather than overheat. Once you have ringed the joint, move the heat from the fitting. Start at the bottom, then the sides should go fast and they should receive heat from the initial work. You should not wipe the joint until it cools down. You can see it if you watch that the braze goes from the silvery color to the dull color. The dulling gets off once it starts cooling down. If the fitting shows too much of rainbows or turn blue then it means that you have used too much of heat.

              If you are new and have any doubts then you should develop some skills on extra copper scrap. Try it on your own with ease.

See the main page for more detail. Follow the same safety tips, cleaning, sanding, and fluxing techniques on the main page  for sweating copper pipe as for brazing.

How to weld copper – oxygen-acetylene

Welding Copper Pipe: Oxygen / Acetylene

Safety: Arrange working conditions per OSHA standard practice and rear the proper  protective gear: Long leather gloves without holes, Safety glasses, welding helmet with auto darkening, welding pants and jacket, solid leather boots, respirator, welding table, a bucket of water, and a certified fire extinguisher. All flammables from your non-flammable working surface must be removed. Remove everything except what you need for welding. The welding helmet, shields your skin and eye(careful here) from any sparks; also,  protects against  damaging ultraviolet rays that can burn  your vision. Note: exposed skin will result in a very bad sunburn, so take care. Fully ventilate the area or work outside. Only have the gas welder on ONLY when welding. Tempting:  leave it lit for a moment while you quickly grab something, but, don’t put a lit torch down!  Keep cylinders away from the welding area and fasten in your cart.

Auto Darkening for copper welding

Figure 1 Auto-darkening helmet: welding copper pipe. Don’t fool around, only use the auto-darkening type, your eyes are worth it.

Only weld clean shiny copper. Remove all contaminants….The weld will turn crappy if everything is not newly shiny(wipe condensation from sweating copper pipes, dirt, with isopropyl alcohol, then,  wipe with a dry, clean,  rag).

Use a grinder, emery cloth, wire brushes, to eliminate copper oxide and make everything new looking(shiny). Clamp work securely.

Picking materials: Try to use oxygen-free copper because it  gives off less hazardous fumes.

Picking your welding equipment: Most welders prefer old school: the oxy/acetylene torch set up. Copper is very heat conducive; heat rapidly spreads across the piece. Torch installs enough heat to easily preheat, conversely, a welding machine applies heat into a very small surface area. So, lets talk about oxy  welding.

Welding Copper pipe

Figure 2 Welded copper pipe

Gas equipment set up: Select your head. Use a number 2 or 3, not a cutting head. Be sure to clean the tip free from contaminants before starting. Turn off all valves, both at the torch and the gas cylinders. Slowly turn on the acetylene about a half turn. Pressure should be around 6 psi. Then quickly turn on the oxygen to about 9 psi and light. Did we talk about how important ventilation is ?  The flame will be smoky orange now…increase the oxygen until you get a white and blue flame, the white should be about .4 inches long. Don’t turn on the oxygen too quickly or you’ll flood out the flame. Better to start with a smaller flame and work slowly when beginning.

 

Test out on scrap metal the same thickness before trying on your final product.

Figure 3 How to weld copper pipe

Start your puddle:. Feed your LEAD FREE silver copper alloy rod into the puddle, again with a small semi-circular motion, then quickly advance the gas tip and rod until complete. Finished result should appear:  a stack of dimes laid aside. The conclusion result is that the two pieces you are welding, and the filler metal all mixes together. Practice with horizontal scrap before attempting vertical joints. The vertical puddle can drip away easily and requires good timing. Always let the copper air cool(not fan assisted) to avoid cracks.

How to Weld Copper Pipe

Figure 4 Welding looks like stack of dimes

Here’s interesting melting point information below. Very hot!

METALs                  Melting points(F)

Copper 1983
Silver, Sterling 1640

How to weld copper with a machine will be in another article. Sweating copper pipe is on the home page.

 

How to weld copper: A welding machine

Welding Copper Pipe: A welding machine

Safety: Wear the correct  protective gear and keep working conditions per OSHA standards: Safety glasses, auto darkening welding helmet, welding jacket and pants, leather boots with rubber soles, long leather gloves(no holes), respirator, grounded metal welding table, and a full fire extinguisher. Remove all flammables from your non-flammable working surface(right?). The welding helmet protects your eyes and skin from any sparks for both, and also shields ultraviolet rays that can damage your vision. Note: any exposed skin will get you a bad sunburn, so be careful, ouch. Be sure to fully ventilate the area. Keep everything dry to protect against electric shock. Use a foot pedal and only have the welder on ONLY when welding. Its tempting to just leave it on for a second while you move to get something but don’t do it!  Keep cylinders away from the welding area and fasten in your cart.

Auto Darkening protective helmet

Figure 1 Auto-darkening helmet for welding copper pipe. Don’t hesitate, use the auto-darkening type

Only weld shiny clean copper. Remove all contaminants including platings….The weld will turn out like crap if everything is not cleaned(wipe sweating copper pipes free of all condensation, dirt, ect with isopropyl alcohol, then wipe dry with a clean rag).

Use a wire grinder, sanding cloth, wire brush, ect. to remove all the copper oxide and make everything shiny. Clamp work in place and you are finally ready to weld copper pipe.

Picking materials: Try to use oxygen-free, or, P-deoxidized copper, it gives off less hazardous fumes. Don’t use copper alloys.

Picking your welding equipment: Most welders prefer an old school oxy/acetylene torch set up. Copper is extremely heat conductive which means the heat spreads quickly from one end to the other. The torch can lay in enough heat on the whole surface to easily preheat whereas a welding machine just injects heat onto a small surface area…leading to a tricky situation to not overheat your copper  but still heat enough to weld copper(preheating in a furnace will resolve some of this issue but who has one of those ??). This welding machine pinpoint heat issue also can cause distortion of the metal and could lead to cracking. But despite this, lets talk about machine  welding.

Welding with a machine. Use a MIG or TIG machine with a pedal. Look at your welders handbook for the proper amperage for the metal thickness you are working with. Because copper is so heat conductive you’ll need a lot of amps. Use argon or helium gas and adjust per the manual…use helium for thicker metals. Test out on scrap metal the same thickness before trying on your final product.

Welding Copper pipe

Figure 2 How to weld copper pipe

Start your puddle: hold the arc at 70 degrees to the surface for a couple seconds with a very small swirling motion to get your puddle started. Once started get moving and feed your LEAD FREE silver copper alloy rod onto the puddle, again with a small swirling motion…keep quickly advancing the welder and rod until you are done. The end result should look like a stack of dimes laid on a steep angle. The end result is that the filler metal all mixes with the two pieces you are welding together. Practice on flat horizontal metal before attempting vertical joints. Its easy for the puddle to just drip away on vertical joints and requires exacting finesse. Let the copper all cool naturally in air to avoid cracking.

Figure 3 Welding like a stack of dimes

 

 

 

 

Here’s some useful melting point info:

METAL                  Melting point(F)

Copper pipe 1983
Silver, Sterling 1640
Tin 449.4

How to weld copper with oxygen acetylene will be in another article. Sweating copper pipe is on the main page.