How to sweat copper pipes with water in it?

Is it possible to sweat copper pipes that are filled with water? Copper pipes filled with water can be soldered only after completely removing the moisture from the pipes. Soldering copper pipes is very difficult in the presence of water. The solder can be applied only on a dry surface. After heating, the solder should be allowed to cool down and get hardened. This process will not go smooth on wet pipes. Prior to sweating copper pipes it is very important to get rid of traces of moisture from the tubes.

The equipment that is required for soldering copper pipes filled with water include gloves, sandpaper, brush, rags, joints, deburring tools, goggles, flux, lead-free solder and torch gun and Plumber’s bread or Jet Sweat.

How to solder copper pipe with water? Make the copper pipes dry.

As the first step, flow of water into the pipes should be arrested. Ensure that water does not enter the tube from any source. As the next step traces of moisture are to be removed completely from the tubes. Plumber’s bread is commonly used to remove moisture from the pipe. The Plumber’s bread is made of corn starch and will absorb the moisture from the copper pipes. Instead of Plumber’s bread, jet Sweat can also be used to remove the moisture from the pipe. Jet Sweat will ensure complete removal of moisture.

Sweating pipes

Once the pipes are 100% dry, the process of soldering copper pipes can be started.

How to polish copper pipe? The edges of the pipe are to be made smooth by rubbing with sand paper or emory cloth. The edges should appear polished and shiny.

A thin coat of flux must be applied around the pipe using a brush. Flux is to be applied inside the fittings also. Ensure to make only thin layer of the flux since too much quantity of flux may facilitate quick oxidization. Wear thick hand gloves and abstain from touching the flux with bare hands. Since flux contains various toxic chemicals it is hazardous to human skin as well as eyes.

After applying the flux, the fittings are to be assembled. Ensure that the fittings are connected properly to the copper pipe and move smoothly.

How to solder pipe: Start heating the copper fitting using propane torch. Always start with low flame and then increase the flame gradually. Evenly apply the flame to the joints. One requires a little practice to use the propane torch to heat the pipe.

When the solder starts to melt keep the tip of the solder on top of the joint so that it starts to melt. The entire surface wrapped by the flux will help the  molten solder flow seamlessly. Slowly wipe off the leftover solder with a wet rag and be very careful while wiping the joints since they will be very hot and fingers may get burnt.

How to sweat copper pipe or tubing:

Copper tubing is used in the supply of water and soldering copper tubes are easy and do-it-yourself process. While soldering copper tubes, the selection of solder, tools and flux plays a vital role.

Selection of tubes: In general the thickness of the tube will increase the diameter of the copper tube by 1/8 inches, that is, 0.125 inches.

Cutting: While cutting a tube it’s better to use a tube cutter to get a cleaner and less burs on the edge.

Joints/fittings: The fittings for the tube should be selected carefully depending on your project.

  • 45 degree joint: this will give a connection turning it 45 degrees.
  • 90 degree: A complete 90 degree joint.
  • Reducing adapters: Used when the tube size changes from wider diameter to a smaller diameter.
  • T and cross joint: Used in branching the pipeline.

Soldering Basics: How to solder pipe…..Soldering ensures the connection between joints and the selection of solder is vital. For water tubing, a lead free solder is required; usually a tin-silver solder gives the best results for your sweat connection.

Steps to soldering copper pipe: How to solder properly

  1. How to clean copper pipe: Clean the tubes thoroughly on the insides as well as on the outsides. Sand paper would do the work for the amateurs and professional plumbers would use a wire brush to remove burs and a cleaning brush to create the perfect bur free and shiny outer rim on the copper tube. This is to obtain a smooth area which will result in no-leak tube.
  2. Flux/soldering flux: Use a brush to apply the soldering flux on the area to be joined. Excess application is agreed harmful, but under coating the flux will not solder the joint/fitting onto the tubes.
  3. Torch: A torch that would give a sharp, blue flame is your weapon. The flame should be in such a way that it doesn’t heat a point but heats up the ring as well. 1-2 inches of flame height is the standard flame size.
  4. How to fit the copper pipe to copper fittings: Fit in the joints in their place and screw them down so that the flux spreads itself on the inside of the joints. Heat up the area and try moving the touch point so that they melts evenly inside.
  5. Sweating pipes: How to solder copper fittings…. Place the tip of the solder onto the hot copper fitting, if it melts and starts to run along the joint in a capillary motion you have attained the correct temperature. Continue soldering the copper tubes till the solder is all around the tube joint.
  6. Wiping: Wipe of the excess solder while the tube is still warm (warm not hot) using a clean rag.
  7. Testing: Flush some water to check for any leakages once the pipes are cool.
  8. Congratulations! You are a soldering pipes master !

How to solder copper pipes in Europe?

Sweating copper pipe

Soldering copper pipe has the same underlying procedure in europe, but has some changes in the copper pipe used.

Countries in US and Australia, there are four classifications of the copper tubing. Whereas in Europe there are only three, Type X, Type Y, Type Z.

  • Type X – They are used in domestic services like Hot and cold water supply, sanitation, heating and other general purposed applications.
  • Type Y- Type Y pipes are thicker when compared to the X, and used in under ground services. The services include gas supply, transportation of hot and cold water and engineering services of general types.
  • Type Z- Type Z is thinner than the others and are used as type X pipes are used but in a lesser rate, given the thickness of the pipe.

Soldering basics – the sweat connection: sweating copper pipe

  1. Please follow the safety suggestions on the main page of this website.
  2. Cleaning copper pipe inside: The tubes should be thoroughly clean on the inside as well as on the outside, isopropyl alcohol works best. Sand paper or a wire brush is used to remove burs and a cleaning brush to create the perfect bur free and shiny outer rim on the copper tube. A smooth area which will result in no-leak tube is obtained.
  3. Flux/soldering flux: Using a brush, apply the soldering flux on the area to be joint. Excess application is fine but under coating the flux will not solder the joint/fitting to the tubes.
  4. Torch: A flame torch that produces a sharp and blue-ish flame is chosen. The flame shouldn’t concentrate the heat to a point but heats up the entire ring as well. 1-2 inches of flame height is the standard flame size.
  5. How to solder copper fittings: Sweating copper pipe. Fit the plumbing joints: Screw them down 1/4 turn so that the flux spreads itself on the inside of the joints. Heat up the area and try moving the flame torch in order to spread the heat evenly across the tube and helps the flux stick to the inner surface as well.
  6. Sweating copper pipe: Place the tip of the solder wire onto the plumbing joint, if it melts and starts to run along the joint in a capillary motion you have attained the correct temperature. Continue soldering the copper tubes till the solder is all around the plumbing joint.
  7. Rag: Wipe of the excess solder while the tube is still warm (warm not hot) using a clean damp rag.

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.

How to solder copper in cold climate like Alaska?


Cold weather or heavy wind is a problem as they to disrupt the work, especially with antennas or roof and wind shelter is awkward to use.

How to solder properly : soldering basics
When soldering in cold weather, the heat you apply on the solder might not be as effective as in a moderate region. To obtain an effective result:

  • Clean and cut the pipes as you would do in normal soldering and make the joints as well. Try to pre-assemble and solder the parts inside shelter as much as possible.
  • As an extra step wrap a aluminum foil over them.
  • The foil layers need not be more than one or two or else the heat transfer would slow down.
  • Now if you apply heat using the torch, you will get a perfect solder even in freezing temperature, don’t worry.
  • On a calm day or while working on thin wires a lighter torch would do the job. But in a cold and windy day or working with a thicker pipe, a blow torch may be required. The new electronic lighter will light in any wind.
  • You can tell it is at correct temperature when the flux burns orange as the flame heats the metal.
  • In Using a torch is the better option but make sure to follow the cut, clean, remove bur and flux the parts carefully. Also use lead free solders.
  • Coax Dielectric handles heat better than others but only in some cases.
  • Another suggestion is the usage of Andrew Heliax on the outside where possible. Andrew connectors need to be heated only on the centre pin and not the entire surface. A connector shield compresses against copper shield which was corrugated.
  • Use short RG213 jumpers on the last few feet on the ends and solder them indoors. Work your way to shelter them outside.
  • A heliax is considerably weightless and better in ladder line.
  • The rest of the process can be done the normal way, i.e. cleaning copper pipes inside and fittings, using a brush to remove burs and flux the outsides as well the insides of the fittings to solder them easily.

How to solder copper flashing?

Copper flashing is used to fix the roof with a copper sheets to stop any water leakage. This is done where the wall meets the roof. Base flashing and counter flashing are the two copper flashing involved in this process. The water from counter flashing is diverted to the base flashing. The base flashing will divert water to composition flashing. There is a minimum weight for copper flashing and counter flashing which is 16 ounces.

Copper counter flashing has many uses:

Soldering Basics – How to flash copper:

  • This attaches and seals the copper. A receiver made in copper is positioned at the joint between two brick layers in the wall. The counter flashing is positioned in such a way that it is locked on the edge of the receiver.
  • In the second method a wood or a strip is used to separate is cast into the concrete wall. The flashing is then inserted into this strip and is held in position by wedges. The strip portion is then filled with a sealing material.
  • To cover exterior counter flashing this is used. The Top portion of the flashing is wrapped by paper used in building. The paper is 4″. The paper is held to the sheaths with a T shaped wooden or metal strip. The T shaped piece can be replaced with wide head nails, but they should not touch or penetrate the flashing.
  • The nails hold the flashing up.

Second: Vertical wall flashing

A vertical wall is flashed in this method. The roof has squares which are locked to the base flashing. The base flashing will extend to a length 8″ up.
Third: Brick wall flashing

In brick wall flashing, Copper flashing is installed to the wall made of bricks. The joint in the bricks is 2 inches of depth. A strip made of wood or metal is formed, making it similar to the first process. The counter flashing is now inserted into this strip and are fixed by the wedges. They are then sealed.

Fourth: Wall intersection:
A cap made out of copper is used in flashing. This cap will extend over the base flashing intersecting the roof and wall. The cap flashing is situated at the joint between bricks. The edge at the bottom is attached and covers the base flashing. This forms a closer fit against the base flashing. The space between base flashing and roof is approximately 12″. The base flashing runs 4″.

Fifth: This is same as the first, but the receiver will hold the upper flashing edge.

Sixth: A Cut is used to hold the flashing with wedges and sealed.

Seventh: Attach a cap flashing to the wall and it is attached to base flashing. Blind riveting method is used.

Seventh: Standing and batten roof
The copper roof is turned upwards to form the base flashing. They are held by the receiver and locked. The counterflashing covers 4″.

Eighth: Batten seam roof
The top of the roof is made into a pan shape. The edge falls above the finished edge and copper flashing is locked here.

Ninth: Standing seam
The standing seam is of 8″ and laid flat on the wall. It is folded and copper pieces shaped in T are used to hold them.

Note: see the ‘How to solder copper roofing’ article on soldering copper

How to solder copper art?

Copper art- Copper has the characteristic of being flexible and it is very famous as copper art is very attractive and detailed due to that character. Copper art doesn’t include only home decor but also copper ornaments and used in refrigerators, fireplaces, etc., The well-known wonder – “Statue of liberty” itself contains 160,000 pounds of copper in it. Sweating copper pipe and soldering copper artworks are no different from each other. Artwork would involve minute pieces to be soldered which would need extra care and handling of right temperature.

How to solder procedure: Soldering Basics

Copper uses a much lower melting point metal as its solder. Select the solder carefully based on the purpose or location of the artwork.

Step 1: Assemble the pieces or sheets required for the artwork. Cut out the shapes from the sheets or trim the copper wires to the required length. Using a filing tool remove burs from the edges. Clean and sand all components to be soldered.

Step 2: Be it a smaller part or a larger part, copper needs to be soldered to hold them in place. Applying flux makes the job possible. Even if the joint of two ends of copper wire look close enough, rub a tiny amount of flux and heat them.

Step 3: Hold them in position to handle the flames in the correct angle and evenly.

Step 4: How to solder properly: When the heat makes the copper to glow red, hold the fire over the area to be soldered and start touching with the soldering wire. Let the flame lick the solder for few seconds to make sure the copper has sucked up the solder.

Step 5: Rub the edges, rims or corners with sand paper to make them get a shine on them. Keep checking the fit of the pieces after every step to ensure you are in place.

Step 6: How to solder copper when soldering a flat surface, Place the two pieces together and heat them up. Do not concentrate the flame towards the centre. Instead move the torch in circles and to evenly spread the head. When the metal glows quickly start touching with the solder and check for any missed spot before cooling them down.

Note: When heating, the size of the copper is to be taken into account. When more heat is applied the metal will glow in an orange shade, indicating its close to its melting point and will be devoid of soldering, or glow yellow, indicating it has melted and would flop down into a ball of metal.

The Lost Secret of How to Clean Copper Pipes Inside

Got green pipes or fittings? Try this evil genius way : how to clean copper pipes inside from copper pipe corrosion.
Green Copper Corrosion

First safety: wear rubber gloves and a full clear facemask(bigger than eyewear protection).

The easiest way to clean copper pipes is to with simple table salt (NaCl), vinegar,  and aluminum foil. Wrap what you want cleaned, Coil the aluminum inside or outside the green dirty copper fitting or copper pipe for its full length. Shape the aluminum so it doesn’t touch more copper than it has to.
Evil Genius stuff#1: The salt moves the oxidizers (SO2 or oxygen) that are chemically bonded to the copper(the green stuff is copper oxide) toward the Aluminum, just like the inside of a battery. In fact that’s how you make a battery.

Now you need an open container. Try a PVC pipe with one end capped. Take your copper and aluminum and put it inside the pipe along with the vinegar – salt solution.

This will yield some results but of course we want it bigger, better, and faster.

Evil Genius stuff#2: Turbo powered

Take two wires, cut one of the wires a couple inches shorter which may help you  to not short out wires together later. Strip the wire ends about ½”. Find a fuse holder, solder to the positive wire to the fuse holder, pop the fuse in and attach to a lantern battery. Put alligator clips on the ends of both wires.

Copper corrosion

Sweating copper pipe

Which wire is positive, and which side is negative? Use a multimeter, or….,   Connect the alligator clips to your battery and separate the ends and place them in your solution. The bubbling lead is your negative. The other big clue is the big plus sign on the battery.

Evil Genius stuff#3: electroplating

. Copper Corrosion

Be sure you have eye protection. Connect your copper  piece to the positive lead of your battery.  Connect the negative lead to your aluminum. The aluminum is being plated and should start to bubble. The solution may get warm. If things get hot, disconnect the battery: you have added too much salt and need to drain and restart.

Figure 2 How to clean copper pipes inside

The aluminum is now being electroplated with copper, there may be gunk forming on it, take the foil out once in a while and hose off to keep the process going…change out the foil once it gets all plated, holey or stops bubbling.

Once the green is gone, rinse off your copper like mad. You have now figured out how to kill the green gunk monster.

How to solder properly – a copper roof!

Copper roofing – Copper roofing is a technique where the roof of the building is designed with copper. It is used in terms of long term roofing. Copper is durable and strong and would make a more attractive roof to the normal roofing. Beautiful!!!

Soldering basics procedure: soldering copper. How to solder.

  1. Measure out the roof and segment them into tiles. The size of the tile is preferable to be in squares as they make it easier to fit in.
  2. Copper sheets are sliced into pieces to the measured length and breadth. An extra 1 1/2 inch is taken up on all the sides for the interlocking and soldering.
  3. Mark off the extra inches to be folded. Two adjacent sides are folded outwards and the other two folded inwards. The outwards would clog to the roof floor or previously soldered copper sheets.
  4. Solder copper along the marked line to make a firm connection when fitting the copper sheets to the roof.
  5. Fold the copper sheets along the marked line with the help of sheet metal brakes.
  6. Other copper pieces about 2 and 3 inches on their sides are required to nail the sheets onto the roof. Bend the sides of these sheets as well with the same technique.
  7. Soldering copper: Apply flux over the ends to be soldered. Use a brush to evenly spread the solder. Soldering copper like these would require a lot of heat and quick fluid motions. How to solder properly? Heavy duty solder irons and big solder bars are often used.
  8. Fix the first sheet with the outward bent edge locking the roof edges. Attach them by locking the outwards of the tiny sheets, two on each side, to the inward fold of the large sheets. Nail down the other end of the tiny sheets to the roof.
  9. Solder the inward fold of the tiny sheet covering the nail part.
  10. Continue the locking of sheets and soldering of tiny sheets. Hammer down the joints using a dead blow hammer to make the joint tight and secure.
  11. Start soldering the large sheets fold after locking them with the second sheet.
  12. Heat the fold and wait until the copper glow. Start soldering the copper folds once they begin to glow and move the torch over the solder to ensure they run down and join the sheets. The heat should not only melt the solder applied on top, but also the already soldered copper edges, strengthening the join.
  13. Pre-tinning helps the solder fully sweat into the joint.

Click on this link to know more.

How to re – solder copper pipe fittings – Repair copper pipe

Points to be cautious about:

  • Mapp gas burns a lot hotter, be careful while handling the Mapp gas torch.
  • Be choosy of your flux. For plumbing use a lead free flux.
  • Cleaning copper pipe: A two way cleaner comes handy and there are different sizes in cleaner brushes too.
  • Cutting copper pipe: while cutting a pipe if you get stuck, take a mini cutter and move it in the opposite direction.
  • While fitting a cutter, snug the cutter onto the pipe. Do not tighten it and form a dent. With each rotation snug the cutter a little more.
  • Do not solder the lower portion first and then move to the top portion, by doing so the heat from the top portion will travel to the closer bottom part and burn the already hot solder. When joints are closer move quickly and evenly on all of them.
  • Do not use your finger to apply flux as they would contaminate the pipes.
  • Have a fire extinguisher or water beside, especially when you are working in wall plumbing.
  • Use a wet rag to wipe the excess solder not a dry one.
  • Wear protective gloves while soldering copper pipe.
  • How to sweat copper pipe?, feed the solder to the opposite side of the flame. The solder will be attracted to the heat source.
  • Do not leave any excess flux. It will turn green and corrode your pipe.
  • Pre-soldered fittings are available at the store. Just apply some flux and attach it to the pipe and heat. The solder will melt and start spreading inside and around the joint.
  • There are fitting that can be just pushed onto the pipe without any soldering. They have teeth on the inner surface which clasps them tight to the pipe. They would require a lot of pressure to clasp them. Mark the depth of the fitting on the pipe to make sure you pushed it deep enough.

Soldering copper pipe – Repair:

-Any leakage in pipes can be fixed by de-soldering copper pipe. Soldered copper joints might wear off and can be fixed too.

-Soldered copper fittings can be removed by heating them again. The copper fittings can be reused by cleaning and sanding them and applying flux.

-Hold the fitting with a tool and heat the joint.

-When the solder melts and starts dripping, twist around the fitting and wrench it out of the tube.

-Use a rag and wipe the tube.

-Take a sand paper and rub them around the pipe.

Then solder the copper pipe or start soldering copper pipe. See other sweating pipes articles on how to solder properly.