Why won't my solder stick to copper? (2024)

What to do when solder won't stick?

Second, make sure your solder tip it tightly fastened to the soldering iron. If it is loose the heat won't conduct right. Also tinning the soldering tip with flux and solder helps it to conduct heat better. Never use sandpaper on your tip.

How do you make solder stick to copper wire?

Add a small spot of solder to the tip. Line up the wire to the connector, usually with a clamp. Hold the tip of the iron on the connector for a short time. Push some solder onto the wire at the edge of the tip, so the solder melts onto the wire.

Will solder stick to copper without flux?

It doesn't matter how much you clean your metal surface, you'll need a flux to make the solder stick. Without this, a solder joint simply will not be strong enough or conductive enough, which is why soldering flux is recommended.

Can you get copper too hot to solder?

Overheating is a major problem when brazing or soldering copper pipe because the flux will burn (become oxidized), stop working, and become a barrier to tinning. In addition, a heavy oxide can be formed on the pipe itself, preventing a bond from forming between the filler metal and the pipe surface.

What causes solder to fail?

According to Rush PCB, there are three main causes for solder joints to fail: Fracture—tensile rupture from overloading. Creep—long-lasting and permanent loading. Fatigue—from cyclic loading.

What are 3 typical soldering mistakes?

Can you solder without flux?

Yes, you need flux. Solder wire usually has flux in its core, but most still apply additional flux. I would figure out what specification of flux is in the solder wire you're using and buy that type. To obtain the best results, always use extra flux!

What temperature do you solder copper wire?

In actual practice for copper systems, most soldering is done at temperatures from about 350°F to 600°F, while most brazing is done at temperatures ranging from 1100°F to 1500°F.

What type of solder to use on copper wire?

The best solder to use for tinning stranded copper wire is electrical-grade rosin-core solder. This is an acid-free solder that contains a flux in the core of the solder. Never use solder that contains acid to strip and tin wires, as this can damage the wire or its insulation.

How long can you leave flux on copper before soldering?

Wipe excess flux off the exterior of the pipe after solder joint has been completed, and never wait more than 4 hours to solder a joint after applying any flux to the joint.

Is there a special solder for copper?

Copper-tin Solder: Contains 97% tin and 3% copper. Lead-free and safe for water supply lines. Designed for sweating copper and brass plumbing joints. Melting range is 440°F to 572°F.

Can vinegar be used as flux?

Vinegar is acid. That is exactly what fluxes are. Use it for a flux if you want.

Do you need flux for copper to copper?

However, in copper to copper applications, the phosphorus in BCuP alloys acts as the fluxing agent. No additional flux is needed, although a small amount of flux may be used for applications with prolonged heating times to improve the wetting action of the filler metal.

What happens if you overheat solder?

Overheating could burn the flux, which will destroy its effectiveness and the solder will not enter the joint properly.

What temperature should you preheat copper to?

Preheating up to 200 °C [400 °F] is recommended.

What temp should I solder at?

600°- 650°F (316°- 343°C) is a good place to start for lead-based solder and 650°- 700°F (343°- 371°C) for lead-free solder. You want the tip hot enough to melt the solder efficiency, but excess heat can damage components as the heat travels along the leads, and it will reduce the lifespan of the soldering tip.

What is the most common problem with soldering?

What are the two main causes of poor solder joints?

Most solder joint failures fall under three major categories: 1) tensile fracture due to stress overloading, which is short-term; 2) creep failure due to the application of a long-term, permanent load; and 3) fatigue failure due to the application of cyclical stresses.

What is the secret to good soldering?

The secret of good soldering is to use the right amount of heat. Many people who have not soldered before use too little heat, dabbing at the joint to be soldered and making little solder blobs that cause unintended short circuits. Solders have different melting points, depending on the ratio of tin to lead.

What is the rule of thumb for soldering?

Proper Temperature Times

As a rule of thumb, tin-lead solder is heated at temperatures from 600° - 650°F and lead-free at 650° - 700°F. However, temperature settings vary with the different variations of solder.

What happens if you don't use flux?

It's ok, if you can do it, but it's very difficult to solder without flux. The flux breaks down the oxide layers on the metal surfaces and allows the solder to "wet" them. If it doesn't wet, it doesn't make a connection.

Can Borax be used as solder flux?

Whether for cleaning, for experiments or for melting silver, borax is an element that will come in very handy in the household. It is also used as a flux for soldering silver and other metals.

How do you know if copper pipe is hot enough to solder?

Heat the fitting just until you notice the flux paste bubbling out and there's a slight green tinge to the flame around the copper. I like to test the readiness by lightly touching the solder to the joint on the side opposite the flame. If the pipe is hot enough the solder will liquify and be drawn into the joint.

Is it too cold to solder?

As long as you get the temperature up to the melting point and keep it there while the solder/flux does its job, you should be fine. The main concern I would have is that the solder joint would most likely cool extremely rapidly and that could cause some issues.

How long should the solder heat?

You need to hold the soldering iron in place for 3-4 seconds in order to heat the pad and the lead. Step 3: Apply Solder To Joint – Continue holding the soldering iron on the copper pad and the lead and touch your solder to the joint.

What does tinning mean in soldering?

Tinning the tip means covering the tip with a layer of solder. Most modern soldering tips are composed of a copper core (copper conducts heat excellently) encased with nickel-plated iron to repel solder.

What happens if you use too much flux when soldering?

Sometimes, the acid may not be fully consumed. When this happens, the excess acid can cause electronic failure. To reduce the risk, engineers need to use a minimum amount of flux for proper soldering.

Will flux eat copper?

Flux, an acidic paste, is used to help solder flow into the copper fittings as they are joined together during initial installation. Because it is an acid it has a corrosive effect on copper.

What do you need to solder copper?

Soldering Torch: Also called a soldering iron, the torch for this project is usually propane. It may also be a MAPP torch, which uses a gas that burns hotter than propane. Deburring Tool: This removes tiny jagged and uneven pieces of metal from your pipe and fitting. You can also use a metal file in a pinch.

What else can be used as soldering flux?

What can substitute flux for soldering? Petroleum jelly is the best effective alternative to commercial flux. Its waxes and mineral water ingredients make it antioxidant thas why you can easily use it as a soldering flux.

Can isopropyl alcohol clean flux?

The most common way to clean flux residues from a repair area is to saturate a cotton or foam swab with isopropyl alcohol or another cleaning solvent, and rub it around the repair area.

Can you use salt as flux?

Fluxes based on a mixture of molten salts are often utilized in the processing of molten aluminum. They are used in a passive role to protect the metal from oxidation and sometimes in an active role to remove the additive elements as impurities from molten aluminum.

What is the best solder for copper?

1. Lead-Based Solder. Lead solder, made of lead and tin, is used for most electronic manufacturing applications to form a strong bond between the joints of other metals, such as copper and aluminum. Lead-based solder is not used with pipes that handle water.

Is it hard to solder copper?

Copper plumbing relies on a procedure called soldering, and it is not as difficult to do as you might think. The following instructions and techniques produce leak-tight soldered joints between copper and copper alloy tube and fittings.

What is the best flux for melting copper?

This high-grade, coarse anhydrous borax flux keeps your metals cleaner during melts and pours. It is also great for seasoning your graphic crucibles, and while melting, casting, and refining metals such as gold, silver, copper, iron, sterling silver, tin, nickel, and their alloys.

Is a lighter hot enough to melt solder?

You can use anything that is able to heat a piece of metal up to the melting point of your solder (between 400°F / 200°C and 700°F / 370°C). Butane lighters work the best. But you can also use candles, oil lamps, alcohol burners, or even open camp fires.

Is it OK to reheat solder?

Yes, once or twice using flux but only with prototype boards. Generally it is unwise to reheat solder, but in the case of repairing the circuit board to experiment with various components it may be necessary to reheat the part a second time.

How do you know if solder is too hot?

Try it with a piece of solder. Assuming the bot has been prepared correctly (called tinning), the solder will instantly melt when the iron is at the correct temperature. If it is too hot, the tip will turn black & become impossible to use.

What happens if copper is heated too long?

Copper oxidizes to copper When copper is heated in air, it is oxidised to copper (II) oxide and the reddish brown metal turns black as the copper is oxidised to copper (II) ions. Hence the copper is changed to copper oxide.

Is propane hot enough to solder copper?

When sweating or soldering copper pipe, we've been asked about using either propane or MAP gas. In truth, both types of fuel will get the job done.

Does heating copper weaken it?

Heat to Alter Metal

Brass, steel, iron copper and silver can all be made weaker by heating the metal to a set temperature and cooling it slowly.

Can you fix a leaking solder joint?

Dry the outside of the elbow and sand (120-grit paper or cloth) around the leaking joint to remove all surface corrosion. Apply soldering flux around the whole joint and apply heat with a torch until the old solder melts. Add new solder until a shiny ring of solder shows all around the joint.

Why must solder not be overheated?

Overheating could burn the flux, which will destroy its effectiveness and the solder will not enter the joint properly.

Is Vaseline good for soldering?

Does Vaseline or petroleum jelly work? No. The main purpose of flux is to act as a cleaner for the soldering process, so that the solder will properly "wet" the joint. Petroleum jelly is a grease - not good for such purposes.

Can you over solder a joint?

Repair: Sometimes the excess solder can be drawn off by dragging the tip of a hot iron between the two solder joints. If there is too much solder, a solder sucker or solder wick can help get rid of the excess. Prevention: Solder bridges most often happen between joints with too much solder to begin with.

What are the 10 errors to avoid in soldering?

How hot is too hot for soldering?

Sure, solder stations may go up to 900°F, but 750°F is the highest you need to go for a lead-free wire. The extra heat can also unnecessarily stress components, increasing the chances of PCB failure later.

What happens if you solder too hot?

The proper amount of heat must be applied to both the foil and the component lead: too cool and the solder won't melt, too hot and the foil will lift off the board or the component could be damaged. Don't move the component until the solder sets up. Don't apply too much solder.

Why won't my solder stick to the wire?

This issue is usually caused by the soldering iron being set to an improper temperature, or the iron itself has a wattage that is too low for the solder size you are using. If you notice your solder isn't sticking, check your solder material and compare it to the wattage of your soldering iron.