Tinning Flux Vs. Regular Flux: Which Should You Choose?

Any time you work to combine two pipes together through soldering, you need to find a way to prevent oxidation from occurring. Since oxidation is a natural process, using something like flux is necessary to prevent oxidation at high temperatures and with lots of moisture. But which type of flux is more effective: tinning flux or regular flux?

Tinning flux is more effective for protecting your pipes from oxidation compared to regular flux. Both can get the job done, but tinning provides more protection at higher temperatures and will clean the pipes better. 

There are several types of flux that can be used in the soldering process and all will have different benefits and limitations. Let’s take a look at how flux works to protect your pipes and some of the differences between standard flux and tinning flux to see which one is the best. 

Standard Flux vs. Tinning Flux: Which is Better?

If you are working on piping, it is important to consider which type of flux is best for your needs. The standard flux works well for a lot of projects you want to handle. It is strong, will protect the pipes, and can make sure you do not end up with water leaking out of the pipes. 

In many ways though, tinning flux will be the better choice. It provides a little more protection to help pipes stay strong, even when the temperatures will get high. Since most piping is used with higher temperatures, the tinning flux can be a good option. 

When choosing the type of flux you want to use in your piping, there are a few things to consider:

  • How much piping you want to solder
  • The temperature that the pipe needs to handle
  • Whether the inside needs to be cleaned out

While most piping will do fine with standard flux, it is best to work with the tinning flux. It can do the same job as standard flux, with some help cleaning out the oxide and other chemicals in the piping not bursting when the temperature gets higher within the pipes. For most jobs you want to do with your pipes, choose to work with tinning flux. 

What is Tinning Flux

There are several types of flux you can choose for your piping and metal needs. One option to choose is tinning flux. Tinning flux is almost identical to the type of soldering flux we discussed above, but it contains a small amount of solder within. This gives a better bond and can help with transferring heat without running the pipe. 

Some of the characteristics of tinning flux include:

  • Comes in a powder form to clean the inside and outside of pipes
  • Makes soldering easier for the pipes
  • Contains a lead-free solder wire
  • Ideal to use with a copper pipe that has a larger diameter
  • It is easy to use, even if you do not have a lot of experience

Tinning flux can work on most different types of piping that you want to use too. It will not get overheated and melt. And since it contains a little bit of soldering inside, it is more effective at helping the metals combine together well. 

The Benefits of Tinning Flux

There are many benefits to using a tinning flux compared to a traditional flux. Not only does it work well like a standard flux, but it will add in a little soldering to the mixture, which makes the pipe resistant to heat and can actually clean the pipe. 

Here’s some more benefits of tinning flux:

  • Works on any type of metal that you need to join together. 
  • Is the most effective for removing any oxides in the pipe to make it more effective. 
  • Does not contain lead inside of it. 
  • Easy for even beginners to use. 
  • Can handle high temperatures so it will not matter what you use the metal for. 
  • Will not turn back into a liquid when it warms up, making it more efficient than other types of flux. 

If the pipe you plan to use will need to withstand higher heat levels or you need it clean to handle drinking water, then the tinning flux is a great option. The pipes will not burst from the water when it gets hot and the oxides will be removed. 

The process of using tinning flux also allows you to test out the pipe to see if there are any leaks ahead of time. If any leaks show up here, then there is still time to make adjustments and fix the pipe. It will prevent you from having a big mess later when you install the pipe. 

How to Use Tinning Flux?

If you do decide to work with tinning flux, there are a few things that you will need to consider ahead of time. Some of the supplies you will need for this includes:

Before you get into the work, you need to prepare the surface that you plan to use. This is where you can use the solder to soften out all of the metal and the joints. You will also notice that when you use tinning flux for most plumbing applications, there will be some solder added to it. This helps with heat transfer and will give a better bond than standard options. 

Putting the Pipes Together

First, we need to test fit to see if the coupler joints and pipes go together. Use a marker or another tool to make a mark on the pipes. This mark needs to be an inch past the ends of your joint. Take the two pieces apart. 

Scour to Clean

After marking up the pipe to make sure it is prepared for you, it is time to scour the sides and insides of your pipes. You can use that steel wool we talked about before. Take your time here to fully prepare the pipe. 

Wipe it Down

Now it is time to finish preparing the pipes to get rid of the residue that may show up on them. 

At this point you should:

  • Wipe off the residue left in the pipes. 
  • Coat the pipe with the tinning flux. You will need to use a brush to help with this. 
  • Put the pipes together. 

Prepare the Wire Solder

Next it is time to uncoil enough wire from the solder so you can circle the circumference of the pipe. You want to do this just once. Then you can straighten out the solder to get it into a straight line. 

Heat the Joint

It is time to put things together now. You can turn on some heat to get the joint with the help of the torch. Heat all of the parts of the joint as evenly as possible so it will stick together well. 30 seconds should be enough for this. 

Finish It Off

The final steps can go quickly so it is best to be prepared:

  • Have the wire over the joint with the tip touching the top-center of your joint. 
  • Move the torch a bit so you see the solder melts a little. 
  • Give the solder time to run along both sides. You want to see the molten solder drop to your joint. 
  • Repeat on both sides of the coupling. 
  • Give this time to cool down. 

When this is done, you can turn on some water and check out the pipe. This gives you a chance to see whether the soldering worked well or if there are some leaks before you install it. 

Does Tinning Flux Go Bad?

Like all other types of flux, tinning flux can go bad over time, and can only be kept for so long. 

How long your tinning flux will last depends on its where it has been opened or not:

  • Shelf life refers to an unopened can of flux
  • “Service life” refers to an open can of flux

For most flux, the shelf life is about a year. You will have a year from when the flux is added to the can to get it all used up, even if you do not open the can. You can’t stockpile flux!

The service life of a can of tinning flux will be a little shorter. There are a few things that will determine how long the flux can last once you pop it open, including:

  • The conditions where you store the flux
  • The dilution of the flux while using it
  • Any contamination from the air or the tools you use with it

It is best to use the tinning flux as soon as you can after opening the container. This will ensure that the flux is in good condition and won’t stop working. Wait until you are ready to use it before opening it up to make sure it is ready and usable, otherwise you might find yourself on an emergency trip to the hobby store. 

Can I Use Tinning Flux for Electronics?

Tinning flux can also be used on your electronics. You do need to make sure that you get the right kind. Several types of flux can be more corrosive, which can ruin the electronics that you want to work with. 

Tinning flux can work better than most other types of flux on your electronics, but it does cost a little more. Regular flux will work in a similar way on your electronics, making the same kind of joint in the process. If you run out of solder, then the tinning flux is a good option to complete the joint on its own. 

There are several types of flux that are safe to use with electronics. These include:

  • Rosin-core flux
  • Water-soluble flux
  • Mildly activated rosin

Always double check the compatibility of the flux that you use with the electronic device. Information should be found on the flux container. While tinning flux is generally fine to use on these devices, you do not want to add something too acidic to the mix and end up with a mess. 

Can I Use Tinning Flux with a Soldering Gun?

There is also a difference between tinning flux and tinning a soldering gun. With tinning flux, you will concentrate on adding the flux directly to the inside of the pipe to help create the joint you want. You will need to completely clean out the pipe and have it ready to go to make the joint work completely. 

You can also work with a soldering gun. This is a small gun, one that looks similar to a pistol, that is electrically powered and used to solder together metals. This is done because you will use a tin-based solder to get a strong bond through the electricity that goes through it. You can use the trigger to help turn on the electrical current with one hand. 

Tinning flux is basically the chemical that you can add to the pipe to create a strong bond between two pieces of metal. A soldering gun can do this from the outside and relies on heat, rather than a chemical, to get the work done. Both are efficient and use tin but rely on a different process to combine the joints of the two metals together. 

There are several benefits to using a soldering gun instead of tinning flux. These include:

  • Doesn’t require any chemicals to make it work
  • Is fast and efficient
  • Can still utilize tin to get the work done
  • Hot temperatures help to make the joint stay in place
  • Can use it with one hand
  • Cools down quickly

Remember that the soldering gun does get to high temperatures so use caution when you turn it on and try to solder your joint. Wear some safety gloves to prevent burns. 

Are There Other Types of Flux?

There are several other types of flux you can use. If you pick out a kit, you will find that the right type of flux will be included inside the core of your solder wire. However, sometimes you may want to work with a different type of flux to make sure it works the best. Most of the time you need to pick a flux that has the least amount of acid. Some great choices include:

Rosin Flux for Low-Heat Applications

Most older types of flux are based out of rosin, a type of pine sap. It is still used in some applications today, but it is often blended together with other options to make it work better. 

Rosin flux in its liquid form is an liquid and then becomes a solid when it cools down, making it a better option for a circuit board. 

Some things to remember with rosin flux includes:

  • Remove this flux from any PCB you use
  • Rosin flux can be removed with isopropyl alcohol
  • Do not use on anything that gets too hot as this flux will return to a liquid

You can also find rosin-core solder, which is exactly what it sounds like. By making the core of the solder rosin, it removes the need to use additional flux yourself. However, it’s not designed to be used in most plumbing applications—stick to acid-core solder.

Water-Soluble Flux for Easy Removal

Another option that you can use is a water-soluble flux. These are stronger compared to other options and can clean off the oxide faster than other options. Because they are soluble in water, you can easily clean any PCB pipes that you use this flux on with regular water. All you need to do is protect any part of the piping that you do not want to get wet. 

Inorganic Acid Flux for Strong Metal Joints

You may also choose to work with inorganic acid flux for some of your metal soldering projects. This is a great type of flux to use with some of the stronger metals that you would like to solder together. A few of the metals that it works with include:

  • Stainless steel
  • Brass
  • Copper

It is a stronger acid so you will need to do a complete cleaning of all the pipe after you use this flux. If you leave it on and do not clean it off well, it can easily destroy all the work that you do on the solder joint. 

Using Tinning Flux for Your Project

If you are choosing a flux for your pipes, it is always best to go with the tinning flux. While standard flux can do the work and is pretty secure and strong, the tinning flux adds another level of protection. 

The soldering added in will make the pipes resistant to heat, helping them stay strong and last for longer. Tinning flux also cleans out the oxides and other contaminants, making the pipe easier to use for any type of project you need. Choose tinning flux each time and see what a difference it can make. 

https://www.homeownershub.com/maintenance/tinning-flux-vs-standard-paste-flux-314641-.htm#:~:text=Tinning%20Flux%22%20that%20supposedly%20%22pre-tins%22%20the%20pips%20and,burning%20out%20or%20the%20pipe%20from%20oxidizing%20%28%22turning

https://www.ehow.com/how_8665214_use-tinning-flux.html

https://www.homedepot.com/c/ab/types-of-soldering-and-flux/9ba683603be9fa5395fab900ac061ee

https://www.lifewire.com/types-of-solder-flux-818849#:~:text=Types%20of%20Solder%20Flux.%201%20Flux%20improves%20the,Types%20of%20Flux.%205%20Rosin%20Flux.%20More%20items

Alexander Berk

A bit about myself: I am a certified international welding engineer (IWE) who worked in different welding projects for TIG, MIG, MAG, and Resistance Spot welding. Most recently as a Process Engineer for Laser and TIG welding processes. To address some of the questions I frequently got asked or was wondering myself during my job, I started this blog. It has become a bit of a pet project, as I want to learn more about the details about welding. I sincerely hope it will help you to improve your welding results as much as it did improve mine.

Recent Posts