Solder not sticking often results from insufficient heat, improper soldering iron temperature, or using a low-wattage iron for the solder size. Ensuring a clean, oxide-free surface and using a suitable flux can further improve solder adhesion for reliable and strong connections.
Most soldering techniques are easy to master, unlike welding. The soldering process is basically joining two metal components together by melting solder.
However, there’s one question that every soldering beginner asks, why is my soldering not sticking?
In today’s article, I’ll tell you all about the common problems that can cause soldering not to stick.
Table of Contents
Common Solder Problems
Is your soldering not sticking? Here’s a list of reasons that can cause this issue:
Solder Tip Oxidized
The soldering iron is perhaps the most crucial component of soldering. The process should be easy and quick if your soldering tip is in good condition. On the other hand, if the soldering tip is oxidized, you’ll face many issues, like the soldering not sticking.
The oxidized layer on your solder tip can create a barrier that affects heat transfer. As a result, the tip won’t be hot enough, and the solder will tend to bull up on the tip.
Oxidization of the solder tip is part of how it works. The solder tip has an iron plating that turns into iron oxide when used.
This creates a thermal barrier that can affect your soldering. The solder sometimes won’t get hot enough due to this barrier.
However, there are some ways to slow up the oxidization process. You can also remove mild oxidization from the tip.
How to Fix This Issue
If the solder tip isn’t severely oxidized, you can clean the tip by proceeding with the following steps:
- Turn on your device and adjust the temperature to the normal work range.
- Apply flux-cored solder to the tip. It can react with the oxidized layer and help clean your tip.
- Use a tip cleaner or brass wool to remove the oxidation.
- You can repeat the previous steps until the tip is completely clean. You’ll need to repeat this process around three times in mild cases.
How to Prevent This Issue
Here are some tips to slow down and reduce the oxidation buildup on your solder tip:
- Add a layer of solder to the tip after using or cleaning. It should contain a high amount of flux core.
- Avoid excessive heat, as it speeds up the oxidization.
- Clean your solder tip regularly.
- Consider upgrading to an advanced soldering system with microprocessor control.
Dirty Parts
Just like oxidization, dirt and debris can build up on your solder tip and other working materials. This can lead to various issues during the soldering process, including the solder not sticking problem.
Additionally, if you’re working on old or dirty metal, the soldering won’t adhere. To elaborate, old metals typically have an oxidized layer that can prevent the soldering from adhering.
How to Fix This Issue
You’ll need to clean any dirty or oxidized work material. You can clean your work metals with a quick scrub with a non-bleach cleanser. Additionally, you can use metal cleaners, like Penny Brite. Strong flux can also work in this case.
Furthermore, after cleaning the metal, make sure to dry it thoroughly with a clean, soft cloth.
Cleaning the solder tip with a wet sponge is a common way to remove any dirt buildup. It’s a cheap, easy, and efficient way to clean your solder tip. The following steps will guide you through the process of cleaning your tip:
- First, grab a sponge and a spray bottle filled with water.
- Second, wet the sponge a little. Make sure the sponge isn’t too wet by pressing on it with your finger. If you see a pool of water, it’s probably too wet.
- Then, drag the solder tip across the sponge on all sides to clean it thoroughly.
- Finally, you can repeat the process until the tip is clean.
How to Prevent This Issue
To avoid this issue, the best thing to do is to store your work materials properly. Each material requires specific storage conditions. So, you need to store your work materials according to their type.
Additionally, regular maintenance and cleaning of your materials before working on them is essential.
Solder Is Not Hot Enough
Soldering is incredibly temperature sensitive. If the solder doesn’t reach the right temperature, it’ll simply not adhere.
The reason behind this is that soldering involves the formation of intermetallic compounds. These compounds are the product of the joining of the soldering metal and the base metals.
To form the intermetallic compounds, the temperature needs to be high enough for the solder to melt and join.
How to Fix This Issue
Before beginning the process, you can fix this issue by ensuring the soldering tip is hot enough.
How to Prevent This Issue
You can prevent this issue by checking if your solder is hot enough. A hot iron tip looks a little shiny; if you touch some solder on it, it should melt in no time. If it takes a long time to melt, you need to raise the temperature.
Metal Is Not Hot Enough
Though the metal shouldn’t melt during soldering, it needs to reach the desired temperature for the solder to stick. In fact, the hot metal causes the solder to flow. If the metal isn’t hot enough, the solder will probably not adhere to it.
How to Fix This Issue
You can fix this issue by holding your soldering iron against the metal until it’s hot enough. This allows the soldering to adhere. In addition, a propane torch can come in handy in this situation. You can use it to torch the external part of the metal you’re working with.
How to Prevent This Issue
You can avoid this problem by simply ensuring the metal is hot enough before starting your work. It wouldn’t hurt to concentrate the heat on the surface first, before using it on the join you’re soldering. It’ll help heat the area a little.
Other Solder Problems
Other issues can cause your solder not to adhere. These issues are more common with beginners. Let’s check them out.
Poor Technique
Soldering techniques aren’t complicated. However, just like any skill, it takes time to get the hang of any technique. You need to practice the techniques before working on any project.
For example, one of the most common mistakes beginners make during soldering is letting the solder sit on the iron and carry it over to the joint. This can burn off the flux, which can cause your soldering not to stick.
Overheating
If the temperature is too high, that might also cause problems with the solder. That’s especially true if you hold the soldering flame for much longer than required.
Though you want the joint to be hot enough, you don’t want to damage the metal. Discoloration is a common sign that the metal has been damaged.
Not Enough Solder
Having insufficient solder can cause poor connection, as well as problems with adhering. Additionally, the join will be weak and susceptible to cracking if you’re not using enough soldering.
Wrong Solder Alloy or Flux
You need to choose a solder alloy with similar conductivity and strength as the base metal. Additionally, the solder should have a lower melting point than the base metal.
In fact, different solder alloys are used for different applications. For example, rosin is commonly used for electronics. On the other hand, the acid core is typically used in plumbing
Additionally, solders come in different forms, including wires, bars, paste, spheres, and preforms. You also need to figure out the suitable size or gauge of the solder that you need for your project.
How to Make Solder Stick
To ensure your soldering is successful, you must clean your metal thoroughly before using it. You’ll also need to clean your iron tip and make sure that it’s not oxidized.
After that, check the temperature of the solder and the metal. The solder needs to be hot enough to melt, while the metal needs to be slightly hot for the solder to adhere to it.
You can heat up the metal you’re working on by simply holding the soldering iron against it. You can also use a propane torch.
Conclusion
So, why is my soldering not sticking?
Well, that can happen due to many reasons. For starters, your iron tip might be oxidized, which can act like a barrier. Additionally, the metal you’re working on might be dirty or oxidized, so you need to clean it thoroughly.
In addition, your solder might not be hot enough. The metal also needs to be slightly hot for the solder to stick.
Many beginners who haven’t mastered soldering might be simply using a poor technique. Another issue most beginners face is overheating. Excessive temperatures can ruin your soldering. Finally, you might be simply using an insufficient amount of solder.