Can You Sandpaper a Soldering Iron Tip? Here’s What I Think

When soldering, good soldering iron tips are essential for a successful experience. While selecting the right tips is part of the battle, maintaining those tips is just as important. Using sandpaper to keep your soldering iron tips is a hotly contested subject. Some are adamantly opposed, and others encourage its use.

Sandpaper can be a useful tool for maintaining your soldering iron tips, but it can also cause damage if misused. Fine sandpaper can be used to clear the outer layer of oxidation or rust off your soldering iron tip but should never be used on the tip itself.

Because there is the potential for damage, you must understand why and how sandpaper is used to maintain soldering iron tips before taking a piece of sandpaper to your equipment. Keep reading to find out everything you need to know to sandpaper your soldering iron tips effectively and safely!

When Should You Sandpaper Your Soldering Iron Tips?

Knowing when to use a tool is the first step in using it correctly and effectively. Sandpaper should never be a part of your daily maintenance and cleaning with your soldering tips. Preferably sandpaper should only be used when a tip needs to be refurbished due to oxidation buildup.

Oxidation: The Enemy of Your Soldering Iron Tip

When soldering, your iron tip will naturally oxidize due to the high temperatures and oxygen exposure. The iron oxide will interfere with both the ability of the solder to flow smoothly along the tip and its ability to heat well, resulting in an iron tip that will quickly become unusable.

Oxidation is the most common form of tip failure. Ideally, oxidation issues are prevented rather than fixed through proper daily maintenance such as keeping the tip tinned (especially when stored), not leaving the system on for long periods, and not soldering at unnecessarily high temperatures.

These methods should be used first to prevent oxidation. However, because oxidation occurs naturally when soldering, there will likely be a point at which your iron tip becomes oxidized badly. This level of oxidation is easy to spot as the iron tip will become black, rusted, or dull.

Sandpaper: The Enemy of Oxidation

When your soldering iron tip looks brown and has lost its shine, it is now time to use the sandpaper. Sandpaper is used to remove this layer of iron oxide, which restores a tip that would otherwise have to be thrown away.

Oxidation occurs where a metal is exposed to oxygen, meaning it only happens on the surface. Sandpaper can thus be used to remove this oxidized surface and leave your tips ready to fight another day.

Remember that sandpaper is a last resort. It should not be used until your soldering iron tip has become completely dull. If you use sandpaper on a shiny non-oxidized tip, you will be removing the tip’s plating and protection, which will only result in faster oxidation and a weaker tip.

How to Sandpaper Your Soldering Iron Tip Effectively

Knowing when to sandpaper your soldering iron tip is only half the battle. You should also be aware of how best to approach this task to maximize the restoration of your tip while minimizing potential damage.

Use Fine Sandpaper

Not all sandpaper is created equal. Sandpaper ranges in type based on its grittiness. The more gritty the sandpaper, the more abrasive it will be. When sanding your soldering iron tip, you want to use a fine, less gritty sandpaper. Fine sandpaper will remove the oxidation level without harming the tip underneath.

If you want a more specific guideline, 600 grit sandpaper is often recommended as the best to use on soldering iron tips. This is a super fine grit that will allow you to remove the oxidation while causing minimal damage.

Less is More

The amount of elbow grease you need to put in will naturally depend on how severe the oxidation is. However, since you want to avoid damaging the tip, using the philosophy of less is more is a good way to keep yourself from overdoing it.

As you work to sand away the oxidation, check your progress often. You do not want to sand any places where the shiny metal has again been exposed. Taking your time and monitoring your work will keep your soldering iron tip in tip-top shape.

While this may sound like an overly tedious suggestion, remember that sandpapering is not a part of daily maintenance. You will only need to sandpaper your tips occasionally. Taking the time to do it right is well worth the extra time and effort because it can prevent you from having to buy new tips.

After Using the Sandpaper

If you do not want all your hard work to go to waste, then you must finish your sandpapering job with an additional step.

The sandpaper removes the layer of oxidation, but this also once again exposes the surface of the iron tip to oxygen and thus more oxidation. Therefore, once you have finished removing the oxidized surface with sandpaper, you need to immediately cover the newly exposed surface to prevent oxidation.

Once you have finished sandpapering, avoid touching the tips with your fingers to limit contamination. Then tin the tip by melting solder to cover the tip. If you cannot get the solder to stick to the tip, this is a sign that you have not thoroughly cleaned the oxidation off the surface. You will need to clean the solder off and try again.

Tinning keeps the oxygen from reacting with your iron tip by covering the exposed tip. Make sure that you tin your tip after sandpapering, or the oxidation that you just cleaned will immediately begin again.

What Tips Should I Sandpaper?

Sandpaper cleaning should only be used with basic tips made of iron and copper. Do not use this method with long life soldering tips. These upper-end soldering tips have special coatings to make them last longer and prevent oxidation.

If you sandpaper a long life soldering tip, you will destroy its special coatings and reduce your investment to a short life tip.

Alternatives to Sandpaper

While sandpaper works when used properly, if you find yourself spooked by the warnings of damage, you can also use chemical cleaners to remove oxidation from your soldering iron tip. Since oxidation occurs through a chemical process, you can use another chemical process to remove it. Here are some options: 

  • Flux-Cored Solder Wire: This can be used to clean mild oxidation by covering the tip with the solder and then cleaning it with a dry material such as brass wool.
  • Tip Tinner/Cleaner: This product is for more severe oxidation. The same method is used in which you dip the heated tip into the cleaner to coat it and then wipe clean with a dry cleaning process.
  • Chemical Pastes: You can get pastes specifically designed to clean your soldering tips. You simply coat the tip in the paste and then wipe it off. Just like with sandpaper, you must tin your soldering tip after cleaning to prevent prolonged oxygen exposure.

The advantages of sandpaper over these chemical cleaners are that sandpaper is a much more cost-effective and easily accessible option. For chemical cleaning, you will need to purchase specific chemical products from soldering companies.

Conclusion

You can sandpaper your soldering tips. You just can’t do it all the time, and you have to do it carefully to avoid damage. However, once you feel comfortable with when and how to sandpaper your soldering iron tips, grab a piece of fine sandpaper, and get started!

Sources

https://www.instructables.com/How-to-repair-your-worn-out-solder-tip/
https://www.hakko.com/english/maintenance/topic_kotesaki.html
https://www.ngineering.com/tip_dos_donts.htm
https://www.newark.com/pdfs/techarticles/oki-metcal/extendingTipLife.pdf
https://www.americanmachinist.com/shop-operations/article/21902896/tips-and-tricks-for-caring-for-soldering-tips
https://www.ngineering.com/soldering.htm

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.

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