My featured image for this article is a picture of ancient Roman brass coins that were kept in leather pouches. Leather and brass often create a great combination – whether for storage (in the form of bags, pouches, wallets, etc) or decoration (in terms of the leather brass hardware like rivets, etc). But leather and brass at the same time react to form green corrosion, verdigris or tarnish.
In this article, I did research to find out the reasons why leather turns brass green, and I’m ready to share all of my findings with you.
So, why does leather turn brass green? Leather will turn brass green, verdigris, or tarnish because of what the leather is made up of. Leather contains oils, acids, and tanning agents that are corrosive and can turn brass green. This can, however, be easily resolved with vinegar and other products you can purchase.
To learn more details about how leather turns brass green and how to easily fix it, keep reading this article.
1. Natural Oxidation on Brass
Let me get this first point out of the way! Any metal that contains high amounts of copper can eventually turn green.
Naturally, anything made of brass will turn green or as it’s commonly referred to as “tarnish” or “verdigris”.
This is because the copper contained in brass when it reacts with oxygen tends to oxidize and subsequently causes the brass to develop a protective greenish or in some cases greenish-blue layer that is meant to protect the metal from any further damage or corrosion.
So when leather is also allowed to come into contact with brass in the form of a case or a holder, it will usually catalyst or fast-forward the appearance of the greenish matter.
Unlike nickel, brass will generally not come with any form of protection over its surface so this will allow leather to initiate a chemical process that will leave the green residue on the brass.
2. What Leather Is Made Up of
Leather as a finished material contains special ingredients that allows it to have its characteristic features of flexibility, pliability, great appearance and nice soft feel.
A few of these active ingredients will be some amounts of moisture, tanning agents, oils, dyes, to mention a few.
While many of the things found in leather are not going to necessarily turn brass green, some tanning substances (especially chemical tanning agents) found in leather like oils, acids, etc can be very corrosive and will usually be the main culprit.
A typical example is chrome tanned leather. Chromium tanned leathers contain corrosive compounds that can turn brass green.
This will be the case for most of the leather on the market as over 80% of all leathers on the market today are chrome tanned leather.
Vegetable-tanned leather can also turn brass green due to the oils in it as copper can also react to these leather oils.
When you store anything brass in leather that is damp or with some amount of moisture on it, then this can cause your leather to turn green.
Same way if you keep leather and brass together and it gets exposed to the elements of the weather especially any type of moisture, this can also cause the brass to turn green.
In such instance where you have a leather item that has brass components that comes into contact with the weather elements, a lot of experts will advise you to treat the leather that’s in constant contact with the brass with wax to help reduce the chances of the leather turning the brass item green.
Pro Tip: Although the elements of the weather such as heat, humidity, and the kind of environment you live in can differ when it comes to how it promotes the appearance of green residue on the surface of the brass, how fast and how severe it’s going to be will vary from place to place.
How To Remove Verdigris Caused By Leather On Brass
Leather can easily turn brass green and it’s the same way it’s going to be easy to remove it especially if you know what you’re doing.
Here’s a quick step by step guide on how to remove verdigris from brass.
- White Vinegar or Lemon Juice
- Towel or rag
- Toothbrush or cotton swabs
Step 1: Pour white vinegar or lemon juice into a container or bowl.
Step 2: Place your verdigris infested brass into the bowl with the white vinegar.
Step 3: Allow the brass to soak for about 3-5minutes.
Step 4: With the brass item still soaked, use a soft toothbrush or cotton swab to clean off the verdigris.
Step 5: If any verdigris or green stains remain, allow the brass item to soak for a couple more minutes and use your brush or swabs again.
Step 6: Repeat steps 4 and 5 until you’re satisfied with the appearance of the brass item or the verdigris or green stains are completely gone.
Step 7: Use a clean rag or towel to wipe the brass item dry.
If you’re more of a visual person, here’s a video I found that can equally help you out.
There are a couple of other simple things and methods you can also use to thoroughly remove or prevent verdigris from your brass items.
1. You can clean the green buildup off your brass with Brasso.
2. If applicable, you can apply a coat of resolene on the inside or outside of a leather item that carries brass items. For example you can do this to your cartridge loops.
3. If your brass items are only meant for display, you can also use lacquer to improve their appearance.
How To Remove Green Stains Caused By Brass On Leather
Now here’s how to remove verdigris or green stains (caused by brass) from leather. In this step by step guide, I’m going to share with you an easy way to remove brass tarnish, verdigris stains from leather using simple home supplies to without damaging the leather.
First, let’s take a look at all the stuff you will need!
- Baking Soda
- White Vinegar
- Leather Conditioner
- Clean Soft Toothbrush
Step 1: Make a mixture consisting of your baking soda and white vinegar into a bowl. Ensure the consistency is a thin paste. The combination of baking soda and white vinegar is going to create some form of a mild acetic acid which is going to help safely remove the verdigris or green stains.
Step 2: Allow the mixture to foam a little. The vinegar and baking soda mixture creates a mild acetic acid which helps remove the brass tarnish.
Step 3: With the help of a soft clean toothbrush, load up the mixture.
Step 4: Using a gentle motion, scrub the mixture of baking soda and white vinegar over the affected area(s) of the leather.
Step 5: Leave the mixture on the leather for 3-5minutes.
Step 6: Using a clean dampened (with ordinary water) microfiber cloth, wipe off the mixture and the green stains from the leather. You can repeat this step if any stains still remain on your leather.
Step 7: Allow the leather to air-dry thoroughly.
Step 8: Finally, apply a leather conditioner to your leather. This going to restore any lost leather nutrients.
- One of the very first things you do when your leather begins to turn your brass green will be to clean it off as soon as possible and you would want to do the same thing if brass stains leather green. This is so that the brass stains do not have time to work their way down into the pores of the leather.
- You might want to consider nickel leather hardware as an alternative to brass. Nickel is coated so you will not have the trouble brass is going to present.
- You can also keep your unused brass items in plastic containers instead of keeping them in leather holders or carriers.
- It’s okay to put any form of brass and leather together temporarily but not for a long extended time.
- Other than how the leather or brass is look, verdigris does not affect the leather or brass unless it’s been in contact for decades.