Salt Water Metal Etching





Introduction: Salt Water Metal Etching

I am a sword and knife enthusiast who always found the little etching on the side of my weapons super cool. I searched the web for several ways to make my own etchings on my weapons. To my dismay, there were few methods that did not contain harsh, dangerous chemicals that I didn't have at that time.Then a little spark of light appeared to me in the form of salt water etching! This method contains a few household items that are readily available and cheap.

WARNING: This method produced a harmful gas that should not be breathed in. Please use in a well ventilated area.

Step 1: Items Needed

All the items that are needed can be found around the house or for cheap elsewhere.




Blade (steel works best, stainless or carbon)

9v Battery

A pair of alligator clips

Alcohol or Windex


Electric Tape

Nail Polish (optional)


Some Artistic Ability


Step 2: Cleaning/Mixing Salt and Water

Take some alcohol or Windex and clean the blade thoroughly. This helps the process go smoother. Also make sure the alligator clips, battery, and all other necessary components are clean and functioning properly.

At this time also mix the salt and water. I find that using one tablespoon of salt per cup of water works pretty well. Warm water makes the salt dissolve quicker. Remember, you don't need much salt water.

Step 3: Plan and Execute

This is were you need a little artistic ability.

If you plan on making pretty simple geometric shapes you can use only electric tape. If you plan on doing any other shape with curvy lines and whatnot you can use nail polish (I've also heard that Sharpie works too, but I have not tried that).

If you feel you cannot do that you can go to any local print shop and ask for custom vinyl stencils. If they cannot do them, they can probably tell you who can.


Place a square around the area you plan on etching. Next get a razor or exacto knife and cut the other shapes needed out of electrical tape. This takes patience and concentration. Lay them down accordingly onto the blade. Make sure you press the tape down really well because if anything gets past it, it will mark areas you don't want to.


Paint down nail polish were you plan on etching. Make a electric tape border once it is dry. Take your pencil, pin, or any other small device and carve away the polish where you want to etch. This takes time because you need to make sure all the little pieces of polish are out of the grooves you create.

Step 4: Almost There

Now you can set up your little etching device.

Take one alligator clip and attach one end to the positive part on the battery (my red clip). Take the other end and put it on an empty part of the blade. Be careful where you place it on the blade, mine slipped off a few times.

Take the other alligator clip and attach one end to the negative part on the battery (my green clip). Dip a Q-tip in the salt water. I find that you need to get it wet enough that it isn't 'just moist' but it isn't dripping wet. Attach the remaining end of the alligator clip to the Q- tip head. You don't need it on the very end, but it needs to be touching the water.

Step 5: Etching

Now we can etch!

Place the Q-tip head onto the blade where you want to etch. Move slowly while passing over your entire design. I like to rock it back and forth while I move. You will notice a little puff of white smoke and a pungent odor as you etch, do not breath this in! Use in a well ventilated area. This is also a sign that it is working. Look at your Q-tip. It should be changing colors, from blue-green to a brown. This is the metal that you are removing. When the Q-tip gets really dirty looking take the clip off, dip the other end in water, add clip, and continue. The more passes you make with new Q-tips, the darker and deeper the etch will be. I use about 3-4 Q-tips.

When you feel like it is ready, remove the clips and walk over to a sink. Wash all the water off (while pointing the blade tip down) and remove the tape then dry. If your etch is still there good! You did it! Congrats! Hope you liked the instructable!

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Hey there, how long would you say it should take to make that letter? And how long do you remain in onw general area before moving on? Thanks!


Nice instructable! But just a side note, the gas that is created is Hydrogen, which is harmless, yet flammable. In fact we breathe it all the time.

works well. not one that's super smooth but I like the look of it. made mine with a dispensary sticker.


Will this work on pewter?

I want to do this with a large outline and fill. Someone mentioned using a cotton ball instead of a qtip. Has anyone done this or would recommend it? Also could I use a higher volt battery if I'm doing a larger piece? Please let me know :)

i tried it it worked but i also had an idea i tried it useing my arc welder and it worked even faster and better plus instead of qtips i used cotton balls coverd a bigger area

Does this work with stainless steel? Has anyone actually etched stainless steel this way and can verify it works?

I will have to try this for free-hand etching sometime. I've never seen a method without immersion before. Thanks!

This process will work on aluminum but it is much slower and less effective.

I usually grab a bottle of heavy tile cleaner (phosphoric acid) from my old mans work (tile shop) and thatll do the trick without any lectricity or anything, but it doesnt seem to work on Cr5Mo15V steel so ill give this ago

How about using a paint brush instead of the Q-tip? Perhaps you could swish the brush around in the saltwater to clean it off, at the same time loading it up.

What do you think about dipping metal in electrified salt water. I'm going to see if I can make it work, but have you thought about it before?

Great instructable! I tried it on a machete and it worked great, thanks for the advice! It took me 2 9-volt batteries to do as much as I did though, it really burns them up.

Will this method work on aluminum?

Have you tried it with wax? How about laser printer transfer for the resist?
Great post. I'm going to try it, but my art skills are lacking. Hope I can generate a design on the puter and transfer for etching with this method

that sounds really neat, I'll have to try it, thanks for sharing

Very nice!!
I find that batteries run out pretty fast, because you are almost short circuiting them
I use an old transformer from a network switch.
12Volst + 1Amp.
Volts and Amps matter, meaning they give you different results

Very cool and thank you for the safer version. I love projects like this that the kids can participate in!