By taking your time and learning how to etch stainless Damascus and carbon Damascus steel properly, you’ll avoid problems like spots in your finished product.
Be sure to always wear the appropriate protective gear when you’re working with acid. Complete etches in a well ventilated space and wear gloves, eye protection, and an apron or old clothes.
Damascus etching is completed with either ferric chloride or muriatic acid. Before you begin, check the expiration date on your acid of choice to be sure that it’s not too old. Using expired acid causes problems with your etch, and you don’t want to find out after you’ve already started that your acid is too old to work properly.
You’ll also need a baking soda bath. Mix baking soda with distilled water, using a generous amount of baking soda, so you can dip your piece to neutralize the acid and stop its dissolving action.
Once you’ve got everything prepared, you’re ready to etch!
How to Etch Stainless and Carbon Damascus Steel
Step 1: Sanding
Bring your Damascus to a 400 to 600 grit finish. If you’re using muriatic acid, you can bring the Damascus up to 1200 grit, or you can leave it at 400 grit. Either is effective. For ferric acid, keep the grit between 400 and 600.
Do not buff before etching! Buffing closes the pores in the metal, which will keep the acid from absorbing, and you’ll end up with an uneven etch.
Step 2: Washing
To etch Damascus, it should be perfectly clean. Thoroughly wash your piece with alcohol and pat it dry with a clean rag.
Avoid using materials like acetone because they leave residue behind that interferes with the etch, and don’t touch the metal with your hands. Acid penetrates correctly on a very clean surface.
Step 3: Dilution
If you’re using ferric acid, dilute it with distilled water until you have pretty close to a 50/50 ratio of acid to water. Never use tap water, spring water, or filtered water – they will all cause problems with the etc. Be sure that your distilled water hasn’t been sitting for more than a year.
Muriatic acid needs no dilution.
Step 4: Warming the acid
For both muriatic acid and ferric chloride, the temperature should be between 70 and 100 degrees Fahrenheit, about room temperature.
If you need to warm your acid for use, the best method is to place your container of acid into a large bowl of warm water. Never put acid in the microwave!
Step 5: Submersion
Hang your damascus piece in the container of acid so that it hangs freely and doesn’t touch the sides or bottom of the container.
To ensure that the acid penetrates, you can swish the piece back and forth in the acid, but brushing is the best way to be sure you get an even etch. Using an old toothbrush, softly brush the Damascus in the acid to help remove any residual oil or grease that you might have missed during cleaning, and to brush away the dissolving material as the acid does its job.
Let your piece remain in the acid for 10 to 15 minutes.
Step 6: Neutralization
Remove your Damascus piece from the acid and dip it into your baking soda bath for 5 minutes to neutralize the acid.
You can also use Windex for this step, but don’t try to spray your piece. Pour the windex into a container deep enough that you can completely submerge your Damascus item.
After 5 minutes, clean your piece with alcohol and pat dry with a clean rag. You can repeat steps 5 and 6 for a deeper etch if you desire.
If you have masked part of your piece so that it doesn’t etch, and you want to do another round in the acid and baking soda, completely remove the mask, clean the blade, and then reapply your mask before the second etch. Skipping this step is not advisable, even if your masking still looks good, because the acid can penetrate the second time around and ruin your design.
Step 7: Polishing
With stainless Damascus, one of the layers within the steel isn’t affected by the etch, which is what gives stainless Damascus that unique texture when it’s finished. Use a fine finishing sandpaper to gently buff the top of that slightly raised steel, and the other steel will remain dark and unpolished, giving you a beautiful and dramatic contrast.
If you prefer, you can polish with a 2000 grit buffing compound and a soft wheel to brighten your Damascus piece, but you’ll lose some of that contrast between the steel layers. Play with both this technique and the sandpaper to see which you prefer. If you decide you want to recover some of your contrast, you can do a quick etch again by dipping your cleaned piece into the acid for a few minutes and then neutralizing with baking soda.
Some makers like to soak finished pieces in WD-40 to get an even darker contrast. This fades with use, but it does produce a striking visual contrast, and it’s great to prepare your pieces for photos.