I began the project with a brand new Mora 840 MG Carbon Clipper. These inexpensive knives have a reputation for being sharp, durable and easy to maintain. I chose a Carbon blade for it's ease of resharpening and fire sparking qualities. The carbon steel is of course more susceptible to rust and corrosion. The fast answer was an acid patina, the fastest patina? Custom Condiment! 
The bright silvery steel of a brand new Mora is beautiful as this picture shows, but will tarnish and pit before very long. The edge of a Mora is sharpened in the traditional Scandinavian or "Scandi "grind. A long flat continuance with a wide easy to follow angle. These knives are renowned for their ability to achieve a "shaving" sharpness.
The application of the acid (Mustard) was easy enough. After cleaning the blade well with solvent (Alcohol wipes) and allowing to dry, I mixed a liberal squirt of Mustard with a table spoon of Apple Cider Vinegar. Mixing it only slightly so I would have a clotty half runny half firm semi paste, I applied the acid to the blade with a Q-tip in an intentional random organic pattern that I hoped would give the blade some character.
I allowed the acid to remain on the blade undisturbed for three hours. I had heard others say six to eight hours was necessary but I doubted this as the carbon is so open and willing to take a stain, I was correct. After washing the blade and neutralizing the acid with WD-40 I only needed to give the Mora a loving wipe down.
The Mora took the acid with better then expected results. A semi spotted pattern not unlike marbled conglomerate or pudding stone was etched in the now grey blue and beautiful steel. The natural, organic look of the metal gave the edge the appearance of a custom knife, only Damascus would have more charm. I think the look is worth it even if the patina did not provide some protection from corrosion....which luckily it does.
How Kool is that? I will never look at a jar of Mustard the same way again. What a fast and efficient way to blue steel. Who knew? Now even if the Mora needs to be re-touched now and again, who cares? It is so easy to produce a delicate and interesting protective pattern on the steel it is no chore at all.
Now as easy as this was to achieve, it was controlled. I planned the application and pattern for this affect. Should you just wipe your blade down with a vinegar type acid, you will only achieve a grey blush and possibly streaking. The protection may be there but the character and raw beauty of the blotching will be missing. Plan out your blade pattern before you commit.
Now as easy as this was to achieve, it was controlled. I planned the application and pattern for this affect. Should you just wipe your blade down with a vinegar type acid, you will only achieve a grey blush and possibly streaking. The protection may be there but the character and raw beauty of the blotching will be missing. Plan out your blade pattern before you commit.
I can't think of a Carbon blade I own that would not qualify and benefit from the "Mustard Treatment". The once plain Jane, purely utilitarian look of the classic Mora now has a personal custom coating that deserves a second glance. This ain't your Daddy's Mora.
Safe Travels
Safe Travels
RJ
