How to patina and finish mild steel

1/19/19

I wanted to outline the steps in creating a beautiful finished surface on a mild steel item. This process is fairly easy but all the steps need to be followed and correct materials used. Some chemical and some physical procedures will to be outlined and my personal process exposed.

Step #1

Fabricating your object is the first step, cut, weld, grind and or form the work to specs, then when item is ready the finishing process begins.

Build your object, grind, sand and shape the piece reading for finish
Build your object, grind, sand and shape the piece reading for finish

Step #2

Using a chemical “bluing agent” the surface of the steel is colored, this is a permanent process and will last many years if sealed properly

Insta Blak Chemical
Second part involves chemicals, don’t forget your gloves and mask… Safety first.
Many chemicals and process involve pollution and carry long term cumulative health risk, always protect your lungs, eyes and skin.


Step #3

The chemical step is pretty easy, after the form is cleaned and ready you apply the bluing agent (I use Instablack) to patina the steel. Let this set for a short time and dry the steel with a clean rag.

A sweet “blued” surface after chemical treatment
A sweet “blued” surface after chemical treatment, a rich color hides all the sanding and grinding marks, almost ready to finish

Step # 4

Rub the newly blued surface after it is totally dry with steel wool, this helps to blend away any streaks or blemishes.

A metalworkers friend, 0000 steel wool
A metalworkers friend, 0000 steel wool. Rub the newly blued metal surface for a lustrous sheen which will next be sealed

Step #5

Penetrol is the first of two sealers I use to finish steel and make it ready for use. This is actually a paint thinner used for oil paint, but applied to steel and given plenty of time to dry acts as a nice hard seal for the surface.

Flood, Penetrol
My favorite first layer of sealer to protect blued mild steel, Penetrol

Step # 6

Next and finally when the Penetrol is hard a polyurethane spray is used on the exterior surface. Two coats area applied and let dry for some time, one final step is all the remains.

Spray polyurethane is the top coat of mild steel
Spray polyurethane is the top coat of mild steel, two coats is best

Step # 7

A hard paste wax is applied over all the other sealers, this is totally waterproof and can be reapplied as often as desired or needed.

A hard paste wax
A hard paste wax is the final step n the bluing and finishing process.
A finished work, blued, sealed and waxed
A finished work, blued, sealed and waxed, ready for your home