8/13/2019 Blueing Steel 3

http://slidepdf.com/reader/full/blueing-steel-3 1/2

Blueing Formula

Chemicals Required 

Caustic Soda (Sodium Hydroxide NaOH) 850 grams per litre of water 

Common drain cleaner available at supermarket or hardware store

Potassium Nitrate (Salt peter KNO3) 150 grams per litre of water Obtain through chemical supplier 

[To convert Grams to Ounces Multiply by 0.03527]

Temperature Control - Is Critical

Temperature required for blueing 1350 Celsius temperature is controlled by adding water during boiling NOT BY VARYING TEMPERATURE

OF HEAT SOURCE. Room Temperature can be used with

Caution. Water is added by trickling down side of container.

Solution is near solid till heated then it liquefies solidifying on cooling.Allowing temperature to vary by more than a few degrees either way

will produce poor blueing. Too hot goes brown, rusts easily. Too cold

does not take up colour. Requires constant checking during heating.

Equipment & Extra Items Required 

Bare Steel or Stainless Steel container  of suitable size for parts

Heat source preferably gas (multi burner) sufficient burners to cover

 base of container. Electric burner’s are slow to heat up & difficult tocontrol temperature with (can be done not recommended)

Thermometer  high temperature type from science supply or Candy

thermometer from supermarket will do.

Acetone for degreasing parts before immersion

8/13/2019 Blueing Steel 3

http://slidepdf.com/reader/full/blueing-steel-3 2/2

Light Mineral Oil - examples Transmission Fluid, Two Stroke oil

Sewing Machine oil, for coating parts after blueing.

Wire or a small Stainless steel basket for dipping small parts

Tongs (kitchen) stainless steel for handling hot parts

Paper Towel or soft clean cloths for wiping partsTwo Plastic Buckets for water 

Elbow length PVC Gloves minor spattering burns the arms

Apron PVC or Leather to protect clothes (Butchers / Meat workers

wear PVC aprons)

Safety Glasses to protect eyesGood Leather Footwear 

A Bucket of cold Water on Standby in case you need to immerse a burn.

The ProcedureClean the parts in acetone avoid getting oily finger marks on metal.

Add chemicals to Cold Water & Heat, Check Temperature frequently

djust burners to obtain near constant 1350 C

At temperature dip parts 15 to 20 minutes has proved sufficient 30

minutes may help with deeper etching of metal but makes no colour

difference. Colour is a deep Blue Black identical to that used on

Anschutz Firearms.

Remove from solution dip & shake about in a bucket of HOT WATER

this helps prevent the chemicals forming a Bloom in small crevices.Dry still warm parts on Towel or Cloth Immerse in Mineral Oil.

Most methods recommend leaving oil on overnight for blue to harden

experience has shown 30 minutes will suffice if you are in a hurry.

Boiling generates very little in the way of fumes. Water needs to be

added frequently as it boils off. If blueing after a few batches seems

slow or insufficient add more chemicals. When finished dispose of mixas per local requirements.