Cold Blue

There is another blacking process that uses no nasty/toxic/expensive chemicals. Rather than write a long explanation, here is a link to a youtube video which covers the process. It is a little more involved than chemical blacking, but very effective. This is one of the old gunsmithing processes and I have read the coating is more durable than off the shelf DIY stuff. I have used this on several bits and pieces and it is very good. The main ingredient, hydrogen peroxide, can be bought in most chemists, but it is 3% strength. You can buy 12% Strength peroxide on the internet, or from industrial cleaning suppliers. 3% works, but not as vigorously as the 12%.

I know this sounds wrong for anybody with an engineering mind, but it is fascinating watching bright steel rust before your eyes.

https://youtu.be/xmv58Z3RZ9c

Forgot to add safety warning - don't let Domestic Management Executive catch you using her saucepans for this. No amount of PPE will protect you.

Edited By Mike Woods 1 on 20/11/2019 19:26:38

COLD PRESSED VIRGIN FLAXSEED OIL (linseed oil) is written on the bottle. The 250mL bottle I have was purchased in the supermarket. It was made by made in Australia by Biogenic Health Foods, and is "rich in Omega 3," but I don't know if it is "raw" or "boiled."

Many years ago when i was just starting out I discovered I could black thins by heating steel until it oxidised, then applying jenolite to convert it to phosphate.

Neil

On the strength of the recommendations in this thread I bought some Abbey Blu Gel to touch up some scratches on a blued surface, worked well.

Then decided to try it on something larger. I had just stripped down a floating reamer holder I made many years ago, it felt a bit "gravelly" so in need of a clean. The photos show the Knurled ring I blued.

It took four coats to get a nice even finish. First coat seemed to make it go rusty! Each subsequent coat improved the appearance. I found applying with a brush and gently scrubbing the surface gave best results. It was somewhat more difficult to get an even finish on the knurled surface.

It will be interesting to see how durable the finish is.

John