Would someone please expain "etching"

Hello Gents.
I saw a guy on you tube dipping his razor in boiling vinegar, and was wondering if this was for rust proofing or what? He said that is how he etches his blades. What exactly is it doing to the metal to help rust proof it? Any comments etc., are always appreciated. Thanks in advance.

I think the video you are referring too was by Charlie Lewis, Spazola on here. It's one of his many useful videos :)

As to what is actually happening I couldn't say but I know it works. You can use pretty much any acid as far as I know, I've used ferric chloride a few times. I think it's mostly used for artistic effect and the anti corrosion is a happy side effect.

Hi,

Have you a link to the video?

Thanks

As far as I know, hot vinegar forces a kind of patina on a blade, and mustard and hot vinegar a particularly mucky looking patina.

It is only a surface thing, and as such any rust-proofing is very minimal. Usually the patination is promoted by a combination effect, some things used are salt water, hydrogen peroxide and hot vinegar. Note that the acids must be neutralised and the patination 'sealed', often with oil, to stop active rusting.

Etching is not the same as rust proofing, as any basic google search will tell you.

If you want to increase the effect of patination with regards to rust control, you get into the russeting/browning/blueing camp - although not particularly complex, these processes, if done correctly, take a lot of time and effort. Stronger acids and alkalis are used, carding (combing) off the rust and re-rusting after boiling is used, except in the brown processes, as boiling converts the red active raust into pasive black rust, the basis of bueing. Hot salts and or fuming are used - these processes are markedly more durable than those bought in bottles and applied cold.

Regards,
Neil

Thanks for the replies.