blueing guitar pickup covers

[simonineaston]

One of my new hobbies now I'm retired is messing around with electric guitars. I've seen some customisers use a torch on metal pickup covers (once removed from the pickup itself of course...) to get a blued effect on the chromium cover... does anyone know how that's achieved ie does the cover have to be dunked in any particular liquid after heating - or can it be left to cool naturally, once the metal takes on a bloom?

[colin54]

I was thinking about this, and thought of chrome plated down pipes on motor bike engines which sometime turn blue.
Here's an article on that.
https://motorcyclehabit.com/why-motorcy ... to-fix-it/

I might be wrong but I don't think you'll need to quench, it's deciding what temperature is required and then working out how you are going to achieve it . Finding out what temperature a slightly too hot motor bike exhaust operates at might give you a clue, does anybody here know ? There's a product mentioned in the article to remove blueing if you don't like the effect you've created.
My only experience of blueing was when tempering metal tools, where you observe the colours whilst heating to know when to quench, but that's steel and a different subject all together I imagine.
I wonder if you'd get enough heat off of a gas hob ?

[Stevek76]

Bluing is something done to steel rather than chrome?

There are a bunch of modern chemically aided ways (both hot and cold) to do it though the oldest method is an offshoot/indication of tempering. Steel is heated then quenched to be hardened and then (relatively) gently heated to temper, sacrificing a little hardness for toughness. The oxidation of the steel changes colour based on temperature with a deep blue being 290-300C. Recall seeing a vid of someone doing the 'traditional' method and they were using a bed of brass filings to keep the heat even. Of course if you want a modern (overdone? ) MTB oilslick look then uneven heat is needed.

You don't requench once the desired colour is reached

[colin54]

I think you may need not need a lot of heat to effect a change.
I had an old gash Les Paul type tailpiece in my guitar spares box. I tried heating it on the lowest setting on the smallest burner to no effect, impatience led me to turn the heat up (too soon probably) ,The chrome started to lift from the base metal
(possibly zinc though it did take a magnet very-very slightly ?). I continued to heat and saw some straw and blue colouring on the string holes. I put it on a recently purchased chinese, very thinly chrome-plated onto steel simmering ring to cool, this already showed the effect you may be trying to achieve ! Doh ! It ( the simmering ring) took on this hue after only one 20 minute use on the lowest setting on the medium ring with a frying pan on top..
Go steady with the heat, if you decide to experiment further.

You don't requench once the desired colour is reached

I'm sure you're correct there Steve, my poor memory from apprentice training days in 1971....

[simonineaston]

Gosh... ! Thanks for the enthusiastic testing. I think the take-away fact for me is to go steady... I have two sorts of gas available to me, plain-vanilla propane and the hotter mapp. I'll start with the propane!