Official Luthiers Forum!
http://mowrystrings.luthiersforum.com/forum/

Potassium permanganate - Faux torrefaction
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=53023
Page 1 of 1

Author:  Clay S. [ Thu Mar 19, 2020 5:07 pm ]
Post subject:  Potassium permanganate - Faux torrefaction

Some people prefer the color of old maple - the yellowish hue it develops over time or through the torrefaction process. Another way to achieve this is with potassium permanganate. It is used in the furniture repair business to make new wood look old.
I did a sample of random dilutions on a piece of curly maple. The darkest is the strongest mix and the lightest (barely perceptible) is the weakest.
The KMnO4 only oxidizes and colors the surface when wiped on. I've never tried soaking bindings in it, but it is possible it might color it all the way through (future experiment?)

Author:  meddlingfool [ Thu Mar 19, 2020 6:20 pm ]
Post subject:  Re: Potassium permanganate - Faux torrefaction

That'd be cool if you could turn maple bindings the color of Koa...

Author:  windsurfer [ Thu Mar 19, 2020 7:37 pm ]
Post subject:  Re: Potassium permanganate - Faux torrefaction

PP can be hard to find. Similar results can be achieved using lye (drain cleaner)

...please remember to use appropriate safety equipment

Author:  Clay S. [ Thu Mar 19, 2020 7:54 pm ]
Post subject:  Re: Potassium permanganate - Faux torrefaction

The picture on my screen has a yellower hue than the real wood. Probably because it was photographed under incandescent light. The treated maple is sitting on untreated maple which is the typical freshly sanded maple color. The "old" photo program I used to use allowed you to do color correction, but the one I have now is pretty basic and only allows resizing, cropping and rotating images, as far as I can tell.

Koa comes in a lot of different shades. The KMnO4 on maple I'm sure could match a few of them depending on the dilution and amount of time it has to work.

I've heard KMnO4 is available at pool supply places. A friend of mine gave me a pint of crystals, which is a lifetimes worth considering how little I use and how far it goes.

Author:  Ruby50 [ Fri Mar 20, 2020 10:57 am ]
Post subject:  Re: Potassium permanganate - Faux torrefaction

You can watch it happen in a Dan Erlewine video my daughter did a couple of years ago:

https://www.youtube.com/watch?v=tViTWUL8Was

at 6:25 she is working on what looks like a piece of maple

Ed

Author:  Clay S. [ Fri Mar 20, 2020 2:08 pm ]
Post subject:  Re: Potassium permanganate - Faux torrefaction

Thanks Ed,
I learned something new with that video. I've used oxalic acid to bleach out iron stains, but didn't know it would work on KMnO4 treated wood. Good to know.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/