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Bleaching wood
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Author:  dertien616 [ Sat Mar 05, 2016 12:10 am ]
Post subject:  Bleaching wood
Was at the hardware store today and seen wood bleach. Anyone ever tried this on a guitar?
Author:  Chris Pile [ Sat Mar 05, 2016 12:26 am ]
Post subject:  Re: Bleaching wood
You mean the liquid stuff in 2 bottles, or the crystals you mix in water?
Author:  dertien616 [ Sat Mar 05, 2016 2:55 am ]
Post subject:  Re: Bleaching wood
Liquid stuff, part a and b
Author:  jfmckenna [ Sat Mar 05, 2016 8:25 am ]
Post subject:  Re: Bleaching wood
I've used it to take the rust off of vintage bicycle parts :D
Author:  Clay S. [ Sat Mar 05, 2016 9:40 am ]
Post subject:  Re: Bleaching wood
If you leave it on the wood too long it can eat away some of the softer fibers of the wood. Sometimes it takes the color out of the wood. What did you want to accomplish with it?
Chlorine bleach is a less aggressive alternative.
Author:  kencierp [ Sat Mar 05, 2016 9:41 am ]
Post subject:  Re: Bleaching wood
Oxalic acid ---- deck cleaner, works well we use the crystal form --- mix with water a little goes a long way
Author:  Greg B [ Sun Mar 06, 2016 11:32 am ]
Post subject:  Re: Bleaching wood
I've been considering making my next guitar with bleached mahogany. It was a very popular furniture finish in the 50s.

I've used Oxalic acid to remove stains, but it doesn't make wood lighter. I'm sure there could be exceptions to this. Two part peroxide bleach is the way to go most of the time, at least if the goal is to make the wood lighter. It will turn walnut into maple, so to speak. Chlorine sometimes makes the wood a humorous shade of yellow, other times it works.
Author:  Chris Pile [ Sun Mar 06, 2016 12:04 pm ]
Post subject:  Re: Bleaching wood
Quote:
I've been considering making my next guitar with bleached mahogany. It was a very popular furniture finish in the 50s.


No... it wasn't bleached in the 50's. It was limed - a pickling process. I have a whole living room set and bedroom set of the stuff.
Author:  Clay S. [ Sun Mar 06, 2016 9:07 pm ]
Post subject:  Re: Bleaching wood
I've been considering making my next guitar with bleached mahogany. It was a very popular furniture finish in the 50s.

Primavera and sometimes white limba is used as a "white (blonde) mahogany". You might consider using those woods instead.
Author:  TimAllen [ Mon Mar 07, 2016 1:32 am ]
Post subject:  Re: Bleaching wood
The way the word "bleach" is used is a bit confusing. It's like referring to wood dye as "stain"--often done, but pigment-based stain is a very different material and produces different effects than dye.

Oxalic acid is called "bleach" sometimes. It is used to remove darker patches in wood that are caused by iron, which usually gets there because it's in water. Hence, "water stains." Oxalic acid does not change the color of the wood itself, as far as I know. It certainly never has when I've used it.

Two-part wood bleach is different stuff. It's hydrogen peroxide and sodium hydroxide (lye). It can remove or lighten the color of wood, sometimes to the extent that there are no visible grain lines. Sometimes the color remaining is unappealing, like a yellowish gray-green.

Chlorine bleach is laundry bleach. In my experience it doesn't lighten wood much. I recently experimented with it because I made some black/blue/black purfling strips without thinking about how the blue color would darken under finish. When I tested finish on them, they were too dark, so I tried laundry bleach to lighten the color, which actually worked pretty well to lighten the blue. It lightened the black a bit, but that turned dark black again under finish. I also tested the laundry bleach on spruce, EIR, walnut, and maple. The spruce just yellowed, while the hardwoods lightened slightly. The bleached layer seemed very thin and sanded off almost immediately.

I've seen furniture called "bleached mahogany" but I think that was a figure of speech used to communicate what the wood looked like, not a literal description of the wood and process used. The furniture I saw looked to be made from a light-colored mahogany-like wood such as limba or avodire.

"Pickled" finishes that I've seen, mostly on oak or ash, use a pigmented stain containing something like titanium oxide, with a light colored filler that makes the pores creamy yellow-white. It's something like a butterscotch blonde Telecaster finish, though I think that's created with a multi-step process that includes spraying toned lacquer.

A few years ago, while looking around on the Internet for information on bleached wood finishes, I found a picture of a suite of office furniture that was veneered with bleached Brazilian rosewood. It was a yellowish beige color that looked truly hideous.
Author:  Ken Franklin [ Mon Mar 07, 2016 3:55 am ]
Post subject:  Re: Bleaching wood
You might try this. http://www.finewoodworking.com/how-to/article/bleach-mahogany-for-a-unique-look.aspx
Author:  Greg B [ Mon Mar 07, 2016 10:51 am ]
Post subject:  Re: Bleaching wood
Allow me to clear this up a bit. Bleached mahogany really is bleached mahogany. I work in the furniture industry as a designer and production manager. I know exactly how this is done. Peroxide 2 part bleach. Also, the 1950s 'limed' finish is not actually limed or pickled. It's done by bleaching the wood, then spraying it with clear lacquer with a bit of white in it to make it translucent. There's a few variations of the recipe, but that's basically it.

Clay, thanks for the suggestion of Prima Vera. I actually picked up a set already. It's pretty neat stuff, but I don't think it will have exactly the look I'm after, so I am still leaning towards bleached mahogany. I'm sure the prima vera will get used for something though, maybe a reverse guitar with a dark cedar or redwood top.
Author:  TimAllen [ Tue Mar 08, 2016 2:46 am ]
Post subject:  Re: Bleaching wood
"Bleached mahogany really is bleached mahogany." When I read this, I blanched.

I'm quite sure, reading the links, that there truly is bleached mahogany, even though I think I've seen some furniture presented as bleached mahogany that was naturally light wood.

I'm also pretty sure that the song I thought expressed nostalgia for bleached mahogany ("Korina, Korina, Where You Been So Long") was about something else entirely.

In terms of how "limed" finishes are created, I think I was correct in saying that they can be created with a semi-opaque stain and a white filler. This used to be done a lot on oak, including on floors, in the 1980s. Those floors looked OK until the finish wore, which didn't take long.

I tried this approach on ash back in the days when I made Mutt-o-casters, and I thought the result was just OK. (I attach pic's of the finish containers and the guitar.) To change wood colors, factories usually use sprayed finishes with added toners, and I think that's how I'd try to replicate a butterscotch blonde finish if I ever try it again.
Author:  jayluthier [ Fri Jun 17, 2016 2:15 pm ]
Post subject:  Re: Bleaching wood
I've used oxalic acid crystals mixed in water to remove iron stains in Koa sides created in my side bender.
Author:  Woodie G [ Sat Jun 18, 2016 6:30 am ]
Post subject:  Re: Bleaching wood
- Oxalic acid to remove stains resulting from the reaction of tannins in wood to metal and some minerals...WILL NOT LIGHTEN WOOD AND WILL NOT REMOVE DYE OR OTHER ADDED COLOR.

- Two part hydrogen peroxide/sodium hydroxide (aka caustic soda lye solution) lightens wood, but does not remove stains caused by tannic acid reactions with metals, nor does it remove some wood dyes that are metallic in nature. For actually lightening or removing the natural color of wood, this is what is used. The peroxide used is a 25%-30% solution, so forget using drug store 3% or 7% hydrogen peroxide...the process needs the sodium hydroxide to make the hydrogen peroxide more effective.

- For removing added dyes from wood, chlorine bleach MAY remove color, but will not lighten the natural color of wood.

So for mineral or iron staining, we use a concentrated oxalic acid solution mixed from dry crystal. For lightening mahogany for a limed or bleached finish on an electric body, we use two-part wood bleach, and for removing RIT dye from wood (please don't ask), we use concentrated chlorine bleach).

There are times when a customer will spill water or other mineral or salt-laden mix inside the guitar (e.g., leaking Planet Waves humidifier packs). When this mess dries, there is usually a stain left at the periphery of the spill due to the wicking effect of the wood fibers carrying the mix to the edges of the wetted area, then depositing as it dries (try spilling water on pure silk fabric...what a mess!). These stains can often be removed or at least made less noticeable with water by first removing as much of the mineral or salt deposit with distilled water wipes (multiple wipes with fresh paper towels dampened with distilled water), then wetting out the area to it's boundaries. Any remaining mineral or salt deposits are distributed along the edges against lining or braces, and usually are much less obvious. This is essentially the origin of the recommendation to use 3% hydrogen peroxide or even window cleaner for the job - the water does the work in distributing the mineral or salt stain, while the hydrogen peroxide or ammonia does little more than affect surface tension characteristics.
Author:  Jason Rodgers [ Sat Jun 18, 2016 11:57 pm ]
Post subject:  Re: Bleaching wood
How does the two-part bleach work on sticker stains (sticker "shadow") left from drying wood? The wood in question is alder: lighter stripes across the lumber where the stickers divided the stack.
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