# Finishing Raw White Oak - Question re: color and sanding



## petem1 (Apr 12, 2011)

I wanted to ask a question regarding the raw wood tabletop project I am currently working on. I have attached some photos - the wood is white oak. 
It might be difficult to see, but there are some inconsistencies in the color. (I have circled the areas in question). In some areas, there is a brown 'patching' effect occurring, though the areas directly adjacent to it are more white, which we would prefer. Is this just the natural coloring of the wood, or is there a way I can make it more consistent (i.e., white). 
Also, please note in one photo the dark marks I have circled, that seem to be in the grain despite my attempt to sand them out. Any thoughts on what these marks are and the best way to get them out, if it's possible to do so? (sandpaper grit, etc.)


----------



## McKinneyMike (Feb 11, 2011)

The areas in question are sapwood. The dark coloration in the first photo looks to be some form of sap staining. No way to remove it and not affect the color of the wood around it..


----------



## Cosmicsniper (Oct 2, 2009)

I'd bleach it first. Then, washcoat everything with a thin cut of shellac. Then, I'd dye it or add some color back by adding a tint (tone) to your choice of finish, preferrably sprayed on.

Should be pretty uniform by then.


----------



## Cosmicsniper (Oct 2, 2009)

BTW, it's not a guarantee that bleaching will work, but I think this .pdf file is really good at diagnosing the problem and giving solutions on how to handle it…

http://www.fpl.fs.fed.us/documnts/fplrn/fplrn165.pdf

With oak, it's normally caused by iron coming in contact with the tannins in the wood…though it could be mineral stains in the sap. Hard to tell.

Oxalic acid or an A B bleach solution will likely handle it. If not, you might have to do something more creative to conceal the stain.


----------



## Waldschrat (Dec 29, 2008)

*Petem1* Hello! I agree with *Cosmicsniper*! At least with the *Oxalic acid*. I would try that or try using some citirc acid. Wash it out with Warm water and Viniger or a citric acid of some sort washing out immediatly, this will reduce or remove completely oxidation stains that are common to tannic acid rich woods such as oak, cherry, walnut and so on. its just important that you repeatedly apply the acid, and wash it out.

To get the wood to a lighter tone again basically the same process over the whole piece of wood… Oxalic acid works here well too! This will lighten the wood, and if you want to keep the finish light, then use a hardening oil or varnish with white pigment in it. The wood will look like its fresh sanded, more or less and will stay that way for quite a while, depending if its exposed to direct sun or not. UV ray will turn most anything yellowish after time, but this process is slown down quite a bit with a white pigmented finish product. Especially if the wood is first washed with the "bleaching" compounds (oxalic acid, citric acid)

Ok good luck!


----------

