4

I'm a novice woodworker making a knife handle from two different woods. The front and back of the handle are Indian rosewood, while the middle part is birch root. During sanding, it looks like some dust from the darker wood is getting embedded in the pale wood. Is there a way to prevent this or clean it up before applying the finish?

I've attached a picture showing the discolored wood next to the block from which it was cut.

knife handle

FishesCycle
  • 143
  • 3

3 Answers3

2

Have you moved up the solvent ladder to lacquer thinner or acetone? That rosewood is oily, and you've likely got to break down that oil to dislodge those particles and dissolve any pigment. Or - just a shot in the dark - maybe a little household bleach, or even oxalic acid (wood bleach, found at Box Stores).

Benchwerks
  • 534
  • 3
  • 7
  • I tried acetone. The acetone-soaked rag picked up a lot of colour, which I'm assuming was an oil from the rosewood. However, this made things worse, as the pale wood become darker as a result.

    In the end, I sanded with 220 grit, removing most of the pigmentation, though there's still a pink cast to some parts. The fact that the colour contamination didn't occur with this sanding makes me think that cleaning with acetone before sanding will help prevent transfer of pigment from the dark wood to the light.

     – FishesCycle Mar 29 '17 at 16:27
  • First of all, nice work. This is more than beginner level woodworking. Ok, those black nylon grommets you have spacing the the burl and the rosewood might help you out. If you haven't tried bleach, you could mask off the rosewood with a seam in the middle of that nylon. (I'd use automotive pinstriping tape). Brush a little on a test piece (everyone had a ton of burl laying around for testing, right?) And stick it out in the sun. I'd start with household bleach and then move to oxalic. – Benchwerks Mar 29 '17 at 16:49
  • You could also fashion a scraper out of a clean piece of glass. Any glass shop could give you a few pieces a couple of inches wide with nice straight edges. You would be surprised at how delicate you can work with that. – Benchwerks Mar 29 '17 at 16:53
  • You should edit to warn not to also wipe the acetone over the rosewood. Now the lighter wood will be stained as well as have particles lodged in pores. – bpedit Mar 31 '17 at 16:05
  • Yes. Great point. I was unclear. Definitely mask over the rosewood, and maybe even mask back over the burl when you go back after the rosewood. Nice catch. – Benchwerks Mar 31 '17 at 16:32
1

Have you tries simply washing the wood with warm water? The water will cause the wood to swell and open it's pores. Then you can scrub the wood with a soft cloth to see what's removed.

Jon Dosmann
  • 237
  • 1
  • 2
  • 6
  • Make sure you give it plenty of time to dry after this before applying a finish – Jon Dosmann Mar 28 '17 at 19:12
  • I think that would raise the grain, making it necessary to sand it again bringing me back to square 1. I tried cleaning with 70% ethanol, which didn't raise the grain but also didn't remove the problem. – FishesCycle Mar 28 '17 at 19:36
1

You can prevent this by applying a wash coat of whatever finish you're going to use before you start sanding. The finish will "seal" the pores of the wood.

Obviously this won't work if you're sanding to remove material, instead of just for surface prep.

SaSSafraS1232
  • 5,510
  • 9
  • 21