Wood Darkening - How To Avoid?

[James Farrow]

I believe that I read that as wood ages it darkens. And exposure to direct sunlight will speed up the process.

Is there any way to avoid this? Or at least slow the process down?

This is in reference to Pyrography. Many people say that over the years some of their works fade. I don't think they are saying that right. The burnt lines don't really fade. As the wood darkens with age the burnt lines look like they are fading but they are actually staying the same. It's the unburnt wood that is darkening to the same shade(s) as the burnt lines.

Anyway, keeping it out of direct sunlight is the obvious way. But are there any other solutions to this darkening effect?

Keep in mind we can only use clear varnishes, lacquers, sealers, etc... as we don't want to distort or cover up the burnt image.

Thanks,

James

[Jim Becker]

Not really...it's a natural process. Avoiding UV helps, but normal oxidation "happens". (Some species get lighter, by the way...air dried black walnut being one of them)

[Steve Schoene]

Jim has it right. There just isn't a practical way to prevent wood from changing color over time. Trying to do this is tilting at windmills. We humans have to take the natural world as given us. If we want an object to never change color, we should make it of something other than wood--plastic perhaps--or stainless steel.

[Lee DeRaud]

Not really...it's a natural process. Avoiding UV helps, but normal oxidation "happens". (Some species get lighter, by the way...air dried black walnut being one of them)

How much of the effect is UV and how much is oxidation? Seems like the oxidation part can be minimized by the choice of finish: no oxygen, no oxidation.

[James Farrow]

Thanks!

That's what I figured. Will pass the info on to the others.

James

[Jim Becker]

Seems like the oxidation part can be minimized by the choice of finish: no oxygen, no oxidation.

Not true. None of the finishes we generally use stops the passing of moisture and or oxygen...it may slow it a little. For example, Shellac is an excellent moisture barrier (moisture being different than water!), but it still passes. Finishes do not really "seal" the wood with any sense of impermeability. (Maybe some epoxy resins may...)

[Dennis Peacock]

Good info here fellers. Thanks.!!

[James Farrow]

Here's something to think about. A lady over on the Pyrography forum said that she uses here pyrography pen to seal the wood. Uses it on a low enough setting not to burn the wood but hot enough to seal it. She runs the hot pen over the entire surface. She said it works and pictures that she has done a long time ago have not oxidized while others she did without this "non-visible burning" have darkened.

I suggested she try a flat iron (not a steam one or one with any lnes/ridges on the bottom) and she said it would probably work. If it got hot enough.

Any ideas on what she may have stumbled upon?

Maybe the heat is sealing the pores/grain?

James