Chatoyancy

[bob vaughan]

I was finishing up some kid chairs and noticed the wood colors really got radical now that the finish was on.
Actually this is pretty typical of newly finished hardwoods that are joined at right angles. The way the light hits the grain makes a big difference. I took a few photos to show the changes. The same side of the little chair is rotated 90º and what was light is now dark.
This goes away somewhat with age.
I just thought it was interesting. Usually chatoyancy is associated with compression figuring like crotch flairs although most hardwoods have it to some degree or another.

The sides being glued. The grain difference isn't so obvious here.

Same side rotated 90º. Quite a difference and somewhat annoying in the right light.

 

[llucas]

actually, I have always like the effect...makes me feel the wood is actively contributing to the final appearance.
Thanks for sharing

 

[LocoWoodWork]

Looks good IMHO

 

[creasman]

Thanks, Bob. I just learned a new word, chatoyancy. I've often seen the effect you're talking about, but never stopped to think there might be a term for this.

 

[chris_goris]

This is why we love wood! we always find the crazy grain. I have found though, its VERY difficult to show chatoyancy in pictures, cameras dont seem to pick up on the depth at all.

 

[Tim Sherwood]

Great demonstration Bob. Just in time to make me pay attention to the light effects on some book matched cherry panels I'm working on. thank you.

 

[creasman]

just in time to make me pay attention to the light effects on some book matched cherry panels I'm working on.

Please post pictures when you're done. This is always something to be aware of when doing book matched pieces. Because of the cut, the grain orientation usually has you looking into the open grain on one and against it on the other, depending on the vantage point.

 

[bob vaughan]

The table top below is a good example of light hitting things just right to show a contrast. Accepted protocol for a table top glue-up is to alternate the boards bark side up, bark side down, to minimize the risk of warpage. When the light hits a finished top just right, one board seems significantly darker than the adjoining piece. This isn't always so obvious unless the light is right. That's just the nature of what we do. To avoid this, the top could have been bleached with a 35% solution of hydrogen peroxide then dye stained back to a uniform color. Yuk!

I really could have staged this photo better, but it was one I had handy in my photo files. That one board really looks dark.

 

[Tim Sherwood]

Good point Jim about book matched panels. Maybe I'll have to slip match instead of opening them to opposite faces?

 

[DickF]

Thanks, Bob! I too learned a new word seen the effect many times but didn't know there was a term for it. Ash can have some nice chatoyance, too. (I've got to use it to remember it!) It makes the wood look alive, I think.

 

[creasman]

Maybe I'll have to slip match instead of opening them to opposite faces?

It can be hard to tell until after the finish is applied. One trick is to wipe mineral spirits onto the pieces to give them a finished look. That will enhance any chatoyancy and help you decide which way to go. The mineral spirits evaporate without affecting the later finish. If you have a highly figured grain the effect of book-matching trumps the light refraction, IMO.

 

[bob vaughan]

A thick glossy finish makes the contrasts show up more. Veneers have been book matched for years but often the finish isn't as heavy as we can take the time to do.

 

[McRabbet]

The most beautiful chatoyance I've every worked with was exhibited by ribbon cut African Mahogany. I finished a wine cellar tasting area top with four coats of Behlens Rock Hard Varnish and it was (and still is) spectacular! As your eye moves across the field of view, the color of the wood changes as you move.

Wine Cellar WIP - Finishing

• McRabbet
• Sep 28, 2006
• finish project wine

African Mahogany countertop board with first coat of sealer varnish

Wine Cellar WIP - Finishing

• McRabbet
• Sep 28, 2006
• finish project wine

African Mahogany Tabletop and center section with first coat of sealer varnish (Behlen's Rock...

 

[Tim Sherwood]

Beautiful wood Rob. These photos show the effect nicely.
I worked on my cherry panels yesterday. I planed them one both sides and then took them outside into raking sunlight. It was still difficult to tell which way showed the best effects. I'll try some mineral spirits today. I think Jim is right though. In the end , the best looking grain pattern will win out. But at least I'll have tried to get both.

 

[LocoWoodWork]

I try and do my final sanding outside in the sunlight. It' brings out all the imperfections, pigtails, swirls, etc. Here is my example of chatoyance: