Thread: Variations in the wood's Appearance

What you are experiencing is called chatoyance, it is the way in which the light gets reflected off the timber, I have noticed this particularly in some blackwood of which I was lucky enough to get the whole tree. Going from a rich brown to a golden colour. Sorry I cannot explain the physics behind it. I'll try to get some pics.

Sorry tegmark, I think still images aren't going to achieve much, but I did have fun mesmerizing myself for 5 minutes, I think that it could be caused by small changes in grain direction.

Chatoyance can be seen very clearly in pile carpet, or the underlying effects which cause chatoyance at least.

Drag your feet through the carpet from left to right, then drag your feet beside the previous mark from right to left. You will clearly see how when you are looking directly at the ends of the carpet fibers, it captures the light, but when looking across the faces of the fibres it will reflect the light.

Timbers which don't have straight grain do this. A tree that grew so huge that the trunk got compressed under the weight of the canopy. It compresses the straight grain into an accordion arrangement, and when you plane a perfect straight line across the accordion grain, you can see where you are looking down through the grain tubes, and where you are looking across the grain tubes.

Trees that favoured the sun a little too much on one side and had too much growth on the north side tend to lean over crushing the grain on the north side of the trunk while stretching the south side. Pick up enough boards of timber and you will see exactly what has happened because the grains will be curved quite noticeably. I had an excellent example of it the other day in some tassie oak, but it's buried somewhere now.

Many fiddle-backed woods exhibit this, Blackwood in particular but I've also had redgum, ironbark and others show it as well.

Even straight-grained pieces can show some chatoyance if you curve the surfaces instead of going for flat, squarely planed surfaces.

Originally Posted by shedbound

Sorry tegmark, I think still images aren't going to achieve much, but I did have fun mesmerizing myself for 5 minutes, I think that it could be caused by small changes in grain direction.

I had a hard time capturing this, the camera shows nothing like what eye sees particularly with the wild swings in appearance & how nice it looks.

Originally Posted by Kuffy

Chatoyance can be seen very clearly in pile carpet, or the underlying effects which cause chatoyance at least.

Drag your feet through the carpet from left to right, then drag your feet beside the previous mark from right to left. You will clearly see how when you are looking directly at the ends of the carpet fibers, it captures the light, but when looking across the faces of the fibres it will reflect the light.

Timbers which don't have straight grain do this. A tree that grew so huge that the trunk got compressed under the weight of the canopy. It compresses the straight grain into an accordion arrangement, and when you plane a perfect straight line across the accordion grain, you can see where you are looking down through the grain tubes, and where you are looking across the grain tubes.

Trees that favoured the sun a little too much on one side and had too much growth on the north side tend to lean over crushing the grain on the north side of the trunk while stretching the south side. Pick up enough boards of timber and you will see exactly what has happened because the grains will be curved quite noticeably. I had an excellent example of it the other day in some tassie oak, but it's buried somewhere now.

Thanks.
I think this piece is Tas Oak from memory, really nice but I wish I could get it in massive wide single pieces. Anyway I would imagine a french polish would make it look far better than just a lacquer or PolyU.

I would agree with the Tas Oak (Vic Ash) assumption

I have made a wall clock out a very highly figured piece of TO ... bugger the plane ... had to use a card scraper ... and then grain filler to get a smooth surface.

Regards

Rob

All hardwoods are made up of bundles of semi-translucent tube. Like bundles of glass drinking straws .......... if your finish is not made up of muddy jamy crap, you may have a chance of seeing THIS true beauty of nice wood.
As the viewing and lighting angles change how the light reflects and transmits thru these tubes can produce stunning effects.
Best effect I have seen is on Syrean Batu .... but blackbut and blackwood can be pretty nice too.

cheers

Originally Posted by Kuffy

Chatoyance can be seen very clearly in pile carpet, or the underlying effects which cause chatoyance at least.

Drag your feet through the carpet from left to right, then drag your feet beside the previous mark from right to left. You will clearly see how when you are looking directly at the ends of the carpet fibers, it captures the light, but when looking across the faces of the fibres it will reflect the light.

Timbers which don't have straight grain do this. A tree that grew so huge that the trunk got compressed under the weight of the canopy. It compresses the straight grain into an accordion arrangement, and when you plane a perfect straight line across the accordion grain, you can see where you are looking down through the grain tubes, and where you are looking across the grain tubes.

Trees that favoured the sun a little too much on one side and had too much growth on the north side tend to lean over crushing the grain on the north side of the trunk while stretching the south side. Pick up enough boards of timber and you will see exactly what has happened because the grains will be curved quite noticeably. I had an excellent example of it the other day in some tassie oak, but it's buried somewhere now.

Forgot to ask, does Chatoyance diminish over time? I ask as the once the wood is processed its no longer compressed.