Sunlight aging

Very interesting... But a very complex subject I guess. Maybe the book "wood and cellulosic chemistry" can tell something.
Unfortunately, I am not familiar with fresh wood. I only cut some elm, which seems light brown when just cut, and then it quickly oxidizes (?) to medium dark brown.
However, I am very curious about this:

Is it easy to achieve this result? Do you sharpen your tools in a specific way? Is it easy for someone who never did it?
I ask because I hear that a very sharp cutting tool provides a better finish (and chatoyance) than any sanding. This is confirmed by some of our tests on veneer as received and then sanded to 1500 grit ( https://www.chatometry.com/case-studies/raw-veneer-vs-fine-sanded/ ).
It's easy for me but like anything, a learned skill. In much of my carving work I could be called a cheater, I don't try for perfectly flat/smooth, I leave the tool marks and facets as part of the finish. But I can get much the same effect on flatwork with a plane or scraper.

Sharpening the tools... in a word, surgical. Risking further Wrath of Phinds, yes, sharp is the top three of five requirements. I have quite a bit of money invested in assorted water stones and oil stones which top out somewhere around 10,000 grit. If I can't read the newspaper in the reflection of my plane blades, they aren't properly polished and won't cut shavings thin enough for me to read the newspaper through.
Absolutely no secondary bevel ever and of course blades must be of high quality steel properly hardened and tempered. My drawknives are over 100 years old, forge welded laminated steel. I don't think you could buy a modern equivalent unless you had it hand made, with old steel.

Not sure what you use but think about a good high quality hand plane, such as a Lie Neilson.
 
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  • #63
Thank you!

It looks like sharpening is an art on its own... I guess it is too challenging for me!

I will see if I can find any "experts" like yourself here in Italy, so that they can help me manufacturing some perfectly planed samples for our chatoyance samples!
 
Thank you!

It looks like sharpening is an art on its own... I guess it is too challenging for me!

I will see if I can find any "experts" like yourself here in Italy, so that they can help me manufacturing some perfectly planed samples for our chatoyance samples!
When your going to the extremes, yes, it's a bit of an art unto itself, but it's not some magic only special people can do. It's really not that hard to learn and get good results pretty fast. In the beginning you can use jigs and fixtures to hold the blades at exact angles and get very good results right away. With experience you learn to do it by hand and on much more than just flat, straight blades but I don't think you need to go there for what you want to do. Good quality steel blade, a set of reasonably good sharpening stones and a bit of understanding, you'll progress by an order of magnitude in no time.
 
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  • #65
Back to the beginning of this thread... Eventually we made some artificial sunlight tests with an old tanning lamp (as per Mark's suggestion).
This is maple, freshly sanded (1500-grit) and after 32hrs exposure - quite a difference!

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The test is ongoing, because results still do not appear stabilized...
Then it would be good to finish the sample and see if the increased chatoyance caused by "tanning" is also carried to the finished surface.

More details here:

Paolo
 
How old would you guess this hand planed only boards are?

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Matching chairs

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Dyes and keys can be very effective to age wood.

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The table is about 12 yrs old, the chairs are made in NH circa 1860s to complete the illusion.
 
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  • #69
I have a piece of quarter sawn oak that has been weathering for a while now. The ray flecks are now visible from 3+ meters when the sun hits it.
Oak will be within our next test batch then! Any othe suggestions? I was thinking about Cherry, Walnut and Padouk.
How old would you guess this hand planed only boards are?
Interesting... I wonder if it would darken further if exposed to direct sunlight.

Paolo
 
One wood that everyone uses its chatoyance to identify, is mahogany. The ribbon figure is what most folks use to differentiate between it and Walnut. I know it doesn't dissappear as it ages but I never thought to check if it gets more pronounced. Interesting thought. I have a piece or 2 around the house. My wife will think I am nuts with my flashlight checking out her furniture. Oh well, she has always suspected it...
 
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  • #71
Well, mine knows it for sure. I check my panga panga floor looking for signs of chatoyance - and I found it on one plank!

Anyway, are you thinking of Entandophragma (Sapele in my case), or Swietenia Macrophylla?

Thanks for the suggestion!
Paolo
 
Oak will be within our next test batch then! Any othe suggestions? I was thinking about Cherry, Walnut and Padouk.

Interesting... I wonder if it would darken further if exposed to direct sunlight.

Paolo
Would think so. Built this about 10 yrs ago from similar local cut and been hanging out of direct sun light since.

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Ok, Swietenia will be then!
Thanks
Paolo
You have to go further up the food chain for genuine mahogany species. If you can find it in Italy, but most likely your search will end up in the UK (history of trade and period furniture). Swietenia mahogani- the ribbon stripe w/ vertical grain or any crotch would blow any s. macrophylla.
 
You have to go further up the food chain for genuine mahogany species. If you can find it in Italy, but most likely your search will end up in the UK (history of trade and period furniture). Swietenia mahogani- the ribbon stripe w/ vertical grain or any crotch would blow any s. macrophylla.
Yep. With true, you don't have to inspect to differentiate from walnut. It will flag you down in passing...
 
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  • #78
both ends of the oak I referred to shot at full overcast outdoor light from 1/2 meter distance
Definitely visible... But it looks like there was some weathering involved too, isn't it?

Would think so. Built this about 10 yrs ago from similar local cut and been hanging out of direct sun light since.
This scares me about some wood species: the risk of having items leaving "shadows" on them after exposure to sunlight, even if not direct. My floor completely darkened, and if I move a piece of furniture I will surely see it. Thumbs down on wood for this...

Swietenia mahogani
Will try, but it's absolutely not common stuff here... Thanks, anyway!

PS after the brexit, if I buy 50€ of goods in the uk I pay 50€ for shipping and another 50€ for import duties... -_-
 
This scares me about some wood species: the risk of having items leaving "shadows" on them after exposure to sunlight, even if not direct. My floor completely darkened, and if I move a piece of furniture I will surely see it. Thumbs down on wood for this...
This does happen especially if your room has southern exposure and if you think little furniture foot prints “scares” you, then this if you have a large area rug (8’ x 10”, 9 x 12’, 10’ x 14’, etc.) in specific room, you will find a nice surprise of color tone difference underneath that area rug if you have wood floors versus wood floors that are exposed directly. This is more obvious on darker stained flooring or dark to medium color tone natural wood (unstained). Your window treatment is your friend.


Will try, but it's absolutely not common stuff here... Thanks, anyway!

PS after the brexit, if I buy 50€ of goods in the uk I pay 50€ for shipping and another 50€ for import duties..
Yes, I know the VAT is a deal killer in Europe especially from purchases overseas. My luthier friend in AU feels the same way- it is really high there. A friend of mine has a connection in the UK (woodworker with really old genuine Swietenia mahogani)- if you are interested I can have him forward me his info. By the way, Cuban mahogany are available here in the US- Florida is a state that has them. I was able to buy some nice 16/4 from an arborist there. Believe it or not Cuban Mahogany was planted by settlers, so The Big Island of Hawaii is where you can get them. I could have both huge 8/4 slabs in the 15” wide plus range, but they are way too heavy for guitar bodies. Good for reproduction shielded back like a Hepplewhite or Chippendale style as the tensile strength is better than swietenia macrophylla.
 
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