Wood Fading/Darkening In Sunlight/UV

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custard

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This cropped up in another thread and I thought it might be of wider interest. Some while ago I ran some tests on the effectiveness of various UV barrier finishes. I won't go into that except to say that even though some finishes hold promise none really provides a silver bullet solution for furniture makers.

Fade-Test-2-Months.jpg


More significant is the huge effect sunlight has on timber. I'm not talking about external woodwork, ultimately all woods just go silvery grey when left outside. But indoors is a different story, some darken, some fade, some change colour significantly.

From the top left and working clockwise these are Oak, English Rippled Sycamore, American Black Walnut, and American Cherry. The right hand side of each sample was treated with a UV inhibiting finish, the bottom half was shielded from the light, the top half had two months in a south facing window. I've got other photos with different woods, different finishes, and different time periods. But they all demonstrate that the furniture that leaves your workshop may look radically different in a fairly short space of time, especially if it's placed in a south facing room.

Probably the worst timber in a bright room is steamed American Black Walnut (and the vast majority of ABW sold in this country is steamed). In direct sunlight it just fades to a nondescript muddy brown. Unsteamed Black Walnut and English Walnut also fade, but they retain more vitality and subtle colour differences in the grain.

Probably the best timbers for a bright room are American Cherry, Mahogany, and most of the fruitwoods. They darken rather than fade, lose any blotchiness, and generally patinate very quickly and attractively. Oak and Sweet Chestnut are fairly stable in colour terms. Holly holds up better in terms of whiteness retention than Sycamore, which after a year or so can end up turning almost orange. The problem there is really good quality Holly is becoming very hard to find.

It's sobering because the combination of ABW and Sycamore has been a basic staple of furniture making for a good few years now. They deliver a dramatic combination fresh from the workshop, but I wonder how many once magnificent pieces are now looking really flat? Maybe the trend towards bigger windows and bi-fold doors means we should rethink timber choices?

Another point to consider is how you store your timbers whilst making furniture. If your workshop has bright, natural light and workpieces are left overlapping they could quickly get "bikini lines". I now usually chuck a blanket over dimensioned components to shield them from the sun in the workshop.

Just some thoughts.
 

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Really interesting, thanks custard! Which finish was used in these examples?

Curious that the bottom half of the walnut that was shielded looks quite ebonised in both sides?
 
I don't make stuff of the calibre required for this to be a problem, but that's a fantastic experiment and it's really interesting to see those results.

I'm positive this will be of interest to a heck of a lot of furniture makers out there.

Also, a good advert for dissuading the use of a table-runner to a potential customer.
 
MattRoberts":32ng2du0 said:
Really interesting, thanks custard! Which finish was used in these examples?

Curious that the bottom half of the walnut that was shielded looks quite ebonised in both sides?

I'd have to check my notes but I think that might have been Epifanes Extra UV Filter, I tried quite a few. What I discovered about the yachting products generally is that they're designed to be refreshed every year or two, and the UV filter chemistry they use actually breaks down in sunlight faster than some other products, even though it provides more protection initially. There are some spray only finishes that are a bit better for interior domestic use, but they're still far from perfect. I sometimes use the Osmo UV product, but what benefit is that really bringing? It might stay fresh for maybe an extra five, six, or seven years (I never ran the tests that long), but I want my furniture to look great in 200 years, and I doubt steamed ABW will ever meet that standard. The only enduring solution I think is in matching timbers to household location...or returning to the Victorian attitude of big thick curtains to block out all that horrible sunshine!

Regarding the carp photos, I have better ones but that's just an old phone snap. In reality the ABW was a prize example, dark and lustrous, shot through with the purple tones that makes it such an appealing timber...pity it just doesn't age very well!
 
I thought about giving up turning in favour of pottery for this reason.
The love of the material and the joy of making blinds us to the demise of our creations.
I'll add some sun tan lotion to my sanding sealer and pray.

Bob
 
NazNomad":1ed6yk5f said:
I don't make stuff of the calibre required for this to be a problem

You're being modest Naz, I was inspired by your Puffin Whirligig to get some books from the library on making them. One said that whirligigs were traditionally only put out on Sundays to protect the finish from fading in the elements!
 
Some food for thought in this thread.I have known mahogany type timbers change colour very quickly,a claw hammer left on a board for a little over an hour left a pale shaped patch.I wonder whether the 2 part yacht varnish would give longer lasting protection,its pretty noxious stuff and one would hope that the stratospheric price buys a lot of protection.
 
very interesting thread custard, it's amazing how much walnut changes, that is the most surprising thing, on my calibrated screen/monitor it looks blue...
 
Interesting thread.

My workshop is pretty dark (dingy garage) and I have some air dried English Cherry that I picked up rough sawn. Planed it all flat and it is very pink!

Wonder if I should bring it in the house so it gets some light for a while?

Dave
 
English Cherry deserves to be better known. In times past it suffered because of its reputation as a woodworm magnet, but with centrally heated houses that's a non issue. It also tends to get overlooked because fresh from the workshop it looks a bit bland, but give it time and those delicate pink and pale green streaks start to develop and mature into something really interesting. On day one American Cherry trumps it for looks, after twenty or thirty years the vote may well go the other way.

This was a table and mirror I made in English Cherry, it has some subtle shaping (the sides and drawer front are fractionally curved to follow the line of the legs, and the bottoms of the drawer and apron rails have barely perceptible curves) so I didn't want a flashy timber that would overpower the design. English Cherry fitted the bill nicely.

Hall-Table-small.jpg


Regarding your boards, wait until you've made a finished item, then make sure it gets some sun (ho, ho, ho in the UK). Exposing it too sunlight as plain boards is a waste of time as you'll sand or scrape most of the colour away.

Good luck!
 

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Thanks Custard!

That table is really nice, probably a little beyond me at the minute :D

I'm planning on saving it for the right project anyway. Got a bunch of bits and bobs from Goulden Hardwoods a few months back and it's stickered in my garage, walnut, sycamore, cherry etc.

Might be paranoid about woodworm now :D
 
custard":1qmmi8w2 said:
English Cherry deserves to be better known. In times past it suffered because of its reputation as a woodworm magnet, but with centrally heated houses that's a non issue. It also tends to get overlooked because fresh from the workshop it looks a bit bland, but give it time and those delicate pink and pale green streaks start to develop and mature into something really interesting. On day one American Cherry trumps it for looks, after twenty or thirty years the vote may well go the other way.

This was a table and mirror I made in English Cherry, it has some subtle shaping (the sides and drawer front are fractionally curved to follow the line of the legs, and the bottoms of the drawer and apron rails have barely perceptible curves) so I didn't want a flashy timber that would overpower the design. English Cherry fitted the bill nicely.



Regarding your boards, wait until you've made a finished item, then make sure it gets some sun (ho, ho, ho in the UK). Exposing it too sunlight as plain boards is a waste of time as you'll sand or scrape most of the colour away.

Good luck!

Is there any way of speeding the process up- take the item to a tanning studio etc?
 
I made a maple sideboard for my conservatory a while back, lovely white wood, bright glow in the dark yellow after 3 months, looked horrible.
 
My father did a lot of marquetry work and refinished some of his early work with rustins plastic coating after a good clean up.
The transformation of 30 and 40 year old pieces was dramatic.
 
Sometimes the effect of sunlight is welcome.
Yesterday I milled up a load of poplar for some wainscotting. Some of it has those green streaks. Normally I wouldn't mind the green I sort of like it if it is used nicely, but this just spoiled the look of the assembly. So it is currently sitting outside in the sunshine. I expect it to be gone by nightfall (the green that is, not the wood - it's not that dodgy, even here).
 
Steve Maskery":35v95n56 said:
Sometimes the effect of sunlight is welcome.
Yesterday I milled up a load of poplar for some wainscotting. Some of it has those green streaks. Normally I wouldn't mind the green I sort of like it if it is used nicely, but this just spoiled the look of the assembly. So it is currently sitting outside in the sunshine. I expect it to be gone by nightfall (the green that is, not the wood - it's not that dodgy, even here).

+1

You might be lucky to lose the green after just one September day of sunshine, but Poplar will turn eventually.

Poplar-Sunlight.jpg


This is a cabinet where the back has been boarded out with Poplar, this has been sitting in the workshop for about four weeks, leaning against it is a Poplar board from exactly the same batch which has been out of the light.
 

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MatthewRedStars":2mmcsbkm said:
How deep does the colour change go? Just curious....

Deeper than dye stain, not as deep as fuming, given time it can go as deep as about half a mill.
 
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