Age-darkening a natural cherry finish

[Jules Dominguez]

I just completed a small cherry project - two tabletop bookstands - and applied Watco Danish Oil Finish - Natural.
After letting them sit overnight, I applied a secoond coat to one of the stands, rubbing it in with 320 grit wet/dry sandpaper. Wiped it dry, let it sit for a couple of hours, then decided to try putting it out in the Georgia sunshine to see if that would speed the darkening as some Creekers have attested.
After it had been in direct sunlight for about a couple of hours, I went to move it under cover for the night. Oil had oozed back out on some areas of the face surface, and dried hard. Not just dots of oil at pore openings, but whole areas of the face. It wouldn't rub off, so I applied more oil and let it sit for 30 minutes, but it didn't re-dissolve, so I ultimately had to sand it off. Not a big deal, since the oil was the only finish, but a nuisance. Next time, I'll give it plenty of curing time before I expose it to the sun's heat.

On a related subject, I've heard that oxidation causes cherry to darken, and also that the ultraviolet rays of the sun are the cause. I have some other cherry projects that are from two years to ten or more years old, that have never been exposed to direct sunshine, and yet they've darkened very nicely. This leads me to believe that oxidation is at least a major factor in the darkening, and makes me wonder if ultraviolet has any direct effect or merely speeds oxidation by raising the temperature of the wood. Can anyone shed any more light on the subject of darkening?

[Bob Wilkerson]

FWIW I put cherry in the sun prior to adding any finish...

Bob

[Dave Wright #2]

I'm not sure what specific reaction makes Cherry darken, but in my projects it's been a combination of finish material and sun exposure. As mentioned before, if you want to use the sun to darken then do it between final finish prep and when you actually put on the first finish coat.

More sun exposure even after finishing will cause some darkening, but the biggest difference that I've seen is with different finishes. The least darkening happens beneath film forming finishes like shellac and polyurethane. Cherry darkens moderately below tung oil based finishes. The darkest is linseed oil finishes. I finished a quilt frame with the Sam Maloof linseed oil/poly/wax finishes a few years ago, and it has gotten shockingly dark. You might mistake it for Walnut except the color is different. My wife wants me to sand it bare and refinish with shellac but I have too much in the hopper to be reworking old projects right now.

Last December I made a couple bookcases for my parents. They wanted Cherry with a somewhat aged look. I used Tried & True. It looked to be well on its way to an aged look right off the bat. I'll be interested to see how the cases look as I visit in the next couple years. People talk about using various chemical aging tricks, but IMO just going with Linseed oil based finishes is enough to get the look.

[Bill Arnold]

I just completed a small cherry project - two tabletop bookstands - and applied Watco Danish Oil Finish - Natural.
After letting them sit overnight, I applied a secoond coat to one of the stands, rubbing it in with 320 grit wet/dry sandpaper. Wiped it dry, let it sit for a couple of hours, then decided to try putting it out in the Georgia sunshine to see if that would speed the darkening as some Creekers have attested.
After it had been in direct sunlight for about a couple of hours, I went to move it under cover for the night. Oil had oozed back out on some areas of the face surface, and dried hard. Not just dots of oil at pore openings, but whole areas of the face. It wouldn't rub off, so I applied more oil and let it sit for 30 minutes, but it didn't re-dissolve, so I ultimately had to sand it off. Not a big deal, since the oil was the only finish, but a nuisance. Next time, I'll give it plenty of curing time before I expose it to the sun's heat. ...

Jules,
I place cherry projects in the Sun to start the finishing process also. My usual procedure is to apply a coat of 1/1 BLO/Naptha while the pieces are in the Sun; this warms the wood and the oil making it soak in better. I wipe on a generous amount and keep wiping periodically as the oil oozes out. By the end of the day the oozing has stabilized and I'm starting to get a nice appearance. Depending on appearance I might repeat the process the next day with a coat of 1/1/1 BLO/Naptha/Poly; again, I rub it occasionally to keep the surface consistent.

Unless you place an item in a pitch dark room, there will be some level of ultraviolet rays present. There is no better finish than time for a wood as beautiful as cherry. Patience is definitely a virtue!

Regards,

[Jim Becker]

Jeff Jewitt has detailed use of chemicals to "instantly oxidize" wood such as cherry. But I generally just use the sun myself on small projects like that. You could also use a dye, but you will be affecting the natural color of the wood.

[Carl Eyman]

A few years ago I was making a cherry piece and working on it just outside my shop; in the shade. I left my card scraper on the piece and went on to other work. By the time I got back the sun had moved and was shining on the piece. When I removed the scraper the whole top was "two shades" darker than where the scraper had been.

[Jules Dominguez]

Thanks, guys, good advice.
Wow, Carl, I wouldn't have thought the reaction would be that fast.
Bill, I'm so absent-minded if I tried to apply finish in the sun I'd probably get started and then get sidetracked to another chore and end up with a MESS.
I agree, Jim, I don't like to apply any colorant to cherry.
I'll definitely do the sunshine trick before I apply any oil in the future. Thanks again, all.

[Jim Becker]

I apply the oil first and then expose to sun, Jules. The oil is to bring out the figure. The sun is to start the darkening process via oxidation and UV.

[Donnie Raines]

You need to be carefeul about the qty of sun the wood is exposed to(though I agree the sun is one of the best ingredients in darkening cherry). If the boards are left out to long they can dry out on the surface and cup toward that side and or check. Maybe not right away...and frankly maybe not at all. But that is why you do not want boards to be directly exposed to sunlight when they are drying out...they can dry to fast on the surface.

I useually apply BLO and then let it sit for about 1 hour. Allow the oil to cure and shoot a firlm finish over top....then nature does it thing.

I have also used potassium dicromite to age the cherry(and mahogany). It works wonders but is pungent to the touch and smell and should be used with extrem caution.

[Raphael Weil]

Pretty old thread to bump, but it covers a topic I'm very interested in. I currently finish my cherry with shellac. I'd love to have it darken (get pinker) before doing so. Is 1 hour in the sun going to cut it? 1 hour per side? I'll do a test piece once the snow is all gone here, and I'd contemplate getting a UV light in the winter!

[Jerry Thompson]

My wife and I have built many project from cherry, e.g., doll cradles, 9 1840 Shaker Clocks and some small jewelry boxes. We used polymerized tung oil on all of these. I usually put them in the sun for a couple of hours then apply the oil.
One doll cradle has been inside for 20+ years and is such a beautiful color I could not describe it.
All of the other pieces we have seen have aged nicely but are not as old as the cradle.
I think time has a lot of play in the color change. it could be that some varnishes could reduce oxidation but that is for a person that has more knowledge about that than me.

[Stan Calow]

I think a tanning bed would work too, without the heat and drying effect of sunshine. Just a thought, in case you know someone that has access to one.

[Raphael Weil]

I certainly noticed today that the Spring sun here for 2 hours probably had far less effect than the high noon sun in some of the hot places you guys might live. Here in Canada the sun in March is pretty far off still. If I allowed for more airflow around the board, is there less chance of one side drying out/cupping or cracking? I assumed the best way to tan my wood (lol) was to allow for some good air flow on the side I don't care too much about. Similar to how I store my wood now.

[Bill McNiel]

Stan - there is a really nice, and well informed, gentleman (http://www.solacure.com/) who makes UV Light fixtures. On one commission where I needed to match existing cherry I did a Cost/Benefit Analysis between buying a Solarcure fixture vs using a commercial tanning bed with the tanning bed winning for single use, but if presented with a larger need to "age" cherry I would go the other way.

Raphael- given your apparent latitude, I don't think you will see any real darkening unless you sun tan the material for many hours/days. I support the material for full air flow and flip the pieces every hour or so to even the tanning/drying process and have found this approach effectively lessens cupping or warping.

I recommend using Charles Neil's Blotch Control as a first step in finishing cherry.