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Hi all - could anyone recommend me a quality UV protection coating for light-sensitive woods (such as redheart, purpleheart, etc)? I tried using the UV protect coating you can get at home depot (for outdoor wood), but my project faded to brown in the sun in a couple days. I had to re-sand it down (gah).

What should I use for super sensitive wood types?

Thanks!
 

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Whatever is used as a clear UV protective coating will be active until its UV inhibitors absorb to the point of becoming inactive. The more pigment a coating has increases its reflective capabilities. Paint would be the best protective coating.


for a clear or translucent coating I would use Penofin Red Label.











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I think the best thing you can do is use a product called Sun Block made by Kwick Kleen. It's kind of like a person using sun screen only it's formulated for wood. Here is the link if you would like to read more about it. http://www.kwickkleen.com/product_info.php/sun-block-p-505 . This product can be used under an oil finish or a film finish. I think a film finish would add to the uv protection however it's a lot more work to take it off if you are frequently refinishing because of the color.
 

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To be honest, I'm thinking you won't be entirely successful with anything. The color change is more than just UV (although that is a lot of it). I do have another recommendation for you to consider: untinted exterior oil base paint. It's likely to be a little cheaper then some of the more exotic stuff, and it does work very well. I've not used it on woods such as purpleheart (although I may try), but I can tell you one more mundane wood like cedar I've had it keep it's color for up to 5-6 years (tossed the piece after that). Anyway, just something to consider...I'd bet you could get a quart of SW #4 oil base for $15 or so. (the only one I've used is the Olympic product).
https://www.hardwoodlumberandmore.com/eStore/tabid/127/rvdsfcatid/79/Default.aspx
 

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This may sound nuts but.... I had a block of redheart I used to make a mallet. It, like purpleheart, was changing color on me almost immediately. I put Thompson's Water Seal clear protector on the redheart. And the redheart is still red after a couple of months.
 

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There are many UV sensitive woods. Some will lighten with UV exposure such as Cedar, Purpleheart, Maple, Yellow/Red Oak, American Walnut, and Redheart.

Others will darken with UV exposure. These include: Cherry, Teak, Brazilian Walnut, Tigerwood

For projects involving UV sensitive woods that lighten I usually apply a UV absorbing stain of the same color as the wood. For example, if the project is made of Purpleheart I apply a Merlot stain. While this process Does Not Prevent fading, it does retard it.

Similarly I apply stain to woods that darken such as Cherry where I apply a Traditional Cherry Stain that also has UV protectorates in it

If I cannot find a stain with UV protectorates, I will add it to the stain. One such product is UV Boost that is added to water-based stains. For oil-based stains I look toward exterior topcoats such as Cabot's Clear Wood Protector. The reason for the exterior finisher is that they contain more of the protectorates than interior stains and topcoats.

Phil Rasmussen
The Mountain Woodworker
Hendersonville, NC
www.mountainwoodworker.com
 

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Don't forget that air is 21% oxygen. And, that oxygen is a very effective bleach for biological (aka wood) molecules. You can slow it down but you can't hide from it.
Western Red Cedar (Thuja plicata) is the most amazing pink when fresh split. Go back to my carving shop the next day = all pale brown and that was not UV damage.
In fact, as peroxide, oxygen is the common bleach used in the pulp and paper industry. Brown paper bags vs computer printing papers.

UV is an issue from fluorescent lighting, more as a leak but recognized as a threat in museums of paintings.
Of course, the UV intensity outdoors is hard on any finish that absorbs any light at all, including sunburn.

Likely the most effective outdoor UV barrier finish, and likely the most expensive, is Sikkens Cetol. I don't like it much as it's a very distinctive pale orange color.
I guess if you just threw $10,000,000 at Pioneer to build you a log home, the Sikkens Cetol finish looks like all the other log homes!
 

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Don't forget that air is 21% oxygen. And, that oxygen is a very effective bleach for biological (aka wood) molecules. You can slow it down but you can't hide from it.
Western Red Cedar (Thuja plicata) is the most amazing pink when fresh split. Go back to my carving shop the next day = all pale brown and that was not UV damage.
In fact, as peroxide, oxygen is the common bleach used in the pulp and paper industry. Brown paper bags vs computer printing papers.

UV is an issue from fluorescent lighting, more as a leak but recognized as a threat in museums of paintings.
Of course, the UV intensity outdoors is hard on any finish that absorbs any light at all, including sunburn.

Likely the most effective outdoor UV barrier finish, and likely the most expensive, is Sikkens Cetol. I don't like it much as it's a very distinctive pale orange color.
I guess if you just threw $10,000,000 at Pioneer to build you a log home, the Sikkens Cetol finish looks like all the other log homes!
I learned about how effective fluorescent lights are, I had sanded some cherry doors and had them leaning on the moulding machine it was a couple weeks and when I was going to squirt shellac on them you could see a perfect line where the shorter doors were leaning on the taller doors
 

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The UV protection in many finishes is there to protect the finish, not the wood. Trying to prevent wood from changing is hopeless, even dyes will change with time. Some woods get nicer color with time: Cherry, purple heart, some not so much, walnut turns very yellow. I prefer to simply live with it, no stain, dye, beach etc.
 

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That's the truth, Larry. Just let it go.
Unless I'm missing some, I have 10 wood carvings out in the weather, 12 months of the year.
Two of them are aspen/poplar and the rest are western red cedar. They are all cracking and bleaching
gray like totem poles. So be it. If anything, the aging process is interesting to watch, maybe 5 years now?
 
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