sun fading of furniture

mikemcgrail

Well-known member
I have an english linen press I made several years ago that has had more exposure to sunlight on one of its doors than the other. The door closer to the window now looks noticeably lighter than its opposite, matching door. The pieces of wood were bookmatched, so it is definitely something the sun/time/exposure has caused. It is finished in shellac totally, I probably used the darker buttonlac. The wood is walnut. I am wondering if the shellac(most probably mosers buttonlac) lightens because of the sunlight, or just the wood? Also, any helpful suggestions on possibly restoring the finish/color would be appreciated. It was a very beautiful piece of lumber and it bothers me that the color is off from side to side. I am certain I used nothing to color it with originally other than the shellac.
Thanks for your time.
Mike
 
I have an old Maine Coon cat. He was a stray my son found and gave to me several years ago. I haven't forgiven my son yet. Anyway, all the cat does is eat, pee, poop, and twice a day change position in his bed in order to weather evenly. Furniture exposed only partially to sunlight also needs to be repositioned in order to weather evenly.

Howard Steier
 
Mike, 
          A simple fix would be to recoat the lighter door with a toner such as Acrylic Modified Lacquer mixed with a toner and misted on lightly. Shellac doesn't spray very well when you are trying to mist on the color. I would probably end up working on both doors to make the finish sheen look the same. If you decide to tone it , don,t brush on any finishes on, use a spray gun or you will end up with colored streaks on the door. Good Luck.
                                                      MIchael Armand,  Lefurnguy
 
Mike-
There are two types of sun fading, the first is when the finish separates from the surface of the wood and leaves a hazy appearance (like putting on a pair of sunglasses). This can be repaired by french polishing with just alcohol to dissolve the finish back into the surface of the wood. and i forgot to mention before starting any repair on any surface, it's important to remove any waxes or other stuff people put on their furnature. I use mineral spirits because if you don't remove all the wax, it'll leave a residue when the spirits dry. After the finish and the color returns simply re-french polish the area. This type of sun fading usually happens on older furniture.
The other type of fading is when the fiber of the wood is sun bleached. This is a little tougher to repair. What i would do is add a small amount of dye to the shellac and tone the faded area out by french polishing. depending on the color of your project, you might have to use multiple colors. If you miss on the color, you can simply pull the color out by rubbing down with alcohol. The other way to treat this problem would be to strip the surface, sand, and start over. because you use shellac in your project (good choice) you have the ability to back up if you miss on the color. If you use any other finishes like lacquer, you'll have only one chance to get the right color. If you miss on the color, you'll have to start over.
I work on high end antiques and seldom allowed to remove original finishes.        I hope this helps.    Randy Bohn          Conserator Wooden Artifacts
 
Thanks Randy, this is what I will try. I think maybe perhaps the shellac might be trying to slighlty separate as you describe. If not, then perhaps a bit of colorant in the french polish solution will help. I do sort of consider it to be some sort of finish "failure", that the sunlight was somehow damaging the shellac. Maybe the damage is the wood/shellac bond- I had not considered that.
It is in a poor place near a window, but is really too big to move around much.
I appreciate all the suggestions.
Thanks.
Mike

 
A side issue. Randy, I would like to hear what you have to say about the relative merits of mineral spirits compared to naptha please.
Thanks
Fran
 
Fran  Good question    For health reasons both should be considered very dangerous. I use both in my shop on a daily basis.I like to use minerail spirits to clean surfaces of wax and other contaminates because it leaves a white residue or haze where wax remains.I use the word [contaminates]because in my 30yrs in this field, I've seen everything from wax to diesel fuel,thinned tar and even a case where a person used SPAM to polish surfaces.On the other hand I use naphtha when a residue is undesirable, like cleaning a lens or a painted surface[carefully].It also works well to see the grain in wood before finishing drying without a residue    Randy
 
Thanks, Randy. I've been using naptha more often than Mineral spirits because I was told it was "cleaner" but I have found it doesn't have the punch mineral spirits has for that layer of 25 year old carnauba or 12 year old jelly. I mostly use it because it goes away fast. Thanks for your thoughts!
Fran
 
'Fading' can also be caused by unstable stains changing colour as they age (hasn't everyone seen that early 20th century mahogany furniture with a greenish hue?). Unfortunately it's the warmer colours (the ones we predominantly use for furniture) that are the least light resistant. What began as a nicely red-brown stained finish can end up a cooler brown or even green.
 
Once the repair is complete, why not have a professional install a UV barrier on the window.  The film is apparently invisible and is supposed to stop most UV light which is what is causing the damage.

Also, I live in Canada and up here Naptha is what we call camp stove fuel, also known as white gas.  Its the liquid we used to put into 1960's camp stove tanks.  We'd then pump air into the tank to build up pressure and the liquid would come out like a vapor which gave you the flame. 

We do have mineral spirits and paint thinner but I have always wondered, what is naptha in the U.S.?  I'm just trying to figure out if we have a similar product up here which perhaps goes by a different name.  For example what you folks call denatured alcohol we call methyl hydrate.
 
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