distressing and accelerated aging study

**GTison** · Mar-07-2006, 12:40pm

I googled "accelerated aging photochemical and thermal aspects wood" (a study by Robert Fellar.)
and got a fine paper (pdf) on the subject of aging. Not all of it applys to wood I don't think but read the table of contents and you may find some items of interest. My questioins were: would UV light affect a mandolin, and what if any chemical could affect the wood? seems there may be some info here.

**Tom C** · Mar-07-2006, 1:00pm

I do not think it would have any effect on anything not living. If it's living, it will die.

**G_Smolt** · Mar-07-2006, 2:37pm

UV would definitely accelerate the ageing process, giving it a yellowed or paled look, but it would *most likely* also weaken the structure of the wood somewhat. I guess it depends on thickness.

Dihydrogen Oxide is a pretty nifty chemical for wood ageing...relatively safe to handle, fairly inexpensive in bulk form, mostly odorless and colorless

Just put it out in the backyard, let it get some sun and rain, and wood will look old in no time.

**tremolo jones** · Mar-07-2006, 4:01pm

UV can affect certain dyes and pigments. In the last 20 years, most inorganic dyes and pigments have been replaced with organic versions. This eliminated the use of heavy metals like cadmium and chromium, and it is why the modern yellow and blue VWs are not as pretty as the beetles of my youth. I digress - some of these modern coloring agents can degrade fairly quickly in UV, so it depends on what the maker used as to whether or not color will change.

I would guess that UV would affect the finish, both lacquer and varish. UV tends to promote organic chemical reactions, meaning it will push them toward completion and cure. Exactly how this may affect sound, appearance, smell, and feel, (taste???) I am not certain. I would guess that it would promote "oldness" in an instrument.

I am not sure of the effect of UV on wood, perhaps there is a forestry major on the cafe that can enlighten us. It may be that the finish would consume the energy of the UV, absorb it if you will, so that the wood is not affected. Interesting question.

After reading the various posts on this topic, the folks at Gibson are onto something that is very interesting and may have some fascinating implications.

**fredfrank** · Mar-07-2006, 4:56pm

Originally Posted by (tremelo jones @ Mar. 07 2006, 17:01)

After reading the various posts on this topic, the folks at Gibson are onto something that is very interesting and may have some fascinating implications.

I'm sure they do, but considering they get a rather healthy markup for this aging or distressing process, they won't be discussing it in detail on this or any other message board.

I suppose we'll have to ruin a few mandolins ourselves to discover the secret.

**chuck.naill** · Mar-07-2006, 8:38pm

I just heard today of a process of spraying the instrument with a product used to freeze electrical components. THis causes the finsih to prematurily check give the instrument an apparent age.

There is a mandolin in the classified that has been played and loved hard. That's the best way to treat a friend.

Chuck

**tree** · Mar-08-2006, 2:45pm

I have to believe that whatever this mysterious distressing process is, it must be relatively simple. #Much like adding Nitrogen to soil accelerates plant growth, this distressing process supposedly accelerates "aging" of the instrument.

Is it misleading to think only of aging the wood, or should we consider the whole picture (assembled wooden components under string tension, glue and finish)?

What actually happens to wooden instruments as they age? Is it oxidation, dessication, reaction to UV light (or some other part of the spectrum), some type of physical change related to string tension? #What else?

Maybe the instrument is exposed to a high concentration of O2 under UV light, or a cycle of heating/cooling regimes, or something else entirely. #I still have some nagging skepticism that "aging" can or should be duplicated. But it is fascinating to try to understand.