How would you reckon uv rays impact a natural finish

[billyfamilyvide]

Mahogany, in particular?

[Wade Hampton]

Well, the finish is on top of the wood, naturally, and how the finish gets affected by exposure to ultraviolet light depends on what sort of finish it is. Nitrocellulose lacquer finishes yellow and darken with UV exposure; polyester-based finishes like what's on Taylors generally do not.

However the wood underneath the finish can and will change. Spruce darkens considerably. Koa darkens some, as well. Honduran mahogany with no stain or pigment on it will darken a little bit, but not as dramatically as spruce.

Rosewood and other dark woods, on the other hand, tend to lighten with exposure to UV light. I once owned a 1970's-vintage Mossman that must have hung on a wall for thirty years; the wood of the back (which presumably rested against the wall) was still very dark, but the sides had bleached out to more of a medium brick red than the purplish color of the back.

So a lot depends on the wood itself.

Hope that makes sense.


Wade Hampton Miller

[billyfamilyvide]

Thanks for the info wade. Appreciate it.

I do want to calrify that when I say natural- I mean the finish (like an open pore type) not the color of the stain.

[J Patrick]

...in my experience genuine Honduran Mahogany can darken quite dramatically....important to note that there is quite a range in its natural color though and i have found some examples to darken more quickly and and to a greater degree than others....

[billyfamilyvide]

My friends Honduran is turning purple. This is what prompted my curiosity.

[Tico]

I play it on the safe side with both my body's skin and my guitars'.
I do not accept gigs in the sun.

If they want Tico's incomparable musical mircacles they must rent a canopy.
If not, they have to compromise and settle for some lower-level guitarist.

[Greg Ballantyne]

Time has an effect - and I'm sure UV along with other light wavelengths are involved. In my experience this is more noticeable with lighter wood, usually guitar tops. A lot of spruce tops get darker with age. I've had guitars for a lot of years, but I can't say I've had meaningful observations of body wood types changing over time as much as tops.