Aging finish with UV flashlight

[eclecticsynergy]

I have a white Burny LP Custom from the 80s. Color has darkened to a nice shade of ivory - except where the pickguard shaded it.
Underneath the pickguard it's still pretty bright white, and I mostly prefer the look of Customs without a pickguard.

I know UV light can age finishes, but it's not worth buying a pro UV setup just for this.
Thinking maybe a big UV flashlight instead; cheap and it doesn't require eye protection.
They don't rate these things in Watts or lumens though, and their LEDs produce UV-B light.

Anybody know if UV-B would do the trick, and whether a handheld flashlight might be powerful enough?
Or do I need something like a sun lamp or decon light that puts out UV-A too?

 

[blakejcan]

that does not seem practical at all

 

[eclecticsynergy]

I figured on making a cardboard stencil to shade the rest of the top, and treating it one hour at a time to darken the pale spot gradually.
I don't need it to match perfectly, just enough that it doesn't stand out like a sore thumb.

But I guess maybe a different pickguard would be simpler. Black pickguard on a white guitar is pretty stark.

 

[Mincer]

I am not an expert on finishes, but I am not sure this would work well. Even if it does darken, getting it so it matches as if they all aged at the same rate would be next to impossible. Either get used to a pickguard, or think about respraying the whole thing.

 

[NegativeEase]

Degradation of a finish via UV exposure is not from unilateral light conditions -its a mix of direct, ambient, and spectrum changes through absorption in the atmosphere etc etc -all kinds of factors, I don't think this would ever look right -plus -how would you avoid a strange box line or overlap from your 2 different eras and where you chose to mate the stencil to the other area.

In a sense you would be attempting to us old photo development dodging techniques to accomplish this over a much much slower period of time

Man, kudos to you, if you can even make it look passible from a distance.

Sounds really difficult.

 

[ICTGoober]

Put the guitar in a south facing window, and let the sun do its thing.

 

[eclecticsynergy]

Put the guitar in a south facing window, and let the sun do its thing.

Yah, that's probably the best way to go. The sun's natural transit should help give a soft edge to the shaded area.
And it'd be the same natural aging as the guitar's received over the decades so far.
If this turns less than great, it'll be no more mismatched than it is now - I could always leave the pickguard over it.

 

[dave74]

I bet the real sunlight would work better. Cover it all but that little area and tan her hide!

 

[dave74]

Or you could just use some stickers on that Gibby. Guessing you will veto that one. lol

 

[Tubes]

Sunlight works. I'm currently sun tanning/aging some light colored white limba korina to try to add some years to the color. The biggest problem with using sunlight is dealing with outdoor humidity/weather so it's really dependent on time of year and where you are. You can try to do it through a window but modern window glass blocks UVB and much of the UVA as well so you might be waiting a while.

 

[uOpt]

Well if you find a light source that ages quickly enough, how do you keep it away from the already darkened parts? They would get even darker.

I don't think you can even out things to a good look even if you find an aging light source.

 

[ICTGoober]

Savvy woodworkers and luthiers learned how to test the color fastness of stains by taping samples of stained woods to southern windows for certain lengths of time. I did one years ago, with red stain on maple. I tested a couple red stains, which were then cleared with different topcoats - this was all on the same board divided into squares with marker, and then small areas covered with tape to determine the amount of fade from the original. Worked great - it was easy to see what the results were.

 

[NegativeEase]

I thought on this more...

I think the best approach would be to build a stencil with a hole cut out of the area to age -made of semi opaque paper that allows some UV through to the already aged area. next, raise the stencil off the surface of the pickguard an inch or two and face the guitar into the sun daily. In the this way the movement of the sun's arc across the sky daily will naturally blend the two areas based on the rays getting some direct sun and not in the "blend area" daily and let the new area "catch up" without a dramatic line between the 2 areas.

Make sense?

 

[Tubes]

I thought on this more...

I think the best approach would be to build a stencil with a hole cut out of the area to age -made of semi opaque paper that allows some UV through to the already aged area. next, raise the stencil off the surface of the pickguard an inch or two and face the guitar into the sun daily. In the this way the movement of the sun's arc across the sky daily will naturally blend the two areas based on the rays getting some direct sun and not in the "blend area" daily and let the new area "catch up" without a dramatic line between the 2 areas.

Make sense?

Might work and probably won't hurt so worth a shot right?

If it were me I'd probably just leave it and let it slowly catch up/blend over time or leave a pickguard on it.

 

[NegativeEase]

Might work and probably won't hurt so worth a shot right?

If it were me I'd probably just leave it and let it slowly catch up/blend over time or leave a pickguard on it.

Yeah, my only concern is you might end up with a flaky too yellowed guitar if it takes too much UV to catch it up..

I guess it's a minor risk.

 

[Tubes]

Yeah, my only concern is you might end up with a flaky too yellowed guitar if it takes too much UV to catch it up..

I guess it's a minor risk.

That's why I'd leave it alone. "One does not simply 'catch up' on 40 years of natural aging" (insert lord of the rings meme picture)

There's no guarantee that directing extra light in an accelerated way will result in the same color/hue/tint that 40 years of normal conditions caused. It might yellow more, or less, or darker... who knows?

Also... this thread would be much better with pictures.

 

[alex1fly]

Seems like a good candidate for a re-finish. I mean if you're going to take months/years to artificially age one spot with UV, refinishing will be a cakewalk in comparison lol

 

[d1dsj]

I’d leave well alone, just leave the guard off and show the world that it once had a guard but now it’s naked. It will dull down and fade a bit over time. It’ll just add to the vintage vibe.

 

[eclecticsynergy]

I thought on this more...

I think the best approach would be to build a stencil with a hole cut out of the area to age -made of semi opaque paper that allows some UV through to the already aged area. next, raise the stencil off the surface of the pickguard an inch or two and face the guitar into the sun daily. In the this way the movement of the sun's arc across the sky daily will naturally blend the two areas based on the rays getting some direct sun and not in the "blend area" daily and let the new area "catch up" without a dramatic line between the 2 areas.

Make sense?

Stencil is my best option at this point I think. If I decide to follow through with the experiment.
I was counting on the sun's transit to give a soft edge to the shaded portions.

 

[eclecticsynergy]

Savvy woodworkers and luthiers learned how to test the color fastness of stains by taping samples of stained woods to southern windows for certain lengths of time. I did one years ago, with red stain on maple. I tested a couple red stains, which were then cleared with different topcoats - this was all on the same board divided into squares with marker, and then small areas covered with tape to determine the amount of fade from the original. Worked great - it was easy to see what the results were.

Good to know that enough UVA penetrates window glass to produce some effect.
That had been a concern of mine and outdoor exposure isn't really an option in the city.