In case anyone cares...

I took 4 strips of cherry cut from the same board; on each strip left
1/3 unfinished, put wb poly on 1/3, and put oil-based poly on 1/3; then
put one strip in sunshine, one strip under incandescent, one strip
under fluorescent, and one strip in dark. After about 4 weeks looked
at darkening to see if poly inhibited darkening.

All portions darkened on the sunlight strip and on the artificial light
strips; however, the oil-based poly darkened the least (hard to
quantify, probably about 1/3 less darkening roughly) and the oil-based
poly clearly had a more yellow tone than the other sections. The strip
in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable darkening
in any of the sections.

Charles

wrote in message
ups.com...
In case anyone cares...

I took 4 strips of cherry cut from the same board; on each strip left
1/3 unfinished, put wb poly on 1/3, and put oil-based poly on 1/3; then
put one strip in sunshine, one strip under incandescent, one strip
under fluorescent, and one strip in dark. After about 4 weeks looked
at darkening to see if poly inhibited darkening.

All portions darkened on the sunlight strip and on the artificial light
strips; however, the oil-based poly darkened the least (hard to
quantify, probably about 1/3 less darkening roughly) and the oil-based
poly clearly had a more yellow tone than the other sections. The strip
in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable darkening
in any of the sections.

Charles

It would be interesting to see what the difference is long term. I hope you
dated and photographed them and repeat this post next year.

in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable darkening
in any of the sections.

I hope you were careful to use a window that didn't block UV...

I wondered about how much UV my windows blocked (assuming UV is what
matters).


toller wrote:
in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable
darkening
in any of the sections.

I hope you were careful to use a window that didn't block UV...

If your windows are newer and coated with silver (LoE or LoE2) they block
most of the UV rays. keep us posted!--dave
wrote in message
oups.com...
I wondered about how much UV my windows blocked (assuming UV is what
matters).


toller wrote:
in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable
darkening
in any of the sections.

I hope you were careful to use a window that didn't block UV...