UV protecting finish

[Jim Boyd]

Hi! First post here and it is a question. How long does it take osage to turn from yellow to brown if left in direct sun light? I am running an experiment with a finish to slow down the process and was wondering how long before I know if it is a flop or not[] So far one pen has been 6 hours with no change and a second was just added. Like a dummy I did not make a control pen to compare to[V]

 

[Rifleman1776]

The time is weeks to months to years depending on the wood. Direct sun full time, months for notable change.

 

[Old Griz]

Jim, I used to be a bowyer and built my fair share of osage self bows... basically just sanded smooth with a little oil as a sealer finish.... it would take a year or more before I saw any appreciable change in color and even then it was no too dark... one bow I still have is 5 yrs old and has developed a nice brownish orange patina...
Osage will change, but not quickly and the change will be subtle over time...

 

[Rifleman1776]

Griz, his question asked about left in direct sun. An item only occasionally outside then stored in doors would react a lot differently. I have a shelf that I put about a dozen small vases turned from osage orange on. It sets next to a pair of doors that receive afternoon sun. One vase, most directly in the light began changing after just a couple weeks. Now several months after being turned is very dark brown. Others, less than a foot away but more shaded have lost their bright yellow color but are still not dark. I do have to wonder, though, what and why he would leave something in direct sunlight except as a test control.

 

[Old Griz]

Frank the average long bow probably spends more time open to the sun than a pen in someone's pocket... I used to take it out every day to shoot and spent most weekends at some tournament or other... I don't know if it was the oil finish that was reapplied after shooting or what, but that particular bow has kept a nice patina... it has darkened as I said, but not spectacularly like you are describing your vase...
But then again each piece of wood reacts differently...
BTW.. do you have a good source of osage.... I may be needed about 20 pieces or more 3/4"x2.5".. my wife has an idea for key chains...

 

[Jim Boyd]

A test is the only reason I have them in the sun. Osage is the only wood that I know the has such a drastic change in color. Plus I had a couple of pieces. There is a fair amount of the stuff around locally and I thought it could be an alternative to canary wood or yellow heart.

 

[Rifleman1776]

Originally posted by Jim Boyd
<br />A test is the only reason I have them in the sun. Osage is the only wood that I know the has such a drastic change in color. Plus I had a couple of pieces. There is a fair amount of the stuff around locally and I thought it could be an alternative to canary wood or yellow heart.

Purpleheart change can be dramatic.

 

[Mudder]

BTW Jim.....

Welcome!

Have we met before?

 

[Jim Boyd]

Originally posted by Mudder
<br />BTW Jim.....

Welcome!

Have we met before?

Maybe not in person but there is a Mudder that hangs out in a cultish forum I'm familiar with.[]

 

[coach]

I see you on woodnet. Wherea abouts in Texas you from?

 

[Mudder]

Originally posted by Jim Boyd
<br />

Originally posted by Mudder
<br />BTW Jim.....

Welcome!

Have we met before?

Maybe not in person but there is a Mudder that hangs out in a cultish forum I'm familiar with.[]

Soooo..........

You followed me eh?

 

[Rifleman1776]

OO test results an Oh-Oh! [:0] To settle this question, I figured we needed a controled test. I did a test with a control. The control piece did just fine sitting in a dark drawer for more than two months. The light exposed hunk is what made the results subject to more cussin' and discussin'. Below are three pictures. The first is the exposed blank in an antique vice I have outside my shop. The top flat is facing the west sky and receives direct sun exposure about have of the day. The second picture is the flat that is facing horizontally to the south. The third picture is the control piece next to the exposed south facing flat piece. As you can see the top exposed piece turned cruddy and moldy (beginning of spalting?) and, in my opinion does not tell us much about color change with exposure to light. The west facing flat, that did not receive direct sunlight but did receive (day) light did turn darker. The test began 9/11/05. No doubt light does change the color of osage orange. To what degree? Make your own conclusions.

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[rtparso]

Well this is a revived topic. I must have missed it the first time. Mullberry changes in a day full color in about a week in full sun.

 

[Randy_]

Originally posted by Old Griz
<br />...basically just sanded smooth with a little oil as a sealer finish.... it would take a year or more before I saw any appreciable change in color and even then it was no too dark...

Tom: I don't know a lot about wood finishes; but it is my impression that a lot of them have UV inhibitors. I wonder if your "oil" was so compounded??

 

[RussFairfield]

An opinion that is based on observation, and has nothing to do with fact, fiction, or scientific analysis.

The durability of the finish is more important than its UV resistance. The wood will turn darker faster from grime and body oils, acids, and moisture than it will from exposure to sunlight.

There is a direct link betweem how long it takes for the finish to wear off and how long it takes for the wood to darken.