purple heart's colour

[mike s]

what makes it go from brown to purple and how do i keep it purple?
thanks

 

[Bodrighy]

As far as I have experience I am not sure you can, it fades back to brown eventually in the light

Anyone know of a solution 'd be glad to hear it as well.

Pete

 

[mike s]

shame

 

[Kalimna]

If you pop over to MIMF (a primarily guitar based music forum), this question pops up regularly, and from what I can remember, the best way of preventing (or at least prolonging) the change from purple back to brown is to use a finish that blocks UV light.
It's apparently the UV light that hastens the colour change, and blocking the UV should help to prevent.
Im not sure, however, off the top of my head what finish this might be. Sorry.

Adam

 

[colin macdiarmid]

I've heard that the clear spray that you use for car dashboards etc has the uv protection in it and dependant on your final finish you spray this on and it is supposed to work, but I have never tried it! something like this
http://www.halfords.com/webapp/wcs/stor ... yId_165651

please delete link if I should not have posted ii.

 

[tekno.mage]

To make it go purple, leave it in bright sunlight. To protect the purple colour, use a finish which contains a UV blocking compound (I use Osmo UV protection oil, 3 coats). It's then best to keep the item out of direct sunlight - ie don't leave it on a window sill! I have a couple of purpleheart boxes I made 2 years ago which are still bright purple - these are kept in a bedroom on a dressing table in an alcove which is not subject to direct sunlight from the window.

I have actually found that Padauk loses it's bright red colour to a deeper reddish brown much faster than purpleheart loses it's purple colour - so maybe Padauk is affected by something other than UV light as well?

 

[myturn]

Pink Ivory is the same, it goes brown if left in the sunlight.

Exposure to UV not only changes the way wood looks, when used in a musical instrument for its resonant properties the sound will change too

 

[NikNak]

I was 99% sure the answer was oxidation.... i.e. leaving it exposed to both light and air.

Wasn't 100% convinced, so i googled it, see here....

http://www.hobbithouseinc.com/personal/ ... eheart.htm

Not sure i'd be allowed to try the oven experiment tho.... :shock: #-o

I've made a few small items with it. A little box was snapped up, but a couple of pens i made were looked at in derision... wont do those again


Nick

 

[János]

Hello,

These color changes of wood are caused mostly by the oxidative decay of lignin. No way to prevent it, but it can be slowed down by the application of a coating with good vapor barrier properties, and UV filtering additives. Exterior grade lacquers and varnishes are such things... Ciba and other companies manufacture UV filtering additives, perhaps you would be able to buy some from a merchant of conservation supplies. Mixed with these additives, even shellac can protect wood from fading...

Bye,

János

 

[CHJ]

Terry at Chestnut Finishes tells me that their Acrylic aerosols have UV inhibitors in them to prevent the lacquer yellowing, don't know if they would help.

 

[jumps]

Terry at Chestnut Finishes tells me that their Acrylic aerosols have UV inhibitors in them to prevent the lacquer yellowing, don't know if they would help.

I got the same from Terry, and have a 235mm D x 100mm chunk of purple heart and 2 cans of Acrylic to test it - unfortunately the results won't have a whole lot of meaning for 10 years (or more)

 

[János]

Hello,

As a simple test, you can place your finished and unfinished wood samples under strong UV light. The mercury lamps used by printed circuit makers (and radio amateurs) will shower your wood with ten years of UV radiation in ten minutes. Or take your samples to a tanning salon; solariums emit the same killer UV rays... And you can get tanned to your wood... :wink:

Have a nice day,

János