Purpleheart

Peter Lyon

Member
Messages
330
Location
Puyallup, WA
I just finished up a few Christmas gifts that I made out of purpleheart. Unfortunately, due to all the cutting, sanding, etc. the "purple" has been mostly taken out of the "purpleheart". I realize that left exposed to UV sunlight, it will (supposedly) revert to its once regal color. However, and to the essence of my dilemma, we presently have very little, if any, sunlight and the forecast is not looking promising anytime in the near future. Do you think if I set it under an artificial light source it would speed the process up? If so, do you think it matters what type of light it is (e.g. fluorescent, incandescent, halogen, etc)?
 
not sure of purple heart but in cherry i tried to hurry the process of color taning on a door that i replaced a broken one .. i used a tannin bed for 20 mins and got very little change.. i ended up taking it to work with me and let it get all of the natural uv i could feed it.. i dont thik that artifical light is gonna do it for you and also its the air that does the color change process as well, not just light.
 
Larry's right on it there - UV accelerates the wood's ability to oxidize, which will happen only in the presence of oxygen (as from the air). If it's been finished, particularly with a yellowing finish like polyurethane, it'll change color very slowly henceforth.

If any light will do it, a black light (available from your friendly Borg) is the light that will.
 
Actually, I believe that UV exposure will actually turn the purpleheart to brown. It's lack of UV exposure that lets it keep its color.

Sanding should have enhanced the purple - unless it's sapwood, which is naturally brownish.
 
Jim in my limited experience after sanding or turning it. you can help bring back the color by placing it a window. I have a piece in my truck that has been sitting behind the seat that was turning brown. after putting on the dash it turned back to the purple it was.:dunno:heres a pic of my tool box that is trimed in purplehart and as you can see it has stayed purple for over 4 years. After sanding when i first made it it had turned brown so i put it where the sun shown on it and it has been purple ever since.
 

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Fortunately, I haven't put any finish on it yet. I guess there's nothing else to do but experiment. I'll leave one in the window, put one under incandescent light source, one under Halogen and will look into the cost of a UV bulb. I think I'll also see if the presence of an acid will accelerate the process (hence the reduction part of the oxidation equation).

I'll let folks know if anything works.:dunno:

PS - if I wasn't clear enough before, the stuff was startlingly purple before machining.
 
It's funny what a little research will turn up. Apparently, a common black light is comprised of mostly UV light. So, first thing tomorrow I'll run up to Walmart and pick up the cheapest little set up they have.

And, even if it doesn't turn the wood back to purple, I'm sure my teenage daughter will get a kick out of it. :D
 
I don't know about it turning color as I turned a small dish buffed and polished with the beal system right after turning. It has been sittiing on my computer desk out of any direct light in front of me and it is still purple. The grain is just beautiful almost reflective right into the wood. I do know that it was difficult to turn and have had to constantly sharpen the tools while trying to work it. I sure appreciate other wood after trying to turn purple heart. Is there some secret to turning it?
 
I posted a reply on this yesterday... don't see it now... must have hit the wrong button and lost it....

but I've heard that if you can heat the wood... sometimes that will bring up the color... I've microwaved pieces and it seems to work on pen blanks.

I haven't had too much trouble with Purpleheart myself, lucky I guess... I've seen some pens done up that was spectacularly purple...
 
When I made this hall table and was milling up the purple heart breadboards they turned a really ugly grayish brown. I started not to even put them on the table. I did and in a few days they turned back purple. I left it in my garage/shop with little sunlight exposure actually none and it turned back purple anyway. I'd just give it a few days.
 

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When I made this hall table and was milling up the purple heart breadboards they turned a really ugly grayish brown. I started not to even put them on the table. I did and in a few days they turned back purple. I left it in my garage/shop with little sunlight exposure actually none and it turned back purple anyway. I'd just give it a few days.

thats one sharp table don,, where did yu get the ambrosia maple?
 
I'm no Purpleheart expert but I've read quite a bit on the subject when I have been using it for boxes. Apparently the purpleheart wood we buy can be from one of many different types (forget my biology from 50 years ago) of trees. Since you don't know which of the sub-species you are getting, you really can't predict how the wood is going to react.

I have read that placing your piece in an oven at 250º - 275º for about a half- hour will cause the purple to intensify but it creates a rather odorous stench that may not be appreciated by others in your home.

Some report that they have purpleheart items that have remained a nice purple for 5 years or more while others indicate that their items have changed to a deep brown within several months. Again, different sub-species of trees is believed to be the cause.

I have found that if I leave a piece of grayed-out purple heart on the bench under a standard incandescent light bulb (not fluorescent/halogen/whatever - actually my drill press light) that the purpleness will return more quickly than if I leave a piece just sitting on the bench without the light. But both will eventually return to the purple color we buy the wood for. I wish that I had some type of color filtering device that would allow me to expose the purpleheart to different color temperatures (Kelvin scale) to see what effects different light would produce.

I think that the color changes, although somewhat unpredictable, follow a curve - cut the wood and it turns a dull grayish-purple; let it set, receive U/V rays and oxidize, and it returns to its most purple color; let it set too long and it turns to a brownish-purple color.

Jim
 
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