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Ozkaban
24th Sep 2009, 10:22 AM
Hi,

I've bought a block of purpleheart from the Sydney WW show (from Trend Timbers, I think). I have a friend who likes all things purple so I'm turning up a bunch of things for her birthday.

From my understanding of purpleheart (reading about it on these forums), heat will make it go darker brown and UV light will make it go darker purple, both being a one-way process.

I usually use Shellawax for a finish, but thought that the heat would make it brown so I've decided to crack out the Rustins plastic finish for this job.

I cut the blanks ok on the bandsaw, noting that the inside of the timber was more of a light brown colour than the edges. No probs, there's be no UV light in there. Drilled it all ok and then turned it as smoothly as I could to minimise sanding. I sanded on the lathe but at the slowest speed I had (~500 rpm) and using a very light touch with brand new sandpaper. Sanded from 180 through to 400, then 600 though 1200 (wet and dry). It seemed to work ok and the brown didn't go any darker. It was actually a good practice in improving my sanding technique - let the paper cut rather than rub it.

At this point I had quite light brown, sanded blanks. I then mixed up the rustins and painted a coat on with a small brush. As expected this made the timber darker and brought the grain out more. I did a further 3 coats once each coat was touch try. I did this at night, but kept the room warm with a small heater. The blanks didn't get very warm at all, but they are now quite a mid-dark brown. Not really much purple in there at all. None of the work was done in the daytime so the stuff has never seen any UV light.

Is this just the result of the finish, and once exposed to UV light they will go purple, or have I stuffed the blanks and will need to rush out and try something new? Sorry for the lack of pics, but they are just small round brown lumps at the moment

Cheers,
Dave

Ozkaban
24th Sep 2009, 10:33 AM
Sorry - forgot to add: I cut one blank too small and drilled out to large and subsequently split it. I noticed that there was a part where the drill bit had heated up too much from being clogged and the wood went a very dark purple - no hint of brown. I would have thought the opposite was true??? I'm tempted to turn another bit forn on the lathe and friction polish it to see what happens...

Cheers,
Dave

Skew ChiDAMN!!
24th Sep 2009, 12:14 PM
I guess it depends on what "variety" of purpleheart you have. All my experience has been with the Brazilian stuff, which seems to work the opposite way; going a dark, muddy brown with heat.

Whatever you have, I imagine it'll purple up with UV exposure, with my stuff a muddy brown "base" colour means it won't be as pretty or vivid a purple. But I've also heard people say they've started with dark brown and it has gone bright purple.

So, it must be the species, I reckon.

Ozkaban
24th Sep 2009, 12:23 PM
Thanks Skew. I guess I'll hang it up in the window on some string (so it can rotate itself in the breeze) and just see what happens.

As for the variety, I think it was the 'damifino' type, so I'll just have to play.

Cheers,
Dave

Texian
24th Sep 2009, 12:45 PM
Dave,
Have also read that exposure to direct sunlight will restore the purple color. May have a 20 year old piece in the shop. Will try it tomorrow if I remember (not likely) and if it stops raining.

Reece
24th Sep 2009, 07:07 PM
i make a lot of pens from purpleheart (people go crazy for them) and have found that it goes bright purple if you leave it in bright light for a while. doesn't need to be direct sunlight, it can be reflected.

eisbaer
24th Sep 2009, 07:15 PM
i find howards feed and wax makes it go a deep purple if you put some on and leave it a while. Don't know if it'll lighten up after time.

Chipman
24th Sep 2009, 07:23 PM
I have heard it is exposure to the air which oxidises it. Light would help too.

Last year I wanted to use some as an inlay... gave up as like Skew said it was just brown. When cleaning up a month later, there was the slice I threw away all nice and purple!!!!

Regards,

Chipman

bowl-basher
24th Sep 2009, 08:30 PM
I found that leaving it for 3-4 days finish sanded with no seal or polish gave me the best results according to the guys at trend it oxadises in the air this was then finished with 3 coats of Glow
Regards
Bowl-Basher

Ozkaban
25th Sep 2009, 10:46 AM
i make a lot of pens from purpleheart (people go crazy for them) and have found that it goes bright purple if you leave it in bright light for a while. doesn't need to be direct sunlight, it can be reflected.


Dave,
Have also read that exposure to direct sunlight will restore the purple color. May have a 20 year old piece in the shop. Will try it tomorrow if I remember (not likely) and if it stops raining.

I left the finished blanks in a spot that had some relflected light yesterday and they did turn purple. I think the dark brown was just the rustins giving the timber that 'wet look'. It has gone a light purple, so I have assembled the pens and hung them up in the corner of the room today where they will get a bit of light and I'll see how it goes. I hung them on string so hopefully the wind will move them about a bit and not just purple up one side!

Cheers,
Dave

Ozkaban
25th Sep 2009, 10:47 AM
I found that leaving it for 3-4 days finish sanded with no seal or polish gave me the best results according to the guys at trend it oxadises in the air this was then finished with 3 coats of Glow
Regards
Bowl-Basher

That's a good idea, BB. How did it go with the Glow? I'm impressed that it didn't go brown from the heat - how did you manage that?

Cheers,
Dave

bowl-basher
25th Sep 2009, 01:32 PM
once the purple colour has come out it did not change with polishing it seems that you are polishing the oxide layer you can not touch it with any abrasive at all or you have to leave it for a further 3-4 days this peice is 18 months old and no sign of any colour change

Hickory
25th Sep 2009, 01:50 PM
I have seen some purple Heart stay bright and colorful for a long time but I also have found the UV rays will Muddy up the results. I tried WB poly on a piece and it seems to colorfast (although I don't like WB Poly, if it maintains the color then I will use it.) ( a personal opinion) but I also keep it away from windows and such.

Same with bloodwood.... but I made a "vase" of Osage Orange and did enjoy the Yellow color for almost a year, but, alas, it also became light brown...

Drillit
25th Sep 2009, 06:58 PM
Hi Dave,
Just to add to the confusion - the PH may stil be a little green - if so, from my use it will dry more towards the purple colour, if left for 1 or 2 weeks. Shellawax works well if you dont cake it on. I guess you know how toxic PH is?. Hope this helps. John M.
PS I am not suggesting you "kiln" dry it in your favourite microwave.:)

Skew ChiDAMN!!
25th Sep 2009, 07:01 PM
:think: It might be more reliable to grab a nice, bland, pale timber like Poplar and simply dye it purple... :innocent:

Broda
25th Sep 2009, 09:03 PM
I found that leaving it for 3-4 days finish sanded with no seal or polish gave me the best results according to the guys at trend it oxadises in the air this was then finished with 3 coats of Glow
Regards
Bowl-Basher



I heard that from trend as well, I havn't tried it yet but they told me it would work. after you finish sanding, take it off and put it in the sun for a few hours, then put it back on the lathe and finish it. after its finished, dont leave it in the sun cause it will go brown

again, I haven't tried this but its what i'v been told

Ozkaban
26th Sep 2009, 09:47 AM
Thanks for your comments. Like your idea Skew! Oh, and the purpleheart is not going anywhere near any microwave of mine.

Turned out ok in the end, though I slightly stuff up the sedona by overheating it a little when using the pen mill by not being careful. No matter, it all looks fine anyway.

I'm happy with the colour, and I'm sure it will go darker over time.

Cheers,
Dave