I have a project with part of one board which will not turn purple:
http://arwomack01.home.att.net/images/butterfly_box.jpg
The layer with the routed compartment below the lid, on the left side
it is still very brown, it is getting purple in the middle of the
compartment and quite purple on the right hand side of the box.
The box has been air exposed for a number of months now and is NOT
purple when sanded or cut. The particular purpleheart I purchased is
brown first then oxidizes to purple. Except this part of one piece.
What other methods are known to transition purpleheart. I've tried
sun exposing a scrap piece of the same brown source wood, it will not
turn either. I'm about to put the whole thing in the oven, has anyone
baked purpleheart purple yet?
http://arwomack01.home.att.net/images/purple_pre.jpg
http://arwomack01.home.att.net/images/purple_sun.jpg
Just to show all purpleheart is not created equal, two turned brown,
one much less so, tape to show the difference.
Does someone have a forest service expert for a relative?
Alan
"Nate" <[email protected]> wrote in message
news:[email protected]...
> Ok, results so far:
>
Have you also given any thought to the post from Mr. Fanelli who is a
cuemaker? He uses ultraviolet light to bring about the purple color. Maybe
the same mechanism can be reproduced chemically. Ultraviolet light seems
easier easy enough, though.
dwhite
On Thu, 20 May 2004 05:28:23 GMT, "Dan White"
<[email protected]> posted:
>"Alan W" <[email protected]> wrote in message
>news:[email protected]...
>> a quick experiment today with Sandy's recommendations:
>>
>> Baking soda paste
>> turns the qood VERY brown, dark like it was aged
>>
>> Lemon juice, difinent color change from the brown, more of an orange
>>
>> Vinegar (white distilled) no change whatso ever
>>
>
>You have to add salt to the vinegar to make it work.
>
>just kidding, (inside joke)
Steady on, Dan or you'll give me a "complex" :)
Just conjecture here, but maybe you're seeing the difference between
sapwood and heartwood.
"Alan W" <[email protected]> wrote in message
news:[email protected]...
> I have a project with part of one board which will not turn purple:
>
> Alan
On 24 May 2004 20:58:08 -0700, [email protected] (Nate) wrote:
>Ok, results so far:
>
... snip of some neat experiments
>
>Another interesting bit: while cutting samples for testing on the
>table saw I noticed that the places that experienced friction with the
>blade (I should really check the alignment on that thing
) showed
>strong purple color, while the cleanly cut portions remained lighter
>colored. Odd. It could be that there is a biological thing going on
>here, wood is made up of cells after all, so the color must be held in
>the cells. Heat doesn't seem to be the factor, as touching it with a
>hot piece of metal simply burns it.
Is it possible that there is a range of temperatures that cause the
change? Perhaps something slightly below that required to burn the wood.
Another thought, how about rather than it being the heat, it is the
friction from the blade?
> Any other experiences with tools
>that affect the purple color?
>
> pretty wild. I wonder wtf the chemistry of PH turning really is....
So do I! As luck would have it I happen to be a dye chemist with
access to all sorts of chemicals and tools for analyzing chemicals.
And I happened to pick up a chunk of Purpleheart.
My plan is to collect the dust from sanding the Purpleheart, then
extract it with a solvent (which one I will have to determine, depends
on what gets the color to disolve, but I have like 40 choices so I'll
find one.) I will then purify the compound that is colored, and run
some chemical tests on it (NMR, IR, UV/Vis, perhaps even a GC/MS.)
Hopefully after that I will be able to report on the nature of the
chemical.
Don't want to wait? Well, my best guess is that the color comes from
a anthocyanin, similar to the the compund giving grape juice it's
color. UV light probably makes it turn brown by activation of the
molecule to oxidize with atmosphereic oxygen. I'm test it with
various acids and bases as well to see if the color is sensitive, and
if the reaction is reversable. (Cherry juice is actually changes
color with pH, acting as an indicator, as do a number of colors fround
in plants.)
Nate
Ok, results so far:
The color is clearly affected by pH. Conc. Sulfuric Acid turns it
deep brown, but HCl (aka Muratic Acid, available at Ace Hardware
stores in 1 liter or 1 gallon sizes) turns it redder. Ammonium
hydroxide causes an immediate color change to green. Treatment of
the green wood with acid returns the red color. Soaking the wood in
NaHCO3, Sodium bicarbonate, aka baking soda, solution turns the wood
green as well.
Now for the fun part, I took some grape juice, Welch's, for
comparison. It displays the same color transitions! I need to produce
some buffer solutions of known pH to narrow in on the color/pH
relationship.
Another interesting bit: while cutting samples for testing on the
table saw I noticed that the places that experienced friction with the
blade (I should really check the alignment on that thing
) showed
strong purple color, while the cleanly cut portions remained lighter
colored. Odd. It could be that there is a biological thing going on
here, wood is made up of cells after all, so the color must be held in
the cells. Heat doesn't seem to be the factor, as touching it with a
hot piece of metal simply burns it. Any other experiences with tools
that affect the purple color?
"Dan White" <[email protected]> wrote in message news:<%[email protected]>...
> "Nate" <[email protected]> wrote in message
> news:[email protected]...
> > Ok, results so far:
> >
>
> Have you also given any thought to the post from Mr. Fanelli who is a
> cuemaker? He uses ultraviolet light to bring about the purple color. Maybe
> the same mechanism can be reproduced chemically. Ultraviolet light seems
> easier easy enough, though.
>
> dwhite
I have tried to soak the wood in grape juice! It doesn't penetrate
well, so all you get is a wet piece of wood. :(
The UV reaction is one I plan to test, I need to get in touch with a
friend who has a UV reactor set up in his lab, it's the kind used when
you want to do photochemical reactions and should be definative on the
effect.
It seems the color is not easily leached out of the wood, conc.
sulfuric acid seems to work, but any of the non polar solvents don't
seem to do anything. I am thinking about boiling methanol, since
methanol is "wood alcohol."
I did some research in to the old chemical literature, it seems this
was actually a target of chemists in the 1930's! The chemical in
question is called peltogynol, purpleheart is a peltogyne hence the
name. The description of the behavior of the wood in the literature
is that it is intitially redish when freshly cut, but changes to
deeper purple with exposure to air and light, eventually becoming
brown. The compounds in the wood were extracted by boiling sawdust in
water to extract some compounds, others were extracted with ethyl
acetate (aka dye preparer for leather dye) The structure of the dye
was determined, but I have yet to find any information on the reaction
that produces the purple color.
But, the color may be extracted in boiling ethanol, and I now have a
sample of it. A description of the isolation noted that the compound
undergoes a change at 200C, but decomposes at 240C. This is in
agreement with my tests using a hotplate here at lab, heating it a bit
does result in darker purple, heating it too much results charcoal
however! I need to bring in a new piece of wood to lab to try more
controlled heating to determine the most effective heating conditions.
Note that 200C is about 392F so I may use the kitchen stove tonight
at home to test it, since that is well with in the range of it. If
the outside of the wood becomes purple, but the inside stays the same
color, then we will know that it is an oxidation, the heat woulod
simply accelerate the reaction. UV also can result in oxidation
through a different mechansim, so the UV route may end up being
gentler for finished products.
As for the color issue, it is red- brown to start then is goes purple,
then if left longer it becomes a darker brown. (just restating that
to clarifiy that the people who said that it gets brown with age and
those that say it goes from brown to purple with aging are both right,
they just aren't talking about the same brown!)
[email protected] (Alan W) wrote in message news:>
> I nuked a piece for a few minutes, it did turn a bit purple where the
> towel concentrated heat and moisture. It did however, also mostly
> burn in the same area. I have this piece sitting on my office floor
> and there is a marked difference in the two pieces of wood it is made
> up of.
>
> Alan
"P van Rijckevorsel" <[email protected]> wrote in message news:<[email protected]>...
> Nate <[email protected]> schreef
> > I did some research in to the old chemical literature, it seems this
> > was actually a target of chemists in the 1930's!
>
> + + +
> Surely that is not surprising?
> + + +
The fact that it was a target is not surprising, but that it wasa
major target worked on by several very big name chemists is a pleasant
surprise.
>
> + + +
> There is no real reason why the reaction at 200C should be the same as the
> well-known one (at room temperature)
> PvR
There is a reason to expect that the reaction is the same as the one
at room temperature, the color is the same. The visual absorption
spectra are fairly good for indentification of molecules. The
simplest explanation is that the heat speeds the kinetics of the
reaction that already occurs at room temperature, since this is
exactly what occurs with thousands of other reactions. It is
actually that there is no reason why the reaction would be different,
the null hypothesis is the reaction is the same.
I doing the controlled temperature tests today, the main goals are to
determine the effective temperatures, and times for color changes.
The reaction should be accelerated until the temperature reaches the
decomposition temperature of the product.
I am putting together a web page of the results with pictures, I'll
post it shortly.
On 22 May 2004 04:17:52 -0700, [email protected] (Alan W)
wrote:
>Steve Knight <[email protected]> wrote in message news:<[email protected]>...
>> On 18 May 2004 19:03:27 -0700, [email protected] (Alan W) wrote:
>>
>> >I have a project with part of one board which will not turn purple:
>> >
>> you still fighting with that box? that thing will be the death of you (G) I even
>> got a visit from that box.
>
>Yep, a couple months of sitting and the rest of the purpleheart has
>gone more purple, but 3" of one of the boards won't change over.
>
>This evening I placed a fresh cut off from the scrap into a plastic
>bag with some household ammonia in it. Effect was immediate of a
>yellowing of the wood. It did not matter if it was months old, sun
>exposed, or freshly cut on this scrap piece, it had a definite yellow
>cast.
>
>If the T-showers stop long enough tomorrow to get strong sunlight, I
>will take another reference photo to post up.
>
>Alan
pretty wild. I wonder wtf the chemistry of PH turning really is....
major snippage
>Talking of toxic, I wonder what the toxic potassium dichromate,
> a powerful oxidising agent, might do to this interesting wood. It has
> some pleasant effects on other woods, IIRC.
It's also pretty nasty stuff and hard to dispose of safely.
Oddly enough, folks who use "natural dyes" because they're
environmentally safe, soak their wool in all kinds of very
toxic "mordants" in order to prepare them for taking and
holding "natural" dye. Sulfuric acid and a Potassium Dichromate
solution were just two of the things I found after divorcing
a "natural" spinner, dyer, weaver. The garbage bags of
onion skins, crushed walnut shells and bard and rotting
flowers were much easier to safely dispose of.
Unless you know what you're doing and how you're going to
safely dispose of chemicals - leave them alone - please.
charlie b
Nate <[email protected]> schreef
> I did some research in to the old chemical literature, it seems this
> was actually a target of chemists in the 1930's!
+ + +
Surely that is not surprising?
+ + +
The chemical in question is called peltogynol, purpleheart is Peltogyne
hence the name. [...]
A description of the isolation noted that the compound
> undergoes a change at 200C, but decomposes at 240C. This is in
> agreement with my tests using a hotplate here at lab, heating it a bit
> does result in darker purple, heating it too much results charcoal
> however!
+ + +
There is no real reason why the reaction at 200C should be the same as the
well-known one (at room temperature)
PvR
Sandy <[email protected]> schreef in
> I've got a bottle of haematoxylin which is the extract of some South
> American tree that I can't quite name at the moment.
+ + +
That would be Haematoxylum ...
Nate <[email protected]> schreef
> here is the URL:
> http://www.organicsculpture.com/Purpleheart.html
+ + +
Nice!
However, it is Peltogyne with a capital "P" (always)
This Peltogyne is a genus, not a family.
The family is Leguminosae (Pea family).
PvR
PS your experiment suggest that the purple-when-freshly-sawn purpleheart may
be a drying defect?
On Monday, March 12, 2018 at 8:14:07 AM UTC-4, Ryan wrote:
> replying to P van Rijckevorsel, Ryan wrote:
> The purple is water or alcohol soluble. The wood gets banal when it is
> freshly cut, or years and years old.
Speaking of "years and years old", did you happen to notice the date of the
posts in this thread?
replying to P van Rijckevorsel, Ryan wrote:
The purple is water or alcohol soluble. The wood gets banal when it is
freshly cut, or years and years old. If the former, just put it outside for a
couple hours. If the latter, just resand it down a touch. If you have a
black light, you can use it to see how much potential for change it has
remaining...you will know.
Once it's cut and shaped or whatever, it will be dull and will get brighter
all by itself. The sun helps quicken it, but at a cost. Think about, say, a
piece of white maple soaked in ooze from a glow stick, and you are trying to
make it glow at night for as long as possible. Purpleheart works the same
way. You *can* charge it in the sunlight when it is freshly cut or resanded.
You *can* heat it gently with a torch or oven or heat gun or lighter. You can
quickly wipe the piece with alcohol or acetone or dunk it in water to pull out
the water soluble dye. You can even use pressure to bring it out, but all of
those things are tantamount to wringing the good stuff out to the surface, so
that it can loose it's glow faster. The maple soaked in glow stick ooze will
shine the best and longest if you keep it dry, cool, and away from UV. It
will shine the brightest and then burn out if you heat it or blast it with uv.
Same reaction.
And don't use acid or base unless you wanna make it bone yellow or green/black
on the other end of the spectrum.
--
for full context, visit https://www.homeownershub.com/woodworking/causing-purpleheart-to-turn-purple-235968-.htm
> > Nate <[email protected]> schreef
> > > I did some research in to the old chemical literature, it seems this
> > > was actually a target of chemists in the 1930's!
> "P van Rijckevorsel" <[email protected]> wrote
> > Surely that is not surprising?
> > + + +
Nate <[email protected]> schreef
> The fact that it was a target is not surprising, but that it wasa
> major target worked on by several very big name chemists is a pleasant
> surprise.
+ + +
Even that is no great surprise: they got their big name for a reason
+ + +
> > + + +
> > There is no real reason why the reaction at 200C should be the same as
the well-known one (at room temperature)
> > PvR
> There is a reason to expect that the reaction is the same as the one
> at room temperature, the color is the same. The visual absorption
> spectra are fairly good for indentification of molecules.
+ + +
Yes, but whole bunches of more or less similar substances (resulting from
different reactions) have more or less similar colors. Besides from your
description it is hard to say how similar. You have seen the color, all I
have to go by is your description.
+ + +
> The
simplest explanation is that the heat speeds the kinetics of the
reaction that already occurs at room temperature, since this is
exactly what occurs with thousands of other reactions. It is
actually that there is no reason why the reaction would be different,
the null hypothesis is the reaction is the same.
> I am doing the controlled temperature tests today, the main goals are to
determine the effective temperatures, and times for color changes. The
reaction should be accelerated until the temperature reaches the
decomposition temperature of the product.
> I am putting together a web page of the results with pictures, I'll
> post it shortly.
Alan: I posted your question over on rec.sport.billiard which I frequent,
and which has several cue makers who are familiar with purpleheart wood.
These are the responses received today. All of the posts below except the
last one were written before I posted your original post with the pics and
all. You may get other responses so you might want to check out that
newsgroup.
good luck,
dwhite
1)
I believe the sun is what causes the browning. I think a light sanding
and refinishing would be best. Use some finish that shield UV rays.
Tracy
2)
It is the sun that caused the color change to start. When PH is exposed to
UV, the nice color goes away. Depending on how badly the color has gone, a
light sanding 'might' bring back some of the color. As a last resort, go to
the art store and buy some pigment the same color as the good PH. Mix with
clear oil and apply very very very very very thin layers, wait until each
layer dries (about a day), and apply until happy with the color. This
technique is called glazing. But again, only a last resort because it is
easy to screw up.
Deno
3)
Sometimes that can be a tough one depending on the wood quality.
I have had Purple Heart wood that turned brown and some that stayed a bright
purple from start to finish.
About the only other thing he might try is heat.
I use a hot air gun (no jokes please <g>) sometimes to deepen the purple
color.
I dont know about chemicals as the only methods I have used are hot air
and/or time under a florescent light.
William Lee
In response to Adam's post:
4)
Adam:
>The particular purpleheart I purchased is
>brown first then oxidizes to purple.
This is the first I have heard of such a wood. Normally it is the
exact opposite.
Tracy
Sandy <[email protected]> wrote in message news:<[email protected]>...
> On Thu, 20 May 2004 05:28:23 GMT, "Dan White"
> <[email protected]> posted:
>
> >"Alan W" <[email protected]> wrote in message
> >news:[email protected]...
> >> a quick experiment today with Sandy's recommendations:
> >>
> >> Baking soda paste
> >> turns the qood VERY brown, dark like it was aged
> >>
> >> Lemon juice, difinent color change from the brown, more of an orange
> >>
> >> Vinegar (white distilled) no change whatso ever
>
> I haven't received this message in full, just what Dan quoted.
> That's interesting that lemon juice had an effect, but vinegar didn't,
> indicating that perhaps it is not a pH colour change but something
> specific to the lemon juice. Now lemon juice has vitamin C in it
> (ascorbic acid which is a reducing agent as well).
> I would be very interested in the effect of oxalic acid (a strong
> reducing agent) on the wood.
> And then perhaps oxalic acid and lemon juice and another test with
> oxalic acid (COOH)2 and baking soda. The purple may in fact be
> something that we won't be able to control. Does Hoadley ever mention
> this wood in his learned tomes? Perhaps one of you guys could email
> him and ask. In a lab I once worked in in a previous life we sometimes
> "washed out" stains with "acid alcohol" which was just alcohol
> (methylated spirit, denatured ethanol or ?rubbing alcohol) with a few
> drops of hydrochloric acid in it. Wouldn't it be great if you guys
> with access to purple heart could wash the stain out of scrap and
> either apply it or sell it? :)
> BTW, oxalic acid might be obtainable as a radiator cleaner, and it is
> toxic. Talking of toxic, I wonder what the toxic potassium dichromate,
> a powerful oxidising agent, might do to this interesting wood. It has
> some pleasant effects on other woods, IIRC.
I've never used Oxalic acid, but could you use a paste of "Bar Keepers
Friend" as a less toxic application of it? It's main ingredient is
Oxalic acid 10% and is only a couple of bucks at wal-mart. MSDS:
http://www.barkeepersfriend.com/PDF/121b.pdf
Just a thought,
Jay
"Sandy" <[email protected]> wrote in message
news:[email protected]...
> >You have to add salt to the vinegar to make it work.
> >
> >just kidding, (inside joke)
>
> Steady on, Dan or you'll give me a "complex" :)
lol. Just read my post on WMD. I'm sure that will give you that complex!
dwhite
"KIM" <nofrag_tnt(remove)@hotmail.com> wrote in message
news:[email protected]...
> I was at a lumberyard yesterday for my first time. I noticed that they
had
> tons of exotic woods, one being a 7 foot board of
Snip!!
I can't wait to get
> good enough in my woodworking to be able to use such nice woods.
Snip!!
Kim,
You should use some of the cheaper exotics in your woodworking now. I'm
only a beginner but I find it inspiring to see the beauty in some of the
small pieces I make, using things like Lacewood, Birdseye Maple or Jatoba.
Also, the beautiful wood helps to make people miss any flaws in joinery or
finish, as long as they aren't too big!!!
Ed
"Alan W" <[email protected]> wrote in message
news:[email protected]...
> a quick experiment today with Sandy's recommendations:
>
> Baking soda paste
> turns the qood VERY brown, dark like it was aged
>
> Lemon juice, difinent color change from the brown, more of an orange
>
> Vinegar (white distilled) no change whatso ever
>
You have to add salt to the vinegar to make it work.
just kidding, (inside joke)
dwhite
On 18 May 2004 19:03:27 -0700, [email protected] (Alan W)
wrote:
>I have a project with part of one board which will not turn purple:
have you tried any chemical approaches? I don't know the chemistry of
purple heart turning purple, but lots of woods respond to alkali and
acid by changing color. I'd start with a paste of baking soda, rubbing
it on a scrap....
On Thu, 20 May 2004 05:28:23 GMT, "Dan White"
<[email protected]> posted:
>"Alan W" <[email protected]> wrote in message
>news:[email protected]...
>> a quick experiment today with Sandy's recommendations:
>>
>> Baking soda paste
>> turns the qood VERY brown, dark like it was aged
>>
>> Lemon juice, difinent color change from the brown, more of an orange
>>
>> Vinegar (white distilled) no change whatso ever
I haven't received this message in full, just what Dan quoted.
That's interesting that lemon juice had an effect, but vinegar didn't,
indicating that perhaps it is not a pH colour change but something
specific to the lemon juice. Now lemon juice has vitamin C in it
(ascorbic acid which is a reducing agent as well).
I would be very interested in the effect of oxalic acid (a strong
reducing agent) on the wood.
And then perhaps oxalic acid and lemon juice and another test with
oxalic acid (COOH)2 and baking soda. The purple may in fact be
something that we won't be able to control. Does Hoadley ever mention
this wood in his learned tomes? Perhaps one of you guys could email
him and ask. In a lab I once worked in in a previous life we sometimes
"washed out" stains with "acid alcohol" which was just alcohol
(methylated spirit, denatured ethanol or ?rubbing alcohol) with a few
drops of hydrochloric acid in it. Wouldn't it be great if you guys
with access to purple heart could wash the stain out of scrap and
either apply it or sell it? :)
BTW, oxalic acid might be obtainable as a radiator cleaner, and it is
toxic. Talking of toxic, I wonder what the toxic potassium dichromate,
a powerful oxidising agent, might do to this interesting wood. It has
some pleasant effects on other woods, IIRC.
Nate wrote:
>>
>> pretty wild. I wonder wtf the chemistry of PH turning really is....
>
> So do I! As luck would have it I happen to be a dye chemist with
> access to all sorts of chemicals and tools for analyzing chemicals.
> And I happened to pick up a chunk of Purpleheart.
>
> My plan is to collect the dust from sanding the Purpleheart, then
> extract it with a solvent (which one I will have to determine, depends
> on what gets the color to disolve, but I have like 40 choices so I'll
> find one.) I will then purify the compound that is colored, and run
> some chemical tests on it (NMR, IR, UV/Vis, perhaps even a GC/MS.)
> Hopefully after that I will be able to report on the nature of the
> chemical.
>
> Don't want to wait? Well, my best guess is that the color comes from
> a anthocyanin, similar to the the compund giving grape juice it's
> color. UV light probably makes it turn brown by activation of the
> molecule to oxidize with atmosphereic oxygen. I'm test it with
> various acids and bases as well to see if the color is sensitive, and
> if the reaction is reversable. (Cherry juice is actually changes
> color with pH, acting as an indicator, as do a number of colors fround
> in plants.)
Way cool.
> Nate
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Mark & Juanita <[email protected]> wrote:
> On 24 May 2004 20:58:08 -0700, [email protected] (Nate) wrote:
(Snip)
>>here, wood is made up of cells after all, so the color must be held in
>>the cells. Heat doesn't seem to be the factor, as touching it with a
>>hot piece of metal simply burns it.
> Is it possible that there is a range of temperatures that cause the
> change? Perhaps something slightly below that required to burn the wood.
It is a specific range of heat. If you carefully apply heat you can it to
change color.
> Another thought, how about rather than it being the heat, it is the
> friction from the blade?
Steve Knight <[email protected]> wrote in message news:<[email protected]>...
> On 18 May 2004 19:03:27 -0700, [email protected] (Alan W) wrote:
>
> >I have a project with part of one board which will not turn purple:
> >
> you still fighting with that box? that thing will be the death of you (G) I even
> got a visit from that box.
Yep, a couple months of sitting and the rest of the purpleheart has
gone more purple, but 3" of one of the boards won't change over.
This evening I placed a fresh cut off from the scrap into a plastic
bag with some household ammonia in it. Effect was immediate of a
yellowing of the wood. It did not matter if it was months old, sun
exposed, or freshly cut on this scrap piece, it had a definite yellow
cast.
If the T-showers stop long enough tomorrow to get strong sunlight, I
will take another reference photo to post up.
Alan
[email protected] (Nate) wrote in message news:<[email protected]>...
> >
> > pretty wild. I wonder wtf the chemistry of PH turning really is....
>
> So do I! As luck would have it I happen to be a dye chemist with
> access to all sorts of chemicals and tools for analyzing chemicals.
> And I happened to pick up a chunk of Purpleheart.
>
Another source, woodcentral.com, suggested a remebered magazine
article that muratic acid (HCL) is capable of causing the change.
Might have to make a trip to the BORG and see how small of a container
I can get.
Alan
[email protected] (Nate) wrote in message news:<[email protected]>...
> "Dan White" <[email protected]> wrote in message news:<%[email protected]>...
> > "Nate" <[email protected]> wrote in message
> > news:[email protected]...
> > > Ok, results so far:
> > >
> >
> > Have you also given any thought to the post from Mr. Fanelli who is a
> > cuemaker? He uses ultraviolet light to bring about the purple color. Maybe
> > the same mechanism can be reproduced chemically. Ultraviolet light seems
> > easier easy enough, though.
> >
> > dwhite
> I have tried to soak the wood in grape juice! It doesn't penetrate
> well, so all you get is a wet piece of wood. :(
> The UV reaction is one I plan to test, I need to get in touch with a
> friend who has a UV reactor set up in his lab, it's the kind used when
> you want to do photochemical reactions and should be definative on the
> effect.
> It seems the color is not easily leached out of the wood, conc.
> sulfuric acid seems to work, but any of the non polar solvents don't
> seem to do anything. I am thinking about boiling methanol, since
> methanol is "wood alcohol."
I nuked a piece for a few minutes, it did turn a bit purple where the
towel concentrated heat and moisture. It did however, also mostly
burn in the same area. I have this piece sitting on my office floor
and there is a marked difference in the two pieces of wood it is made
up of.
Alan
>
> But, the color may be extracted in boiling ethanol, and I now have a
> sample of it. A description of the isolation noted that the compound
> undergoes a change at 200C, but decomposes at 240C. This is in
> agreement with my tests using a hotplate here at lab, heating it a bit
> does result in darker purple, heating it too much results charcoal
> however! I need to bring in a new piece of wood to lab to try more
> controlled heating to determine the most effective heating conditions.
> Note that 200C is about 392F so I may use the kitchen stove tonight
> at home to test it, since that is well with in the range of it. If
> the outside of the wood becomes purple, but the inside stays the same
> color, then we will know that it is an oxidation, the heat woulod
> simply accelerate the reaction. UV also can result in oxidation
> through a different mechansim, so the UV route may end up being
> gentler for finished products.
>
> As for the color issue, it is red- brown to start then is goes purple,
> then if left longer it becomes a darker brown. (just restating that
> to clarifiy that the people who said that it gets brown with age and
> those that say it goes from brown to purple with aging are both right,
> they just aren't talking about the same brown!)
>
>
> [email protected] (Alan W) wrote in message news:>
> > I nuked a piece for a few minutes, it did turn a bit purple where the
> > towel concentrated heat and moisture. It did however, also mostly
> > burn in the same area. I have this piece sitting on my office floor
> > and there is a marked difference in the two pieces of wood it is made
> > up of.
> >
> > Alan
Nate, fabulous information on purpleheart. I await your stove
experiements. Would it be possible for the peltogne to be reapplied
to a piece of purpleheart from a chemical supply house? E.g. to cause
the wood to be able to change again?
Thanks
Alan
[email protected] (Nate) wrote in message news:<[email protected]>...
> I now have a preliminary webpage setup detailing some of my
> experiments. It doesn't cover everything I have done but represents
> some interesting findings. As I find more out I will add to it. If
> anyone has images or other information to add please let me know.
>
> Nate
I will email along some photos from last evening's work. In a nut
shell, unless the piece was purple already, I experienced no older cut
pieces changing from brown to purple.
Do you know if the peltogyne (sp) dye is available from any chemical
supply houses?
Alan
On Fri, 21 May 2004 17:07:32 -0700, charlie b <[email protected]>
brought forth from the murky depths:
>major snippage
>
>>Talking of toxic, I wonder what the toxic potassium dichromate,
>> a powerful oxidising agent, might do to this interesting wood. It has
>> some pleasant effects on other woods, IIRC.
>
> It's also pretty nasty stuff and hard to dispose of safely.
>
> Oddly enough, folks who use "natural dyes" because they're
> environmentally safe, soak their wool in all kinds of very
> toxic "mordants" in order to prepare them for taking and
> holding "natural" dye. Sulfuric acid and a Potassium Dichromate
> solution were just two of the things I found after divorcing
> a "natural" spinner, dyer, weaver. The garbage bags of
> onion skins, crushed walnut shells and bard and rotting
> flowers were much easier to safely dispose of.
>
> Unless you know what you're doing and how you're going to
> safely dispose of chemicals - leave them alone - please.
Hopefully, most people will keep the label attached and already
know about the thousands of hazardous waste facilities in this
country which accept it freely. Alternatively, the guys could
recycle the chemicals to the rest of us Wreckers. Just ask!
I'm looking for some fuming ammonia right now.
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On Fri, 21 May 2004 17:07:32 -0700, charlie b <[email protected]>
posted:
>major snippage
>
>>Talking of toxic, I wonder what the toxic potassium dichromate,
>> a powerful oxidising agent, might do to this interesting wood. It has
>> some pleasant effects on other woods, IIRC.
>
> It's also pretty nasty stuff and hard to dispose of safely.
>
> Oddly enough, folks who use "natural dyes" because they're
> environmentally safe, soak their wool in all kinds of very
> toxic "mordants" in order to prepare them for taking and
> holding "natural" dye. Sulfuric acid and a Potassium Dichromate
> solution were just two of the things I found after divorcing
> a "natural" spinner, dyer, weaver. The garbage bags of
> onion skins, crushed walnut shells and bard and rotting
> flowers were much easier to safely dispose of.
>
> Unless you know what you're doing and how you're going to
> safely dispose of chemicals - leave them alone - please.
Good advice. Same with electricity and WW machines. Only use them if
you know what you are doing.
On 19 May 2004 21:40:33 -0700, [email protected] (Alan W)
wrote:
>a quick experiment today with Sandy's recommendations:
>
>Baking soda paste
>turns the qood VERY brown, dark like it was aged
>
>Lemon juice, difinent color change from the brown, more of an orange
>
>Vinegar (white distilled) no change whatso ever
>
>Alan
some other things to try:
a stronger acid. if you know someone with a swimming pool ask them for
a small amount of HCL
ammonia vapor. read up on "fuming oak"
On Tue, 25 May 2004 04:01:33 GMT, Mark & Juanita
<[email protected]> wrote:
>On 24 May 2004 20:58:08 -0700, [email protected] (Nate) wrote:
>
>>Ok, results so far:
>>
>... snip of some neat experiments
>>
>>Another interesting bit: while cutting samples for testing on the
>>table saw I noticed that the places that experienced friction with the
>>blade (I should really check the alignment on that thing
) showed
>>strong purple color, while the cleanly cut portions remained lighter
>>colored. Odd. It could be that there is a biological thing going on
>>here, wood is made up of cells after all, so the color must be held in
>>the cells. Heat doesn't seem to be the factor, as touching it with a
>>hot piece of metal simply burns it.
>
> Is it possible that there is a range of temperatures that cause the
>change? Perhaps something slightly below that required to burn the wood.
>
> Another thought, how about rather than it being the heat, it is the
>friction from the blade?
if it was heat range or friction the color change would show up during
sanding. I've never had that happen, but I'm not a big PH user....
>
>
>> Any other experiences with tools
>>that affect the purple color?
"Nate" <[email protected]> wrote in message
news:[email protected]...
> Ok, results so far:
>
> The color is clearly affected by pH. Conc. Sulfuric Acid turns it
> deep brown, but HCl (aka Muratic Acid, available at Ace Hardware
> stores in 1 liter or 1 gallon sizes) turns it redder. Ammonium
> hydroxide causes an immediate color change to green. Treatment of
> the green wood with acid returns the red color. Soaking the wood in
> NaHCO3, Sodium bicarbonate, aka baking soda, solution turns the wood
> green as well.
>
> Now for the fun part, I took some grape juice, Welch's, for
> comparison. It displays the same color transitions! I need to produce
> some buffer solutions of known pH to narrow in on the color/pH
> relationship.
>
What color do you get if you mix the grape juice with the wood? Problem
solved!
Sorry, someone had to say it. I've been posting your discussion in
rec.sport.billiard as there are a number of people there who build cues with
purpleheart.
dwhite
In article <[email protected]>,
[email protected] (Alan W) wrote:
> Do you know if the peltogyne (sp) dye is available from any chemical
> supply houses?
>
> Alan
I don't know if it is available, my best guess is no. I can exract it
from sawdust, but it is unclear to me how one would get it in to the
wood effectively. Perhaps I will take some extract and soak it in to a
piece of soft maple to see if I can make "fake" purpleheart.
I was at a lumberyard yesterday for my first time. I noticed that they had
tons of exotic woods, one being a 7 foot board of ebony. As I fondled it,
the owner walked by and said, "I'll let you know that is a $700 piece of
wood you are handling." - Wow!
I did ask if they had any purpleheart as I have been following this thread.
They went and showed me a nice specimen. I also mentioned the dilemma of
getting the wood to go purple and their response was to simply flame it. I
think you have tried this? Their explanation was that flaming it would kill
all the white pigment in the cells. Then it would turn purple.
On another note, I happened to look around at more of the exotic woods.
They showed me a nice bright red, bloodwood? I was quite intrigued with the
lacewood, I thought it looked a lot like a cheetah. I can't wait to get
good enough in my woodworking to be able to use such nice woods.
Good luck with the purpleheart!
KIM
"Sandy" <[email protected]> wrote in message
news:[email protected]...
> On Fri, 21 May 2004 17:07:32 -0700, charlie b <[email protected]>
> posted:
>
> >major snippage
> >
> >>Talking of toxic, I wonder what the toxic potassium dichromate,
> >> a powerful oxidising agent, might do to this interesting wood. It has
> >> some pleasant effects on other woods, IIRC.
> >
> > It's also pretty nasty stuff and hard to dispose of safely.
> >
> > Oddly enough, folks who use "natural dyes" because they're
> > environmentally safe, soak their wool in all kinds of very
> > toxic "mordants" in order to prepare them for taking and
> > holding "natural" dye. Sulfuric acid and a Potassium Dichromate
> > solution were just two of the things I found after divorcing
> > a "natural" spinner, dyer, weaver. The garbage bags of
> > onion skins, crushed walnut shells and bard and rotting
> > flowers were much easier to safely dispose of.
> >
> > Unless you know what you're doing and how you're going to
> > safely dispose of chemicals - leave them alone - please.
>
> Good advice. Same with electricity and WW machines. Only use them if
> you know what you are doing.
On 20 May 2004 08:36:52 -0700, [email protected] (Jay) posted:
>Sandy <[email protected]> wrote in message news:<[email protected]>...
>> On Thu, 20 May 2004 05:28:23 GMT, "Dan White"
>> <[email protected]> posted:
>>
>> >"Alan W" <[email protected]> wrote in message
>> >news:[email protected]...
>> >> a quick experiment today with Sandy's recommendations:
>> >>
>> >> Baking soda paste
>> >> turns the qood VERY brown, dark like it was aged
>> >>
>> >> Lemon juice, difinent color change from the brown, more of an orange
>> >>
>> >> Vinegar (white distilled) no change whatso ever
>>
>> I haven't received this message in full, just what Dan quoted.
>> That's interesting that lemon juice had an effect, but vinegar didn't,
>> indicating that perhaps it is not a pH colour change but something
>> specific to the lemon juice. Now lemon juice has vitamin C in it
>> (ascorbic acid which is a reducing agent as well).
>> I would be very interested in the effect of oxalic acid (a strong
>> reducing agent) on the wood.
>> And then perhaps oxalic acid and lemon juice and another test with
>> oxalic acid (COOH)2 and baking soda. The purple may in fact be
>> something that we won't be able to control. Does Hoadley ever mention
>> this wood in his learned tomes? Perhaps one of you guys could email
>> him and ask. In a lab I once worked in in a previous life we sometimes
>> "washed out" stains with "acid alcohol" which was just alcohol
>> (methylated spirit, denatured ethanol or ?rubbing alcohol) with a few
>> drops of hydrochloric acid in it. Wouldn't it be great if you guys
>> with access to purple heart could wash the stain out of scrap and
>> either apply it or sell it? :)
>> BTW, oxalic acid might be obtainable as a radiator cleaner, and it is
>> toxic. Talking of toxic, I wonder what the toxic potassium dichromate,
>> a powerful oxidising agent, might do to this interesting wood. It has
>> some pleasant effects on other woods, IIRC.
>
>I've never used Oxalic acid, but could you use a paste of "Bar Keepers
>Friend" as a less toxic application of it? It's main ingredient is
>Oxalic acid 10% and is only a couple of bucks at wal-mart. MSDS:
>
>http://www.barkeepersfriend.com/PDF/121b.pdf
>
>Just a thought,
Can't see why not, if that's what's in it.
Looks like there is detergent and perhaps a scourer.
I'd try to dissolve the stuff and let any insoluble stuff settle out
and use the clear solution.
The detergent should wash away, but will help the oxalic acid
penetrate the wood. Give it a try, if it doesn't do anything to the
wood, you have a good bath cleaner :)
On 18 May 2004 19:03:27 -0700, [email protected] (Alan W) wrote:
>I have a project with part of one board which will not turn purple:
>
you still fighting with that box? that thing will be the death of you (G) I even
got a visit from that box.
--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.
On Tue, 18 May 2004 20:18:01 -0700, [email protected] posted:
>On 18 May 2004 19:03:27 -0700, [email protected] (Alan W)
>wrote:
>
>>I have a project with part of one board which will not turn purple:
>
>
>
>have you tried any chemical approaches? I don't know the chemistry of
>purple heart turning purple, but lots of woods respond to alkali and
>acid by changing color. I'd start with a paste of baking soda, rubbing
>it on a scrap....
That's an interesting tack.
Some of those colours act as "indicators" changing colour with
different pHs and also with oxidation or reduction.
You could try the baking soda for the alkaline, and then maybe vinegar
or lemon juice for an acid treatment.
Then to oxidise, you could try household bleach, and to reduce, some
oxalic acid solution (caution -- toxic). You could also try these in
acid and alkaline conditions. Ammonia might also be interesting.
I've got a bottle of haematoxylin which is the extract of some South
American tree that I can't quite name at the moment.
It is reddish in acid environment and bluish purple in alkaline IIRC
from 40 years ago. I am going to experiment with that on some bland
boring wood sometime. I have a 12' x 14" poplar log drying in the shed
at the moment that might be interesting to try things on.
I just scored a street-tree log that was hollow and met the
chain-saw-and-chipper-brigade this morning. It has some very
interesting grain patterns next to the hollow section. It will be
interesting to split it in a few years and run it over the jointah.
Oh, its a London Plane BTW.
I have some rosewood and other stains that are excellent for colour
matching my jarrah when needed.
I also intend to experiment with strong black tea on piney wood.
I've tried the other solvent-based stains with rather poor results,
being rather blotchy. Piney wood can be a real challenge at times, but
when a clear length has those straight grains close together, it is
stronger than steel, weight for weight.
The best wooddorking book I ever read from cover to cover was George
Frank's Adventures in Wood Finishing. I see there is a new edition out
with Bruce Hoadly. Now that seems a must read for those interested in
the science of wood finishing :)