I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker reddish
color. I know this is primarily from exposure to UV light. I finish my
bowls with a few coats of Formby's Tung Oil Finish and then after thorough
drying, I use my Beall system to polish and wax. Does anyone know of
procedures to use to accelerate the rate of darkening. What might be a good
UV source that could be used close to the wood to darken it. I have a
halogen work light but I don't know the primary wavelengths of emission for
those bulbs.

Bob

In article ,
"Bob Daun" wrote:

I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker reddish
color. I know this is primarily from exposure to UV light.

Well, there's that big light in the sky outside - cheap, too. Put them
out in the sun for a while.

Halogen won't do much for you. And most lights that would do much are
shielded to reduce shortwave UV so they won't hurt people. Skin cancer
and itchy eyes both hurt.

You could get a germicidal UV lamp (florescent, usually - seen in things
like water filters and cabinets to store safety glasses). Some metal
halide or mercury vapor lamps sold in the aquarium trade lack the usual
UV shield layer since some UV is good for mimicking sunlight.

A good old fashioned carbon arc light is a wonderful UV source, but not
one that's all that easy to find these days. If you happen to have an
arc welder and a twin carbon arc torch, that would be the ticket to
rapid results - but wear your helmet and leathers, and don't catch the
wood on fire.

I suppose tanning lamps would likewise work, and you could get a lot of
bowls on a tanning bed if you found a tanning store going out of
business.

With any of the lights, you should arrange the lights and bowl to be in
a box or cabinet that keeps the light off your skin and eyes, and use
safety glasses and gloves/long sleeves if you are rearranging bowls with
the lights on. A better box/cabinet design would have a switch that
turned them off if the door was unlatched, and shiny reflective insides
so you got maximum use from the light.

--
Cats, coffee, chocolate...vices to live by

In article , "Bob Daun" wrote:
I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker reddish
color. I know this is primarily from exposure to UV light. I finish my
bowls with a few coats of Formby's Tung Oil Finish and then after thorough
drying, I use my Beall system to polish and wax. Does anyone know of
procedures to use to accelerate the rate of darkening. What might be a good
UV source that could be used close to the wood to darken it. I have a
halogen work light but I don't know the primary wavelengths of emission for
those bulbs.

There are a couple of chemical treatments you can choose from, prior to
applying finish: ammonia fuming, or lye. A solution of 1 teaspoon of lye in a
pint of water will darken cherry quite satisfactorily. Make sure to wipe it
down with diluted vinegar, and again with water, before finishing.

"Ecnerwal" wrote: (clip) A good old fashioned carbon arc light is a
wonderful UV source, but not
one that's all that easy to find these days. If you happen to have an
arc welder and a twin carbon arc torch, that would be the ticket to
rapid results - but wear your helmet and leathers, and don't catch the
wood on fire. (clip)
^^^^^^^^^^^^^^^^^^^^
They used to use carbon arc lights for burning plates in the printing
industry--they have been phased out because of the toxic fumes they produce.
I think it is hard to get the copper-coated carbon rods they use. When they
were used, they were never run more than a few minutes at a time, which I
think would be insufficient for your purposes.

Also. if you intend to use any kind of light source, you have the question
of how to get even exposure all around the bowl. You would have to rotate
it on a spit, or devise a reflective surround for the light and the bowl.

It just don't strike me as very practical.

I think the suggestion to use sunlight makes the most sense.

acid activates purple heart and makes it a very vivid color - might be worth
a try

"Bob Daun" wrote in message
...
I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker
reddish color. I know this is primarily from exposure to UV light. I
finish my bowls with a few coats of Formby's Tung Oil Finish and then
after thorough drying, I use my Beall system to polish and wax. Does
anyone know of procedures to use to accelerate the rate of darkening.
What might be a good UV source that could be used close to the wood to
darken it. I have a halogen work light but I don't know the primary
wavelengths of emission for those bulbs.

Bob

In article , "Bill Noble" wrote:
acid activates purple heart and makes it a very vivid color - might be worth
a try

Not on cherry. Use alkali instead -- even a weak lye solution makes cherry
quite dark. Ammonia will darken it also. I haven't tried washing soda yet to
see if it has a similar effect, but I imagine it will.

"Bob Daun" wrote in message
t...
I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker
reddish color. I know this is primarily from exposure to UV light. I
finish my bowls with a few coats of Formby's Tung Oil Finish and then
after thorough drying, I use my Beall system to polish and wax. Does
anyone know of procedures to use to accelerate the rate of darkening.
What might be a good UV source that could be used close to the wood to
darken it. I have a halogen work light but I don't know the primary
wavelengths of emission for those bulbs.

Bob

"Bill Noble" wrote in message
...
acid activates purple heart and makes it a very vivid color - might be
worth a try

Vivid purple turned brown when turning and sanding a pen..... what kind of
acid are you using to bring back the pruple?

"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to the
surface on exposure to air. Exposure of the purple surface to sunlight will
turn it to an ugly brown. So, after turning a pen, just wait, and don't
leave it in the window.

In article , "Leo Lichtman" wrote:

"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to the
surface on exposure to air. Exposure of the purple surface to sunlight will
turn it to an ugly brown. So, after turning a pen, just wait, and don't
leave it in the window.

Not in my experience -- I've observed the purple to be *intensified* by
sunlight.

"Leo Lichtman" wrote in message
...

"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to
the surface on exposure to air. Exposure of the purple surface to
sunlight will turn it to an ugly brown.

I don't buy it.. LOL... This pen is 1 year old now and some 10 year old
purple heart candle holders I made still have the same brown spots.

"Doug Miller" wrote in message
...
In article , "Leo Lichtman"
wrote:

"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to
the
surface on exposure to air. Exposure of the purple surface to sunlight
will
turn it to an ugly brown. So, after turning a pen, just wait, and don't
leave it in the window.

Not in my experience -- I've observed the purple to be *intensified* by
sunlight.


I have heard it both way over the years.... From what I understand it is
loke people and will react differently to being handled differently. I have
had it go extreme purple when cutting.

In article ,
(Doug Miller) wrote:

In article , "Leo Lichtman"
wrote:

"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to the
surface on exposure to air. Exposure of the purple surface to sunlight will
turn it to an ugly brown. So, after turning a pen, just wait, and don't
leave it in the window.

Not in my experience -- I've observed the purple to be *intensified* by
sunlight.

I've had PH bleach out brown (certainly seemed to be sun-exposure
related, though filtered through two sheets of glass and a coat of
finish), but I wouldn't call it an ugly brown - more like brittle,
tool-dulling black walnut - ie, pretty good looking, but not as nice to
work with as walnut. It's mostly "not purple" rather than "ugly", IMHO.
YHO may vary, or not be H. Last I looked the bag of shavings I tucked
away in the shed was still nice and purple.

--
Cats, coffee, chocolate...vices to live by

I think internal oils in the silicon based wood turns it purple while
a hot bandsaw or sun will dry (evaporate) the surface and turn brown.

Consider Coastal Redwood decks. Pinkish color until it gets boiled in the
sun - then it turns a silver gray. Sand off that surface and back in the pink.

Most wood changes color and gets hard in the sun.

I have purple heart tree elements (heavy) and sewing wall hanger.
I made some nice file handles out of it and white oak. It was a
diagonal layered design - looks like a candy cane of sorts - oiled it
and it is in my file drawer with the others. It is large as it holds
a 3/4" round wood rasp.

Martin

Ecnerwal wrote:
In article ,
(Doug Miller) wrote:

In article , "Leo Lichtman"
wrote:
"Leon" wrote: Vivid purple turned brown when turning and sanding a
pen..... what kind of
acid are you using to bring back the pruple?
^^^^^^^^^^^^^^^^^^^^^^^
Purple heart is brown when it's cut or turned, but the color returns to the
surface on exposure to air. Exposure of the purple surface to sunlight will
turn it to an ugly brown. So, after turning a pen, just wait, and don't
leave it in the window.
Not in my experience -- I've observed the purple to be *intensified* by
sunlight.

I've had PH bleach out brown (certainly seemed to be sun-exposure
related, though filtered through two sheets of glass and a coat of
finish), but I wouldn't call it an ugly brown - more like brittle,
tool-dulling black walnut - ie, pretty good looking, but not as nice to
work with as walnut. It's mostly "not purple" rather than "ugly", IMHO.
YHO may vary, or not be H. Last I looked the bag of shavings I tucked
away in the shed was still nice and purple.

"Leon" wrote in message
...

"Bill Noble" wrote in message
...
acid activates purple heart and makes it a very vivid color - might be
worth a try

Vivid purple turned brown when turning and sanding a pen..... what kind of
acid are you using to bring back the pruple?

HCL

"purple heart will turn purple due to heat or HCL or other acid - if you
don't believe me, try it. colors are different but both are arguably shades
of purple - the HCL is more red, the heat more blue in my experience

"Bill Noble" wrote in message
...


"purple heart will turn purple due to heat or HCL or other acid - if you
don't believe me, try it. colors are different but both are arguably
shades of purple - the HCL is more red, the heat more blue in my
experience


I have had purple heart turn both brown and stronger purple when cutting
different pieces of purple heart.

What I would like to know is how to turn the piece that turns brown with
heat, back to purple, what kind of acid?

"Bill Noble" wrote in message
...


"Leon" wrote in message
...

"Bill Noble" wrote in message
...
acid activates purple heart and makes it a very vivid color - might be
worth a try

Vivid purple turned brown when turning and sanding a pen..... what kind
of acid are you using to bring back the pruple?

HCL


Hydracloric?

"Leon" wrote in message
...

"Bill Noble" wrote in message
...


"purple heart will turn purple due to heat or HCL or other acid - if you
don't believe me, try it. colors are different but both are arguably
shades of purple - the HCL is more red, the heat more blue in my
experience


I have had purple heart turn both brown and stronger purple when cutting
different pieces of purple heart.

What I would like to know is how to turn the piece that turns brown with
heat, back to purple, what kind of acid?


Ah... HCL got it.

In article , "Leon" wrote:

"Bill Noble" wrote in message
...


"Leon" wrote in message
...

"Bill Noble" wrote in message
...
acid activates purple heart and makes it a very vivid color - might be
worth a try

Vivid purple turned brown when turning and sanding a pen..... what kind
of acid are you using to bring back the pruple?

HCL


Hydracloric?

Right pronunciation, wrong spelling: hydrochloric (hydro[gen] + chlor[ine]).
Any swimming-pool supply shop will have it, but it may be pretty pricy. It's
also available in many hardware stores under the name "muriatic acid" -- same
stuff, but usually much cheaper than at a pool shop.

If you're a stickler for correctitude, make that HCl.

Leo Lichtman wrote:
If you're a stickler for correctitude, make that HCl.

And if you dilute it, be sure to observe the safety rule of *always*
pouring the acid into water rather than the other way around.

That way, it will be the diluted acid that splashes or spills, not the
full strength...

--
Kevin Miller
Juneau, Alaska
http://www.alaska.net/~atftb
In a recent poll, seven out of ten hard drives preferred Linux.

In article ations,
Kevin Miller wrote:

Leo Lichtman wrote:
If you're a stickler for correctitude, make that HCl.

And if you dilute it, be sure to observe the safety rule of *always*
pouring the acid into water rather than the other way around.

That way, it will be the diluted acid that splashes or spills, not the
full strength...

The reason is a bit less obvious than that, as demonstrated in
high-school chemistry to make the point. At least back when I went to
high school it was - with all the skittishness about exposing young
persons to the faintest shred of real life, it's no doubt no longer in
vogue, regardless of proper safety precautions.

When you add water to acid, the water can be heated to boiling - I
forget the details of why, but I remember the effect. Effectively, you
can consider acid dilution to be an exothermic "reaction." The heat is
there in either direction, but the distribution of heat is significantly
different with acid to water .vs. water to acid. When water is added to
acid and the water flashes to steam, you get acid being flung out of the
container by the steam - not good.

Chemistry students who retained more are welcome to fill in the details,
or the web probably can as well. I don't need them, I recall the effect
and that's plenty for me.

--
Cats, coffee, chocolate...vices to live by

"Leon" wrote in message
...




"purple heart will turn purple due to heat or HCL or other acid - if you
don't believe me, try it. colors are different but both are arguably
shades of purple - the HCL is more red, the heat more blue in my
experience


I have had purple heart turn both brown and stronger purple when cutting
different pieces of purple heart.

What I would like to know is how to turn the piece that turns brown with
heat, back to purple, what kind of acid?


Ah... HCL got it.

you can wipe it on, or put it in a container near the wood and cover the
pair and the fumes will do the trick.

Ecnerwal wrote:

The reason is a bit less obvious than that, as demonstrated in
high-school chemistry to make the point. At least back when I went to
high school it was - with all the skittishness about exposing young
persons to the faintest shred of real life, it's no doubt no longer in
vogue, regardless of proper safety precautions.

When you add water to acid, the water can be heated to boiling - I
forget the details of why, but I remember the effect. Effectively, you
can consider acid dilution to be an exothermic "reaction." The heat is
there in either direction, but the distribution of heat is significantly
different with acid to water .vs. water to acid. When water is added to
acid and the water flashes to steam, you get acid being flung out of the
container by the steam - not good.

Chemistry students who retained more are welcome to fill in the details,
or the web probably can as well. I don't need them, I recall the effect
and that's plenty for me.

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

Makes all the more sense; the likely hood of it splashing/spilling is
much more likely if it tends to explode on you!

....Kevin
--
Kevin Miller
Juneau, Alaska

http://www.alaska.net/~atftb
In a recent poll, seven out of ten hard drives preferred Linux.

"Ecnerwal" wrote in message
...
In article ations,
Kevin Miller wrote:


The reason is a bit less obvious than that, as demonstrated in
high-school chemistry to make the point. At least back when I went to
high school it was - with all the skittishness about exposing young
persons to the faintest shred of real life, it's no doubt no longer in
vogue, regardless of proper safety precautions.

When you add water to acid, the water can be heated to boiling - I
forget the details of why, but I remember the effect. Effectively, you
can consider acid dilution to be an exothermic "reaction." The heat is
there in either direction, but the distribution of heat is significantly
different with acid to water .vs. water to acid. When water is added to
acid and the water flashes to steam, you get acid being flung out of the
container by the steam - not good.

Chemistry students who retained more are welcome to fill in the details,
or the web probably can as well. I don't need them, I recall the effect
and that's plenty for me.

I'll attest to that. Brought back memories of my early automotive days and
filling dry batteries with suulfuric acid and topping off a battery with
water. Adding water to a charged battery would result in what appeared to
be boiling acid.
Then there was the time I was filling a new battery with sulfuric acid and
the hose came off of the acid container, tghe acid poured right into my
crotch. Thank goodness there was a Coke machine near by.

"Kevin Miller" wrote in message
mmunications...
Ecnerwal wrote:

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

I recall doing that in chemistry, however we were trusted to slice off a
piece of the sodium ourselves and then cover it back up quickly. The sodium
would also react to being exposed to air although not as voilently as
dropping a piece in a beaker of water. I forget how the sodium was stored
to stop the reaction with the air. Corpus Christi was/is a very humid
city.


Makes all the more sense; the likely hood of it splashing/spilling is much
more likely if it tends to explode on you!

...Kevin
--
Kevin Miller
Juneau, Alaska

http://www.alaska.net/~atftb
In a recent poll, seven out of ten hard drives preferred Linux.

"Leon" wrote: (clip) acid poured right into my
crotch. Thank goodness there was a Coke machine near by.
^^^^^^^^^^^^^^^^^^
What a strange time to stop and drink a Coke. G

In article , "Leon" wrote:

"Kevin Miller" wrote in message
ommunications...
Ecnerwal wrote:

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

I recall doing that in chemistry, however we were trusted to slice off a
piece of the sodium ourselves and then cover it back up quickly. The sodium
would also react to being exposed to air although not as voilently as
dropping a piece in a beaker of water. I forget how the sodium was stored
to stop the reaction with the air. Corpus Christi was/is a very humid
city.

IIR, it's usually stored in kerosene.

"Doug Miller" wrote in message
...
In article , "Leon"
wrote:

"Kevin Miller" wrote in message
communications...
Ecnerwal wrote:

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

I recall doing that in chemistry, however we were trusted to slice off a
piece of the sodium ourselves and then cover it back up quickly. The
sodium
would also react to being exposed to air although not as voilently as
dropping a piece in a beaker of water. I forget how the sodium was stored
to stop the reaction with the air. Corpus Christi was/is a very humid
city.

IIR, it's usually stored in kerosene.

That would sound reasonable... I wonder how it is preserved in nature.

"Leo Lichtman" wrote in message
...

"Leon" wrote: (clip) acid poured right into my
crotch. Thank goodness there was a Coke machine near by.
^^^^^^^^^^^^^^^^^^
What a strange time to stop and drink a Coke. G


LOL, and thank goodness a quarter would buy you a Coke.

On Jan 15, 10:39*pm, "Leon" wrote:
"Ecnerwal" wrote in message

...





In article ations,
Kevin Miller wrote:

The reason is a bit less obvious than that, as demonstrated in
high-school chemistry to make the point. At least back when I went to
high school it was - with all the skittishness about exposing young
persons to the faintest shred of real life, it's no doubt no longer in
vogue, regardless of proper safety precautions.

When you add water to acid, the water can be heated to boiling - I
forget the details of why, but I remember the effect. Effectively, you
can consider acid dilution to be an exothermic "reaction." The heat is
there in either direction, but the distribution of heat is significantly
different with acid to water .vs. water to acid. When water is added to
acid and the water flashes to steam, you get acid being flung out of the
container by the steam - not good.

Chemistry students who retained more are welcome to fill in the details,
or the web probably can as well. I don't need them, I recall the effect
and that's plenty for me.

I'll attest to that. *Brought back memories of my early automotive days and
filling dry batteries with suulfuric acid and topping off a battery with
water. *Adding water to a charged battery would result in what appeared to
be boiling acid.
Then there was the time I was filling a new battery with sulfuric acid and
the hose came off of the acid container, tghe acid poured right into my
crotch. *Thank goodness there was a Coke machine near by.

The order of mixing water and acid is very important with sulfuric
acid, but of no real concern with hydrochloric.
In the lab we keep 1+1 hydrochloric acid (1 part water + 1 part 30%
acid) on the shelf for routine use. It doesn't
fume like the concentrated stuff and is generally easier to handle.
You can spill the 1+1 on your skin and simply
rinse it off with water with no damage. It is concentrated sulfuric
acid (battery acid) that is dangerous to handle.
FWIW, the worst burn I ever got in 30 years in the lab was from
Hydrofluoric acid (the stuff used to etch glass).
Now that's some bad s---!
Paul Gilbert - retired chemist

In article , "Leon" wrote:

"Doug Miller" wrote in message
...
In article , "Leon"
wrote:

"Kevin Miller" wrote in message
icommunications...
Ecnerwal wrote:

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

I recall doing that in chemistry, however we were trusted to slice off a
piece of the sodium ourselves and then cover it back up quickly. The
sodium
would also react to being exposed to air although not as voilently as
dropping a piece in a beaker of water. I forget how the sodium was stored
to stop the reaction with the air. Corpus Christi was/is a very humid
city.

IIR, it's usually stored in kerosene.

That would sound reasonable... I wonder how it is preserved in nature.

It's not. Sodium doesn't occur in pure form in nature. *Can't* occur in pure
form, in fact, since it reacts spontaneously with both air and water.

"Doug Miller" wrote in message
...
In article , "Leon"
wrote:

"Doug Miller" wrote in message
...
In article , "Leon"
wrote:

"Kevin Miller" wrote in message
cicommunications...
Ecnerwal wrote:

Interesting. I never took chemistry but my biology teacher did drop a
small ball of sodium in water once. That was fun.

I recall doing that in chemistry, however we were trusted to slice off
a
piece of the sodium ourselves and then cover it back up quickly. The
sodium
would also react to being exposed to air although not as voilently as
dropping a piece in a beaker of water. I forget how the sodium was
stored
to stop the reaction with the air. Corpus Christi was/is a very humid
city.

IIR, it's usually stored in kerosene.

That would sound reasonable... I wonder how it is preserved in nature.

It's not. Sodium doesn't occur in pure form in nature. *Can't* occur in
pure
form, in fact, since it reacts spontaneously with both air and water.

Ahh.. So that raw Na is processed? IIRC in the more pure form it was more
like clay.

"Paul Gilbert" wrote in message
...
On Jan 15, 10:39 pm, "Leon" wrote:
"Ecnerwal" wrote in message

...


I'll attest to that. Brought back memories of my early automotive days and
filling dry batteries with suulfuric acid and topping off a battery with
water. Adding water to a charged battery would result in what appeared to
be boiling acid.
Then there was the time I was filling a new battery with sulfuric acid and
the hose came off of the acid container, tghe acid poured right into my
crotch. Thank goodness there was a Coke machine near by.

The order of mixing water and acid is very important with sulfuric
acid, but of no real concern with hydrochloric.

Unknown back then to me and unfortunately there was not much choice to
topping off a battery with water unless the battery was dead. Then you were
basically adding water to water. I recall so many customers wanting to add
sulfuric acid to a dead empty/low battery. That could not be done, you had
to add water and recharge. Simply refilling a dead battery with acid would
not allow the recharge/chemical reaction to take place. Back then batteries
were charged at the factory and drained. The shop would then refill the new
empty charged batteries with acid.

I suspect that the sulfuric acid we used to refill the new batteries was a
weaker mix that a strong solution of sulfuric acid.
I recall that if you got it on your bare skin nothing happed immediately but
shortly you would get this severe itch. If you got it on a cut it was like
pouring alcohol or lemon juice on the cut. Any piece of cloth, like your
cloths, that it came in contact with was immediately predestined to
descenegrate in the wash. Ahhh.. sulfuric acid has a very tart salty sour
taste. ;~) I some times would touch an itchey spot very lightly to the
very tip of my tongue to determine if the itch was natural or caused by
acid. Like being electrocuted with 110-120 volts you instantly knew if
there was acid on your finger using the taste test. :~) I filled lots and
lots and lots of batteries when I was a kid 5-10 a day.





In the lab we keep 1+1 hydrochloric acid (1 part water + 1 part 30%
acid) on the shelf for routine use. It doesn't
fume like the concentrated stuff and is generally easier to handle.
You can spill the 1+1 on your skin and simply
rinse it off with water with no damage. It is concentrated sulfuric
acid (battery acid) that is dangerous to handle.
FWIW, the worst burn I ever got in 30 years in the lab was from
Hydrofluoric acid (the stuff used to etch glass).
Now that's some bad s---!
Paul Gilbert - retired chemist

In article , "Leon" wrote:

Ahh.. So that raw Na is processed? IIRC in the more pure form it was more
like clay.

It's a very soft metal. As far as I can remember, most of the methods of
purifying it involve passing an electric current through one of its compounds
(for example, I believe that electrolysis of molten sodium hydroxide yields
the pure metal plus oxygen and hydrogen as gases).

I am very inexperienced at this, but I have made 5 cherry bowls. I
spend more time sanding them than anybody else does, probably. As I am
sanding/polishing them them with pretty fine grits, let's say 600 or so,
the heat from the sanding darkens them a fair amount. I even tried
polishing a couple with the back side of the sandpaper, and I can see
definite darkening from that. So far, I have only been finishing them
with a can of natural ancient linseed oil and that darkens them even
more. This is all air dried for 5 or 6 years, cherry that I cut myself.

Pete Stanaitis
---------------------

Bob Daun wrote:

I currently am working on a few cherry bowls. I know that cherry will
darken upon exposure to sunlight from a maple type color to a darker
reddish color. I know this is primarily from exposure to UV light. I
finish my bowls with a few coats of Formby's Tung Oil Finish and then
after thorough drying, I use my Beall system to polish and wax. Does
anyone know of procedures to use to accelerate the rate of darkening.
What might be a good UV source that could be used close to the wood to
darken it. I have a halogen work light but I don't know the primary
wavelengths of emission for those bulbs.

Bob

In article , spaco wrote:
I am very inexperienced at this, but I have made 5 cherry bowls. I
spend more time sanding them than anybody else does, probably. As I am
sanding/polishing them them with pretty fine grits, let's say 600 or so,
the heat from the sanding darkens them a fair amount.

That's called "burning". It's entirely different from the rich red-brown
patina that cherry acquires after a few years of exposure to sunlight.

We bought a Cherry Grandfather clock in 87 and it glows very nice.
Sadly spiders got into it and jammed the gears. Put camphor balls to run off
people and spiders. :-)

Martin

Doug Miller wrote:
In article , spaco wrote:
I am very inexperienced at this, but I have made 5 cherry bowls. I
spend more time sanding them than anybody else does, probably. As I am
sanding/polishing them them with pretty fine grits, let's say 600 or so,
the heat from the sanding darkens them a fair amount.

That's called "burning". It's entirely different from the rich red-brown
patina that cherry acquires after a few years of exposure to sunlight.

As the originator of this thread and a retired chemist, I am glad someone
finally clarified the situation with acid and water. The only real
dangerous actor is concentrated sulfuric acid as far as reacting violently
with water. And I agree about Hydrofluoric acid (HF). This is really nasty
corrosive stuff. On the other hand, sulfuric acid has little odor but a
sniff of hydrochloric with clear up your sinuses real quick (not
recommended). Do not really want to prolong this thread too far but I have
another question to throw out. What about turning immature black walnut.
It has a lot of grain but not the typical walnut color. Is there a way to
treat a bowl turned with immature walnut to convert it to the typical Brown
color. I tried ammonia but it didn't seem to have any effect.

Bob
"Paul Gilbert" wrote in message
...
On Jan 15, 10:39 pm, "Leon" wrote:
"Ecnerwal" wrote in message

...





In article ations,
Kevin Miller wrote:

The reason is a bit less obvious than that, as demonstrated in
high-school chemistry to make the point. At least back when I went to
high school it was - with all the skittishness about exposing young
persons to the faintest shred of real life, it's no doubt no longer in
vogue, regardless of proper safety precautions.

When you add water to acid, the water can be heated to boiling - I
forget the details of why, but I remember the effect. Effectively, you
can consider acid dilution to be an exothermic "reaction." The heat is
there in either direction, but the distribution of heat is significantly
different with acid to water .vs. water to acid. When water is added to
acid and the water flashes to steam, you get acid being flung out of the
container by the steam - not good.

Chemistry students who retained more are welcome to fill in the details,
or the web probably can as well. I don't need them, I recall the effect
and that's plenty for me.

I'll attest to that. Brought back memories of my early automotive days and
filling dry batteries with suulfuric acid and topping off a battery with
water. Adding water to a charged battery would result in what appeared to
be boiling acid.
Then there was the time I was filling a new battery with sulfuric acid and
the hose came off of the acid container, tghe acid poured right into my
crotch. Thank goodness there was a Coke machine near by.

The order of mixing water and acid is very important with sulfuric
acid, but of no real concern with hydrochloric.
In the lab we keep 1+1 hydrochloric acid (1 part water + 1 part 30%
acid) on the shelf for routine use. It doesn't
fume like the concentrated stuff and is generally easier to handle.
You can spill the 1+1 on your skin and simply
rinse it off with water with no damage. It is concentrated sulfuric
acid (battery acid) that is dangerous to handle.
FWIW, the worst burn I ever got in 30 years in the lab was from
Hydrofluoric acid (the stuff used to etch glass).
Now that's some bad s---!
Paul Gilbert - retired chemist

In article , Bob Daun
wrote:

Do not really want to prolong this thread too far but I have
another question to throw out. What about turning immature black walnut.
It has a lot of grain but not the typical walnut color. Is there a way to
treat a bowl turned with immature walnut to convert it to the typical Brown
color. I tried ammonia but it didn't seem to have any effect.

I remember reading that this is done commercially to stretch out the
amount of marketable Black Walnut.

Someone will doubtless jump in here with the relevant details, but if I
recall correctly, it involved heating in water [?] to dissolve some of
the colored substances from the heart and deposit same on the lighter
sapwood...

It's probably more complicated than that :-)

-j