- Early Experiments -
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- A short poem by Langston Hughes:
Gather out of star-dust
Earth-dust.
Cloud-dust.
Storm-dust.
And splinters of hail.
One handful of dream-dust
Not for sale.
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Before the description starts of the first attempts at seeing
how the brown wax works, I think that it's appropriate here to
pause and have a look at some of the information that can be
gleaned from the formula given in the old book.
The formula as given lists the ingredients as:
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Stearic acid: 12 pounds
Lye: 1 pound
Aluminum Oxide: 1 ounce
Tempering (ceresin or paraffin): 2 pounds
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Right away it can be seen that this would make about 15 pounds
of wax! That is not exactly a small amount that lends itself to
experimentation. To do the experiments in order to get the feel
of how it works, or more like: whether it is even going to work
at all, the first thing that is needed is to cut down all the amounts
to a workable size for testing.
Since it is all in weights, a scale will be needed, but right at
the very start I only had the crudest old spring-type postal scale
which is not very accurate. By looking at the formula, the following
things can be seen:
1) The ratio of stearic acid to lye is 12 to 1.
2) The ratio of stearic acid to tempering is 6 to 1.
3) The ratio of stearic acid to aluminum oxide is 192 to 1.
4) The ratio of lye to aluminum oxide is 16 to 1.
It appears that for any given amount of stearic acid that is used
as the base, that all other amounts of the other ingredients can
be calculated using ratios.
Also, referring back to the text of the recipe, it makes no
mention of how the lye is added to the melted stearic. Is it supposed
to be dumped in all at once? Or is it supposed to be added slowly,
a bit at a time and allowed to cook in? The procedure as listed in
the book formula is only a most general description, not at all
specific nor detailed. It is...an outline...at best.
By the way, Paul Morris in the U.K. has a great web site where he
describes in some detail how the lye solution is indeed added
"portionwise", slowly, a bit at a time, and allowed to cook in
thoroughly. At the time of these first experiments though, this
was a long way off. I needed to see if any of it was going to
work at all, in the slightest. Never mind how good or how poorly
it might work, does it even work at all? That needed to be answered.
I should say here, now, in case you are wondering about what
stearic acid looks like: It's white and soft and rather crystaline
looking. It comes as flakes usually. Flat little white flakes
about half the size of cornflakes and it has a somewhat waxy
feel. The lye is usually hard white small crystals.
The ceresin wax looks pretty much like paraffin, only ceresin
has a finer "grain" when looked at under magnification. More about
that later.
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The following is taken out of my notebook and scrap papers:
7/30/09:
1 cup distilled water.
2 heaping teaspoons lye crystals.
Dissolved in aluminum foil until reaction cooled and slowed
way down. Filtered liquid through paper towel to separate
black powder precipitate from liquid.
Lesson #1: Do not use plastic jar to do the lye/aluminum reaction.
It gets hot and deforms the bottom of the jar.
Saturated solution with as much aluminum as it can possibly hold.
Too much aluminum probably will try less aluminum to find
correct amount. It is also good to point out here that the old-time
cylinder wax makers called the lye/water/aluminim solution by various
names. It is sometimes seen noted as "hydrated alumina", "caustic
alumina", "hydrated aluminum", "caustic aluminum". I later settled
on calling it "hydrated alumina", but in the very beginning I was
still thinking of it as aluminum oxide.
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Determine melt point of stearic: 53 C----> 127 F
Melted 2 teaspoons of stearic in aluminum pan. Pan was warm from
cleaning. Did not even heat it to melt stearic.
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Notes from first batches attempted:
Batch #1: 1 cup stearic acid. 1/12 th cup lye. 2/3 cup distilled water.
This batch was attempted in big crock pot. It was a miserable failure.
All clumpy and dry and all the hellfire in hades will not melt it.
Added raw lye crystals. Later determined that too much lye had caused
the curdling. No hope. This batch is ruined. NO GOOD!
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Batch #2: Tiny sample: 1/4 teaspoon hydrated aluminum.
1 tablespoon stearic acid. (measured 3/4 inch deep in
orange-juice glass. Cooked in stainless measuring cup)
Stayed clear. Kept adding hydrated aluminum until it turned dark.
Added a few shavings of ceresin. Cooked. Lots of smoke. No fire.
Temp was 220 C and climbing to 230 C. Looks good. Sample wrinkled
as it cooled. Hopeful. (this was made in a 1/2 cup stainless steel
measuring cup on the kitchen stove). This tiny batch
was no more than a few tablespoons, but it did turn brown and it
wrinkled up after cooling and it has a waxy texture.
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Batch #3: Next try melting stearic and adding hydrated alumina.
Appears to work. Must keep adding alumina until it gets thick and dark.
Added a generous amount of ceresin. Poured it out to harden and it was
lighter colored than batch #2. It also exhibited the "flash-cooling"
[outside case] of good wax that surrounds the less good wax. Remelted
and added more alumina. Added too much alumina. All foam. Added a
little bit more stearic. The foam settled down. Color darker now.
Sample has white in middle.
Remelted, added alumina, cooked again at 230 C.
This time it came out dark and homogeneous. No rippling though.
About 3 crystals of lye. A few dashes of distilled water.
1/2 of an orange-juice glass of stearic acid.
A few ceresin shavings. A few drops of aluminum oxide (the lye/water/
aluminim solution previously made). This batch also turned brown
and wrinkled cooling. Using the end of a Pentel mechanical pencil
tip with the writing lead pushed in, I reasoned that this has the rough
shape of an Edison recorder cutter. I placed this against the cooled
test sample of wax and tilted it at about a 15 degree angle and
pushed it along slowly. I saw a nice curly little shaving turning
up very nicely from the end of it. It was cutting the wax!
"This is going to work".....I knew it right then.
Will now attempt to adjust the M16 batch further.
All of the above small samples were made using the concentrated
saturated solution of lye/water with as much aluminim as it could hold.
This explains the very dark color so easily obtained.
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7/31/09:
Batch #4: 3) plastic orange-juice glasses full of stearic acid.
A few drops of distilled water, (18) lye crystals. Ceresin shavings
off of block, A few drops of the concentrated hydrated alumina solution.
First batch big enough to cast a cylinder.
Casting M13: FAIL. Seized core, middle molten. (a real mess) Re-melted.
Casting M14: FAIL. But did record a few tests before remelting.
Had heated mold core with heatgun prior to casting.
Casting M15: Successful! Used aluminum foil over core. Core extracts
easily. Poured in to stone-cold mold. Lots of white precipitate in
this one. Noticed before that flash-cooling creates a nice surface layer
about .050" thick. Wax may have been heated too hot this time for
good flash-cooling. Next time try pouring wax a bit cooler.
7/31/09:
Casting M16: Successful. Used aluminum foil wrapped around mold
core. Taped at outside. Melted wax. Let stand to cool a bit.
Poured into cold mold. Mold release no problem. Flash cooling of
wax by cold mold produced some better thin-shell of good wax this
time, than M15 did. Some air bubbles near the surface. Not so many
bubbles deeper in. This casting still has a lot of white precipitate.
Some ediphone shavings included.
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Note from 4/15/13:
Even though casting M16 was a workable blank, it was not good
enough and so after a few recording tests, back into the pot
it went with the rest of the M16 batch. Now back to the 7/31/09 notes:
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This wax is runny when melted.
It has white streaks. Runny + low melt point + streaks seems to mean:
Not enough alumina.
Heated up this batch and melted in casting M16.
Added all the reamining alumina slowly, cooking between each
small addition. The final addition foamed it all up, and that is
the sign it is getting close. Too much and it's all foam, then some
stearic must be added to reliquify it. Final result is thick to
stir and dark. Recall the sticky "chocolate fudge" batch, which turned
out very dark. That I think is the extreme of too much alumina.
It makes a sticky, tarry, gummy mass, or it is all foam.
When mold gets pre-heated in oven, if aluminum foil is wrapped
around the core, a better way than scotch tape will have to be
used to fasten the outside of it.
----> This way turns out to be superglue.
7/31/09:
Heated up M16 batch and that just got cooked with lots
of additional alumina, and cast it into cold mold with aluminum foil
around core. This is casting M17. It has an air hole 7/8" from
right side, and a crack that goes in from left 1-1/4". Rough casting
otherwise ok. Very dark brown.
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Noticed that when heating the M16 batch, that it went through a
rather tarry, gummy, fudge-like stage. This may mean that this
batch has very nearly too much alumina. Could try adding some stearic.
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Also noticed today 7/31/09 that cookng small batches of wax in a tall
container such as a can or an old coffee pot tends to maybe prevent
flashing. (catching on fire)
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8/1/09:
Casting M17 is hard, brittle and noisy. M17 has air pockets.
Possible reasons for noise:
-Maybe the white powder in the aluminum solution needs to be
excluded from the wax.
-Maybe just the liquid is all that is needed.
-The shaved surface is textured and not smooth.
The texture could be from too much ceresin.
-Maybe need to try casting with this batch using pre-heated mold.
-Maybe add cersesin to soften and try to filter this batch.
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8/1/09:
Idea: Original recipe calls for 1 oz aluminum oxide and 1 pound
of lye. This is a ratio of 1:16 by weight. This might imply that
a fairly weak concentration of aluminum in lye water may provide more
nearly the correct ratio.
Experiment: Start with:
1 cup distilled water.
2 heaping teaspoons lye.
1 square foot of the thin .0005" aluminum foil.
Filtered 3x through heavy paper towel.
Filtered 2x more through double light paper towel.
Ratios by weight:
stearic 12 --------> 1
lye 1 -------------> 1/12
alum oxide 1/16 ---> 1/192
ceresin 2 ---------> 1/6
No particles.
No precipitates.
Just clear liquid.
Not nearly as much aluminum as the first batch had.
8/1/09
1) Heating in 1/3 cup stainless container.
Used 2 teaspoons stearic melted.
Added many eyedroppers full of alumina until brown.
Let sample cool and harden a few times.
Added a lot more ceresin.
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2) Tried boiling alumina, then adding cold stearic = hopeless
dry dough ball just like the very first failure in the crock pot!
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3) Melted stearic added to boiling alumina all at once, no ceresin.
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4) Plain stearic and lye water. No aluminum. No ceresin. Very brittle.
Later added some of the granular 252P ceresin.
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5) Try adding ceresin to M17 batch. Tried filtering again thru paper
towel and old T shirt. No good. Added ceresin. This becomes M18 batch.
SEPARATED by heating and pouring off top and wiping
out bottom of pot to get out particulate stuff.
(This ended up quieting-up this batch to some extent)
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M18 FAIL
16:53 Mold in oven
17:47 Poured. Wax was 175 C (about 350 F).
17:54 Failed: Released from steel cyl. first. Casting held fast to core.
Perhaps mold was way too hot. Noticed wax on outside of mold still
soft when mold was still warm 45 minutes after pouring.
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M19
19:35 Mold cylinder and base in to oven.
Core stays cool this time, with alum. foil taped on.
Mold will be hot outside, cold inside.
Oven peaked at 475 F (19:55)-----> 500 F at 19:59
Poured 20:01
Core out 21:00 Casting was defective. Inside ok. Outside had large
long cooling slumps about 1/32" deep x 1/2" wide. Shaved down to
2.12" dia. then cut 1-1/16" off of right side to record on.
Results encouraging. Then shaved remaining 3-5/16" lg. cyl. down to 2.088"
dia. and recorded on it. Surface noise is present but not absolutely
horrible.
Notes from 8/1/09: Casting of M19:
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Preheating the outside steel cylinder only, leaving the core cool
does not produce a good casting. This produces cooling slumps in
the outside surface of the casting. The wax actually pulls away from
the mold's surface while cooling.
The M19 wax batch has a long range of temperature as it cools where
it is soft, nearly melted, but not liquid, but very pliable.
This property (sort of a melting-point hysteresis) may cause this
wax to never release properly from this mold. The wax is almost
rubbery when warm but not melted.
Maybe try a lower preheat such as 200 to 300 F to see if there is
any possible way to get this batch to release properly.
Also noticed this batch has excessive shrinkage.
The excessive shrinkage may be due to the excessive amount of aluminum
in this batch. Recall that this batch was cooked with the addition
of all the reamining original concentrated aluminum solution.
I think there is a way to make a correctly concentrated aluminum
solution which can be used as the only ingredient to be added
to the stearic, except for the ceresin.
The first aluminum solution was as saturated as I could make it.
It ended up with lots of settled black powder on the bottom which
was filtered and removed.
But then, a day later, a white precipitate appeared on the bottom.
I made the mistake of pouring this in to the wax after agitating
it in to the alumina solution.
This particulate adds noise I think.
Ended up getting most of it out by pouring off the hot wax and wiping
the bottom of the pot twice. That reduced surface noise. It amounted
to a crude form of gravity separation to get the paticulate matter out
of the wax.
My theory is that by carefully mixing a known quantity of aluminum
with a known quantity of lye and distilled water, that the proper
mixture can be had that will darken and thicken the melted stearic
just right so that it has good shrinkage, but not too much, and
also the correct chemical balance to use up all the free stearic acid
so there is no internal white mottling or streaking.
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<end of quoted text from my notebook>
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And so the experiments continued all the way through August, 2009.
Blanks M20 through M30 were all variations of the basic things
discussed so far. Various concentrations of lye/water were tested,
along with varying amounts of dissolved in aluminum.
Some very encouraging blanks came along in the M20s.
By the 9th wax batch and casting M28, I finally had a cylinder
that is the exact color of an Edison original. M28 was by far my
best yet, and it still is a milestone even looking back now in 2013.
Its only flaw is that it's a bit "chippy". That is my term for
somewhat brittle. The recorder cutters tend to dig in a little bit
at first, throwing out tiny chips before it starts cutting regular
fine swarf. Things improved somewhat more after M28, and up to M33.
Those 5 blanks were not bad. But, after M33, everything changed.
The biggest and most valuable lesson so far was that the
grit in the bottom of the solution made with the aluminum
reacting with the lye is indeed partly the dreaded abrasive
aluminum oxide! Using much less aluminum so that the solution
is nowhere near saturated keeps there from being much of that
precipitate, and what little is there can easily be filtered
out using proper filter paper. Using a weakly concentrated
solution that has been filtered until absolutely water-clear
improves this wax a lot!
The pre-heat temperature of the mold got adjusted several
times using many trials and tests. By the time M33 was cast
on 8/26/09, some of the blanks were actually starting to be
worth saving and recording upon.
But by 9/1/09 I had another hard look at the aluminum/lye/water
ratio, and the relative ratio of all of those things to the
stearic. There had to be a better way to measure everything, and also
some way to know how much aluminum is really needed.
In order to improve things beyond this point, I first needed an
accurate scale to weigh the ingredients, then I also needed to
know what the relationship is between aluminum oxide and pure aluminum,
so that I could somehow match what the formula in the old book was
calling for, only substituting pure AL metal instead of AL2O3 that
the book called for.
This situation led to a flurry of activity during the last few weeks
of August and the first week of September, 2009.
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Thermometer
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Being situated out in a very small town in a farming community in
the vast flat fields of rural Illinois, where the closest store is
7 miles away, and the closest real store is 23 miles away, things there
must usually be done using available materials. That is, if you want
to get anything done. Sure, you can spend all of your time endlessly
chasing around trying to find things at stores, or you can spend time
online trying to buy things on Ebay. Indeed I did find a very nice proper
old-fashioned laboratory thermometer which is made of glass and it has
mercury in it. Its range is from -5C to 250C, and above 250C the tube
continues for about 1-1/4". There are no marks above 250C, but the
mercury continues right on up there and if one estimates, one can
use this thermometer for temperatures of 280C and just a hair over.
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Beam Balance
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As for an accurate scale to weigh ingredients: that was not so
easy to find. Sure, there are lots of newfangled digital scales
that must have a battery put in them to operate. There are also tons
of old analog scales on Ebay all the time made by O'haus. Some of those
have springs in them that are used in the fine adjustment. Springs
of any kind in a scale always introduce temperature variations.
I was after a beam balance.
So, I constructed one from scratch. Materials: Old wooden yardstick.
Roll of strong nylon cable-lacing cord. Drill with 1/16" bit.
Various small pieces of stout steel wire. Small plastic drawer full
of #10 split washers. Method: one 1/16" hole was drilled through
the yardstick in the middle, at the 18" mark. Then it was hung
from the rafters using the nylon cord and calibrated to balance
perfectly level by adding a small amount of weight by twisting a
wire around the right side. The nylon string being looped through
the center-hole provides a very low-friction pivot. If a fly lands
on the yardstick, it tilts way off of level.
Once in balance, I then went about drilling holes at the following
inch marks: 1, 2-7/8, 6, 16, 20, 30, 33-1/8, 35.
Then went about making (8) identical "S" hooks that all have the
same weight. By this time enough of this balance was working that
making the hooks all the same weight was easy. Then the hooks were
installed in the (8) holes in the yardstick. That's it! It was finished!
It is a beam balance that has the following ratio-arms:
1:1
1:7.5625
1:8.5
1:6
The handiest and best little weights I could find for use on this
new balance were found right in my screw cabinet on the workbench.
They are #10 split washers. I weighed them repeatedly to find out
if they average out to nearly the same identical weight. They are
remarkably accurate in this regard. After some amount of calibration
and testing, it was determined that each of these washers weighs about
.2674 grams each.
This was found by noting that 106 of these washers weighs exactly
1 ounce. I borrowed the 1.000 ounce calibration weight from the
local post office one afternoon to arrive at this finding.
I copied that calibration weight, making my own version of it which
I keep with the beam balance in order to make sure it is always
accurate.
So, if 106 washers weighs one ounce then 1/106 = .009433962 ounce
per washer.
Then by hanging the wax ingredients in small plastic bags which all
have the same weight, and by using the ratio-arms on the balance, it
is possible to accurately weigh out the lye, aluminum, stearic acid,
and ceresin wax in precise amounts, in the exact ratios needed.
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Back to the Aluminum
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From my notebook:
8/31/09: If lye=1 then alum. oxide = 1/16 that amount.
If lye=1 then alum. metal = (1/16)x(.5294) = .0331 = 1/30.2229
<note from 2013: where does .5294 come from? Read the next
segment to see it.>
Using yardstick balance: 1/30.2229 -----> 1/15.1114 -----> 1/7.5557
2/15.1114 -----> 2 to 15.11 ------> .1324 ratio = 1/7.5557
This is where the hooks on the yardstick come in.
There is a hook 2 inches from the central pivot.
There is another hook 15.125 from the central pivot.
15.125/2 = 7.5625. The number we are after is 7.5557. We have available
the number 7.5625.
Make balance with ratio 2" to 15.11. (settle for 15.125)
Weigh lye and aluminum accordingly.
Then divide aluminum in half, then in half again (divide by 4)
to obtain 1: 30.2229 ratio by weight.
Starting with 4 teaspoons of lye on the 2" side balanced by (16)
split washers on the 15.125" side, therefore 4 split washers of
aluminum is the correct weight of aluminum.
A 6" x 6" piece of .0005 thick aluminum foil balances (4) washers using
equal balance arms.
6" square is 1/4 of a square foot of aluminum used for 4 teaspoons of
lye. Previously, there had been 2 square feet of aluminum foil used
for 2 teaspoons of lye. This is a difference of 16 times!!
Sixteen times too much aluminum! No wonder blank M28 was "chippy".
<end of quoted text from my notebook>
The above description shows a few of the fundamental ratios of the
ingredients which were made possible by having an accurate scale
on which to weigh them. My process has been all calibrated in
"washers", and is very easily converted to more conventional measuring
systems such as ounces, pounds, or grams.
The yardstick balance is accurate within a range of roughly +/- 0.1 grams
Each washer weighs roughly 1/4 gram, and it is very easy to spot
"a half a washer" weight difference by eyeballing how far off of
level the yardstick is when balanced.
What it lacks in convenience it makes up for in cost (which was zero).
And...the best part is that it totally blows an O'haus "Dial-O-Gram"
scale clear out of the water because the hillbilly beam balance
retains accuracy over all temperatures, where as the "Dial-O-Gram"
gives vastly different readings when it is 95 degrees F versus what
it says when it's 60 degrees F. The "Dial-O-Gram" scale uses
springs which is a no-no. The beam balance uses gravity which does
not vary.
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Next segment: How's your chemistry?
