drying acetone

[Frozentech]

What is the procedure used to ensure that acetone used as a solvent in
compositions is as anhydrous as possible ? I have seen mention of
"Damp-Rid" Calcium Chloride, and molecular seives being used. Is CaCl
added into Acetone, then filtered out ? How exactly does one go about this?
I don't think moisture will be a problem with a new can of solvent, but as
time goes by and the level drops in the can I imagine it will pick up H2O.

Mark

[h***@yahoo.com]

Mark, are you joking?

Then too, what fireworks compositions is it in which you are using
acetone that create this concern.

Also, being baked out in the sun can do wonders, as can a simple drying
box.

Harry C.

[Frozentech]

Post by h***@yahoo.com
Mark, are you joking?
Then too, what fireworks compositions is it in which you are using
acetone that create this concern.
Also, being baked out in the sun can do wonders, as can a simple drying
box.
Harry C.

No, not joking... most of the go-getter inserts call for acetone as the
solvent, with the comp at "pancake batter" consistency for filling the
inserts. I had read a few cases of problems caused by excess moisture
picked up in the acetone.

[Frozentech]

Post by Frozentech
What is the procedure used to ensure that acetone used as a solvent in
compositions is as anhydrous as possible ? I have seen mention of
"Damp-Rid" Calcium Chloride, and molecular seives being used. Is CaCl
added into Acetone, then filtered out ? How exactly does one go about this?
I don't think moisture will be a problem with a new can of solvent, but as
time goes by and the level drops in the can I imagine it will pick up H2O.
Mark

Ack ! I just found some good info on using 3A molecular sieves to dry
acetone, but it's pricey. I thought some pyro chemicals were expensive,
but $80 range for 100g ? Even if I could regenerate the sieves
(safely), Damp Rid is dirt cheap... I am looking for details on using
CaCl.

Mark

[Leo]

Post by Frozentech

Post by Frozentech
What is the procedure used to ensure that acetone used as a solvent in
compositions is as anhydrous as possible ? I have seen mention of
"Damp-Rid" Calcium Chloride, and molecular seives being used. Is CaCl
added into Acetone, then filtered out ? How exactly does one go about this?
I don't think moisture will be a problem with a new can of solvent, but as
time goes by and the level drops in the can I imagine it will pick up H2O.
Mark

Ack ! I just found some good info on using 3A molecular sieves to dry
acetone, but it's pricey. I thought some pyro chemicals were expensive,
but $80 range for 100g ? Even if I could regenerate the sieves
(safely), Damp Rid is dirt cheap... I am looking for details on using
CaCl.
Mark

I thought Skylighter or maybe firefox used to sell molecular sieves as
star cores? I can't find them at either site now. I did find some
listed under Star-Rolling Cores at discountpyro.com. It says 50 Cents
but could that really be a pound for that price? Maybe it's per ounce
or something? Still much better than the price you mentioned.

It's been mentioned here before that you can use plaster of paris to dry
acetone then filter it out.

Leo

[Frozentech]

Post by Leo
I thought Skylighter or maybe firefox used to sell molecular sieves as
star cores? I can't find them at either site now. I did find some
listed under Star-Rolling Cores at discountpyro.com. It says 50 Cents
but could that really be a pound for that price? Maybe it's per ounce
or something? Still much better than the price you mentioned.
It's been mentioned here before that you can use plaster of paris to dry
acetone then filter it out.
Leo

Not sure, I have heard of molecular sieves as star cores though. The info
I was finding through Google indicated that 3A (3 angstrom porosity)
sieves were used to dehydrate acetone, and those were spendy.

I tend to trust this group or PML above google search results. I was
hoping for a 1st person report on the procedure is all :) Thanks for the
lead on using Plaster of Paris.

Mark

[Andy H. <andys_junk_address at yahoo dot com>]

The sieves sold by DiscountPyro are $.50/lb and are the correct size
for drying acetone. David (the proprietor) has so much (a few drums
worth) that he's selling them CHEAP and giving them away with orders
of plastic shell casing. He's a great guy.

Post by Leo

Post by Frozentech

Post by Frozentech
What is the procedure used to ensure that acetone used as a solvent in
compositions is as anhydrous as possible ? I have seen mention of
"Damp-Rid" Calcium Chloride, and molecular seives being used. Is CaCl
added into Acetone, then filtered out ? How exactly does one go about this?
I don't think moisture will be a problem with a new can of solvent, but as
time goes by and the level drops in the can I imagine it will pick up H2O.
Mark

Ack ! I just found some good info on using 3A molecular sieves to dry
acetone, but it's pricey. I thought some pyro chemicals were expensive,
but $80 range for 100g ? Even if I could regenerate the sieves
(safely), Damp Rid is dirt cheap... I am looking for details on using
CaCl.
Mark

I thought Skylighter or maybe firefox used to sell molecular sieves as
star cores? I can't find them at either site now. I did find some
listed under Star-Rolling Cores at discountpyro.com. It says 50 Cents
but could that really be a pound for that price? Maybe it's per ounce
or something? Still much better than the price you mentioned.
It's been mentioned here before that you can use plaster of paris to dry
acetone then filter it out.
Leo

[r***@bestweb.net]

Post by Frozentech
What is the procedure used to ensure that acetone used as a solvent in
compositions is as anhydrous as possible ? I have seen mention of
"Damp-Rid" Calcium Chloride, and molecular seives being used. Is CaCl
added into Acetone, then filtered out ? How exactly does one go about this?
I don't think moisture will be a problem with a new can of solvent, but as
time goes by and the level drops in the can I imagine it will pick up H2O.

If I NEED anhydrous (not all recipes using acetone do), I dry the
acetone "over" MgSO4 or CaSO4, just because these are readily available
& cheap. The MgSO4 is purchased as Epsom salts and then dried to about
1.5 moles hydration (known by weighing) in the microwave oven and then
cooled just before use. That takes some doing, so now I use only
CaSO4, purchased as Plaster of Paris, which may be used as such or with
a mole's hydration similarly driven off by microwaving.

The acetone is put into a bottle and swirled with an excess of the
drying agent with a good cap on tight. The drying agent may be allowed
to settle and the liquid decanted, or it can be filtered into another
container. If you decant, you can keep adding acetone & drying agent
to the bottle as needed. If you use a color changing drying agent, you
get a strong indication of whether you need more, but you can also get
good at recognizing the change in hydration of MgSO4 or CaSO4. Use a
drying agent compatible with your formula, figuring on a little
contamination if you decant.

If you use an expensive drying agent, you can "recharge" it by
carefully drying it of solvent in the air (so as not to damage your
apparatus) before oven drying it and cooling it either just before
reuse or after storage in an air tight container.

Robert

[Frozentech]

On Thu, 20 Oct 2005 10:38:57 -0700, robgood wrote:

Thanks Robert ! I doubt I will need 'dry' acetone very often myself, just
wanted to know how best to do it. I've read accounts of overly wetted
acetone leading to a mess while loading go-getters and wondered how they
got past it.

Mark

[donald haarmann]

<***@bestweb.net>| If I NEED anhydrous (not all recipes using acetone do), I dry the
| acetone "over" MgSO4 or CaSO4, just because these are readily available
| & cheap. The MgSO4 is purchased as Epsom salts and then dried to about
| 1.5 moles hydration (known by weighing) in the microwave oven and then
| cooled just before use. That takes some doing, so now I use only
| CaSO4, purchased as Plaster of Paris, which may be used as such or with
| a mole's hydration similarly driven off by microwaving.
|


[snip]


------------
I would note in passing - There are 2 hydrates of calcium sulphate ....

- 2.0 H2O
- 0.5 H2O (plaster of Paris)

Anhydrite - anhydrous CaSO4 is found in nature. A special form of anhydrous
calcium sulphate having a highly porous granular structure and a high affinity for water,
coated with a cobalt compound that changes from blue to pink when wet is the
common laboratory dehydrating agent DrieriteT.

The premier desiccating agent is phosphorus pentoxide. For gasses a LN2 cold trap can
work wonders.

[r***@bestweb.net]

Post by donald haarmann
| If I NEED anhydrous (not all recipes using acetone do), I dry the
| acetone "over" MgSO4 or CaSO4, just because these are readily available
| & cheap. The MgSO4 is purchased as Epsom salts and then dried to about
| 1.5 moles hydration (known by weighing) in the microwave oven and then
| cooled just before use. That takes some doing, so now I use only
| CaSO4, purchased as Plaster of Paris, which may be used as such or with
| a mole's hydration similarly driven off by microwaving.
------------
I would note in passing - There are 2 hydrates of calcium sulphate ....
- 2.0 H2O
- 0.5 H2O (plaster of Paris)

Heh...then it looks like I can't drive off a whole mole's worth of H2O
from the latter after all! I thought I'd bought the dihydrate as P of
P. Maybe I actually prepared anhydrous by microwaving; took a while,
anyway.

Robert

[Tim Williams]

<***@bestweb.net> wrote in message news:***@g44g2000cwa.googlegroups.com...
<MgSO4>

Post by r***@bestweb.net
That takes some doing, so now I use only
CaSO4, purchased as Plaster of Paris, which may be used as such or with
a mole's hydration similarly driven off by microwaving.

Erm? As sold, PoP comes with a half mole of hydration, i.e.
CaSO4.1/2 H2O. It hydrates to CaSO4.2H2O, which is stable, neither
deliquescent (to my knowledge) nor hygroscopic in any humidity. This form,
known as gypsum, dehydrates around 250°C (450°F) to the hemihydrate, which
is stable until approximately red heat (650°C/1200°F).

So in the microwave, you're getting it red hot? I doubt it, so if you are
indeed measuring a loss of 1 mole hydration, the PoP must not be what it
claims to be...

FYI, I've got an open bucket of sand + plaster mix (I use it for lost wax
casting) in the humid basement, and as far as I know it still works just
fine and is still free and loose, not caked up, so if it is still setting by
dehydration, I wouldn't put too much stock in using the hemihydrate as
dessicant.

Tim

--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms