A book I have (Renovating Old Houses by George Nash) noted as an aside
in one sentence that plaster will only stay usable for around a year. I
just bought 100 lb. of plaster (50 lb. USG Struct-o-lite and 50 lb. USG
Diamond Veneer Finish plaster) and wonder if it will last longer if I
store it in air-tight containers and store in a cool location. When I
bought these last week I had no idea it wouldn't keep indefinitely. I
have a lot of plaster work to do, but may well not get around to 95% of
it for a year or longer. Anyone have experience with these things?
Thanks for any info.

Dan

Dan_Musicant writes:

wonder if it will last longer if I
store it in air-tight containers and store in a cool location.

Plaster will strike in the bag due to infiltration of humidity. It will
still be a powder that mixes up OK, but given enough storage time and
humidity before use it will have a final strength of a Ritz cracker.

I would think the cost of proper containers would approach the cost of the
plaster.

Most cost effective would be 5-gallon paint buckets with the O-ring lids,
with a sock full of calcium chloride as a dessicant.

Easy enough to do your own "lab" testing later to verify setting quality.
Make some cylindrical samples (cast in a pill bottle) now and when you plan
to use it. See if you find any difference in strength or setting time.
Better than wasting a lot of labor on material that turns out to be flawed.

Steady non-condensing relative humidity is more important than cool.
Warmer may make your RH lower.

In article , Dan_Musicant wrote:
A book I have (Renovating Old Houses by George Nash) noted as an aside
in one sentence that plaster will only stay usable for around a year. I
just bought 100 lb. of plaster (50 lb. USG Struct-o-lite and 50 lb. USG
Diamond Veneer Finish plaster) and wonder if it will last longer if I
store it in air-tight containers

Yes, absolutely. In an air-tight container, it will stay fresh for a long time
(at least two years, in my experience, and I live in an area with fairly
humid summers).

and store in a cool location.

Temperature doesn't really matter that much. What's important is keeping it
dry.

When I
bought these last week I had no idea it wouldn't keep indefinitely. I
have a lot of plaster work to do, but may well not get around to 95% of
it for a year or longer. Anyone have experience with these things?

It's better to use your plaster as soon as possible after opening the bag, but
the stuff will keep a long time as long as you keep it dry.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Tue, 29 Aug 2006 01:57:23 GMT, Dan_Musicant
wrote:

A book I have (Renovating Old Houses by George Nash) noted as an aside
in one sentence that plaster will only stay usable for around a year. I
just bought 100 lb. of plaster (50 lb. USG Struct-o-lite and 50 lb. USG
Diamond Veneer Finish plaster) and wonder if it will last longer if I
store it in air-tight containers and store in a cool location. When I
bought these last week I had no idea it wouldn't keep indefinitely. I
have a lot of plaster work to do, but may well not get around to 95% of
it for a year or longer. Anyone have experience with these things?
Thanks for any info.


It will keep longer in an airtight container with dessicant, but
still not forever. Plaster is cheap. Give the excess to your kids to
play with.

On Mon, 28 Aug 2006 21:53:19 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: wonder if it will last longer if I
: store it in air-tight containers and store in a cool location.
:
:Plaster will strike in the bag due to infiltration of humidity. It will
:still be a powder that mixes up OK, but given enough storage time and
:humidity before use it will have a final strength of a Ritz cracker.
:
:I would think the cost of proper containers would approach the cost of the
laster.
:
:Most cost effective would be 5-gallon paint buckets with the O-ring lids,
:with a sock full of calcium chloride as a dessicant.
:
:Easy enough to do your own "lab" testing later to verify setting quality.
:Make some cylindrical samples (cast in a pill bottle) now and when you plan
:to use it. See if you find any difference in strength or setting time.
:Better than wasting a lot of labor on material that turns out to be flawed.
:
:Steady non-condensing relative humidity is more important than cool.
:Warmer may make your RH lower.

Thanks for the post. I cut open the bags last week and put the plasters
in plastic bags, fairly thick ones mostly. But I got the idea shortly
thereafter to use some plastic buckets I have. These aren't 5 gallon
buckets but food service buckets I got from a fast food place. They gave
them to me free. They had 10 lb. potato salad in them and I got them
with the tops. I have 13 of them now, and can get an unlimited supply in
the future for free (I made an arrangement with another source.

I presume they will be air tight, but I think your admonisions are
advisable - dessicant and testing. I would never have thought of the
dessicant, and I wouldn't have done the testing without your suggestion.
However, like you say, it's really important that I not invest time and
materials into repairs that turn out to be crap.

Great ideas with the old pill bottles. I have a bunch of them, been
saving them for some good use, and this is sure one. Thanks again.

Dan

PS: Anyone know where I can get calcium chloride in quantity
economically? Thanks!

In article ,
says...

snip

Thanks for the post. I cut open the bags last week and put the plasters
in plastic bags, fairly thick ones mostly. But I got the idea shortly
thereafter to use some plastic buckets I have. These aren't 5 gallon
buckets but food service buckets I got from a fast food place. They gave
them to me free. They had 10 lb. potato salad in them and I got them
with the tops. I have 13 of them now, and can get an unlimited supply in
the future for free (I made an arrangement with another source.

Nice. I buy them at the BORG. Free is better. ;-)

I presume they will be air tight, but I think your admonisions are
advisable - dessicant and testing. I would never have thought of the
dessicant, and I wouldn't have done the testing without your suggestion.
However, like you say, it's really important that I not invest time and
materials into repairs that turn out to be crap.

Not to mention the work to tear out crap.

Great ideas with the old pill bottles. I have a bunch of them, been
saving them for some good use, and this is sure one. Thanks again.

It is a good idea. I may have a little grout and thinset to do
this with.

PS: Anyone know where I can get calcium chloride in quantity
economically? Thanks!

The better sidewalk/driveway ice melter is calcium chloride (read
the container, NaCl isn't a desicant). You should be able to find
it for $12is for a 50lb bag at the BORG or a bit more at a hardware
store. It's also available (for a lot more $$) at grocery stores
in the winter (too soon now :-( ).

--
Keith

Dan_Musicant writes:

I cut open the bags last week and put the plasters
in plastic bags, fairly thick ones mostly.

Polyethylene bags are poor vapor barriers.

Anyone know where I can get calcium chloride in quantity
economically?

Swimming pool store.

On Wed, 30 Aug 2006 16:51:45 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: I cut open the bags last week and put the plasters
: in plastic bags, fairly thick ones mostly.
:
:Polyethylene bags are poor vapor barriers.

Thanks.
:
: Anyone know where I can get calcium chloride in quantity
: economically?
:
:Swimming pool store.

Thank you. It doesn't snow here, so swimming pool water conditioner is
easier had than snow melter.

On Mon, 28 Aug 2006 21:53:19 -0500, Richard J Kinch
wrote:

:Most cost effective would be 5-gallon paint buckets with the O-ring lids,
:with a sock full of calcium chloride as a dessicant.
A pool supply place I'm talking to doesn't have it but they stock
calcium hypochlorite, which he says is a "pool shocker" or some such
thing. Is that a dessicant (i.e. OK) or do I want calcium chloride? TIA

Dan

In article , Dan_Musicant wrote:
On Mon, 28 Aug 2006 21:53:19 -0500, Richard J Kinch
wrote:

:Most cost effective would be 5-gallon paint buckets with the O-ring lids,
:with a sock full of calcium chloride as a dessicant.
A pool supply place I'm talking to doesn't have it but they stock
calcium hypochlorite, which he says is a "pool shocker" or some such
thing. Is that a dessicant (i.e. OK)

No.

or do I want calcium chloride? TIA

In my experience, an air-tight container is sufficient. No need for a
dessicant.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Dan_Musicant writes:

A pool supply place I'm talking to doesn't have it but they stock
calcium hypochlorite, which he says is a "pool shocker" or some such
thing. Is that a dessicant (i.e. OK) ...

No. Calcium hypochlorite is an elemental chlorine source. You don't want
that near anything or even inside the house.

You want calcium chloride. Any pool supply place will have that. Perhaps
they're too typically ignorant to know the chemical name. They might only
know it as some variation of the words "calcium hardness increaser." Look
on the bag or tub for a chemical ingredient.

On Tue, 05 Sep 2006 16:42:19 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: A pool supply place I'm talking to doesn't have it but they stock
: calcium hypochlorite, which he says is a "pool shocker" or some such
: thing. Is that a dessicant (i.e. OK) ...
:
:No. Calcium hypochlorite is an elemental chlorine source. You don't want
:that near anything or even inside the house.
:
:You want calcium chloride. Any pool supply place will have that. Perhaps
:they're too typically ignorant to know the chemical name. They might only
:know it as some variation of the words "calcium hardness increaser." Look
n the bag or tub for a chemical ingredient.
The guy I had on the phone was far from knowledgable. Sounded like a
kid. He said to call tomorrow (which is today) and ask for his boss,
which I'm going to do right now...

I talk to him and he says they don't supply it. It's a place called HD
Pool and Patio Supply. I ask him for recommendations near me and he
gives me the name of a place that's around 15 miles from me. I think
I'll try looking up wholesale chemicals warehouses. I bought some
chemical some years ago from such a place and thought it reasonable.

On Tue, 05 Sep 2006 18:39:50 GMT, (Doug Miller)
wrote:

:In article , Dan_Musicant wrote:
:On Mon, 28 Aug 2006 21:53:19 -0500, Richard J Kinch
:wrote:
:
::Most cost effective would be 5-gallon paint buckets with the O-ring lids,
::with a sock full of calcium chloride as a dessicant.
:A pool supply place I'm talking to doesn't have it but they stock
:calcium hypochlorite, which he says is a "pool shocker" or some such
:thing. Is that a dessicant (i.e. OK)
:
:No.
:
: or do I want calcium chloride? TIA
:
:In my experience, an air-tight container is sufficient. No need for a
:dessicant.

The problem is that I'm uncertain if these containers will indeed be air
tight or not. I think they may be absolutely air tight, but I'd hate to
find out they aren't by having my plaster go bad, especially if I've
gone ahead and used it. I'll try to find a cheap source of calcium
chloride.

In article , Dan_Musicant wrote:
On Tue, 05 Sep 2006 16:42:19 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: A pool supply place I'm talking to doesn't have it but they stock
: calcium hypochlorite, which he says is a "pool shocker" or some such
: thing. Is that a dessicant (i.e. OK) ...
:
:No. Calcium hypochlorite is an elemental chlorine source. You don't want
:that near anything or even inside the house.
:
:You want calcium chloride. Any pool supply place will have that. Perhaps
:they're too typically ignorant to know the chemical name. They might only
:know it as some variation of the words "calcium hardness increaser." Look
n the bag or tub for a chemical ingredient.
The guy I had on the phone was far from knowledgable. Sounded like a
kid. He said to call tomorrow (which is today) and ask for his boss,
which I'm going to do right now...

I talk to him and he says they don't supply it. It's a place called HD
Pool and Patio Supply. I ask him for recommendations near me and he
gives me the name of a place that's around 15 miles from me. I think
I'll try looking up wholesale chemicals warehouses. I bought some
chemical some years ago from such a place and thought it reasonable.

Why bother, Dan? You _don't_need_it_. An airtight container is all you need.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article , Dan_Musicant wrote:
On Tue, 05 Sep 2006 18:39:50 GMT, (Doug Miller)
wrote:

:In article , Dan_Musicant
wrote:
:On Mon, 28 Aug 2006 21:53:19 -0500, Richard J Kinch
:wrote:
:
::Most cost effective would be 5-gallon paint buckets with the O-ring lids,
::with a sock full of calcium chloride as a dessicant.
:A pool supply place I'm talking to doesn't have it but they stock
:calcium hypochlorite, which he says is a "pool shocker" or some such
:thing. Is that a dessicant (i.e. OK)
:
:No.
:
: or do I want calcium chloride? TIA
:
:In my experience, an air-tight container is sufficient. No need for a
:dessicant.

The problem is that I'm uncertain if these containers will indeed be air
tight or not. I think they may be absolutely air tight, but I'd hate to
find out they aren't by having my plaster go bad, especially if I've
gone ahead and used it. I'll try to find a cheap source of calcium
chloride.

Haven't you been reading my posts? I've said at least twice that in my own
experience, putting it in an airtight container is enough. How hard is it to
find an airtight container? All I'm using is a five-gallon bucket and lid that
I bought at Lowe's for about $8, and it works _just_fine_. No dessicants.
No driers. Just a tight lid.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Dan_Musicant writes:

The problem is that I'm uncertain if these containers will indeed be air
tight or not.

Putting a dessicant in a leaky or permeable container just lengthens the
time the interior stays dry. Eventually the dessicant saturates and
becomes inert. In the case of a deliquescent like calcium chloride, it
turns into a nasty, corrosive goo. Thus the advantages to silica gel or
molecular sieves.

On Wed, 06 Sep 2006 16:29:41 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: The problem is that I'm uncertain if these containers will indeed be air
: tight or not.
:
:Putting a dessicant in a leaky or permeable container just lengthens the
:time the interior stays dry. Eventually the dessicant saturates and
:becomes inert. In the case of a deliquescent like calcium chloride, it
:turns into a nasty, corrosive goo. Thus the advantages to silica gel or
:molecular sieves.

I've spent an hour or two trying to locate CaCl2 hereabouts, but not
done well. The pool supply places say they don't carry it and most are a
ways from me, anyway.

Chemical supply places are too expensive. I did find one that will sell
me 50 lb. for around $55 including tax, so that's a possibility. But 50
lb. seems like a lot and I'll have to store IT somehow so it stays dry!!
Pretty funny, in a way. I found some on eBay, 5 lb. for around $22
shipped. Maybe I'll do that. The CaCl2 is $10, the shipping $12. Or 10
lb. for around $32. I guess if I can keep it dry, it might be a good
investment.

On Wed, 06 Sep 2006 19:15:30 GMT, (Doug Miller)
wrote:

:The problem is that I'm uncertain if these containers will indeed be air
:tight or not. I think they may be absolutely air tight, but I'd hate to
:find out they aren't by having my plaster go bad, especially if I've
:gone ahead and used it. I'll try to find a cheap source of calcium
:chloride.
:
:Haven't you been reading my posts? I've said at least twice that in my own
:experience, putting it in an airtight container is enough. How hard is it to
:find an airtight container? All I'm using is a five-gallon bucket and lid that
:I bought at Lowe's for about $8, and it works _just_fine_. No dessicants.
:No driers. Just a tight lid.

It's hard for me to be certain that my containers are tight. I better do
something soon, though, because I have the plaster in my garage and the
rainy season is around the corner. On top of that, my garage needs a new
roof! I'm gonna be a busy guy.

On Wed, 06 Sep 2006 19:13:31 GMT, (Doug Miller)
wrote:

:Why bother, Dan? You _don't_need_it_. An airtight container is all you need.
I can and may well just try that. I can test my plaster if I'm nervous.
Thanks.

Dan_Musicant writes:

The pool supply places say they don't carry it ...

That's odd. It is a necessary ingredient to protect any plaster pool
surface from soft-water etching. Maybe the pool supply places are in the
replastering business, too.

Another source is concrete suppliers, where it is used as an accelerant.

I would also ask at an Agway feed store type place.

Or just the 42 oz DampRid refill at Home Depot.

In article , Dan_Musicant wrote:


It's hard for me to be certain that my containers are tight. I better do
something soon, though, because I have the plaster in my garage and the
rainy season is around the corner. On top of that, my garage needs a new
roof! I'm gonna be a busy guy.

Jeeeezzzzz.... Quit over-thinking this, and just go to Lowe's or Home Depot
and buy the damn bucket and lid already. It'll be tight enough to keep your
plaster from going bad. Worked for me over a period of several years.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article ,
Dan_Musicant wrote:
On Wed, 06 Sep 2006 16:29:41 -0500, Richard J Kinch
wrote:

an_Musicant writes:
...snipped...:
: The problem is that I'm uncertain if these containers will indeed be air
: tight or not.

I've spent an hour or two trying to locate CaCl2 hereabouts, but not
done well. The pool supply places say they don't carry it and most are a
ways from me, anyway.

...snipped...

I didn't catch your location, nut if you live in an area that gets
snow, you should be able to find CaCl2 pretty cheap, it's often sold
as a deicer for driveways & sidewalks.

I have to agree with the other poster who said that no dessicant is
necessary, though. I keep small quantities of mortar mix, sakrete, etc.
in old, cleaned 5 gal paint or drywall buckets, and haven't
seen any go bad for periods of at least a couple-few years. If your
just talking about a small box or bag of patching plaster or plaster
of paris, you could also just put it in a heavy-duty zip lock bag.

3D
3D
in old 5 gal paint containe
--

Larry Wasserman Baltimore, Maryland

On Wed, 06 Sep 2006 20:13:20 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: The pool supply places say they don't carry it ...
:
:That's odd. It is a necessary ingredient to protect any plaster pool
:surface from soft-water etching. Maybe the pool supply places are in the
:replastering business, too.
:
:Another source is concrete suppliers, where it is used as an accelerant.
:
:I would also ask at an Agway feed store type place.
:
:Or just the 42 oz DampRid refill at Home Depot.
I called HD, but they couldn't find it. Orchard Supply tells me they
have calcium chloride in 26 oz. packages for $3.99. I think I may get a
couple of those. Cheaper and faster than eBay.

On Thu, 07 Sep 2006 19:56:36 GMT, Dan_Musicant
wrote:

On Wed, 06 Sep 2006 20:13:20 -0500, Richard J Kinch
wrote:

an_Musicant writes:
:
: The pool supply places say they don't carry it ...
:
:That's odd. It is a necessary ingredient to protect any plaster pool
:surface from soft-water etching. Maybe the pool supply places are in the
:replastering business, too.
:
:Another source is concrete suppliers, where it is used as an accelerant.
:
:I would also ask at an Agway feed store type place.
:
:Or just the 42 oz DampRid refill at Home Depot.
I called HD, but they couldn't find it. Orchard Supply tells me they
have calcium chloride in 26 oz. packages for $3.99. I think I may get a
couple of those. Cheaper and faster than eBay.

rice is pretty hygroscopic.

On Wed, 30 Aug 2006 14:20:04 -0400, Keith Williams
wrote:

:In article ,
says...
:
:snip
:
: Thanks for the post. I cut open the bags last week and put the plasters
: in plastic bags, fairly thick ones mostly. But I got the idea shortly
: thereafter to use some plastic buckets I have. These aren't 5 gallon
: buckets but food service buckets I got from a fast food place. They gave
: them to me free. They had 10 lb. potato salad in them and I got them
: with the tops. I have 13 of them now, and can get an unlimited supply in
: the future for free (I made an arrangement with another source.
:
:Nice. I buy them at the BORG. Free is better. ;-)
:
: I presume they will be air tight, but I think your admonisions are
: advisable - dessicant and testing. I would never have thought of the
: dessicant, and I wouldn't have done the testing without your suggestion.
: However, like you say, it's really important that I not invest time and
: materials into repairs that turn out to be crap.
:
:Not to mention the work to tear out crap.
:
: Great ideas with the old pill bottles. I have a bunch of them, been
: saving them for some good use, and this is sure one. Thanks again.
:
:It is a good idea. I may have a little grout and thinset to do
:this with.
:
: PS: Anyone know where I can get calcium chloride in quantity
: economically? Thanks!
:
:The better sidewalk/driveway ice melter is calcium chloride (read
:the container, NaCl isn't a desicant). You should be able to find
:it for $12is for a 50lb bag at the BORG or a bit more at a hardware
:store. It's also available (for a lot more $$) at grocery stores
:in the winter (too soon now :-( ).

What is the BORG? I'm in Berkeley, CA. A Google search on BORG doesn't
seem to come up with anything. Is it like Lowe's and Home Depot? Thanks.

On Thu, 07 Sep 2006 21:29:43 GMT, Dan_Musicant
wrote:

[snip]


What is the BORG? I'm in Berkeley, CA. A Google search on BORG doesn't
seem to come up with anything. Is it like Lowe's and Home Depot? Thanks.

We are the Borg.
You will be assimilated.
Resistance is futile.

But what if we don't want to be assimilated?

That is irrelevant.
You are irrelevant.
You will be assimilated.

On Thu, 07 Sep 2006 17:08:32 -0400, Goedjn wrote:

:On Thu, 07 Sep 2006 19:56:36 GMT, Dan_Musicant
:wrote:
:
:On Wed, 06 Sep 2006 20:13:20 -0500, Richard J Kinch
:wrote:
:
:an_Musicant writes:
::
:: The pool supply places say they don't carry it ...
::
::That's odd. It is a necessary ingredient to protect any plaster pool
::surface from soft-water etching. Maybe the pool supply places are in the
::replastering business, too.
::
::Another source is concrete suppliers, where it is used as an accelerant.
::
::I would also ask at an Agway feed store type place.
::
::Or just the 42 oz DampRid refill at Home Depot.
:I called HD, but they couldn't find it. Orchard Supply tells me they
:have calcium chloride in 26 oz. packages for $3.99. I think I may get a
:couple of those. Cheaper and faster than eBay.
:
:rice is pretty hygroscopic.

Yes, I always have some in my salt shakers. Would it make a decent
dessicant?

In article , Dan_Musicant wrote:

:
:rice is pretty hygroscopic.

Yes, I always have some in my salt shakers. Would it make a decent
dessicant?

While you're farting around looking for a dessicant which you don't even need,
your plaster is sitting in its bag in your garage absorbing moisture from the
air and getting ruined. I told you a week ago what you needed to preserve it.
Buy the damn bucket and lid, and be done with it.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Dan_Musicant wrote:

What is the BORG? I'm in Berkeley, CA. A Google search on BORG doesn't
seem to come up with anything. Is it like Lowe's and Home Depot? Thanks.

Big Orange Retail Giant = Home Depot

a guess.

On Sat, 09 Sep 2006 11:56:02 GMT, (Doug Miller)
wrote:

:In article , Dan_Musicant wrote:
:
::
::rice is pretty hygroscopic.
:
:Yes, I always have some in my salt shakers. Would it make a decent
:dessicant?
:
:While you're farting around looking for a dessicant which you don't even need,
:your plaster is sitting in its bag in your garage absorbing moisture from the
:air and getting ruined. I told you a week ago what you needed to preserve it.
:Buy the damn bucket and lid, and be done with it.

Actually, I already had the dessicant as of about 4 days ago. However, I
hadn't seen the sun for several days and didn't want to repackage the
plaster in cool, moist conditions and decided to wait for the sun to
return, which it did yesterday afternoon. I started this thread with no
idea of using a dessicant, only solid plastic containers. However, I
thought it best to ask about the whys and wherefores on the subject
stated in the subject of this thread.

I only got the idea to include dessicant on recommendation from
obviously knowledgable posters in this thread. I already had the plastic
containers I intended to use. They may or may not be as air tight as the
$8 plastic 5 gallon containers I could buy at Home Depot or similar, but
they will undoubtedly be more convenient to use. They are approximately
1 gallon containers.

I'm glad I included dessicant (CaCl2), and have an idea that I did the
right thing.

Not that I haven't been guilty of "farting around" on some jobs.

I also decided not to keep the plaster in my garage after all. I have
the 1 gallon plastic containers (12 of them for the 100 lb. of plaster)
stored in the house, under a stairwell. There will be MUCH less moisture
to deal with there, at least until the garage is renovated.

Dan