Paint shelf life?


Charles Hladik
 

Brian,
A couple of years ago the LHS I worked at had some Modelflex set up in
the bottle. Badger replaced it. IIRC Accuflex was the precursor to Modelflex
and it was taken off the market due to some of the problems that you relate.
Sorry, but I don't know what to do to rectify your problem.
Chuck Hladik



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Greg Martin
 

In a message dated 1/11/2008 7:41:12 PM Pacific Standard Time,
brian@... writes:

SGL wrote; Plastic bottle, Brian?

Yes, plastic bottle. The paint wasn't solid, very liquid in fact. Just a
strange painting experience. It went through my airbrush like water.
Brian J Carlson P.E.
Cheektowaga NY

Brian,

It is likely still good. The stuff is very "thin" but covers well and needs
no thinning. You got good color coverage, correct?

Greg Martin



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Brian J Carlson <brian@...>
 

Tonight I tried to paint a Bowser X31 using Badger Accuflex (yes Accuflex,
not Modelflex) Light Tuscan Oxide Red. I've used Accuflex before, but
probably not in 3 years, this was a brand new (to me) unopened bottle that I
mixed well. The coverage was spotty and wet and no combination of air and
paint would produce smooth results. Nor did it matter how close or far away
I held the brush, the paint stayed spotty. The paint did exhibit a "funky"
odor that I never noticed when using acrylic paint before. My question is
can acrylic paint go bad in the bottle? I have no idea how long the bottle
was on the shelf at my local hobby shop. Normally, I use Polly S acrylics.
Any thoughts?

Brian J Carlson P.E.
Cheektowaga NY


Schuyler Larrabee
 

Plastic bottle, Brian? Polyethylene or similar? I suspect that is the problem. Accuflex is also
the paint that had the major meltdown IIRC, and there was a huge batch of it made with polluted
water, as I understood it, which made it go solid in the bottle . . . and in your airbrush while you
were painting with it. I had a near (airbrush) death experience with it. Really too bad, too,
because when it first came out I painted a three-color passenger car AND decaled it in one 7 PM to
11 PM session.

SGL

Tonight I tried to paint a Bowser X31 using Badger Accuflex (yes Accuflex,
not Modelflex) Light Tuscan Oxide Red. I've used Accuflex before, but
probably not in 3 years, this was a brand new (to me) unopened bottle that I
mixed well. The coverage was spotty and wet and no combination of air and
paint would produce smooth results. Nor did it matter how close or far away
I held the brush, the paint stayed spotty. The paint did exhibit a "funky"
odor that I never noticed when using acrylic paint before. My question is
can acrylic paint go bad in the bottle? I have no idea how long the bottle
was on the shelf at my local hobby shop. Normally, I use Polly S acrylics.
Any thoughts?

Brian J Carlson P.E.
Cheektowaga NY




Brian J Carlson <brian@...>
 

SGL wrote; Plastic bottle, Brian?

yes, plastic bottle. The paint wasn't solid, very liquid in fact. Just a
strange painting experience. It went through my airbrush like water.
Brian J Carlson P.E.
Cheektowaga NY


Dennis Williams
 

Brian.
My luck dealing with acrylic paints was not that
great. The "spotty" sounds like some oils
(fingerprints)were left on the car surface. Seems to
be no matter how much I cleaned, I still had that
problem.
I heard that one time, correct me if I'm wrong, one
brand had problems with their paint. May have been
Badger.
For the past 20 years that I have been airbrushing,
I try to stick with Scalecoat I and II, II is for
plastics. Also it has a nice decal surface. Now, talk
about shelf life, Scalecoat seems to jell after a long
while. My opinion is the large bottle. 1/2 paint, 1/2
air. I started to use smaller bottles and it seems to
work.
To answer your last question, paints can go bad over
time. I have some Floquils that are 20 years old with
no problems. But I had some that did not last a year
after opening. I guess that it all depends on the mix
at the time.
Dennis
--- Brian J Carlson <brian@...> wrote:

Tonight I tried to paint a Bowser X31 using Badger
Accuflex (yes Accuflex,
not Modelflex) Light Tuscan Oxide Red. I've used
Accuflex before, but
probably not in 3 years, this was a brand new (to
me) unopened bottle that I
mixed well. The coverage was spotty and wet and no
combination of air and
paint would produce smooth results. Nor did it
matter how close or far away
I held the brush, the paint stayed spotty. The
paint did exhibit a "funky"
odor that I never noticed when using acrylic paint
before. My question is
can acrylic paint go bad in the bottle? I have no
idea how long the bottle
was on the shelf at my local hobby shop. Normally, I
use Polly S acrylics.
Any thoughts?

Brian J Carlson P.E.
Cheektowaga NY



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Douglas Harding <dharding@...>
 

Brian, in short, Yes. Badger offers a guarantee on their paint. Contact them
and they will replace the paint. I did this recently after discovering a
number of new bottles, and some open ones, that were just as you describe,
including one with a really bad odor. Badger was very cordial, all I had to
do was send them a list of the paint colors that were bad and they replaced
them.

I have been using Accuflex and later ModelFlex since it first came out.
Requires different airbrush techniques, but I have not had problems with
paint quality until this last year. I attritubted the problem to a couple of
recent moves when my paint was in storage for a length of time.

I have learned when using ModelFlex that I want a supply of hot water handy
for cleaning the airbrush or removing a bad paint job immediately, ie paint
next to the laundry tub if possible. Also have a bottle of Windex/window
cleaner, use it for a final cleaning of the airbrush. The ammonia in the
window cleaner cuts the paint when the hot water doesn't. If you begin
cleaning within 5 minutes you can usually remove the paint with no trouble
(provided you have not set the paint with the hair dryer).

Doug Harding
www.iowacentralrr.org

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Bob Sterner
 

I'm not the fastest modeller in the world and and thus I always seem
to have lots of old paint that I can no longer use. I have been
fantasizing about having compressed nitrogen at my work bench so that
I could replace the atmosphere in opened paint with N2. I believe
(though don't know for certain) that this would dramatically improve
shelf life. Unfortunately, even a small cylinder ("lecture bottle")
is > $100, at least as far as I've been able to determine. If this
is a valid technique, commercial paint shops should already be on to
it. Anyone heard of anything like this?

Bob Sterner

--- In STMFC@..., RUTLANDRS@... wrote:

Brian,
A couple of years ago the LHS I worked at had some Modelflex
set up in
the bottle. Badger replaced it. IIRC Accuflex was the precursor to
Modelflex
and it was taken off the market due to some of the problems that
you relate.
Sorry, but I don't know what to do to rectify your problem.
Chuck Hladik



**************Start the year off right. Easy ways to stay in
shape.
http://body.aol.com/fitness/winter-exercise?
NCID=aolcmp00300000002489


[Non-text portions of this message have been removed]


Dennis Storzek <destorzek@...>
 

--- In STMFC@..., "Bob Sterner" <rwsterner@...> wrote:

I'm not the fastest modeller in the world and and thus I always seem
to have lots of old paint that I can no longer use. I have been
fantasizing about having compressed nitrogen at my work bench so that
I could replace the atmosphere in opened paint with N2. I believe
(though don't know for certain) that this would dramatically improve
shelf life. Unfortunately, even a small cylinder ("lecture bottle")
is > $100, at least as far as I've been able to determine. If this
is a valid technique, commercial paint shops should already be on to
it. Anyone heard of anything like this?

Bob Sterner
Bob,

You might take a look at the small cans of pressurized nitrogen and
argon mix made for the yuppie oenophile (wine connoisseur) market.
The idea is the nitrogen displaces the air, then the argon settles
over the surface of the liquid. Argon is totally inert, and so
prevents any oxidation. However, the solvents in the paint will still
evaporate into the rare gas atmosphere in the bottle, so I'm not sure
preventing oxidation will make that much difference. The only way to
find out is to try it.

I just ran into a catalog page for the argon wine preserver on the
Plastic Process Equipment web site; can't figure out why, most the
people I know in the tool making and molding industries drink stronger
stuff than wine, and don't leave partial bottles around long enough
for oxidation to be a problem :-) I suspect that this stuff has
probably found some industrial uses too varied to list, possibly
conserving partially filled cans of coatings. Whatever, here's a link
to the page. I'm sure the PPE will take credit card orders.

http://www.ppe.com/08cat/1022.pdf

Or see your local wine shoppe :-)

Dennis


Dennis Williams
 

Question I would have is: Do you have to remove the N2
before mixing the paint or it does not matter? That
sounds like it may help prevent jelling of scalecoat
paints. Dennis
--- Dennis Storzek <destorzek@...> wrote:

--- In STMFC@..., "Bob Sterner"
<rwsterner@...> wrote:

I'm not the fastest modeller in the world and and
thus I always seem
to have lots of old paint that I can no longer
use. I have been
fantasizing about having compressed nitrogen at my
work bench so that
I could replace the atmosphere in opened paint
with N2. I believe
(though don't know for certain) that this would
dramatically improve
shelf life. Unfortunately, even a small cylinder
("lecture bottle")
is > $100, at least as far as I've been able to
determine. If this
is a valid technique, commercial paint shops
should already be on to
it. Anyone heard of anything like this?

Bob Sterner
Bob,

You might take a look at the small cans of
pressurized nitrogen and
argon mix made for the yuppie oenophile (wine
connoisseur) market.
The idea is the nitrogen displaces the air, then the
argon settles
over the surface of the liquid. Argon is totally
inert, and so
prevents any oxidation. However, the solvents in the
paint will still
evaporate into the rare gas atmosphere in the
bottle, so I'm not sure
preventing oxidation will make that much difference.
The only way to
find out is to try it.

I just ran into a catalog page for the argon wine
preserver on the
Plastic Process Equipment web site; can't figure out
why, most the
people I know in the tool making and molding
industries drink stronger
stuff than wine, and don't leave partial bottles
around long enough
for oxidation to be a problem :-) I suspect that
this stuff has
probably found some industrial uses too varied to
list, possibly
conserving partially filled cans of coatings.
Whatever, here's a link
to the page. I'm sure the PPE will take credit card
orders.

http://www.ppe.com/08cat/1022.pdf

Or see your local wine shoppe :-)

Dennis




____________________________________________________________________________________
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Charles Morrill
 

Micro-Mark also sells the small spray cans --- principly to help preserve the RTV and urethane liquids.

Around here, good wine in an open bottle doesn't stay around long enough to worry about it. Bad wine, why preserve it?
Charlie

----- Original Message -----
From: "Dennis Storzek" <destorzek@...>
To: <STMFC@...>
Sent: Sunday, January 13, 2008 12:38 PM
Subject: [STMFC] Re: Paint shelf life?



Bob,

You might take a look at the small cans of pressurized nitrogen and
argon mix made for the yuppie oenophile (wine connoisseur) market.
The idea is the nitrogen displaces the air, then the argon settles
over the surface of the liquid. Argon is totally inert, and so
prevents any oxidation. However, the solvents in the paint will still
evaporate into the rare gas atmosphere in the bottle, so I'm not sure
preventing oxidation will make that much difference. The only way to
find out is to try it.

I just ran into a catalog page for the argon wine preserver on the
Plastic Process Equipment web site; can't figure out why, most the
people I know in the tool making and molding industries drink stronger
stuff than wine, and don't leave partial bottles around long enough
for oxidation to be a problem :-) I suspect that this stuff has
probably found some industrial uses too varied to list, possibly
conserving partially filled cans of coatings. Whatever, here's a link
to the page. I'm sure the PPE will take credit card orders.

http://www.ppe.com/08cat/1022.pdf

Or see your local wine shoppe :-)

Dennis


Dennis Storzek <destorzek@...>
 

--- In STMFC@..., Dennis Williams <pennsy6200@...> wrote:

Question I would have is: Do you have to remove the N2
before mixing the paint or it does not matter? That
sounds like it may help prevent jelling of scalecoat
paints. Dennis
The real question is, why do they jell? If they are jelling because
the resin (the binder in the paint) is chemically reacting with the
oxygen in the air, then removing contact with oxygen should do the trick.

However, if they are jelling because loss of solvent allows the resin
molecules to coalesce, the solvent is still going to be lost as vapor
in the headspace, no matter what gas the headspace is filled with. In
which case, the solution is to reduce the amount of headspace, usually
by transferring the paint to a smaller container. I've also heard of
floating a bit of thinner on top of the paint before closing the
bottle, but this tends to cause the paint to become thinner with each use.

Dennis Storzek


Dennis Storzek <destorzek@...>
 

--- In STMFC@..., "Charles Morrill" <badlands@...> wrote:

Micro-Mark also sells the small spray cans --- principly to help
preserve
the RTV and urethane liquids.

Around here, good wine in an open bottle doesn't stay around long
enough to
worry about it. Bad wine, why preserve it?
Charlie
Urethanes are a special case; they react with water, which acts as a
foaming agent. This is exactly the way urethane insulating products,
such as Great Stuff work; you inject the liquid resin from the can,
and atmospheric water vapor causes it to foam and cure. So the secret
to keeping urethane resins for any amount of time after opening is to
purge the headspace with something totally devoid of moisture, and
canned nitrogen is cheap.

Considering our atmosphere is already 80% nitrogen, I don't think this
will do anything to reduce solvent evaporation.

Dennis


Dennis Williams
 

Thanks
--- Dennis Storzek <destorzek@...> wrote:

--- In STMFC@..., Dennis Williams
<pennsy6200@...> wrote:

Question I would have is: Do you have to remove
the N2
before mixing the paint or it does not matter?
That
sounds like it may help prevent jelling of
scalecoat
paints. Dennis
The real question is, why do they jell? If they are
jelling because
the resin (the binder in the paint) is chemically
reacting with the
oxygen in the air, then removing contact with oxygen
should do the trick.

However, if they are jelling because loss of solvent
allows the resin
molecules to coalesce, the solvent is still going to
be lost as vapor
in the headspace, no matter what gas the headspace
is filled with. In
which case, the solution is to reduce the amount of
headspace, usually
by transferring the paint to a smaller container.
I've also heard of
floating a bit of thinner on top of the paint before
closing the
bottle, but this tends to cause the paint to become
thinner with each use.

Dennis Storzek




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ed_mines
 

--- In STMFC@..., "Bob Sterner" <rwsterner@...> wrote:
I could replace the atmosphere in opened paint with N2. I believe
(though don't know for certain) that this would dramatically improve
shelf life.
Bob, a past employer used to sell very reactive moisture cure coatings.
We used to recommend blanketing the unused coating with nitrogen. I did
this on many occasions, blowing the liquid out of the cans (or bottles)
about half the time.

I don't think the coatings sold for model railroads are that reactive
though. In fact many aren't reactive at all. (Tradional Scalecoat is
reactive and traditional Floquil isn't.) Some reactive coatings like
traditional Scalecoat smell for weeks; the smell is linseed oil which
reacts with oxygen like an old fashioned paint.

Coatings in polyethylene bottles sometimes loose cosolvents through the
plastic.

I found that traditional Floquil lasted a lot longer if the circular
plastic seal on top of the bottle was put back intact. I many have even
bought some replacement seals.

Ed Mines


Steve Lucas <stevelucas3@...>
 

I painted with both Floquil and Scalecoat about a month back. So
that's what I smell when Scalecoat is drying. It smelled like linseed
oil, but I didn't think it could be used in a "model" paint.
Interesting that they'd use it in a lacquer. Perhaps that's why it goes
through an airbrush so well?

Floquil is everyone's old standby, what with the problems many
including myself have spraying Modelflex. Tamiya stuff sprays far
easier than Modelflex. I have made new liners out of thick plastic
from water bottle packaging. The jury's still out on these.

Steve Lucas.

--- In STMFC@..., "ed_mines" <ed_mines@...> wrote:

--- In STMFC@..., "Bob Sterner" <rwsterner@> wrote:
Some reactive coatings like
traditional Scalecoat smell for weeks; the smell is linseed oil which
reacts with oxygen like an old fashioned paint.

I found that traditional Floquil lasted a lot longer if the circular
plastic seal on top of the bottle was put back intact. I many have
even
bought some replacement seals.

Ed Mines


Charles Hladik
 

When you speak of linseed oil, is it "boiled linseed oil" or "raw". Years
ago when trying to refinish a gunstock I was told to use linseed oil, well, it
never dried. I then learned about boiled linseed oil, it dries.
Chuck Hladik



**************Start the year off right. Easy ways to stay in shape.
http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489


Bob Sterner
 

I looked into books on the chemistry of surface coatings. I found
the book, Paint and Surface Coatings: Theory and Practice (2nd ed.,
Lamborne and Strives, eds., 1999) the most helpful. Most if not all
of it is free and searchable on Google Scholar. I'm not pretending
to have turned into a surface chemist overnight but here's what I
found.

Both oxidative polymerization and solvent loss are involved in paint
drying or "curing". It appears to me from my reading that oxidation
is more associated with oil-based rather than water-based paints,
though nothing I found came right out and said that real clearly.

It seems quite logical to me that an N2 or argon atmosphere will
lengthen the shelf life of paints that cure by oxidation (yes, most
of the atmosphere is N2 but O2 is a strong oxidant). The oenophile
industry has helpfully provided just the product we need (thanks for
finding that, Dennis!). I haven't decided if I'll try that but I
just might.

For that matter, if curing of water-based paints is largely due to
evaporation of the water out of the bottle, then presumably one could
greatly lengthen shelf life of aqueous paints by simply storing them
in some kind of sealed container containing water, maintaining
humidity at 100% and thus keeping the dang water in the paint
bottle. That's basically free. I think I'm going to start doing
that immediately. The only cost is convenience so even if its hokum,
little is lost.

Bob S.

--- In STMFC@..., "ed_mines" <ed_mines@...> wrote:

--- In STMFC@..., "Bob Sterner" <rwsterner@> wrote:
I could replace the atmosphere in opened paint with N2. I
believe
(though don't know for certain) that this would dramatically
improve
shelf life.
Bob, a past employer used to sell very reactive moisture cure
coatings.
We used to recommend blanketing the unused coating with nitrogen. I
did
this on many occasions, blowing the liquid out of the cans (or
bottles)
about half the time.

I don't think the coatings sold for model railroads are that
reactive
though. In fact many aren't reactive at all. (Tradional Scalecoat
is
reactive and traditional Floquil isn't.) Some reactive coatings
like
traditional Scalecoat smell for weeks; the smell is linseed oil
which
reacts with oxygen like an old fashioned paint.

Coatings in polyethylene bottles sometimes loose cosolvents through
the
plastic.

I found that traditional Floquil lasted a lot longer if the
circular
plastic seal on top of the bottle was put back intact. I many have
even
bought some replacement seals.

Ed Mines