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paint cap plastics
Ok a question someone
asked led to look further -- I am not sure what plastic
is used for the Tamiya caps. It could be LDPE, HDPE, or Polypropylene. All
of them are known for chemical resistance! The #5 recycling symbol is for some
form of "PE" and commonly used for food packaging as well as medical supplies
such as disposable syringes. I think all of them may be perfectly ok to use with
solvent paints. For years I have used strips of #5 (LDPE I think?) for use with CA
-- make a little puddle to pick up with a pin or other tool. When it dries the CA just
peels off, because nothing sticks to the #5. I also use the strips for mixing epoxy and
the cups for mixing polyurethane resin. All I know is that the Tamiya caps are
great. Not sure of the other brands. The strips I cut from 1 gallon plastic milk jugs
when I need some.
--
Tim O'Connor
Sterling, Massachusetts
is used for the Tamiya caps. It could be LDPE, HDPE, or Polypropylene. All
of them are known for chemical resistance! The #5 recycling symbol is for some
form of "PE" and commonly used for food packaging as well as medical supplies
such as disposable syringes. I think all of them may be perfectly ok to use with
solvent paints. For years I have used strips of #5 (LDPE I think?) for use with CA
-- make a little puddle to pick up with a pin or other tool. When it dries the CA just
peels off, because nothing sticks to the #5. I also use the strips for mixing epoxy and
the cups for mixing polyurethane resin. All I know is that the Tamiya caps are
great. Not sure of the other brands. The strips I cut from 1 gallon plastic milk jugs
when I need some.
--
Tim O'Connor
Sterling, Massachusetts
Dave Parker
I wouldn't store straight lacquer thinner in an LDPE bottle (it would likely evaporate out through walls anyway). Note the "D" grade for MEK:
https://www.calpaclab.com/ldpe-chemical-compatibility-chart/
But with paint, you are looking at a fairly low vapor pressure of the solvent components in the head space (assuming the bottle is stored upright), so I personally wouldn't worry about LDPE liners.
HDPE, PP, and of course Teflon liners would all be better if anybody had any residual angst about the LDPE. I would definitely avoid the expanded LDPE foam liners.
--
Dave Parker
Swall Meadows, CA
https://www.calpaclab.com/ldpe-chemical-compatibility-chart/
But with paint, you are looking at a fairly low vapor pressure of the solvent components in the head space (assuming the bottle is stored upright), so I personally wouldn't worry about LDPE liners.
HDPE, PP, and of course Teflon liners would all be better if anybody had any residual angst about the LDPE. I would definitely avoid the expanded LDPE foam liners.
--
Dave Parker
Swall Meadows, CA
As I said, the Tamiya bottles are GLASS. Plastic bottles suck, in my experience. The plastic
caps on the glass bottles is what works.
On 3/8/2023 1:42 PM, Dave Parker via
groups.io wrote:
I wouldn't store straight lacquer thinner in an LDPE bottle (it would likely evaporate out through walls anyway). Note the "D" grade for MEK:
https://www.calpaclab.com/ldpe-chemical-compatibility-chart/
But with paint, you are looking at a fairly low vapor pressure of the solvent components in the head space (assuming the bottle is stored upright), so I personally wouldn't worry about LDPE liners.
HDPE, PP, and of course Teflon liners would all be better if anybody had any residual angst about the LDPE. I would definitely avoid the expanded LDPE foam liners.
--
Dave Parker
Swall Meadows, CA
--
Tim O'Connor
Sterling, Massachusetts
Tim O'Connor
Sterling, Massachusetts
Dave Parker
Poor wording on my part. I was trying to illustrate the worst case scenario, i.e., straight solvent in an LDPE bottle. Paint in a glass bottle with an LDPE-lined cap shouldn't be a problem. BUT, LDPE has a (sometimes deserved) reputation as a poor choice for some solvents, so some folks might still have concerns.
--
Dave Parker
Swall Meadows, CA
--
Dave Parker
Swall Meadows, CA
Indeed, but I'm telling you whatever the Tamiya caps are made from, they work with every solvent I've put into the bottles.
They are a milky white color (no pigment) and are not "hard" ... No idea whether LDPE or PolyPro. Someone pointed out
that web site that sells those bottles and caps (not Tamiya) in singles, so it's easy and cheap enough to try one's worst. :-)
On 3/8/2023 3:04 PM, Dave Parker via groups.io wrote:
Poor wording on my part. I was trying to illustrate the worst case scenario, i.e., straight solvent in an LDPE bottle. Paint in a glass bottle with an LDPE-lined cap shouldn't be a problem. BUT, LDPE has a (sometimes deserved) reputation as a poor choice for some solvents, so some folks might still have concerns.
--
Dave Parker
--
Tim O'Connor
Sterling, Massachusetts
Tim O'Connor
Sterling, Massachusetts
The bottle caps are probably a Japanese specialty blend plastic not known to the US. I can't remember the last time I emptied a bottle of Tamiya paint as they seem to last at least a decade. The same plastic may be used on the liquid plastic cement bottles that I always save when empty and find ideal for water, IPA and other fluids for Acrylic brush painting.
--
Ken Adams
Covid Variants may come and go but I choose to still live mostly in splendid Shelter In Place solitude
Location: About half way up Walnut Creek
Owner PlasticFreightCarBuilders@groups.io
--
Ken Adams
Covid Variants may come and go but I choose to still live mostly in splendid Shelter In Place solitude
Location: About half way up Walnut Creek
Owner PlasticFreightCarBuilders@groups.io
Jeffrey White
I keep MEK in a Tamiya Extra Thin Cement bottle. I don't have any problem with evaporation however the gasket in the cap is loose, I assume the fumes from the MEK dissolved the glue.
Jeff White
Alma IL
On 3/8/2023 4:14 PM, Ken Adams wrote:
The bottle caps are probably a Japanese specialty blend plastic not known to the US. I can't remember the last time I emptied a bottle of Tamiya paint as they seem to last at least a decade. The same plastic may be used on the liquid plastic cement bottles that I always save when empty and find ideal for water, IPA and other fluids for Acrylic brush painting.
--
Ken Adams
Covid Variants may come and go but I choose to still live mostly in splendid Shelter In Place solitude
Location: About half way up Walnut Creek
Owner PlasticFreightCarBuilders@groups.io
Jack Mullen
On Wed, Mar 8, 2023 at 09:25 AM, Tim O'Connor wrote:
Otherwise as you describe. It's used for a lot of takeout food containers, which do make handy palettes for whatever glue I'm using - CA, epoxy, PVA, silicone...
Your milk jugs are almost certainly #2, HDPE.
Jack Mullen
The #5 recycling symbol is for someClose, but no. #5 is PP (polypropylene)
form of "PE" and commonly used for food packaging as well as medical supplies
such as disposable syringes.
Otherwise as you describe. It's used for a lot of takeout food containers, which do make handy palettes for whatever glue I'm using - CA, epoxy, PVA, silicone...
Your milk jugs are almost certainly #2, HDPE.
Jack Mullen