Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?

"john ryan" wrote in
:

Carbon steel knife inadvertently left 'wet' on top of the white
plastic lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

Rust is mostly a hydrate of Fe(II) oxides and hydroxides (if memory serves
right). Oxidizing the "rust" and chelating/complexing the Fe(III) ions
should remove this. I'd recommend oxalic acid for all this. Soft water
(as opposed to calcium containing "hard" water) is best. Calcium oxalate
forms hard, sharp, needle-like crystals, which are mechanically poisonous
(part of the green leafy parts of rhubarb that should NOT be eaten).


--
Best regards
Han
email address is invalid

john ryan wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?




Oxalic acid, dilute hydrofluoric acid ("Whink"), or "Iron Out" (contains
sodium hydrosulfite and bisulfite.)

-Bob

"dadiOH" wrote in
:

john ryan wrote:
Carbon steel knife inadvertently left 'wet' on top of the white
plastic lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

Any commercial rust remover like CLR.

Any acid like vinegar, lemon juice, etc. Concentrated sulfuric,
nitric or hydrochloric not recommended.

Hydrochloric acid doesn't do the required oxidation, so, no, not
recommended.
Depending on the kind of plastic sulfuric or nitric acids should work fine.
You likely only need a little bit and it doesn't need to be too
concentrated, with a short time of exposure. Rinse well. Wear eye
protection (DAMHIKT).
--
Best regards
Han
email address is invalid

On May 18, 7:42*am, "john ryan" wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. *Is there any chemical that
might remove the stain please?

The scouring powder Barkeeper's Friend has oxalic acid in it. I'd
make a paste, apply it, and wait. Keep the paste moist if you
can. For example, lay a moistened paper towel on top.

BF is not very abrasive, but I'd be careful about rubbing it
on plastic, which is quite soft.

Cindy Hamilton

"zxcvbob" wrote in message
...
john ryan wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic
lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?


Oxalic acid, dilute hydrofluoric acid ("Whink"), or "Iron Out" (contains
sodium hydrosulfite and bisulfite.)

FFS DON"T EVER USE HYDROFLUORIC ACID, DILUTE OR OTHERWISE, UNLESS YOU WORK
IN A LAB WITH ALL THE REQUISITE SAFETY GEAR!!!!!

Graham

graham wrote:
"zxcvbob" wrote in message
...
john ryan wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic
lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?

Oxalic acid, dilute hydrofluoric acid ("Whink"), or "Iron Out" (contains
sodium hydrosulfite and bisulfite.)

FFS DON"T EVER USE HYDROFLUORIC ACID, DILUTE OR OTHERWISE, UNLESS YOU WORK
IN A LAB WITH ALL THE REQUISITE SAFETY GEAR!!!!!

Graham



It's available in the laundry aisle at the supermarket in a little
brown plastic squeeze bottle for removing rust stains. It's called
"Whink". It's important to wear rubber gloves when using it cuz it
will F! you up (in a bad way) if absorbed through the skin.

-Bob

"zxcvbob" wrote in message
...
graham wrote:
"zxcvbob" wrote in message
...
john ryan wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic
lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

Oxalic acid, dilute hydrofluoric acid ("Whink"), or "Iron Out" (contains
sodium hydrosulfite and bisulfite.)

FFS DON"T EVER USE HYDROFLUORIC ACID, DILUTE OR OTHERWISE, UNLESS YOU
WORK IN A LAB WITH ALL THE REQUISITE SAFETY GEAR!!!!!

Graham

It's available in the laundry aisle at the supermarket in a little brown
plastic squeeze bottle for removing rust stains. It's called "Whink".
It's important to wear rubber gloves when using it cuz it will F! you up
(in a bad way) if absorbed through the skin.

Christ!! It's one of the more dangerous acids and should NOT be available
to the general public. I'm fully aware of the dangers having used it under
lab conditions and having to develop procedures in the case of accidents.
These days, my processing work is handled by a contract lab so I don't go
near the stuff.
Graham

"graham" wrote in
:

It's one of the more dangerous acids and should NOT be available
to the general public. I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract lab
so I don't go near the stuff.

It's all in the dose. Moreover, HF is readily soluble in water, so it
washes away easily. I am NOT recommending sniffing it or drinking it, or
washing your hands in it. On the other hand, it is present in toothpastes
in various forms as a minor, but active ingredient.

--
Best regards
Han
email address is invalid

Cindy Hamilton wrote:
On May 18, 7:42 am, "john ryan" wrote:
Carbon steel knife inadvertently left 'wet' on top of the white
plastic lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

The scouring powder Barkeeper's Friend has oxalic acid in it. I'd
make a paste, apply it, and wait. Keep the paste moist if you
can. For example, lay a moistened paper towel on top.

BF is not very abrasive, but I'd be careful about rubbing it
on plastic, which is quite soft.

Cindy Hamilton

BF powder is 100% oxalic acid

http://www.barkeepersfriend.com/file...owder_2010.pdf

and is pretty abrasive. i use it to remove mineral deposits on the kitchen
sprayer head.

On 18/05/2011 19:02, Han wrote:

It's all in the dose. Moreover, HF is readily soluble in water, so it
washes away easily. I am NOT recommending sniffing it or drinking it, or
washing your hands in it. On the other hand, it is present in toothpastes
in various forms as a minor, but active ingredient.

It scares me too. Rumoured to go straight for the bones.

But the stuff in toothpaste is NOT HF, it's NaF. About as dangerous as
common table salt.

fx googles OK, so 5g may well kill you, it takes a bit more table
salt. Whereas HF will kill you at 30ppm in the air...

Andy

In article , "john ryan"
wrote:

Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?

does the rust stain affect the operation of the rice cooker?

On May 18, 2:20*pm, "chaniarts" wrote:
Cindy Hamilton wrote:
On May 18, 7:42 am, "john ryan" wrote:
Carbon steel knife inadvertently left 'wet' on top of the white
plastic lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

The scouring powder Barkeeper's Friend has oxalic acid in it. *I'd
make a paste, apply it, and wait. *Keep the paste moist if you
can. *For example, lay a moistened paper towel on top.

BF is not very abrasive, but I'd be careful about rubbing it
on plastic, which is quite soft.

Cindy Hamilton

BF powder is 100% oxalic acid

http://www.barkeepersfriend.com/file...owder_2010.pdf

and is pretty abrasive. i use it to remove mineral deposits on the kitchen
sprayer head.-

On May 18, 2:20*pm, "chaniarts" wrote:
Cindy Hamilton wrote:
On May 18, 7:42 am, "john ryan" wrote:
Carbon steel knife inadvertently left 'wet' on top of the white
plastic lid of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical
that might remove the stain please?

The scouring powder Barkeeper's Friend has oxalic acid in it. *I'd
make a paste, apply it, and wait. *Keep the paste moist if you
can. *For example, lay a moistened paper towel on top.

BF is not very abrasive, but I'd be careful about rubbing it
on plastic, which is quite soft.

Cindy Hamilton

BF powder is 100% oxalic acid

The MSDS indicates 5-10% by weight.

http://www.barkeepersfriend.com/file...owder_2010.pdf

and is pretty abrasive. i use it to remove mineral deposits on the kitchen
sprayer head.

I generally use it to remove baked-on grease from cookware.

Cindy Hamiton

Andy Champ wrote in
:

On 18/05/2011 19:02, Han wrote:

It's all in the dose. Moreover, HF is readily soluble in water, so
it washes away easily. I am NOT recommending sniffing it or drinking
it, or washing your hands in it. On the other hand, it is present in
toothpastes in various forms as a minor, but active ingredient.

It scares me too. Rumoured to go straight for the bones.

But the stuff in toothpaste is NOT HF, it's NaF. About as dangerous
as common table salt.

fx googles OK, so 5g may well kill you, it takes a bit more table
salt. Whereas HF will kill you at 30ppm in the air...

Andy

NaF or SnF2 would become HF when it gets acid (like in a stomach). And
[H+] is always there in some concentration.


--
Best regards
Han
email address is invalid

"zxcvbob" wrote in message
...
docholliday wrote:

MSDS for this (Whink rust remover) doesn't mention HF at all, nor any
fluorides.
Mike


Did you actually look?
http://www.whink.com/images/msds/Rus...r_10062008.pdf

And there are DANGER! warnings about hydrofluoric acid printed on the
bottle. (not many consumer products use "DANGER" anymore, most say
"Caution" or "Warning")

-Bob

It should be taken off the market for ordinary consumers. That
concentration of HF (1.5-3.5%) is dangerous. If any is absorbed by the
skin, it causes gangrene!
Graham

In article ,
docholliday wrote:

...snipped...
MSDS for this (Whink rust remover) doesn't mention HF at all, nor any
fluorides.
Mike


Whink makes several products with "Rust" as part of the name. Not all of
them contain HF acid. The MSDS for their product named "Rust Stain Remover"
and sold in a brown bottle, does clearly list "Hydrofluoric Acid
(Hydrogen Fluoride)" as an ingredient and has all kinds of warning
statements, including this line in the Emergency Overview section:
"Will penetrate skin and attack underlying tissues and bone."



--
The best argument against democracy is a five-minute conversation
with the average voter. (Winston Churchill)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

Why not just leave it alone?

On May 18, 7:42*am, "john ryan" wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. *Is there any chemical that
might remove the stain please?

Rust doesn't "soak in" to iron anymore than soup does. Whatever rust
you see is on the surface. If you care about the appearance, get a
knife not to use, as some people do with copper pans. Remove the rust
with steel wool or (after wetting it with oil) with a razor-blade
paint scraper. Then sharpen it. Cosmetic damage is the least that
happens when a carbon steel knife is left wet. The first damage is to
the edge. If you can't tell, it wasn't sharp to begin with.

Jerry
--
Engineering is the art of making what you want from things you can get.

On May 18, 2:02*pm, Han wrote:
"graham" wrote :

It's one of the more dangerous acids and should NOT be available
to the general public. *I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract lab
so I don't go near the stuff.

It's all in the dose. *Moreover, HF is readily soluble in water, so it
washes away easily. *I am NOT recommending sniffing it or drinking it, or
washing your hands in it. *On the other hand, it is present in toothpastes
in various forms as a minor, but active ingredient.

So wrong! There are fluorine compounds in toothpaste, but not
hydrofluoric acid. Usually sodium or potassium fluoride. Check the
label.

HF isn't basically more dangerous than HCl. It's primary claim to fame
its ability to attack glass. Don't confuse it with HCN.

Jerry
--
Engineering is the art of making what you want from things you can get.

"pamjd" wrote in message
...
Why not just leave it alone?

Because HF shouldn't be part of ANY consumer product.

On 5/26/2011 8:38 PM, Jerry Avins wrote:
On May 18, 2:02 pm, wrote:
wrote :

It's one of the more dangerous acids and should NOT be available
to the general public. I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract lab
so I don't go near the stuff.

It's all in the dose. Moreover, HF is readily soluble in water, so it
washes away easily. I am NOT recommending sniffing it or drinking it, or
washing your hands in it. On the other hand, it is present in toothpastes
in various forms as a minor, but active ingredient.

So wrong! There are fluorine compounds in toothpaste, but not
hydrofluoric acid. Usually sodium or potassium fluoride. Check the
label.

HF isn't basically more dangerous than HCl. It's primary claim to fame
its ability to attack glass. Don't confuse it with HCN.



That's wrong. HF is not nearly as strong an acid as HCl, but it is much
more poisonous, and it will easily penetrate the skin without causing
any apparent damage at first.

Wear rubber gloves and try not to spill the stuff on yourself and the 2%
isn't all *that* bad. I keep a bottle handy and use the stuff; usually
a drop at a time. Handle a rag sopped with the stuff for very long
without wearing rubber or plastic gloves and you just might need you
hand amputated -- or worse.

-Bob

On 5/26/2011 9:33 PM, Jerry Avins wrote:
On May 18, 7:42 am, "john wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. Is there any chemical that
might remove the stain please?

Rust doesn't "soak in" to iron anymore than soup does. Whatever rust
you see is on the surface. If you care about the appearance, get a
knife not to use, as some people do with copper pans. Remove the rust
with steel wool or (after wetting it with oil) with a razor-blade
paint scraper. Then sharpen it. Cosmetic damage is the least that
happens when a carbon steel knife is left wet. The first damage is to
the edge. If you can't tell, it wasn't sharp to begin with.

Jerry
--
Engineering is the art of making what you want from things you can get.

Uh, you do know OP was talking about the stain on the rice cooker, right?

--
aem sends...

On Thu, 26 May 2011 18:38:21 -0700 (PDT), Jerry Avins wrote:

On May 18, 2:02*pm, Han wrote:
"graham" wrote :

It's one of the more dangerous acids and should NOT be available
to the general public. *I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract lab
so I don't go near the stuff.

It's all in the dose. *Moreover, HF is readily soluble in water, so it
washes away easily. *I am NOT recommending sniffing it or drinking it, or
washing your hands in it. *On the other hand, it is present in toothpastes
in various forms as a minor, but active ingredient.

So wrong! There are fluorine compounds in toothpaste, but not
hydrofluoric acid. Usually sodium or potassium fluoride. Check the
label.

The good ones use tin fluoride. ;-)

HF isn't basically more dangerous than HCl. It's primary claim to fame
its ability to attack glass. Don't confuse it with HCN.

F is certainly worse than Cl, in almost every way.

Jerry Avins wrote:
On May 18, 2:02 pm, Han wrote:
"graham" wrote
:

It's one of the more dangerous acids and should NOT be available
to the general public. I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract
lab so I don't go near the stuff.

It's all in the dose. Moreover, HF is readily soluble in water, so it
washes away easily. I am NOT recommending sniffing it or drinking
it, or washing your hands in it. On the other hand, it is present in
toothpastes in various forms as a minor, but active ingredient.

So wrong! There are fluorine compounds in toothpaste, but not
hydrofluoric acid. Usually sodium or potassium fluoride. Check the
label.

HF isn't basically more dangerous than HCl. It's primary claim to fame
its ability to attack glass. Don't confuse it with HCN.


HF interferes with the body's calcium and potassium metabolism and can cause
death by cardiac arrest.

On May 26, 10:14*pm, aemeijers wrote:
On 5/26/2011 9:33 PM, Jerry Avins wrote:









On May 18, 7:42 am, "john *wrote:
Carbon steel knife inadvertently left 'wet' on top of the white plastic lid
of a rice cooker, overnight.

Brown rust stain has soaked into the plastic. *Is there any chemical that
might remove the stain please?

Rust doesn't "soak in" to iron anymore than soup does. Whatever rust
you see is on the surface. If you care about the appearance, get a
knife not to use, as some people do with copper pans. Remove the rust
with steel wool or (after wetting it with oil) with a razor-blade
paint scraper. Then sharpen it. Cosmetic damage is the least that
happens when a carbon steel knife is left wet. The first damage is to
the edge. If you can't tell, it wasn't sharp to begin with.

Jerry
--
Engineering is the art of making what you want from things you can get.

Uh, you do know OP was talking about the stain on the rice cooker, right?

No, I obviously didn't. "Soaking in" should have given me a clue.

Jerry
--
Engineering is the art of making what you want from things you can get.

On May 26, 11:54*pm, "HeyBub" wrote:
Jerry Avins wrote:
On May 18, 2:02 pm, Han wrote:
"graham" wrote
:

It's one of the more dangerous acids and should NOT be available
to the general public. I'm fully aware of the dangers having used it
under lab conditions and having to develop procedures in the case of
accidents. These days, my processing work is handled by a contract
lab so I don't go near the stuff.

It's all in the dose. Moreover, HF is readily soluble in water, so it
washes away easily. I am NOT recommending sniffing it or drinking
it, or washing your hands in it. On the other hand, it is present in
toothpastes in various forms as a minor, but active ingredient.

So wrong! There are fluorine compounds in toothpaste, but not
hydrofluoric acid. Usually sodium or potassium fluoride. Check the
label.

HF isn't basically more dangerous than HCl. It's primary claim to fame
its ability to attack glass. *Don't confuse it with HCN.

HF interferes with the body's calcium and potassium metabolism and can cause
death by cardiac arrest.

From skin contact? I suppose I've been lucky, then. To clean nitric-
acid stains off my hands, I would go to the plating shop, dunk my
hands in the bright dip to be sure there were no cuts, then rinse them
in the cyanide bath. Plenty of running water after than.

Jerry
--
Engineering is the art of making what you want from things you can
get.

Jerry Avins wrote:

From skin contact? I suppose I've been lucky, then. To clean nitric-
acid stains off my hands, I would go to the plating shop, dunk my
hands in the bright dip to be sure there were no cuts, then rinse them
in the cyanide bath. Plenty of running water after than.

Isn't that how the Iceman killed his targets, spraying them with
cyanide or just spilling it on them as he went by?

nancy