semi off-topic: how to clean ferrichloride stains

[Ivan]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

 

[MooseFET]

First of all, sorry on OffTopic. My question is how to clean stains made
by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no
effect.

Stain = Oxidation only appears on the surface, you have to sand it off a bit
before applying Acetone.

 

[www.ningbo-electric.com]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect..

Hope you can quickly find how to clean stains .
Btw, know something about the manufacturer of electirc products:
China air source treatment,pressure regulating filter ,atomizer
lubricator,oil sprayer,two-point,three-point F.R.L
combination,pressure regulating valve,filter
regulator,SDA,CQ2B,CJ2B,CM2B thin type cylinder,MAL aluminum alloy
mini,pneumatic cylinder,CXSM double,single acting cylinder,double
acting,STMB,CX2 skid platform,solenoid valve,pneumatic magnetic
valve,hand valve,cylinder manifold,
www.ningbo-electric.com

 

[John Fields]

Hope you can quickly find how to clean stains .
Btw, know something about the manufacturer of electirc products:
China air source treatment,pressure regulating filter ,atomizer
lubricator,oil sprayer,two-point,three-point F.R.L
combination,pressure regulating valve,filter
regulator,SDA,CQ2B,CJ2B,CM2B thin type cylinder,MAL aluminum alloy
mini,pneumatic cylinder,CXSM double,single acting cylinder,double
acting,STMB,CX2 skid platform,solenoid valve,pneumatic magnetic
valve,hand valve,cylinder manifold,
www.ningbo-electric.com

 

[Tim Williams]

Acid. Try vinegar or oxalic acid. Think rust remover. For that matter,
CLR sounds like yet another option.

Tim

 

[J.A. Legris]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect..

From the blog of a very smart guy, Michael Covington:

( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
)

"The other day, in our robotics lab, I gave a demonstration of making
a printed circuit board. I used ferric chloride etchant because it
doesn't require heating.

Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
static mat that was somewhat porous. As you know, ferric chloride is
yellowish-brown, a lot like rust, and tends to stain everything it
touches. So despite some cleanup attempts with water and various
cleaning products, there was a stain.

Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
acid and water and left it on the stain for 2 hours. That removed
about 80% of the stain.

I may go at it again with citric acid and hot water. I'm told that
oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
but I didn't have any.

Addendum: I'm told that oxalic acid is also the active ingredient in
Bar Keepers Friend powder (not liquid). If so, this should be just the
thing for removing FeCl stains.

Another addendum: This source indicates that FeCl stains can be
decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
that. As close as the nearest vending machine!"

 

[D from BC]

From the blog of a very smart guy, Michael Covington:

( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
)

"The other day, in our robotics lab, I gave a demonstration of making
a printed circuit board. I used ferric chloride etchant because it
doesn't require heating.

(I microwave Ferric Chloride for really fast etching..and pressurize
it too.)

Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
static mat that was somewhat porous. As you know, ferric chloride is
yellowish-brown, a lot like rust, and tends to stain everything it
touches. So despite some cleanup attempts with water and various
cleaning products, there was a stain.

Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
acid and water and left it on the stain for 2 hours. That removed
about 80% of the stain.

I may go at it again with citric acid and hot water. I'm told that
oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
but I didn't have any.

Addendum: I'm told that oxalic acid is also the active ingredient in
Bar Keepers Friend powder (not liquid). If so, this should be just the
thing for removing FeCl stains.

Another addendum: This source indicates that FeCl stains can be
decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
that. As close as the nearest vending machine!"

Interesting but I avoid cleaning.
If something gets stained, too bad. Chuck it in the garbage... Unless
you splattered Ferric Chloride all over your new spectrum analyzer.

I use Ferric Chloride like a neat chemist. No mess.
Ammonium Persulfate doesn't make yellowish stains.
However, Ammonium P. can eat rugs.. Made a nasty hole one time


D from BC
British Columbia
Canada.

 

[Tom Bruhns]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

Doesn't seem so off-topic to me...assuming of course that you were
using the ferric chloride to etch something electronic and not
something else. ;-)

As others have pointed out, acid solvents work well on ferrous/ferric
ions. Both ferric and ferrous hydroxide have very low solubility, but
the acid removes the hydroxide part and lets the iron go into
solution. If the thing you're cleaning can stand it, you can use
(dilute) hydrochloric acid (muriatic acid), commonly available very
cheaply at places that have masonry supplies, as it's used to clean up
mortar splashes and the like. It works really fast to remove iron
stains, generally won't hurt anything you'd put ferric chloride in,
but like ferric chloride is best kept away from skin. I find it's
also good to have a little HCl around to add to the ferric chloride
solution, to insure the ferric stays in solution. Acid also keeps
cuprous ion in solution.

I believe Zud is another cleanser that works well on iron stains: as
I recall, it has a little oxalic acid in it.

Cheers,
Tom

 

[The Phantom]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

Get some commercial rust remover at the hardware store.

 

[Phil Hobbs]

From the blog of a very smart guy, Michael Covington:

( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
)

"The other day, in our robotics lab, I gave a demonstration of making
a printed circuit board. I used ferric chloride etchant because it
doesn't require heating.

Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
static mat that was somewhat porous. As you know, ferric chloride is
yellowish-brown, a lot like rust, and tends to stain everything it
touches. So despite some cleanup attempts with water and various
cleaning products, there was a stain.

Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
acid and water and left it on the stain for 2 hours. That removed
about 80% of the stain.

I may go at it again with citric acid and hot water. I'm told that
oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
but I didn't have any.

Addendum: I'm told that oxalic acid is also the active ingredient in
Bar Keepers Friend powder (not liquid). If so, this should be just the
thing for removing FeCl stains.

Another addendum: This source indicates that FeCl stains can be
decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
that. As close as the nearest vending machine!"

Rust stains on sinks can be got rid of with Naval Jelly, which is
jellied phosphoric acid. Works right away.

Cheers,

Phil Hobbs

 

[Robert Baer]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

Use a deadly poison: Oxalic acid.

 

[Leon]

Baking soda?

As previously suggested, oxalic acid is the stuff to use. Rhubarb
leaves contain it, BTW.

Leon

 

[JosephKK]

Baking soda?

I don't think so, but some judicious googling should find you some.
Preferably less expensive that sodium bismuthate.

 

[JosephKK]

As previously suggested, oxalic acid is the stuff to use. Rhubarb
leaves contain it, BTW.

Leon

Yep. Also sodium sulfite (not sulfate) is good.

 

[Dave Platt]

First of all, sorry on OffTopic. My question is how to clean stains made by

ferrichloride? Thanks!

One commercial product made for this purpose (sold by Mega
Electronics) consists of 100% oxalic acid powder. 100 grams of
powder, dissolved in 500ml of warm water, is the recommended starting
concentration). Immerse items and soak until the stain is removed.

For other sorts of iron stains (e.g. rust stains from a nail left a
pocket) I've seen citric acid recommended.

In both cases, I believe that the principle is that the acid reduces
(de-oxidizes) the iron, converting it back to a soluble form that can
then be rinsed away.

Apply all appropriate safety precautions when working with these sots
of organic acids (protective gloves and goggles for starters)!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

No, I don't think that organic solvents would be helpful.

 

[Tom Bruhns]

On Mar 2, 4:37 pm, [email protected] (Dave Platt) wrote:
....

In both cases, I believe that the principle is that the acid reduces
(de-oxidizes) the iron, converting it back to a soluble form that can
then be rinsed away.

It is, I believe, much simpler than that. It's simply that ferric and
ferrous hydroxides each have such low solubility products that they
don't dissolve readily in neutral water whose [OH-] is about 10^-7.
By acidifying the water with a weak acid, you reduce the [OH-] to
perhaps 10^-13 or 10^-14. That's a result of the characteristic of
water that maintains [H+]*[OH-] at about 10^-14. That lets the ferric
and ferrous dissolve much more readily.

Cheers,
Tom

 

[JosephKK]

On Mar 2, 4:37 pm, [email protected] (Dave Platt) wrote:
...

In both cases, I believe that the principle is that the acid reduces
(de-oxidizes) the iron, converting it back to a soluble form that can
then be rinsed away.

It is, I believe, much simpler than that. It's simply that ferric and
ferrous hydroxides each have such low solubility products that they
don't dissolve readily in neutral water whose [OH-] is about 10^-7.
By acidifying the water with a weak acid, you reduce the [OH-] to
perhaps 10^-13 or 10^-14. That's a result of the characteristic of
water that maintains [H+]*[OH-] at about 10^-14. That lets the ferric
and ferrous dissolve much more readily.

Cheers,
Tom

PH per se is a separate issue from redox. The most effective way to
handle ferric chloride is by reduction. In well done cases you will
get fe+2 in solution (or possibly if sufficiently extreme cases micro
powder elemental iron in suspension, temporarily). If appropriate
ionic species are provided you can remove most of the Cl- ions.

 

[Tim Williams]

PH per se is a separate issue from redox.

It is, but they are all equilibria. ;-)

Since we're going to invoke chemistry, I'm just going to go overboard and
rattle off some stuff here: ;-)

Hydroxy:
Fe(OH)3 <--> Fe(3+) + 3 OH- pKs = 38.8
Fe(3+) + H2O <--> FeOH(2+) + H+ pKa = 2.19
Fe(OH)(2+) + H2O <--> Fe(OH)2(+) + H+ pKa = 2.41
Fe(OH)2(+) + H2O <--> Fe(OH)3(aq) + H+ pKa = 7.97
(Note this doesn't include the solubility of the Fe(OH)3 species.)
Chelates:
Fe(3+) + EDTA(4-) <--> [FeEDTA]- pKf = -25.1
Chlorides:
Fe(3+) + Cl- <--> FeCl(2+) pKf1 = -1.48
FeCl(2+) + Cl- <--> FeCl2(+) pKf2 = -0.65
FeCl2(+) + Cl- <--> FeCl3(aq) pKf3 = 1.00
Oxalates:
Fe(3+) + C2O4(2-) <--> [FeC2O4]+ pKf1 = -7.54
[FeC2O4]+ + C2O4(2-) <--> [Fe(C2O4)2)]- pKf2 = -7.05
[Fe(C2O4)2]- + C2O4(2-) <--> [Fe(C2O4)3)](3-) pKf3 = -5.41
(So total pKf = 20.00.)
Citrate:
Fe(3+) + Cit(3-) <--> [FeCit](aq) pKf = -11.8
Redox:
Fe(3+) + e- <--> Fe(2+) Eo = 0.771 V
SO4(2-) + H2O + 2e- <--> SO3(2-) + 2OH- Eo = -0.936 V
(Hmm, that's in alkali.)

So: Fe(OH)3 is damned insoluble; Fe(3+) is pretty acidic (as aqueous ions
go); FeCl3 is somewhat more soluble, but it still takes a lot of chloride
and acid to overcome the insolubility of Fe(OH)3; chelates like EDTA, et
al., oxalate, citrate, etc. grab on real tight, solvating iron well; and a
variety of reducing agents will suffice, but only if you get the iron into
solution to react with it.

Tim

 

[Paul Hovnanian P.E.]

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

What did you stain?

I have some ideas, but they may not work well on the cat.

 

[Michael A. Terrell]

What did you stain?

I have some ideas, but they may not work well on the cat.

The cat? How about a belt sander? ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida