Stains on sink

GG1 · 01-30-2005, 04:33 PM

Has anyone encountered stains on the bathroom sink? There are a few stains that have appeared on the sink in the commode area that look like rust stains but there has never been any metal in the sink. It started with one now there are 4 spots. They look like they are under the surface. Maybe it would be easier to just replace the sink.

GG1 · 01-30-2005, 04:33 PM

Has anyone encountered stains on the bathroom sink? There are a few stains that have appeared on the sink in the commode area that look like rust stains but there has never been any metal in the sink. It started with one now there are 4 spots. They look like they are under the surface. Maybe it would be easier to just replace the sink.

The Shadow · 01-30-2005, 04:58 PM

Haven't enountered that in the MH yet but sure have in the house - from very hard water with lots of iron in it.

DonavonP · 01-31-2005, 06:32 AM

If your sink is a resin mold, you could try a light acid to try to neutralize the rust stains in the sink. This should be your last effort just before replacing the sink as the acid might dull the finish on the resin as well as the stopper finish.

There might have been some metal filings in the resin at the time of manufacture. Because you say the stain (probably iron oxide) is within the material you could start out with mild acid like vingar but probably easier to use and keep directly on the rust spot - try Cream of Tartar (tartaric acid).
Let it sit on one of the less obvious spots for a few days - keep it damp with a wet rag.

Cream of Tartar is available at grocery stores.

Kiwi · 01-31-2005, 06:46 AM

DO NOT READ....MORE THAN YOU WANT TO KNOW.
++++++++++++++++++++++++++++++++++++++++++

When a droplet of water containing a little dissolved oxygen falls on an iron pipe, the iron under the droplet oxidizes:
Fe(s) Fe2+(aq) + 2 e-

The electrons are quickly snatched up by hydrogen ions and oxygen at the edge of the droplet to produce water:
4e- + 4 H+(aq) + O2(aq) 2 H2O(l)

More acidic water is expected to increase corrosion so long as there is a sufficient supply of oxygen. If the pH is very low, and there isn't enough oxygen, the hydrogen ions will snatch up the electrons anyway, making hydrogen gas instead of water:
2 H+(aq) + 2 e- H2(g)

But where's the rust? The equations above tell only a small part of the story.

Hydrogen ions are being consumed by the process. As the iron corrodes, the pH in the droplet rises. Hydroxide ions (OH-) appear in water as the hydrogen ion concentration falls. They react with the iron(II) ions to produce insoluble iron(II) hydroxides:

Fe2+(aq) + 2 OH-(aq) Fe(OH)2(s)

The iron(II) ions also react with hydrogen ions and oxygen to produce iron(III) ions.
Fe2+(aq) + 4 H+(aq) + O2(aq) 4 Fe3+(aq) + 2 H2O(l)

The iron(III) ions react with hydroxide ions to produce hydrated iron(III) oxides (also known as iron(III) hydroxides).
Fe3+(aq) + 3 OH-(aq) Fe(OH)3(s)

These can dry to make plain iron(III) oxide, Fe2O3. This is the red, powdery stuff we call "rust".
Since these processes involve hydrogen ions or hydroxide ions, they will be affected by changes in pH.

If you have other ions like calcium or carbonate present, they make a variety of precipitates that mix in with the iron hydroxide precipitates to produce a crusty, gnarled coating which can slow corrosion under some circumstances by cutting the iron off from the acid, water, and air supply.

Allegro Happy · 01-31-2005, 07:32 AM

Kiwi, are we having a test??????Do I have to memorize this?

Kiwi · 01-31-2005, 08:25 AM

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Allegro Happy:
Kiwi, are we having a test??????Do I have to memorize this?

<HR></BLOCKQUOTE>Yes, you must learn it all or your sink will turn to rust.

I WARNED YOU..but you read it anyway.
Walt

Lorna · 01-31-2005, 09:08 AM

Try using a paste made of baking soda and water on your rust stains. Don't forget to add a little elbow grease.

The Shadow · 01-31-2005, 09:11 AM

It gets worse, the entire MH turns to rust.

<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Kiwi:
<BLOCKQUOTE class="ip-ubbcode-quote">quote:<HR>Originally posted by Allegro Happy:
Kiwi, are we having a test??????Do I have to memorize this?

<HR></BLOCKQUOTE>Yes, you must learn it all or your sink will turn to rust.

I WARNED YOU..but you read it anyway.
Walt <HR></BLOCKQUOTE>

RV Roadie · 01-31-2005, 09:28 AM

Cute thread!
You guys are great! And the info was good about how the rust got there.

Having had the same problem with the RV we also fought it for a year or two until a miracle product was brought to our attention.

Just go to any Home depot and get some "Iron out." Be sure to read the directions first in case there are any warnings about materials you have. It worked great in our plastic RV sink, our porcelain RV Kitchen sink, and our plastic RV thetford toilet.

No scrubbing either, just wet the surface, sprinkle a little on, spread it evenly as a wet paste, watch the iron get eaten off, rinse well.

It has an odor which is not toxic and goes away fast. I called the company and they told me that it is not a hazard except for folks allergic and the usual that it isn't for skin, eye, or eating contacts.

But boy does it work!