Good Rust Stain Remover?

We had a bathroom renovated, whch is right over my shop. I carefully
covered everything up during the construction, but they left a time bomb
for me. The shut off valves for the water were right over a workbench, and
after using them for the first time in decades, the packing on both the hot
& cold water are leaking. Not so fast that it's easy to spot, but over a
couple of weeks, it was enough. I think they leak a bit every time the
washing machine does the water hammer thing. Ground zero for the drips was
the steel table for a 12" sheet metal shear I'm rebuilding, which I had
spent hours derusting & cleaning up. I had placed it on some paper towels,
which caught the drips, and proceed to wick under the entire bottom of the
table, rusting it thoroughly. I will deal with that later...
The bench is nominally for electronics work, and is covered with a rubber
ESD mat. This now has nice rust stains all over it. I know oxalic acid is
the classic cure, but I've never used it & was wondering if there is a
pre-mixed version I should look for at the store, or some other flavor of
chemical. I don't need much, but the bench look like hell, and I'm pissed
off enough as it is without a constant reminder.
Thanks!
Doug White
Reply to
Doug White
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It clearly needs a pair of water hammer arrestors, to prevent problems in the washing machine valves. Make sure to get a large enough unit, in terms of internal volume. Put the arrestors no more than two or three feet of pipe away from the washer. Do not subject arrestors to soldering heat.
For instance
There are pre-mixed version, at some expense. Paint and hardware stores often carry oxalic acid.
Why is mixing it yourself a problem? You will need the same precautions while using it.
Joe Gwinn
Reply to
Joseph Gwinn
Mentioned numerous times in the past, diluted phosphoric acid is an excellent treatment for rust, also oxidation on aluminum, cleaning/etching stainless and galvanized.
Used for generations in autobody bare metal etching treatment to prepare metal surfaces for primer, phosphoric acid solutions commonly referred to as metal prep, twin/triple etch and other terms, will effectively remove oxides from metals.
Phosphoric is a relatively safe acid (also found in foods) when diluted (not commonly available at 100%), with normal safety precautions such as protective eyewear. The diluted strengths aren't particularly hazardous to hand skin, although a small cut will sting like it would if exposed to lemon juice.
The basic procedure is to dilute to the recommended strength (varies for steel, aluminum etc) and to apply to the area for a specified period (of about 20 minutes), while keeping the surface wet (trigger spray bottle, paper towels applied to area to maintain moisture level). For minor stains wetting a steel wool or scuff/scratch pad (scotch brite or similar) and rubbing after a wetting period will remove staining or light rust down to clean bare metal. Etched bare metal items should be quickly rinsed and dried after treatment, followed by any appropriate surface corrosion treatment desired. An etched bare surface isn't especially prone to further oxidation, but in humid or damp locations some surface coating is required (paste waxing, light oil film, primer/paint etc).
For mild surface rust, I generally use a single-edge razor blade scraper held at a low angle to separate the fuzzy rust from the surface. This works well on old items where it's desirable to keep the aged patina on flat steel/iron surfaces. Application of some oil is useful for wiping away the removed rust with a rag.
If it's apparent that the razor blade corners are catching on a surface that's not uniformly flat, using a stone to remove/radius the blade corners will prevent digging and scratching.
More advanced rusting (scaley pitted) is more quickly removed with an abrasive, followed by a phosphoric solution treatment followed by wire brushing while the surface is still wet. Any rust remaining in deep pits will continue to spread if not completely removed.
The phosphoric etching treatment is often more practical than the rust-converter type products (also phosphoric acid), which leave a crusty residue/scab after treatment.
Reply to
Wild_Bill
Joseph Gwinn wrote in news: snipped-for-privacy@news.giganews.com:
I have arrestors, but they are the "Mini-Restor" compact units, and the O-rings have begun sticking. I need to either replace them or take them off & un-stick them. I was a beta-tester for Sioux Chief for several generations of these things when they first came out. My old house had low water pressure, and they would start sticking very quickly. Still plenty of water flow to make a good Bang! when the washer valves kicked off, but not enough to kick the O-rings loose. Sioux Chief must have sent my 6 or 8 different revisons over the course of several years.
The ones you linked to are the larger "Industrial" version. One issue is that the spec on these things is to keep ther pressure spike below 150 PSI. That can still make quite a bang, and vibrate/damage stuff. They claim they are "permanent", and can be installed in walls with no access, but I have years of experinece that says otherwise. I suppose they may have improved them further, so maybe I'll buy some new ones.
I just figured a small bottle of remover would be plenty. No point in filling the house up with more large quantities of toxic/corrosive stuff.
Doug White
Reply to
Doug White
I bet the bangs well exceed 150 psi.
From the reviews, they seem to have solved the problem, although a few people said the unit never worked. My suspicion is that they soldered the Tee in with the arrestor in place, and cooked it.
If you like, you can make one's own arrestor from some pipe, a cap, a reducer, and a Tee. This will not have a problem with too-low pressure to keep the piston unit moving, but you will need to drain it every so often to reestablish the air bubble. Or, provide a way to introduce compressed air to replenish the bubble. But one can install a dead-end pipe in an area where access is difficult.
Well, the local hardware store sells small bottles for small dollars.
Joe Gwinn
Reply to
Joseph Gwinn
Citric acid is nice.. For small needs, the stuff meant for cleaning coffee maker is 100% citric acid..
I just cleaned a REALLY rusty wire-EDM stainless steel water storage tank and associated parts with citric acid.. Works really well. Just leave the citric acid solution for a day and the rust is gone..
The nice that is that citric acid is really safe, you can drink it mixed to water as lemon juice.. It is used in many foods.. Afterwards, there is no chemical waste that is difficult to get rid of..
Kristian Ukkonen.
Reply to
Kristian Ukkonen
Kristian Ukkonen wrote in news:qKlLq.2781$ snipped-for-privacy@uutiset.elisa.fi:
Thanks! I'll give it a try. At least it's plenty safe.
I looked at some commercial stuff called "Whink", and it's hydroflouric acid! I don't care how dilute the stuff is, I ain't going near it.
Doug White
Reply to
Doug White
That is their toilet bowl cleaner. "Rust and Iron Stain Remover."
You want their laundry rust remover. "Rust Stain Remover" From the MSDS Sodium Bisulfate, Sodium Hydrosulfite, Sodium Chloride (NaCl), Sodium Carbonate, Citric Acid, Blue Crystals.
It's in the laundry aisle at the supermarket.
Paul K. Dickman
Reply to
Paul K. Dickman
DON'T use oxalic on the STEEL; it's good to clean rust from the ESD mat, as long as you don't get it near any steel hardware. Oxalic acid removes rust, but also etches steel (and even stainless steel).
To clean the steel, I'd use those metal-finish Scotchbrite pads (gray or maroon color codes), and maybe finish with some metal polish. Either blue the steel or paint it immediately after you get it clean. Wax, oil, and clear finishes are a bad idea (you can wear through 'em and never know).
Even if the valve packing is good, water pipes can be covered with condensation (like dew, only indoors) in some atmospheric conditions, so insulation on the pipes is a good idea if you see moisture.
Reply to
whit3rd
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Really? I have had very good results with Barkeepers Friend and so have many others.
Michael Koblic, Campbell River, BC
Reply to
mkoblic
Go down to the grocery store and look in the detergents section and you should find "Barkeeper's Friend" powder. Does a fine job on the kind of stain you're talking about, it's cheap, and works fine on cookware as well (it's recommended by several high-end manufacturers). Only ingredient listed on the MSDS is oxalic acid at 10 percent.
Reply to
J. Clarke
CLR makes a good rust remover too - and IIRC ZUD is an oxalic acid product that works good taking rust stains out of sinks and toiletss.
Reply to
clare

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