How do I remove rust stains off brick and stone?

Question

I'm replacing my rusting iron railings that have stained the brick and decorative wall stone with rust.

Answer 1

good god no !

Don't even dare using muriatic acid or bleach or hydrochloric acid on stone ! and never use a metal-bristle brush with acid, on brick and stone !!! it'll leave a lot more staining and be too abrasive on the bricks ! Any brush you use should be stiff nylon bristle brush or wood fibre brush.

You'd be risking damaging or staining the stone with acid-burn, "vanadium stain" on the stone and brick, or disintigrating the surface of the stone or mortar, while at the same time, not removing the rust !

I've had so many people come to me whining about following someone's misguided advice to use muriatic acid for the wrong purpose, and they had to remove and replace brick and stone.

There are two functions you want to achieve:
1 - to remove the rust,
2 - to not cause more staining or damage to the stone or open the surface of the brick making it more susceptible to weather related damage.

Muriatic acid and most acids will fail both those functions.

Brick manufacturers advise NOT to use muriatic acid, they know the damage it can do. Its famous acid, but very often used or advised wrongly, even for the wrong purpose. Sloppy bricklayers of older times used it to clean off cement smudges and calcium-salt efflorescence, you know from public school science class, acid will eat away at chalk and calcium stuff. But its not good for rust. Only kind of acid which would be very effective taking rust off, is Oxalic acid, but still an acid, could damage the brick and stone and leave its own stain. You can get something that is an "already re-acted acid" or something guaranteed to contain no acid.

A liquid called "Klenztone" is made for all this in mind. Its the very best thing you can get. You can see it on their website and find out from there who sells it. http://www.klenztone.com/

IF you still want to try other stuff, like CLR, which is modified acid, or some car rust-remover chemical, do this to reduce the risk of damage:
- Pre wet the wall with plain fresh water, until its saturated and cannot absorb anymore water, (thats so that your cleaning solution and the stain don't get soaked into the bricks and stone, but remain at the surface until you rinse it off)
- Then try a small "test spot" of your cleaning solution, in an inconspicuous area if possible, and see what the results are before you carry on with the rest of the stained part of the wall.
- Pay strict attention to the time you leave your cleaning solution on there, and make sure it does not dry out in the meantime.
- Remember don't use metal-bristle wire brush, use a wood-fibre or nylon type fibre bristle brush
- Then rinse thoroughly with fresh water. If it achieves both functions, cleans of rust, and leaves no further stain, then do the rest of it. If it fails either function, try another product meant for that purpose, and test that one too, before you do the rest of it.

Also, keep in mind, sand-blasting also does damage to the surface of bricks, making it more porous and open to accelerated weathering and future staining. Sandblasting is not advisable considering the long-term results.

Don't go by "good luck"
Go by true advice and cautiously procede with all the possible short-term and long-term results in mind !

Answer 2

Muriatic Acid To Remove Rust

Answer 3

Stain For Brick

Answer 4

This Site Might Help You.

RE:
How do I remove rust stains off brick and stone?
I'm replacing my rusting iron railings that have stained the brick and decorative wall stone with rust.

Answer 5

First scrub the stained area with water using a stiff brush. Then, if some stain residue remains, use a muriatic acid product designed to remove stains from brick. Before you mix the acid, make sure put on protective clothing (a cheap rain suit will do the job), safety glasses and acid-proof gloves. - See more at: http://www.proconstructionguide.com/efflorescence/

Answer 6

Remove rust stains with one cup of muratic acid mixed with one gallon of water. Muratic acid is inexpensive, and can be purchased at Hardware stores, Pool supply stores and pharmacies. Follow instructions on the bottle such as using rubber gloves and avoid breathing the fumes. You may need to use several applications, and scrubbing will help. Good Luck.

Answer 7

I had the same problem, but it was on an end table, I used baby oil (which helps remove the sticky feeling from the face after waxing) and nail polish remover. But if you have a carpet shampooer/cleaner try using that to scrub it out, or you can buy a hand held pretty cheap at walmart.

Answer 8

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Yes it can be done it will require alot of hard work, because once you have stripped the varnish you still may need to sand down areas. I found this for you - Home Strip Paint and Varnish Remover Home Strip is a new and extremely effective water-based, vapour free paint, varnish and coatings remover based on dibasic esters. Home Strip has a slightly longer dwell time than more dangerous solvent based strippers based on Methylene Chloride and NMP. It allows the removal of up to 5 coats in one application. Clings 100% to vertical surfaces. No discolouration of timber, washes off with just water. Safely remove multiple layers of anti fouling and marine paints from Glass Fibre and GRP without affecting the gel coat. Home Strip does not dry out after short periods of time, allowing large areas to be stripped successfully, unlike some solvent strippers which quickly evaporate. Because Home Strip does not give off any fumes, there is no need to work out of doors or ventilate the area by opening doors and windows as you would with solvent strippers. Suitable for all woods, metals, stone, brick, marble, GRP (Glass Reinforced Plastic) etc. Recommendations: try a small test area first. Coverage: 1 litre will cover approximately 4 - 6 square meters, depending on coating and thickness. Available in 500ml, 5 Litre, and 15 Litre sizes. Recommended Stripping times: Varnish, Shellacs, French Polish - 15-30 minutes Under normal circumstances only one application required. Lacquers, Polyurethane's - 30-45 minutes 2-3 applications may be required. Anti Fouling Coatings, etc. from GRP - 30-45 minutes 2-3 applications may be required. Multi-layered paint - 1 hour then scrape off. Repeat process. For more than 5-6 coats of paint (such as a door) Apply liberally and leave for 1 hour and scrape off. Apply second coat and leave overnight. To prevent drying out in hot conditions, or when left overnight we recommend that the treated area is covered with a plastic film. Instructions for use: Apply liberally on surface. Remove after required time with scraper, or ideally use a stainless steel scouring ball. Do not use wire wool as this will cause rust marks to penetrate into wooden surfaces. If required, apply a further liberal coat and repeat until bare surface is visible. Wash off any residue with a damp cloth or water. Use sandpaper to remove any small traces of finish, once the the surface has completely dried out. Price Size 0.500 Litre £7.98 15.00 Litre £99.98 5.00 Litre £42.98 *prices include VAT Good Luck with your project.

Answer 9

Hydrochloric acid will do, but you are going to have to do the whole wall unless you want a slightly discolored wall. Muratic or hydrochloric removes the outer layer including the stain.

Answer 10

try using some bleach on the rust stains,works for me.