What is Limescale?
Lime forms when hard water is heated above 61 ° C or when it is allowed to evaporate on surfaces such as faucets and showers. Hard water is water that contains large amounts of calcium and magnesium ions. These hardness minerals, in the form of calcium carbonate and magnesium carbonate, are what precipitate out of hard water to form lime. Therefore, to clean or remove limescale, we need something that dissolves or softens the calcium carbonate and / or magnesium carbonate.
Acids are generally very good at dissolving things and in particular the following list of acids will dissolve lime.
Warning: some of these acids are extremely dangerous and its use as a descaler is best left to professionals. Also, some acids, particularly hydrochloric acid, will discolor (blacken) chrome faucets and fixtures.
1) acetic acid
Vinegar is just dilute acetic acid, so it is available at home.
Mix half a cup of water and half a cup of white vinegar (not malt vinegar) to remove limescale from an electric kettle. Bring the mixture to a boil and leave it overnight. Rinse the next day.
Clean your shower heads by soaking them overnight in a tub of undiluted white vinegar. Mix with borax (50:50) to make your own inexpensive lime scale cleaner for faucets, tiles, bathrooms and sinks.
2) citric acid
Citric acid is present to some degree in all citrus fruits, but lemons generally have the highest concentration. Lemon juice generally works better than vinegar and leaves a more pleasant smell.
To clean dishwashers and washing machines, use a cup of lemon juice instead of normal detergent. Run a normal wash cycle without clothes / dishes. For washing machines, put the lemon juice in the powder soap dispenser. For dishwashers, you just have to insert it directly into the bottom of the machine.
To clean electric kettles, follow the vinegar directions but replace the vinegar with lemon juice. The same goes for shower heads.
When it comes to cleaning the taps, the problem arises when trying to keep the lemon juice in contact with the lime long enough for it to dissolve or soften. One way to overcome this problem is to soak a cloth in lemon juice, wrap it around the faucet, and leave it overnight.
Citric acid is also the main ingredient in Limelite sprays, gels, descalers, and wipes.
3) formic acid
Formic acid, naturally produced by ants and contained in bee stings, will dissolve lime. It can be purchased as Kilrock K or in diluted form as Techno Swan. It is also one of the two acids used in Cillit Bang Grime and Lime (the other is sulfamic acid).
4) glycolic acid
Although primarily used in cosmetics, glycolic acid is a minor ingredient in several commercial lime cleaning products, including R8 Kettle Descaler. DuPont markets glycolic acid to remove hard water scale deposits in industrial water and boiler systems.
5) hydrochloric acid
It is sold in Spain as strong water. Be careful, hydrochloric acid is a strong acid and will burn your skin; Please read all safety data carefully. It bubbles in contact with lime and the vapor it gives off (hydrogen chloride) is toxic, so this is probably best left to the experts.
If you still want to give it a try, then a safer alternative, containing hydrochloric acid as the main active ingredient, is No Nonsense Path Patio & Driveway Cleaner. Other kitchen and bathroom cleaners that contain hydrochloric acid include Harpic duraguard lime remover and Lifeguard lime remover.
6) lactic acid
Sometimes known as lactic acid, lactic acid is also a good lime remover. Lactic acid is formed when lactose, which is found in milk, is broken down by bacteria and is therefore found in sour milk. However, we do not recommend trying to de-lime with sour milk. Instead, buy something from Oust. The Oust Universal Descaler contains 30 to 50 percent lactic acid and can be used to clean kettles, coffee makers and irons.
7) oxalic acid
Oxalic acid is 3,000 times stronger than acetic acid and is used primarily as a bleaching agent or to remove rust. Removes limescale, but is rarely used in household cleaning products. It is used in Oxal Wash to remove limescale (among other things) from the exterior of trains.
8) phosphoric acid
Phosphoric acid’s primary use is as a rust remover, but it is also used in many commercial lime cleaners and is found in some soft drinks, especially cola.
In the movie, Limescale, the main character stops drinking water and only drinks cola in the belief that lime is building up on his body and the glue will dissolve the hardened deposits. Urban Myth according to the movie synopsis, but both major glue brands contain phosphoric acid (E338).
Phosphoric acid is sold in its raw state as a descaler on eBay and is used in many commercial lime cleaners. Proprietary cleaners that contain phosphoric acid include HG Professional Limescale Remover or Hagesan Blue.
9) sulfamic acid
Sulfamic acid is widely used in commercial lime cleaning products and is a less dangerous alternative to hydrochloric acid. For professional use, it is an active ingredient in Fernox DS3 limescale remover and at home it is one of the components of Cillit Bang Grime and Lime.
10) sulfuric acid
Knock Out Drain Cleaner is almost pure sulfuric acid, but it is not marketed as a lime cleaner (although it works). Sulfuric acid is extremely dangerous and is best left to the experts. Even then, few, if any, descaling products on the market contain sulfuric acid. Avoid!