Rust removal
Methods of Rust removal from iron
1) water - 1000 ml concentrated phosphoric acid (H3PO4)- 150g, butyl alcohol 4 g
2) water - 1000 ml, citric acid 15 g, concentrated phosphoric acid (H3PO4) - 280 g
3) water - 1000 ml concentrated phosphoric acid (H3PO4) - 280g, butyl alcohol 30 g, ethyl alcohol 120 grams hydroquinone -1 g (used as a reductant metal in photographic technique).
These solutions are used to remove rust at a temperature of 200 C. The Solution was applied on an iron surface, wait some time and then clean it off with a brush or cloth. Restored iron surface was washed with water and dry.
Rust removal from steel
Treatment of the steel surface by some of the following recipes removes rust and attaches to steel objects resistance to corrosion and in some cases (the first of the recipes) and Shine.
1) Simple solutions can be diluted acids:20% sulfuric acid (50 0 C), 25% solution of hydrochloric acid (at room temperature), 15% solution of phosphoric acid up to 70 0C
2) sodium Hydroxide(NaOH) - 75 g, sodium carbonate (Na2CO3, soda ash) - 87.5 g, potassium permanganate (potassium permanganate KMnO4) - 1 g, water - ml (solution should be prepared immediately prior to use)!
3) Oxalic acid -16 g, ammonium sulfate (NH4SO4 or ammonium nitrate) - 33 g, acidic sodium sulfide (NaHS) -120 g, water - 1000 ml.
4) concentrated phosphoric acid (H3PO4) - 285 g, tartaric acid 12 g, zinc phosphate (Zn3(PO4)2) - 8g, the chromium trioxide - 3 g, isopropyl alcohol 6 g.
Thiocarbamic inhibitor , therefore, prevents metal dissolution in acids
Rust removal from cast iron
1) 10-12% sulfuric acid; soaked in the solution temperature is 30..40 0C for 10...15 minutes or 5-10% hydrochloric acid, soaked at room temperature for 15...40 min with the lowering in dilute phosphoric acid. Then rinse thoroughly with water.
2) 15% phosphoric acid; process for 15 to 20 minutes at a temperature 50 0C. This method is used for items with a thick oxidized layer.
3) 2% phosphoric acid; the surface is treated for 30 minutes at a temperature 80 0C. This method is used for items with a thin oxidized layer.
4) 10% solution of chloride of tin - 100 ml and 0.25% solution of tartaric acid - 100 ml. Solution was mixed before use, process for about 30 minutes at a solution temperature 40 0C. This method is used for the most valuable objects with strong oxidation.
Rust removal from stainless steel
Although it is called stainless steel (stainless steel) - with time, it may also be covered by a layer of oxide. Here the following compositions to Rust removal:
1) water - 530 ml, concentrated hydrochloric acid - 430 ml, concentrated nitric acid and 55 g, hydrofluoric acid - 80 g (with a density of 1.13). Surface treatment at 40 0C. After removing the rust, the surface acquires a silvery color!
2) water - 750 ml, concentrated hydrochloric acid 150 g, concentrated sulfuric acid and 200 g, concentrated nitric acid - 14 g.
In both cases, items after processing, washed with water and degreased.
Rust removal from copper and copper alloys
1) concentrated sulfuric acid - 300 g and water - 1000 ml. Processing is conducted at room temperature.
2) 40% nitric acid - 300 ml, concentrated sulfuric acid - 200 g, sodium chloride - 2 g, zinc sulfate - 1 g dissolved in 5 mg of water. Processing is conducted at room temperature for an hour, then washed with water thoroughly and dried. The object surface becomes uniformly rough and dull.
3) for aluminum bronze - 10 % sulfuric acid solution. After treatment with the solution the object dipped in a solution of 1 kg of concentrated nitric acid and 1.5 kg of sulfuric acid for a few seconds, then washed with water and dried.
Rust removal from zinc
1) water - 1 liter, concentrated sulfuric acid and 180 ml, concentrated nitric acid - 130 ml (for galvanized iron, which degreased and cleaned previously). Treatment is carried out for one minute at room temperature of a solution, then the surface washed with water and dried. Using 3% sulfuric acid for very thin iron.
2) water -1 l, chromium trioxide - 150 g, concentrated sulfuric acid - 3...4 g. Treatment is carried out for 3...10 s at room temperature, then the surface is washed with water and dried. The subject gets Shine. Shiny
Rust removal from aluminum items
1) water -1 l, sodium hydroxide - 100 g, sodium chloride - 20 g. Treatment is carried out at a temperature of 50...60 0C of a solution within a few seconds, then washed with water. Aluminum darken, so to light the surface the object should be handled with 50% nitric acid, then washing with water and drying.
2) water -1 l, sodium hydroxide - 55 g, sodium fluoride - 44 g. Treatment is carried out at 55 0C for a few seconds.
Rust removal from magnesium alloys
1) water -1 l, concentrated sulfuric acid - 17 g, chromic acid -150 g. Temperature of solution should be 75 0C, the treatment is conducted for 30 min, then washed thoroughly with water. The solution cleans and adds resistance to sea water.
2) water -1 l, bichromate of potassium - 40 g, concentrated nitric acid - 180 g. Treatment is carried out at a temperature of solution 800C for a few seconds, then washed with water.
Rust removal form lead
- to do this, take 1 liter of water, concentrated hydrochloric acid - 100 g. Processing need to keep at room temperature to remove the oxide layer, then rinse with water.
Rust removal with nickel items
For solution required: water - 100 ml, concentrated sulfuric acid - 280 g, concentrated nitric acid 300 g and sodium chloride -3 g. Treatment is carried out at room temperature for 10...20 0C. Washed with water, then nickel subject treated with 1% solution of ammonia for the neutralization of the acids, then need to rinse with water again.