There are a number of ways to create rust patterns on cotton and silk fabric and here is a simple controlled method. Natural fibres take the rust colours better than synthetic fibres and fabrics should be free from oils or starches. Prepare your fabric by rinsing in a solution of synthrapol and water (half a teaspoon to 5 litres of water). A 5 litre solution will dye approximately 1 kg dry weight of fabric or fibres, ensuring that there is room to move the materials around in the dye vat. If you intend to dye wool fibres with this method, use salt as a substitute for soda ash.
Use this method to colour your fabric all over. Add patterning by using the Shibori technique.
- 500gm Iron Mordant (ferrous sulphate)
- 10gm soda ash (sodium carbonate)
- Flat bottomed bucket or pan for heating dye vat (to take 5 litres including fabric)
- Add ferrous sulphate to 5 litres of warm water and stir gently to mix.
- Add fabric (ready tied if you wish to add patterning) and bring to the boil slowly.
- Simmer and stir for 5-10 minutes, making sure that the fabric remains submerged.
- Remove your fabric and spread out to dry. Contact with the air causes oxidation to take place which is how rusting occurs.
- Rinse out your bucket and add 5 more litres of warm water.
- Stir in the sodium carbonate until dissolved.
- Place fabric in bucket and allow to soak for 10-15 minutes. The fabric will change from green into a rust colour.
- Rinse under cold running water and then warm water with a small amount of synthrapol.
- Finally, rinse thoroughly in cold water and leave to dry.
Safety: remember to wear a mask and gloves when handling chemicals and to follow good house keeping practice.
Other Methods for Staining Fabric with Rust
You can place wet fabric next to a rusty object to create a stain over time. Soaking your fabric in vinegar helps to speed up the rusting process. The wet fabric can then be tied using rusty wire or tied with string around a rusty object such as a pipe. Rusty items such as nails or screws can also be placed on the fabric or ferrous sulphate can be sprinkled onto it. Allow at least 24 hours for the oxidation to occur. The longer you leave your fabric in contact with the rust, the more likely it will disintegrate and cause holes. You will need to neutralise the fabric if this is not the desire effect.
To neutralise the effect of oxidation, rinse the fabric in a soda ash solution (10gm to 5 litres water) before rinsing with diluted synthrapol. This will help to prevent the rust from rotting the fabric. Periodically, at least once a year, you will have to neutralize your fabrics as once the rust has bonded with the fibres it will continue to rust indefinitely.
The method, although fascinating, shortens the life of fabrics and is not recommended for items that need to be laundered regularly or subjected to bright sunlight.