One safety note before I begin. You are using rusty objects so you should make sure your tetanus immunization is up to date and use rubber gloves when dying so you don't absorb too much iron. It can be a health hazard.
1. I simply wet a natural fiber fabric with vinegar and then wrap it around a rusty object or else lay rusty items on top of the vinegar soaked fabric. You need to keep the fabric moist while the rust transfers so cover with plastic but not tightly. You need to allow the air in to make the rusting happen. It usually only takes a couple of hours if you use full strength vinegar. Most recipes say to dilute the vinegar 50% with water because the full strength vinegar may degrade the fabric. In my experiments I didn't find any holes in the calico that I used but some of the others that tried it said their silk turned to shreds after 2 hours.
2. After you have enough rust on your fabric rinse it off in salty water until the water is clear then dry on the line. That is it. Now you have wonderful fabric to play with.
3. When I read up on the technique I saw that many people mentioned the fabric would continue to rust over time and degrade your fabric. I found a simple way to get around this is to wash the fabric in a bicarbonate soda and water rinse (about 1/4 cup soda to 4 liters of water) to neutralise it. You need to repeat this yearly to stop the rust developing over time. If you don't want to bother with that then don't use the fabric for something special that you want to keep for a long time.
Below are some of the samples (click on photos to make them larger) I made and some of the other techniques I tried:
The first time I did this I layered the fabric in a long plastic tub then spread over the rusty objects and sprayed each layer with vinegar. This was plain calico. It had some steel wool spread over it. The steel wool started to rust within an hour but I left it overnight to see how dark it would get. I like the random pattern it made.
This was another piece of calico that I did at the same time. You can sort of see the outline of some washers I used. On the calico the rusting makes a blurry image.
This piece of calico was wrapped around a large bolt and left overnight in an open plastic bag. You can see some of the detail of the thread.
Someone at the class mentioned that tea staining the rusty fabric makes a grey color. With this sample I used 5 teabags and boiling water to soak the fabric. I left it for 5 minutes and it became really dark. After I rinsed and dried the fabric it remained a dark color.
This sample is another tea stained one. I only used 1 tea bag this time. I just dipped the right hand side in and removed it straight away. You can see it has changed the orange color of the rust to a brown shade. The left hand side was dipped for about 3 minutes and is darker in tone.
This sample was dyed on the stove with RIT liquid dye. The rust has not really changed color much. I really like the autumn tones of this piece.
The calico was fun for my first attempts but I wondered why they always say to use natural fibers. I have a huge roll of man made fabric so I wanted to try that. I don't know what it is because I picked it up at a garage sale but it looks like some sort of sheeting. It is not 100% cotton but it does feel like there is some in the mix. It is probably polyester.
The polyester fabric worked. The images of the rusty objects I used is much sharper than on the cotton calico. I am showing both sides of the fabric here. You can see that the color is softer on the side that doesn't touch the rust.
When I was pulling the steel wool apart to lay on my fabric I noticed little fibers of steel wool were covering the table so I decided to pull the steel wool apart over the top of one of the pieces of fabric. If you look at the larger version of this photo you can see the lacy pattern it made.
The man made fabric did not absorb as much rust in the open areas as the calico did so there is much more contrast in the color. I also like the high definition patterns that formed.
This piece was wrapped around the big bolt but this time I used a skein of embroidery floss to hold the fabric on tightly. I was surprised to see it made a sort of tie dye effect on the material. It also dyed the floss a rusty color too so I can't wait to use it to make something.
My final experiment was to dye the polyester with the same dye I used for the calico. It changed the rusty color very slightly and didn't dye evenly but I like that. I looks like it will be fun to use.
Now that I have all this fabric I am going to make a few things. I want to keep a record of all my experiments with each technique I learn this year so I will make a fabric art journal where I will have examples and also written pages with instructions. I will be starting with a page that uses these rusty fabrics I have made. This technique is so much fun that I had to stop myself doing even more fabric. I need to find ways to use it first.