I needed some rusty pipes to go into my new escape room and wanted something simple and quick. Here’s what I did.
Step 1
Spray paint a simple PVC pipe metallic silver.
Step 2
Get your paint ready. I used 3 different colors for this. Black, a reddish-brown, and orange. Note that I used a bright, orange. Trust me, it will look good once it mixes with the other paint, especially the black. You can see I actually sprayed some of the black paint in the bottom of a little container and then sprayed the orange on top of it. Don’t mix it up, but when you use it, press the tip of the brush into the orange and you will end up with both orange and black on the brush.
Step 3
Spray paint some random, black splotches on the pipe. This will be the base for rusty spots. You don’t have to do this, but after lots of experimentation I found the key to good looking rust is layers. Blacks and reds and oranges. So I would always start with some black.
Step 2: Spray some black splotches 
Black splotches on pipe
Step 4
Dabble on some of the red color. I like using an older, stiff paint brush. Just touch the tip of the brush to the lid of the open can of paint to get the tips red. No need to dip the entire brush in the paint. Then just dab it over the black.
Step 5
Use the orange/black mixture and dab on some of that on top of the black and red. Use the method explained in Step 2 with the orange paint.
I usually did this twice, though the second layer I skipped the black, and just went back to the reddish color, then again the orange/black mixture. You’re not trying to cover the previous layer up, some of it should show through to give you that depth.
And that’s it.
Aged Brass Pipes
Once I was done with that I found I had some brass spray paint. So I took another piece of PVC sprayed it copper. Then I took some blue and some green craft paints, mixed them together, added in a bunch of water to make it nice and thin, and then I just dumped it on the pipe so it ran down. After a minute I took a cloth and gently wiped it down. The effect turned out quite well. As I hadn’t expected to do it I didn’t take any photos, but here are the finished pipes.
