To make the candleholder, the first thing you'll need is some pipe fittings. They are easily acquired at any plumbing supply or hardware store. I got mine at Center Hardware in San Francisco for 40 bucks. They didn't even seem to mind me sitting on the floor playing erector set as I worked on my design. You can use galvanized or black iron pipe, but the black pipe is cheaper so I went with that (see next step for full parts list).
About Powder Coating
Powder Coating is an electrostatic process where a charged pigment dust is sprayed into the air with a handheld gun. The pigment particles become positively charged in the gun and stick to the part which is connected to ground. You see powder coating all over the place: bicycles, motorcycles, park benches, cars. My initial impression was that it looks so good I figured the process would require expensive equipment or some hard-won skill. Turns out neither is really the case--you can powder coat at home with an inexpensive kit and an electric oven.
Powder Coating Kit
The powder coating kit I used was $140 online from Eastwood. The deluxe kit comes with two free colors, so I picked red and yellow, both very vibrant. You'll also need an air compressor with a regulator that can be set to 8 PSI. Pretty much any small air compressor will do, and if it doesn't have a pressure gauge, just pick one up with 1/4" NPT fittings.
To flow and cure the powder coating for small parts you can use a toaster oven, but for this project I wanted to assemble the pipe fittings into several large segments and coat them all together, so I needed a bigger oven.
One gotcha is that you can't use a gas oven to cure the powder coating, so the thing that made this project more complicated was getting and installing an electric range (my house only has gas). In the end I was glad I did, because I wouldn't want to eat anything out of the oven I used anyway. I picked up a used electric range for $75 off of Craig's List.
Another gotcha is that you have to thoroughly clean your parts. Oil, dust and any label glue on the iron will prevent the powder from sticking. I boiled my parts to get the labels off then cleaned them with acetone (outside).
Finally, remember that the powder pigment is a very fine dust and will easily coat your lungs and get in your eyes, so get a NIOSH-approved respirator and wear goggles while working. You'll need a workspace you can sweep or hose down after the dust settles. I made the mistake of leaving the door open between my workshop and a room where I keep some computer servers. Afterward, I noticed the server filters had turned red and yellow from all the powder they sucked in. But it all vacuums up or blows off easily.
These little things aside, this project was doable over a weekend. Ok, on to assembly!