Basically pinning is the process of drilling a hole in both pieces to be joined and gluing a piece of wire or rod in the hole. This increases the amount of area that has glue on it, and thus strengthens the hold. This post will cover the steps I take when pinning as well as some of the pitfalls I have learned to avoid along the way.
First off you are going to need some tools. Well to drill the holes you will need a device called a pin vise. A pin vise is simply just a really small hand drill. It has a collet (the piece that holds the drill bit) and often has a rotating ball or knob on the other end. This allows you to twist the vise while applying pressure with the palm of your hand.
|Click for larger version with sizes.|
Drill bits this small are often measured in wire sizes or wire gauges. After a bit of experimenting I managed to find the sizes that work for the materials that I use as a pin. I have seen people buy brass rod to use as a pin. I tend to prefer cheaper and more commonly available options. I use either a large paper clip, a small paper clip, or a simple stick pin. They are all readily available at your local mega store and they are extremely cheap. You get 100 paper clips for less than a dollar and the stick pins are similarly priced.
For the pins I use I have found that the following bit sizes are pretty close to perfect; Size #53 for a large paper clip, Size #63 for a small paper clip, and size #71 for stick pins.
Now with the spot marked we can drill the hole for the arm side. You want to drill as straight as you can, and be careful that you do not drill to far in and come out the other side.
Once the new pin is dry I cut it to a rough length that I think will fill the hole. Then I dry fit the arm onto the pin. If needed I cut a bit more off the pin until the arm fits properly. If you need too you can bend the pin a bit to make sure a good tight fit. Finally I apply some glue to the pin and the metal on the model and put the two pieces together. Let it dry and you should have a good firm joint that should resist most bangs and knocks.
Well I hope this helps you. Feel free to post any questions if you have any.