Binding gives a nice finish to the contours of your guitar. You can opt for natural materials such as wood or abalone, but there is also a lot of choice in celluloid binding in all kinds of colors. The height and thickness of the binding and whether it is a single or a double bond are also decisive for the ultimate appearance of your instrument. When you have the picture complete and your materials in house, then you can proceed as follows:
The most common way to make the channels for your binding is to mill them. Preferably use a small router, such as a Dremel. A router with a small foot is less affected by any height differences in your top. Use a router bit with a blade that is high enough and with a wheel at the bottom which is so much narrower than the blade as the thickness of your binding. It is even easier if you have a binding jig.
First of all make sure that the sides of your project are completely smooth and square. The follower wheel of your router also follows any bumps and dents. So you want to have this eliminated first. If you have a top with a strong curve in it, you may have to make a wedge to ensure that your router remains horizontal. Also make sure that your project can not slide while routing and clamp it, for example, in between pieces of wood that you stick with clamps on your work bench. Check if nothing can obstruct your router and you can move freely around your project.
Set your router at height and mill a test channel on a piece of waste wood. Are you satisfied? Then you can also 'dry-cut' a circle along your project. Check-check double check. Ready to start (inhale, exhale), then first start with the most curvy parts and do not mill too deep or too much at once, this prevents you from tearing out pieces of wood. After that you can do a full round of your project, again not too deep in 1 time, but work in 2 or 3 rounds.
When you're done, check your binding channel and necessary adjust with a small file or a micro chisel.
Then the binding is next! You can easily bend wooden binding with a bending iron. Make sure that your wood is damp and use a cloth to protect it from burning. Plastic binding requires less heat and you can bend it by heating it with a hair dryer or a paint burner. Keep 20cm away from the binding and move back and forth over your binding. Beware, binding can become too soft and melt due to overheating.
When you feel that the binding becomes softer, place it in the binding channel and form it in place while applying some pressure. Securing it with tape ensures that the binding stays in this shape during cooling. Make sure that you use tape that does not take wood when you remove the tape. Better to test your tape in advance. In this way, bend part by part until you are all the way around. If you want to join two pieces of binding together, prepare 1 side and do not finish the other end until you are fully around.
When your binding is completely formed, it is time to glue. Make sure your channel is free of grease and dust. You can glue wooden binding with Titebond, but plastic bond is best glued with UHU Allplast binding glue.
Work in parts of about 40 cm. Provide the channel with glue (not too much, not too little) and press your binding into place and secure with tape. Work this way around bit by bit. Complete the end and also glue the ends together. If you prefer not to use tape, you can wrap an elastic band in loops around your project, this also gives a nice pressure for curing the glue. For this we simply use a bicycle wheel inner tube that has been cut open. You can test if you have enough length for gluing, then you will not run into surprises when you are in the heat of the moment.
Drying of glue requires time, but more importantly, with the moisture in the glue the binding can sometimes expand slightly. This needs time to evaporate again. Wait at least 2 days before you start cleaning your binding.
If there is a lot of binding, you can remove the largest parts with a rasp or a (fret level) file. Stop when you are just above the wood and then switch to a scraper steel. Make smooth movements and do not put your scraping steel in too harsh, it can cut into your binding. When your binding is at the same level as your wood, you can start finetuning by sanding. Start with 120 grit and go on until 320.
Now you are ready for the next step in finishing your instrument!