After completing the mock-up phase of a custom bike-building project, many custom motorcycle builders send their frame… or even possibly some of their sheet metal components out for powder coating.
Essentially, powder coating is a thin durable, oven-baked plastic coating. And, after it’s applied, does not require any further finishing like paint does. It’s also a lot stronger than paint so it will resist road dings.
There are some techniques you may want to consider for prepping your components before sending them out. But, first, there are a few situations where powder coating might not be the way to go.
Take a gas tank or fender for instance. If those components have been filled with “putty” or some other kind of plastic fillers or compounds, you can not use the powder coating process. The reason is, all that filler stuff is going to melt in the curing oven. So you need to keep that in mind if you’re thinking about doing your fenders or tank or any other sheet metal parts.
Prepping Your Components For The Powder Coating Process:
Specifically, what we’re talking about here is your frame. So, the first thing that will need your attention is making sure you’ve removed any bearings, races or bushings from the neck and swing arm etc. And, you have to make sure you remove any Powdercoating other components that may be attached to the frame because the powder coating cannot get in between any of those parts that haven’t been removed.
Once you’ve got everything all pulled apart, any old finish… or any other kind of crap on the parts that are to get powder coated, needs to be cleaned up. You may want to consider doing the prep work yourself to save some time and money, and there’s nothing wrong with that. But, keep in mind, you want to do a good complete job with this procedure because good prep work is what separates a quality powder job from one that sucks… and prep work is what separates a “real” powder coating shop from the pretenders.
There’s a few ways of getting the metal ready and they include sand blasting, glass beading, using a wire wheel and chemical stripping. A few thoughts on sandblasting…
This process has a tendency to leave a “profile” on the metal. That’s when the force of sand removing finite pieces of metal creates a series of valleys and peaks. If you were blasting your heads or barrels, sand blasting really wouldn’t be a problem due to all the imperfections in those parts anyway… plus there are no flat surfaces.
After sand blasting a frame, you may want to take a piece of medium to fine grit sandpaper, to smooth out the surface and break down any “profiles” caused by the process. Keep in mind that too much blast material or too much air pressure can easily damage any “thin areas”.
Glass bead is probably the more preferred method because of its less aggressive nature and will leave your metal surface a whole lot smoother. But, if the surface you’re trying to clean up has some real caked on crud, sand blasting is probably the best choice.