Tech Tips

Powder Coating 101

Written by  January 31, 2006

We have all been exposed to the art of painting through the television shows that cover motorcycles being painted; the Discovery Channel has opened this process up to the custom chopper builders to the point where they now compete against one another in stiff competitions that truly are spectacular. When the time comes to have the original painted items on your motorcycle repainted, have you considered powder coating?

Powder coating is not a new process that has been recently introduced. This process has been around since the late 70’s and more widely used in the 80’s up to this present day more than ever. Most of us have been to at least one bike show in the past and have seen some really cool stuff created by local and not-so-local artists I prefer to call them artists instead of painters because anybody can paint, but it takes a real wizard to make these exotic schemes that we have seen at the local bike shows come to life.

You must ask yourself what kind of riding you will be doing, or will this just be a show bike when complete. If you can separate those two factors you are much better than me.

When you are ready to powder coat some items that have lost that glossy new oh-my-goodness luster, these parts will have to be removed from the motorcycle and cleaned thoroughly so this will not contaminate the new paint when it goes into the furnace for baking. I am getting ahead of my self again so let’s back up and explain a little more about the process altogether.
Powder coating is an advanced method of applying a decorative finish to a wide range of materials and products that are used by both industries and consumers. The powder used for the process is a mixture of finely ground particles of pigments and resin, which is sprayed onto a surface to be coated. The charged powder particles adhere to the electrically grounded surfaces until heated and fused into a smooth coating in a curing oven. The result is a uniform, durable, high-quality, and attractive finish. Powder coating is the fastest-growing finishing technology in North America, representing over 10% of all industrial finishing applications.
The powder will remain attached to the part as long as some of the electrostatic charge remains on the powder. To obtain the final solid, tough, abrasion resistant coat, items are placed in an oven and heated to temperatures that range from 160 to 210 degrees C (depending on the powder).
When you have picked out a shop that you are ready to bring your parts to, you must first have the oils and greases removed in weak alkali or neutral detergent such as parts washing fluid. This will get rid of the road grime and all of that nasty chain lube that has collected through the years that pressure washing has failed to remove.
When you are having the mag wheels on your bike powder coated you must remove both wheel bearings and discard. Some of these bearing can be used again; however, this is not a time to cut corners. Most replacement sets of wheel bearings can be purchased so cheap that it will amaze you that you have not done this before now. And do not rule out your local bearing distributor. For example: Timken Bearing Co. sells American-made roller bearings that cross reference the metric motorcycle line and will work the same and give long years of service at a fraction of the price. I prefer to buy my parts within my area so I do not have to ship anything back. Where you buy your parts is your preference, so make no mistake, I am just telling you what works for me!
You will also want to remove the valve stems. Current models use a typical rubber stem that can be cut with a razor blade and thrown away. Some of the earlier models had a valve stem that was metal and two rubber sealing washers. This can be reused if it is rust free and looks good.
When it comes to the rear wheel swing arm, which is a part that a lot of people are coating these days, the bearings for the pivot bolt that runs from one side of the frame to the other must be removed and thrown away as well. Some swing arms have a grease fitting and this can be removed as well. Besides, it will prevent the fitting from getting broken. The reason behind all of the bearing removal is that when these parts are in the oven at temperatures to bond the powder, grease can be hiding in the bearings and will melt causing the oil to get onto the newly coated surface. This will not let the coating stick to the metal and will be a problem. So removing the bearings first is a great preventative before cleaning that part.
In summary, powder coating is the hottest thing going and by far outlasts normal painting. I currently have been a believer in this process for quite some time now and will continue to have this done to my motorcycles new and old. So this winter when you are wondering what you can do to make your bike that much better, do not forget that you have many options out there and they do work. But will they out-perform and look great for years to come? That will be the biggest factor you are faced with and this is a decision that only you can make.
B-safe out there!
By Dave Miller