It is said that "fashion starts at the feet" in the world of fashion, but it is safe to say that fashion for motorcycles also starts at the feet. Even if you are not a fan of old motorcycles, you would want to beautify your dirty, rusty, or corroded cast wheels. However, the reality is that even if you try to clean them, it is difficult to do so. However, by using a "special barrel polishing" process, the wheels look brand new! But with the "special barrel polishing" process, you will be able to achieve "more than that! Once you see the result, you'll be hooked.
Gradual finishing from groundwork
Moisture and corrosion had cracked the paint on the front and rear wheels of this '80s Kawasaki, and cast wheels from '80s models generally look dirty when they've been driven without maintenance. We decided to refresh these wheels with a special barrel polish. First of all, old paint and stains were removed with sandblasting alumina media to expose the aluminum surface. Then, the wheels were set in the barrel finishing machine and polished with rough finishing media. It is important to get a uniform surface finish by sandblasting before the barrel polishing.
After barrel finishing treatment with rough finishing media, barrel finishing treatment is performed with "finishing media" like BB bullets, where the ceramic media reaches deep into the part shape. These continuous work practices give the machined surface of the cast wheel a beautiful finish that looks as if it has been buffed.
Masking the shining part
The normal wheels are painted after casting and then machined, so the machined parts are shiny and bright. The parts that were originally cast are not shiny but grayish. Even after barrel polishing, the unevenness of the cast surface is still there, and you can see that the clogged dirt has been completely removed.
The hardest and most careful part of the process of reconditioning a cast wheel is masking the polished and cut surfaces. If the entire wheel is finished with a full coat of paint, only the mounting surface of the disc rotor and the bearing press-fit area need to be masked. If the wheel is finished with a full coating, there is no need for special barrel polishing treatment, only sandblasting is necessary.
Guncoat paint with cast surface effect
Guncoat paint was chosen because we wanted to create a strong casting effect. The powder coating has high adhesion, but the paint film is slightly thicker than a gun coat. Kawasaki's stock rims and spoke sides are machined, so after barrel polishing, we used masking to recreate the look of a machined surface.
Paint drying temperature reaches 180°C for 1 hour
Guncoat paint is a complete one-component finish with no hardener or thinner mixed in, so it has a high yield and a great reputation among professional painters. The paint is sprayed thinly over the entire surface and then finished off with multiple coats. It is available in a wide variety of colors, including metallics. Please check the Kerbeck website for more information. The drying time is one hour after the temperature of the drying equipment reaches 180℃.
Stock look but better than stock texture
Kawasaki GPZ cast wheels finished in Guncoat Satin Black (black with an 8-minute luster). Guncoat is a high-performance paint, and despite its thin coating, it is highly effective at dissipating heat. It's also the perfect finishing touch for the black engine. If you're not looking for the stock look, but want a shiny round black finish, powder coating is the way to go.
This is an example of a wheel that has been finished to look like the manufacturer's genuine gold cast wheel. Painting in the original color will allow the custom machine builders to assert their individuality even more. However, the trend over the past few years seems to be that many fans prefer the manufacturer's genuine specifications, including the coloring of the exterior parts.
- Point 1: The special barrel polishing used to reclaim cast aluminum wheels can give the machined surface a buffed look and feel.
- Point 2: Gun coat finish is the best for painting with the texture of cast surface. Powder coat finish is recommended for round coating of wheels.
- Point 3: Special barrel finishing is not limited to cast-aluminum wheels, but by applying the installation jig, various parts can be polished.
As long as the corrosion is not so severe that it penetrates the surface of the wheel, it is possible to recreate the cast aluminum wheels of the past models, even if the paint is peeling off or the cast wheel is corroded to white. Kerbeck's "Cast Wheel Refurbishment Order" can bring back the shine of a new part or even better, and the equipment used for this is a three-dimensional special barrel finishing machine.
In general, it is difficult for a polisher to reach the complicated design of the spokes and the detailed design of the hub part. Of course, there is a limit to how much you can polish with your fingertips. Also, even with a high-performance polisher, it would be difficult to polish all 360 degrees of the rim shape evenly and with the same texture. For these reasons, repainting wheels is a tedious task, and in many cases, repainting was done by sandblasting followed by "round coating" or hand buffing and painting.
The process of wheel refurbishment undertaken by Kerbeck starts with peeling off the paint from the wheels brought in. The paint on the original wheels reacts easily to the chemical treatment, so after the chemical stripping, the wheels are sandblasted to prepare the surface for barrel polishing. When removing paint that does not react easily to chemicals, sandblasting is used from the beginning. Once the base surface preparation is complete, the special barrel finishing machine developed and sold by the company finally comes into play. First, rough finishing is performed, followed by final finishing. At this stage of the polishing process, the machined parts of the cast wheel acquire a beautiful shine with no irregularities as if they were buffed. For wheels that have scratches on the rim edge, as much as possible scratches are removed by polisher before barrel polishing.
After the barrel finishing process, the wheel is ready for the painting process as ordered by the customer. The metal surface after barrel finishing is characterized by its resistance to corrosion due to work hardening and the rust inhibiting effect of the treatment solution, despite the fact that the aluminum surface is smooth. Therefore, a certain level of rust prevention effect can be expected even without clear painting. However, if you want thorough rust prevention, it is recommended to use clear finish with acrylic powder, which is known as Guncoat's Super Clear, or the finish coat of high-class foreign motorcycles.
The cost to be concerned about is 35,000 yen per wheel with a full course finish of the same type of manufacturer's genuine specifications as this time. In the case of used parts, the condition of each part is different, so it is best to start by requesting a quote. For reference, a powder coat finish without the barrel polishing process costs 20,000 yen per wheel. In any case, it is always a good idea to get an estimate before requesting work.
The quality of the manufacturer's genuine cast wheels finished with these work processes is astonishing to anyone who sees them. In the out-of-print old motorcycle scene, models produced in the late 70's to early 80's are also attracting attention. If you are restoring a model from the early days of cast wheels, we hope you will consider this product.
Interviewed corporation: carvek
