Renovating Aluminum Parts
Renovating Aluminum Parts
When the Honda Canada’s Riders Association Club decided to restore a 1975 Honda GL1000 Gold Wing, they knew there would be many challenges along the way--especially when the finished bike will be displayed at the importer’s museum in Canada.
One of the most important factors for the team to keep in mind at all times was that the bike must be kept as near as possible to its original appearance and specification.
If keeping the bike original was simply a case of changing parts, the task would be easy; unfortunately, a number of parts are no longer available (even to importers).
One area of the bike's restoration that many owners of Japanese classics have come across that can be challenging is the surface finish of aluminum components. Many of the aluminum components on older Japanese bikes were sprayed with a clear coat or lacquer at the factory. In some instances the component would be sprayed with a paint that resembled aluminum in a semi-gloss finish, before being lacquered.
Tools and Equipment Needed
On the Gold Wing, the inlet manifolds and the engine cases were in need of renovation. As the refinishing process required was somewhat specialized, the team turned to a former employee with experience in this area: Jordan Mulcock.
The process Jordan follows will work on most Japanese motorcycle aluminum components and requires few tools to get an excellent, original looking finish. It is, however, a time-consuming exercise requiring lots of patience.
Tools required:
Chemical paint stripper
220, 400 and 600 grit sand paper
Cleaning compound and bench grinder with 8” polishing wheel
Autosol type metal polish
Acetone and lint free cloth
Clear coat (spray can)
Before commencing the process of renovating the surface finish, it is important to establish what the original item looked like. To meet this criterion, Jordan removed the Honda logo/badge from a valve cover to observe the original surface finish beneath (the area beneath the badge had not been subject to the environment and was therefore near to the original factory finish).
From the sample it was decided that the finish would not be highly polished, however it would share the characteristics of a brushed finished, but without any visible brush (scratch) marks.
It was also determined that Honda did, in fact, use a clear coat to seal and protect the final end product.
As with any surface finish, the person doing the work must follow a set procedure. The following are the steps Jordan took in the correct order (seen important safety note below before commencing):
Step 1 – Apply chemical paint stripper to remove any remaining clear coat
Step 2 – Using 220 grit sand paper, remove all surface imperfections
Step 3 – Using 400 grit sand paper, remove sanding lines created from step 2
Step 4 – Using 600 grit sand paper, remove sanding lines created from step 3
Step 5 – Apply cleaning compound (not polishing compound) to an 8” polishing wheel and remove any remaining sanding lines
Step 6 – Apply a metal polish such as Autosol to a clean, lint free, clothe and remove the sheen created by the buffing wheel
Step 7 – Clean part with acetone and apply a clear coat
Step 8 – After clear coat is completely dry, cure part as per the clear coat manufacturer’s instructions in a suitable curing oven
Safety note: It is critically important to wear protective gear as recommended by the manufacturers during any of the above steps, in particular when working with chemical painter stripper and acetone. In addition, curing the lacquer in an oven can produce toxic fumes. Again, follow the manufacturer's instructions and the OSHA (Occupational Safety & Health Administration) recommendations.
Further reading:
Motorcycle Workshop Safety
When the Honda Canada’s Riders Association Club decided to restore a 1975 Honda GL1000 Gold Wing, they knew there would be many challenges along the way--especially when the finished bike will be displayed at the importer’s museum in Canada.
One of the most important factors for the team to keep in mind at all times was that the bike must be kept as near as possible to its original appearance and specification.
If keeping the bike original was simply a case of changing parts, the task would be easy; unfortunately, a number of parts are no longer available (even to importers).
One area of the bike's restoration that many owners of Japanese classics have come across that can be challenging is the surface finish of aluminum components. Many of the aluminum components on older Japanese bikes were sprayed with a clear coat or lacquer at the factory. In some instances the component would be sprayed with a paint that resembled aluminum in a semi-gloss finish, before being lacquered.
Tools and Equipment Needed
On the Gold Wing, the inlet manifolds and the engine cases were in need of renovation. As the refinishing process required was somewhat specialized, the team turned to a former employee with experience in this area: Jordan Mulcock.
The process Jordan follows will work on most Japanese motorcycle aluminum components and requires few tools to get an excellent, original looking finish. It is, however, a time-consuming exercise requiring lots of patience.
Tools required:
Chemical paint stripper
220, 400 and 600 grit sand paper
Cleaning compound and bench grinder with 8” polishing wheel
Autosol type metal polish
Acetone and lint free cloth
Clear coat (spray can)
Before commencing the process of renovating the surface finish, it is important to establish what the original item looked like. To meet this criterion, Jordan removed the Honda logo/badge from a valve cover to observe the original surface finish beneath (the area beneath the badge had not been subject to the environment and was therefore near to the original factory finish).
From the sample it was decided that the finish would not be highly polished, however it would share the characteristics of a brushed finished, but without any visible brush (scratch) marks.
It was also determined that Honda did, in fact, use a clear coat to seal and protect the final end product.
As with any surface finish, the person doing the work must follow a set procedure. The following are the steps Jordan took in the correct order (seen important safety note below before commencing):
Step 1 – Apply chemical paint stripper to remove any remaining clear coat
Step 2 – Using 220 grit sand paper, remove all surface imperfections
Step 3 – Using 400 grit sand paper, remove sanding lines created from step 2
Step 4 – Using 600 grit sand paper, remove sanding lines created from step 3
Step 5 – Apply cleaning compound (not polishing compound) to an 8” polishing wheel and remove any remaining sanding lines
Step 6 – Apply a metal polish such as Autosol to a clean, lint free, clothe and remove the sheen created by the buffing wheel
Step 7 – Clean part with acetone and apply a clear coat
Step 8 – After clear coat is completely dry, cure part as per the clear coat manufacturer’s instructions in a suitable curing oven
Safety note: It is critically important to wear protective gear as recommended by the manufacturers during any of the above steps, in particular when working with chemical painter stripper and acetone. In addition, curing the lacquer in an oven can produce toxic fumes. Again, follow the manufacturer's instructions and the OSHA (Occupational Safety & Health Administration) recommendations.
Further reading:
Motorcycle Workshop Safety
