By Dale Anderson
Imperial Homepage -> Imperials By Year -> 1968 -> Bronze Restoration -> Part 3
Now that the bronze has been through the tarnish removal process and the polishing regime it is time to apply the finish. This is probably the most demanding aspect of the project. Your final product will reflect the amount of patience and time you spend applying the lacquer. Remember dust is your enemy. The tiniest little particle can ruin the finish. Take time to completely clean all dust and lint from the metal piece before spraying a fresh coat of lacquer. Don't forget your clothes as they will bring dust and lint particles into the spray booth with you.
To build my booth I purchased 2 large 10'X12' plastic painter's drop cloths. I stapled the plastic sheeting to the ceiling and walls of a small area in my basement. I used a tall workbench to form the surface on which to do my spraying. On the table I placed a piece of plywood that had been cleaned with water. It is important to keep out as many dust particles as possible. When hanging the plastic I enclosed all sides of the table except the front and the underside. I left places for air to escape along the lower edge of the table. For the front of the booth I over lapped the plastic to create an opening. I was then able to only put my head and torso into the booth to do the spraying. Once out of the booth the plastic can overlap to keep dusty air out.
- Gillespie Brass Cleaner/Neutralizer - I found this product at a local paint and wall-covering store. It is made for brass and is used in the refinishing of brass items such as lamps and candleholders
- Gillespie Brass Finish - This is the lacquer made by Gillespie for the refinishing of brass items.
- Rubber gloves - These are the same as used in step two.
- Soft lint free cloth
- 3M brand emblem adhesive. Product # 08069 - Available at NAPA or an auto body supply store.
- Paint Booth - This will greatly reduce the amount of airborne particles that fall on your bronze as it is being coated. It is an easy project to construct a booth
- Booth construction items:
- Box window fan
- Sheet plastic
- Furnace duct filter
- Workbench or table
- Compressed air in cans (like the kind used to clean keyboards or other electronics)
I hung a 20” box fan from the ceiling and cut a hole in the plastic sheet to the size of the fan. Have the fan blow into the booth. This will create the positive pressure that will blow the dust particles out of the lower edge of the plastic under the table. I taped a furnace filter to the inside grill of the fan. This will collect the dust particles coming through the fan. A second filter can be used on the other side of the fan to trap more dust. I found a filter that would contain fairly small particles. Use a filter that will filter our very small micron size dust particles. Again, these can be purchased at a building supply store.
On the plywood I placed a disposable aluminum-baking pan. It was the size of a large roasting pan, something you would use to cook the holiday turkey. I did this so that the bronze pieces would not be placed directly on the wood. To elevate the bronze off of the pan I used several plastic sticks. You do not want the metal to be sitting in any over spray. Someone on the IML suggested using a copper wire attached to metal plumbing as a ground wire. This is done to attract those negatively charged particles as they are created when leaving the spray can or spray gun. To do this I ran a copper wire the length of the pan across the plastic sticks and taped it at each end with black electrical tape. I ran the other end of the wire up the wall and out of the booth to the copper plumbing pipe overhead. If you take this step be sure to periodically clean the copper ground wire, as it will become coated with spray. Run the fan for a sufficient length of time before spraying the bronze to evacuate any dust particles that may have accumulated in the spray booth when the fan was not running. I would run the fan for 20-30 minutes prior to my first spray and keep it running until the last piece was dry and removed from the booth.
Earlier I said it is important to only work a few pieces at a time. Once the bronze is exposed to air it will begin to tarnish. Once you have washed the piece of all the steel wool dust, the stripper and the brass cleaner it is time to prepare the surface for lacquer. I had a difficult time with the finish adhering to the bronze. I experimented with several products and finally settled on the Gillespie line of brass products. The cleaner/neutralizer is used to remove any residual chemicals from the tarnish removing. Wearing rubber gloves I thoroughly wet the surface of the bronze with the cleaner/neutralizer and wiped it with the soft cloth. You can pour the liquid onto the cloth and wipe each piece of bronze. Once it has been rinse in clear water. Dry each piece thoroughly.
Place the bronze in the paint booth. It is best to use something to keep the piece elevated from the surface. I used a couple of short plastic dowels. You want a space for the over spray to collect. I made sure the bronze was still touching the grounding wire. Once the pieces are in the booth carefully dust each piece with the compressed air. This is the same product used to remove dust from electronic keyboards. It does not take much. Arrange the pieces to be sprayed on the dowels. Allow some space between pieces if you are going to spray several pieces at once.
The Gillespie lacquer is sold specifically for refinishing brass accessories. Follow the label directions for use. The lacquer does flow well onto the piece and as it dries it becomes nice and smooth. Be careful to not apply the lacquer in heavy coats. It can puddle and will look dark on the metal or will be thick and milky. In either case you will have to strip the piece and begin again. What you want is a nice even coat across the surface of the metal. The directions state you can recoat after 10 minutes. I would apply two coats and then I would allow the piece to dry for 7-10 days before applying a third coat. This seemed to allow the lacquer time to dry thoroughly. Several coats applied too close together caused the finish to peel off of the metal in one sheet. I would recommend 4-5 coats of finish with sufficient drying time between the final coats.
The curved pieces that trim the door armrest and the metal pieces that surround the window controls are the most difficult to spray. It requires a two step process to avoid drips and runs. As an example, when I sprayed the piece for the driver's door I sprayed the lower section while propping the upper section against a support. When the lacquer was almost tacky but not quite set I carefully tipped the piece so that I could spray the second section. I allowed a slight over lap. Once the piece was completely sprayed with the first coat I gently and slowly rocked the piece on the curve until the lacquer was beginning to set. This helped the lacquer to smooth across the surface and reduced the risk of runs forming on the upper end of the piece. For the second coat I started at the opposite end as the first coat. I did this so that the slight over lap of the spray would not be in the same location as the first coat. Watch your spray pattern to make sure coverage is even and not heavy at either end of the spray stroke. Longer pieces required support to ensure the piece is flat. Practice your technique before you begin with the bronze. It is extremely important to be slow and methodical.. After I had sprayed finish on a piece I returned to the worktable and completed the final stages of the cleaning process so that I could continue spraying pieces much like an assembly line process. I did not find the fumes from the lacquer to be overwhelming. I did have a fan in the room to move the air. Be sure to follow the label directions! Keep in mind lacquer is a volatile product and there are health risks if not used correctly. Be sure to take the proper safe guards while working with all of these products. Again, these are product suggestions. You may find products that work better. Temperature and humidity are important so be sure the environment is conducive to applying the finish.
Once the final coat of lacquer has been applied and the pieces are completely dry it is time for installation. Before you install the bronze you will need to remove the glue residue that is on the backing in the car. I found that much of this residue could be removed by using a putty knife and scraping the metal. The glue turned to powder and I used the vacuum cleaner to remove the dust. In areas where the glue was still in tact I used a light coat of the citrus stripper. Apply the stripper with a small brush, let sit for about 20 minutes, and wipe clean with a paper towel. I was surprised at how easily the stripper loosened the nasty old glue. Be careful to not get the stripper on any painted surfaces! Since my car is a coupe there is a painted band between the thin bronze trim pieces on the door panels. I taped the painted area with the correct size painter's tape. Once the glue is removed, clean the metal backing with an all-purpose cleaner to remove any residue from the stripper.
The 3M-emblem adhesive is a nifty product that was recommended by a friend that works in a body shop. It comes on a paper backing. A thin sheet of paper covers the adhesive. To apply the adhesive all you need do is cut the sheet to the size of your piece of bronze. Pull the thin paper off of the adhesive sheet. Press this exposed side to the bronze. Rub the backing to ensure there was good contact with the bronze. Don't pull off the backing. There is now a thin layer of adhesive on the bronze. Test the piece in its proper location to ensure you have the piece correctly oriented. Many of the pieces in the car are tapered or shaped to fit only one way. Once you are certain you have the correct piece oriented correctly simply remove the paper backing from the adhesive strip. Be careful not to touch the adhesive or it will come off on your fingers. Press the bronze in place. I used a very soft cloth and gently pressed the bronze in place and to remove any fingerprints. Avoid rubbing the surface with too much force. The lacquer can still be soft and you don't want to scratch the metal. If you do, it's back to square one!
The emblem adhesive is used to apply trim and name plates to the exterior of cars. It ought to have enough strength and durability to hold the bronze in place. Using this product is an experiment so I cannot guarantee the long-term durability. Using this product does avoid the problems inherent with using contact cement or other liquid adhesives. I did not completely cover the back of each bronze piece. I believe that a refinishing project will be inevitable so I do want to be able to remove the bronze without damage. I am hopeful that the lacquer will protect the metal and that a tarnish removal project will not have to be done for another 20-30 years!
Continue the spraying and installation process. The interiors of these cars are stunning when the bronze is clean and bright. The use of bronze and chrome is beautiful!