Painting Chrome — Jan. 1990, page 20,21
I realize that most motorcyclists buy chrome-plated parts to dress up their bike rather than paint over them, but there are some who like more paint than chrome. Af¬ter Wayne Hart and I discussed building a "Midnight Venture" earlier this year, I real¬ized that there is a need for more informa¬tion on this procedure. To ensure proper paint adhesion and life there are certain steps that must be taken. Last year when I painted our XS1100/Watsonian rig, the chromed front fender looked terrible, so it was painted the same color as the rig. It has now lasted two riding seasons, so I feel con¬fident enough to let others know the tricks of this procedure.
In this article, I'll be using RM and Ditzler product numbers. This is not to say Dupont and other companies do not make suitable products, it's just that I'm more fa¬miliar with their products because that's what I use in our shop. I'll be going through this step-by-step and it's important to stress not to skip or short-cut any of the steps. Re¬member that any mistakes you make in the preparation of the metal or undercoats will show up in the final coats as well, ruining your paint work.
The first step in paint work or repair is to wash the pieces thoroughly with a mild de¬tergent, such as dish liquid or a car soap. This removes dirt, tree sap, acids, etc., that accumulate on the paint or chrome.
Second, clean the piece with a wax and silicone remover such as part #900 Pre-Kleano or Dupont Prep-Sol 3919S. This removes all waxes, silicones or polishes. Believe it or not, without doing this you can actually sand wax and silicones right into the pores of the metal or plastic. Then when you paint these pieces, fish eyes could oc¬cur.
Third, and this is an important part in get¬ting paint to stick to chrome, sandblast through the shiny layer to the nickel layer underneath. Or you can take them to an in¬dustrial plating firm and have them chemically stripped. I usually sandblast them because the plating firms charge a large amount to do this and you can get someone to sandblast them cheaper and at your con¬venience--but not the platers. Sometimes they will make you wait months until they get enough small pieces to make it worth their while.
Fourth, within an hour after sandblasting if possible, treat the piece with one of the available metal conditioners. This is a mild acid which chemically cleans the metal piece and prepares it to accept a primer surfacer. Usually you mix this two or three parts conditioner to one part water. Do not let this dry on the piece. Rinse it with water or clean it with Pre-Kleano #900. I prefer to clean it with Pre-Kleano although the product label says to rinse with water. Blow dry the piece afterwards to remove any remain¬ing Pre-Kleano and/or dirt.
Now it's time to start spraying. Most primes must be sanded after they dry. On a piece such as this chrome, which was sand¬blasted, I prefer to use a non-sanding primer. If you recoat this primer with the paint of your choice within a certain time period you don't have to sand it. That time period is usually one hour to a few days with this type of primer. I use Ditzler DP-40 Ep-oxy primer. This is an epoxy chromate primer which has excellent adhesion prop¬erties on prepared metals and plastics, is very flexible and is corrosion resistant. It must be mixed in a one-to-one ration with DP-40 catalyst, no thinner or reducer.
Before you spray, tack rag the piece to re¬move any dirt you have missed. I won't go into how to spray as this is a large topic it¬self, so if you want to know this, buy some books on the topic, read them and practice like hell. Or, hang out with an experienced painter for awhile. Anyway, apply a me¬dium wet coat of DP-40 to the piece and let dry for 10-15 minutes. If the piece looks good, let it dry for about an hour more. If it doesn't look like the coat was uniform or some imperfections show up, give it a sec¬ond coat and let it dry for an hour.
After it has set an hour or so, look it over. Do you see any dirt or marks? If so, let it set a few days and wet sand it with 600 to 1000 grit sandpaper. If it looks good with no flaws, you're ready to apply your color coats and/or clear coats.
For my color coats, I use Ditzler Radi-ance II Acrylic Lacquer. I can get this in a lot of colors or have a special color mixed to my approval. Mix this according to the label and use the thinner best suited to your shop temperature. Yes, they have different thin¬ners for different temperature ranges. Be¬fore applying your color coat, tack rag the piece once again to remove any dirt that might have settled on it. Apply one me-dium-wet coat and wait about five minutes or until it gets tacky. Apply a second color coat wetter than the first to hide any primer spots showing through the first coat. After this tacks, apply a third full wet coat to achieve a uniform color and to get a deep¬ness to the color, especially with dark metallics.
Now, you could let this dry overnight and buff this out to gloss, but I go one step fur¬ther to achieve a richer gloss and a more du¬rable finish. After this lacquer dries about an hour, tack rag it again and apply one or two coats of R-M RV-86 Polyurethane clear. This RV-86 is an extremely durable and glossy polyurethane that protects and en¬hances the color coats. Mix two parts of RV-86 clear with one part of RV-87 cata¬lyst. Apply one medium coat and let set for 10 to 15 minutes. If necessary, apply a sec¬ond coat and let it sit for about 24 hours. Af¬ter it has set, there's no need to buff or polish unless you have some dirt in the clear or you need to sand out a run or two. In that case, wet sand it with 1200 grit or finer paper and buff back to its original shine.
I've used this RV-86 on a sprint car and it has held up beautifully. These cars abuse paint terribly, but RV-86 seems to hold up against the rigors of racing. I like this stuff so much I use it on every trailer and sidecar we paint!
If you follow these instructions and have some painting experience, your chrome pieces should look great painted.
Maple Leaf Carriage Works