UPDATE: The Paint Work I Did Here Failed. I Learned That the Primer I Used Disolved When The Glasurit Paint Was Applied. DO NOT USE SPRAY CAN PRIMER WITH PROFESSIONAL PAINTS. Read This Part Of The Project As A WARNING.
As With Most Things I Try For The First Time, I Make Mistakes And Learn Something I Apply The Next Time I Do It. That Is Called “Gaining Wisdom”. 🙂
I Plan To Repaint The Bike With The Correct Primer And Post That Material When I Am Done.
As noted in an early chapter, the cost of having the body parts painted by a professional caused me to head towards doing it myself. I wasn’t afraid of learning by doing, which is another way of saying making mistakes and fixing them. So, far, I’ve gotten my money’s worth 🙂
I have a friend, Brian House, who has rebuild several vintage English motorcycles and does his own painting. So, I’ve borrowed equipment and knowledge freely from Brian. He does his painting “on the back porch”, no paint booth thank you very much. He uses lacquer and does a lot of sanding between coats to get the smutz (junk) out.
Okay, I have a garage bay, so I created a simple paint booth when I painted the frame. I rebuilt that booth again with a 3-side design so fumes would not build up. I picked up a roll of painter’s plastic (12 feet wide) at my local paint store and stapled it to the rafters and taped it to the floor. It was big enough that I could still park my R1150-RS when not painting as I figured I’d need the booth for a couple of days. It turned out to be needed a “little longer” than that.
I added a simple parts stand I had used earlier. The vertical 2×4 posts fit the center of the tank and the inside of the fenders to hold them steady. I had plenty of room to move around inside without fear of tripping over things or bumping freshly painted parts.
Light is your friend. So, I picked up a 1,000 watt halogen work light with stand for less than $30 at my local Home Depot. Things are a bit rocky with the stand, but the light is great.
All the parts had the final primer coat wet sanded with 600 grit paper. I cleaned the parts with paper towel and Windex to remove lint, finger prints and any other contaminants (or at least I thought I did. See below.).
The paint kit was ordered from Holt BMW, the US supplier of Glasurit paint that is used by BMW. Holt also paints BMW bikes for restoration so I called them and spoke with Kent who is their painter. He provided lots of tips and sent me a pint kit for Smoke Silver. It has a pint each of silver, black and clear coat, 1/2 pint of clear coat hardener and 1 1/2 pints of reducer. I picked up a pint of cheap lacquer thinner at my local Ace Hardware for clean up. The paint kit cost about $330 shipped, so you don’t want to waste it or make too many mistakes and have to buy more.
I borrowed Brian’s compressor and paint spray gun. I had to run the compressor on a separate circuit from the halogen lights as the lights draw 10 amps and the compressor pretty close to 15 amps. Don’t ask me how I figured that out 🙂
I practiced using the spray gun with cheap paint (Duplicolor $25/pint ready to spray) from my auto parts store and got the hang of the gun and setting the paint flow mixture on the gun.
I made a paint test board using some scrape 1/4 inch masonite and covered it with newspaper. I sprayed that first to adjust the paint flow and compressor air pressure until I got a “medium wet” covering on each pass. Its important to always test spray like this each time you start painting and make any adjustments before you put paint on parts.
For painting, Kent advised a 50% mix of thinner to paint. To be clear, that means if you have 1 oz of paint, you add 1/2 oz (50% of the paint volume) of thinner. I used a dark room plastic measuring cup to mix the paint and popsicle sticks to stir the thinner so it mixed evenly with the paint.
Painting requires a respirator in my opinion. I found one at my local Sherwin Williams store that comes with disposable filters to keep you from breathing the fumes. I work in a long sleeve shirt, saftey glasses, baseball cap and rubber nitrile gloves when painting to keep down the paint on my skin.
The silver was laid down in 2 coats. Wait for the first coat to “flash” which is when it goes from shiny wet looking to dull. Then you can spray the 2nd coat. Kent said you could also do a light 3rd coat at 45 degree angle to help hide any streaks as silver is very unforgiving. On some parts (fairing and tank) I did need the light 3rd coat.
When I painted with the gun, I kept a small cup of lacquer thinner (the cheap Ace Hardware stuff) in a cup. When I finished a coat, I would detach the paint cup from the gun, stick the paint tube in the cup of lacquer thinner and spray it through the gun to keep the very small internal passages clean and to prevent paint from drying in them.
It took a while to finish the silver coat. I kept the left over silver paint reduced at 50% in a clean new 1 Qt paint can I got at my Ace Hardware. I could mix up 4 – 5 oz of final mix that way and not waste paint. As becomes clear later, I had to repaint some parts, so saving the reduced silver was the right idea.
Note, a pint of silver is barely enough to paint all the parts and allow a little left over to fix mistakes … I got my fingers in the paint, brushed a part with my sleeve, and had to sand out the error and touch up. Here’s the parts with the silver coat. The R75/6 is under the plastic to keep it from picking up any of the paint particles.
The next day, I started to paint the smoke layer using the black paint. It is reduced at the same 50% rate as the silver. Kent said to dial back the paint volume, dial up the pressure (45 psi) and use the trigger (it increases paint flow as you pull more) to get a very light layer of black. I practiced and pretty soon was ready to start. I visualized where I wanted the edge to be, moved over a bit (to where the full black would be) and started a pass. As I saw the paint lay down on the silver, I’d adjust my trigger and my rate of sweep and then move over to where the edge would be so it was a very light layer in a straight (or for the fairing, curved) line. Then, I’d continue adding paint in successive passes towards the black edge building up the layers as I went. It took 5 -7 passes to build up the black at the very darkest areas. Here are the side covers to show how the faint “smoke” edge follows the contour lines of the cover. You can see the light smoke on the silver panel.
I made a mistake on the front fender and had to reapply the silver down the middle and then come back and reapply the light black layers to fix that. Here’s the other parts with the black smoke coat applied.
Now, the problems started. I had taped the fairing holes to prevent the silver from getting on the inside of the faring which I had painted black. As I took the tape off, the silver coat lifted. It failed to bond to the primer correctly. So, I had to sand out the silver to feather it, and re-shoot it :-(.
That set me back a day. But I finally got the fairing painted with black and got a nice circular edge between the silver and smoke areas of the black.
Next, is the clear coat. That requires a hardener at a 40% ratio and thinner at a 10% ratio. That means, if you use 2 oz of clear coat, you will need 0.8 0z of hardener and 0.2 oz of thinner. I used milliliters which also are marked on my dark room measuring cup. 500 ml of clear coat, 200 ml of hardener and 50 ml of thinner. Now, you can’t save any unused clear coat like you can unused paint as the hardener turns it into a solid mass in a couple hours. So, try to mix up what you are going to use and not waste a lot of it. Kent said 2 coats of clear works well.
By this point I had a little bit of reduced silver paint left, a bit more of reduced black and more than that of the clear coat left. I had taped the fairing over the holes again and this time, when I removed the tape, all the paint pealed off 🙁 :-(. It once again had not adhered and could be pealed off in strips.
It was a large downer when I saw that. I pulled all the paint off. I re-sanded the primer with 400 grit, and then shot two new primer coats on top. As I thought about what might be going on, I remembered that at one point I had been using dish detergent in my water for final sanding. I was suspicious that this left a residue that kept the paint from adhering. I final sanded with wet 600 grit and cleaned it all again with Windex and paper towels. I re-shot the silver, black and clear coat over the next couple of days and was back to getting ready to buff out the clear coat. At this point, the silver is all gone … so I was hoping I was good to go for buffing out the clear coat.
And then, one of the side covers also peeled 🙁 :-(. I spoke with Kent and learned that he uses a special primer that has a hardener in it. I am not. I am using Ace Hardware Krylon primer. Maybe that’s the issue. His primer is about $100 a quart and I suspect I’d need more than one. I need more silver paint and decided to order another pint paint kit in case I have to start over again and repaint all the parts. (I’m an eternal optimist. Maybe the other parts are fine …)
But, I’m going to conduct an experiment with the side cover. I used the Krylon primer again and carefully cleaned with windex (which Kent has used in the past, so that’s likely not the problem). On half of the side cover I applied a Rustoleum “Primer Sealer” at $4.25 per can, its a lot less than Kent’s special primer with hardener. I’ve wet sanded out the side cover ( no detergent in the water) with 600 grit. When the paint arrives, I’m going to shoot two coats of silver on the cover and wait over night. Then I’m going to put masking tape on it and peel … repeatedly … and see what happens. I’ll certainly learn something useful and can proceed accordingly. Stay tuned …