Painting Engine Parts

Fellow Airheads,

I've lost my mind! Decided to completely disassemble. R65 now a project bike!
Below are two pictures of front of engine painted black with aluminum exposed and same for starter/solenoid top cover.

What qualities should the paint have? I know heat resistant but anything else?
What is the technique to paint it black but leave the BMW symbol in aluminum?

Lastly, want to clean the cylinders & heads - lots of corrosive gunk. How easy or difficult is it to soda blast? What type of unit do I need to purchase? I have a heavy duty air compressor.

Thanks much,

Ken in MN

Top cover

Here is top cover

Powder coat them. Paint won't last as long as powder coating.

I would recommend using POR-15 brand paint - they have a high temp engine paint (flat black) that is called "Black Velvet". I would get rid of any loose, flaking paint with light sanding or wire brushing or soda blasting first. The POR paint can be put on with a brush - resist the urge to keep touching it up while it is drying and it will come out quite smooth. on the engine casing and label, you can just paint over all of the area in question and after it dries, go back with some fine sandpaper wrapped around a block of wood and you can get your polished bare aluminum fins and "BMW" back to original appearance.

I bead blasted mine, then cleaned them numerous times to ensure no beads left over. Then wiped down with reducer and painted with a satin black engine enamel in a rattle can. Once I had a few coats on and they had dried for a few days (cured?), I then very carefully sanded the spots I wanted to be nice bright aluminum. I attached the sandpaper to a flat piece of wood to keep it from sliding onto an area I wanted to keep black. Looks great, very cheap to do, just takes a little time. Can of paint was about $8.00 and a few cheets of 400 and 800 grit emery paper. I use the 800 to get an absolutely smooth finish.

I would not be without my beadblasting cabinet. It is absolutely amazing how well it cleans up bike parts. Prior to blasting, I do soak the parts in a solvent first to remove all built up grease and road gunk. Then once dry, blast away.

I have used paint stripper to remove old paint, followed by scrubbing down with hot soapy water,brushed and scotchbrite pads, rinsing well, drying well, spray with etching metal primer lightly, color coat with engine enamel. paint over the letters, ribs and fins then clean off these areas with sand paper or fine files after the paint has cured if you want ...

I've had nice results every time from Dupli-Color ceramic engine enamels, available at most auto parts stores for around $6 a can. Get the 500 degree rated stuff for your aluminum covers, the 1200 degree is really only required for exhausts. Do your prep work right, follow the directions, and you should too.

+1 on the Dupli-Color Ceramic enamels. I have had excellent results with them. The low luster (not flat) black is excellent for BMW parts. If the S.O. is understanding, an hour in the oven at 250 degrees really hardens it up, too!

Thanks for the great input!

Please explain "if the S.O. is understanding"

kentuvman said:

Please explain "if the S.O. is understanding"

Click to expand...

Politically correct code for spouse, literally "significant other". In plain English - don't cook your motorbike parts in the oven without your mate's permission.

kentuvman said:

Thanks for the great input!

Please explain "if the S.O. is understanding"

Click to expand...

You're not married are you? to steal a quote- " Hell hath no fury like a Significant Others wrath when you mess with their oven..."

Yea - I'm married just not always up on all the abbreviations

I repainted exactly those parts on my R100 restoration last year.

I had them bead blasted by a local machine shop. Afterwards, I cleaned them thoroughly in my parts cleaner.

Prior to painting, I degreased them thoroughly with brake cleaner and handled them with rubber gloves.

I painted mine and they came out wonderfully. I used PJ1 SemiGloss Black Engine paint. I painted them with a few light coats, allowing each coat to dry before application of the next coat.

I used a Dremel tool with a Scotchbrite-like bit to remove the excess paint from the ribs and lettering.

Before:



After:



It was cheap and the paint, based on previous experience, is durable.

Oh - Ken, be sure you take tons of pictures of the routing of the various wires and such as you prepare to remove the cam chain cover. You'll need to buy a new seal for the alternator nose, as well as the gasket behind what BMW calls the Timing Chain Chest. When you remove the bolts holding the cover to the front of the cases, don't lose the little tiny washers that fit on the upper bolts. The upper bolts will need them to keep the cover evenly oriented against the cases. Inspect the fiche at Max BMW before you take it apart.