Painting continues

I apologise that the Blog hasn’t been update very frequently the last two weeks. I’ve been doing lots of other thinks than working on the Bimota, and the work I do have done is mainly preparing the engine case for painting. A boring and time consuming job!

The work flow:

1. Clean off all dirt and grid using paraffin based oil as solvent.
2. De grease using a detergent such as Shell Bike Cleaner.
3. Mechanically remove loose oxides using stainless steel brush or plastic abrasive wheel. Do not use a non stainless steel brush on aluminium!
4. Etch the aluminium surface a couple of minutes using sodium hydroxide applied with a brush.
5. Rinse, rinse, rinse!!!
6. Clean and gloss-etch the surface using phosphoric acid. (Phosphoric acid was hard to find so I used a product (Kalkosan) for removing calcium oxide (lime) from coffee makers etc. containing mainly phosphoric acid.
7. Rinse, rinse, rinse!!!
8. Dry with a heat gun
9. Spray paint. I’m using a touch up spray paint for outboard engines.

My theory is that the aluminium doesn’t need to be glossy before painting. The important thing is to get a grease and oxide free surface that gives the paint good adhesion. For this purpose a dull surface is better.

I’ve been painting one part of the engine at a time. It would have been better do it all at once, but since the motor is quite heavy it’s hard to move it around to get access to all areas, so I settled with doing it bit by bit.

It’s hard to show the finish in pictures but I think it’s all right. Below you find pictures just before and just after spray painting.

So far I’ve done about half the engine. Hopefully I can finish painting this weekend and continue with something more inspiring!