Old Britts – Painting Norton Commando Crank Cases
Download the complete PDF version using the green download button at the top right of this page for an Old Britts technical article covering the preparation and painting of Norton Commando crank cases. This workshop guide explains how to restore the cases to a more original-looking factory finish during an engine rebuild, including paint selection, surface preparation, masking methods and the order used when applying the finish.
The article notes that the previously recommended PJ1 paint was found to change color when heated and was no longer considered suitable. Old Britts instead tested VHT Flat Aluminum SP117 and Dupli-Color Clear DE1636, reporting acceptable results when the crank cases were properly prepared and the paint was set with heat.
Further sections cover cleaning the split case halves, removing old paint by walnut-shell bead blasting where possible, roughing surfaces manually if blasting is unavailable and completing dry-fitting work before painting. The guide also shows how to bolt the case halves together, blank off openings, mask mating surfaces, protect studs and tape off areas such as the timing cover, tach drive housing, breather pipe and oil junction block surface before applying light coats of paint.
Contents Include
- Painting Norton Commando crank cases during engine rebuild work
- Factory-style appearance and finish considerations
- Old PJ1 paint warning and alternative paint recommendations
- VHT Flat Aluminum SP117 and Dupli-Color Clear DE1636 notes
- Cleaning and surface preparation before painting
- Walnut-shell bead blasting recommendation
- Dry-fitting and crank bearing installation before paint work
- Masking crank case openings and mating surfaces
- Timing cover, tach drive and breather pipe protection
- Light coat application and drying order
- Temperature and ventilation guidance for painting
