Hi all. Ok this is my first effort at posting some photo's on this forum with the help of my better half.....It is about the subject of Pyluminising, which is a process known to Vincent's with black painted crankcases, and I guess may well also have been used on Flashes as well. If I am incorrect on any of the following, I would be more than happy for others to join in and help, but this is my take on it, and it stems from the experience I have had working in Aviation to somewhere near correct. It is a process that involved the dipping of alloy engine parts into a solution which etches into the porous surface in a similar way to how the old anodizing pots and pans used to be years ago. Although the term pyluminised does not exist any more, it is still used in aviation, in a form that uses a solution known as Alodine. This may well be no more than a company name, but it is the only one I know of, and aircraft parts including sheetmetal are prepared by thorough cleaning first, then submerged into a tank of this solution for around 30 to 45 seconds. After which, you remove from the tank and hose off with a jet of water. This process is a corrosion barrier, and given that alloy engine parts on Shadows and similar where not primed with paint as such, perhaps this was the next best thing. It may well have been done to save on the extra thickness a paint etch primer would have created, as we know the original paint was quite thin, and it's quality was very high. The Pyluminised process would have added no extra thickness in any way, and gave the paint something to adhere to. In my photos you will see the two covers I have just paint stripped (literally today) and you can see that the kickstart cover still shows the Pyluminise finish under the original paint. The timing cover has also been stripped, but you can see it's external finish has been either lightly sanded, or possibly sand blasted, and has lost its coating.....It is still however visible on the inside of both covers. You can see around the inspection cap hole on the kickstart cover, that the original finish has been polished away, and you can still see the initials of the previous owner, who had owned this Shadow since 1961.....He stamped most of the major parts in an effort to avoid theft.......Seems even all those years ago, that owners thought their bikes more valuable than most. If anyone else can add to this, that would be great, but I just wanted to show some who may not understand what this mysterious process used by the factory was all about......Cheers........Greg.
