The Primary Chaincase

I managed to score a Triumph Thunderbird outer primary cover for a reasonable price a couple of weeks ago. Its foot rest hole had been welded up, but badly and with no blending of the shape attempted, and a patch had been done at some point when the clutch had made a bid for freedom.

I blended the the foot rest area to match the top side with a disc sander attached to my drill. Several times I broke through the old welded patch and had to reweld the holes that I made. Once that are was looking about right, I welded up the two lower screw holes that were cracked, and then set about polishing.

First the wet sanding - 240 grit in one direction, followed by 320, 400, 600 and finally 1500, all in opposing directions making sure to totally remove the previous sanding marks. This was followed by buffing on the polishing wheel and finally out with the Mothers Mag and Aluminum Polish . Overall I am pretty chuffed with the results. There is a slight ripple where the patch was done, but I don't think it will be noticeable when it is on the bike. Now I just need to find the matching inner cover - back to Ebay....

Unfortunately no before pictures, but here is the finished cover...