Scooterotica

hydra wrote:Hi,
Maybe we should accept that it isn't the welding that creates a porous Casing here. If you look at some of the photo's, especially of inside the Crank area and cylinder base Gasket area, there are blow holes where there hasn't actually been any welding done, add to this 50 years of petrol/oil soaked Casings and i reckon it's an up hill task to weld perfect. Adding more and more layers of weld does seal the Casing better and gives strength to the Pins that are welded into the casing for the new stud holes and re welding blow holes after machining could cause issues with heat distortion, as prior to welding, a steel plug is fitted into the Casing to help stop this, although the Mag transfer port always moves and as a consequence the Mag flange/transfer port area is machined also. As a note Indian Casings weld up better, whether that's because of the Aluminium casting or because they have not had as much petrol/oil, I don't know. Also, as previously mentioned we do also now sand blast and wash with Acetone prior to welding, but even this can't reach into 50 years of soaked Casings and so as soon as welding starts, the Casing turns into a volcano and the gases can create blow holes. So if anyone can get a Crystal ball and see if there Casing is one of these....don't send it. You wouldn't believe the state of some of the Casings that arrive, some look like they have just been removed from a swamp, some have all the studs and Bearings in, etc, etc.
The choice of whether or not you send a Casing or not is yours, but if you want perfection....buy a new Casing, simple.
Thank you, Paul - Oiltek