Modern Vespa

Hi all. Might have to do a little welding to my scoot, a GT 200. I know I should disconnect the battery but should I also be disconnecting the CDI? Thanks for any feedback!

I've done many welding jobs just by removing the ground wire off the battery. Everything else is fine.

You also have to make sure that you are not passing current through any bearings...probably not much of a chance of doing that on a scooter but try to keep the ground as close to the weld area as possible.

If you were to weld on the forks with the ground on the body of the scooter you would damage the bearings in the headset.

I like to get a piece of compatible scrap metal in the ground clamp and then tack weld the scrap piece very close to where I need to weld on the scooter but not in the way.

Any time you weld where the ground clamp is located on the work will be an arc strike. All of the codes allow for certain discontinuities in the weld that are still acceptable, it does not have to be perfect it just has to not have more discontinuities than is allowed by the code...Nowhere in any of the very different codes for any welding are arc strikes allowed. None.

So if you make an arc strike every time you weld where the ground is attached to the work what do you do?

One of the codes defines an arc strike as a weld of less than 1" of lineal length. After you have welded one inch it is no longer an arc strike as it is now a weld zone. You can also remove an arc strike by grinding or filing or sanding but the way I recommend, having a scrap piece in the ground clamp that you weld to the work piece and then when you are done removing the built up section of weld where the scrap was tacked with the grinder does a pretty good job of eliminating the arc strike.