I need to weld some standard BZP bolts onto my kart chassis to mount the brakes.

Do I need to grind off the zinc plating before welding?

I normally do, it's worth cleaning up anything your going to weld even it looks clean!

Aaron

Ideally remove the bzp although I don't tend to because they are usually only on jigs and the like which are not expected to last a long time. Welding bolts on for something substantial like brake mounts seems a bit of a badge to me. Is there a more "proffesional" at of doing it?

Also of you are welding galvanized parts avoid brething the fumes at all costs... Bad things are released when you burn the coatings

To get a nice weld with decent penetration, then you need to grind the zinc plating off. You can get away with leaving it on when you are MIG welding them on a high amperage settings, but since you are welding it to a kart chassis, then your power will be turned down. If you are TIG welding, then you definately need to remove all traces of the zinc, as it will explode, and contaminate your tungsten