Nothing that I know of that would withstand the heat. If you have any, mica sheet ( e.g. from the heating element of an iron ) inserted between the coils would work. Otherwise, if there is space to the rear of the current layout, I would spread the coils so that the shape is more of a "U" rather than the existing "C". Not much point in getting a new one, it will have the same issue after you fit it. Fixing this resistor issue will hopefully prevent the arcing seen inside the welder. It may or may not solve the breaker tripping.