I strip seams to bear metal and spray weld through primer before plug welding. But I have seen some people painting the seams with epoxy first, removing the epoxy where the plugs are to go and then plug welding, possibly after applying a bit of weld through as well. Wouldn't this potentially contaminate the weld and increase the chances of rust?
Anybody tried it... or any other method for that matter? And has anyone opened an old seam to see how well the weld through did its job?
Cheers and tables everyone.