The repro fender clips use to be and may still be made of cast iron. Welding cast iron is totally different from steel . When I installed the new repro fenders on our 31 coupe, I lightly spotted the repro cast clips in place with brass . I always avoid brass for bodywork but this was almost a necessity in this case. The only brass rods that I had at the time was coated with white flux. I used the wire brush on my bench grinder to remove the flux from the brass rod. I didn't need to do the whole rod because I only needed minute amounts of the brass rod to connect the clips to the underside of the fenders. Brass only bonds and there is no actual penetration of metals as in an actual weld. Clean metal needs NO flux and this removes problems with paint adheasion. The minute brass spots are on the under side of the fender and if the brazing job is properly performed will cause no problem. It doesn't take a lot of heat for the brass to bond. The small braze spots only need to be cherry red for a good bond .
