Generally when repairing rusted sections if you are not cutting the entire piece out and splicing in a whole new piece the "best" most acceptable method is to cut out the rusted part either in a square, rectangular, or circular pattern, make up a piece of the same thickness and similar type of steel and weld it into it's place. Grind the welds smooth and paint. It is more complicated than this of course but that is the outline. You can use a "weld-through" type primer. Eastwood sells it and you can get it in any large welding supply. Plating patches over rusted out sections is not a good way to repair but I see it often because it is fast to do and takes less skill. If you can piece a section in properly there is no need to plate over it. When you cut out the rusted piece you should clean up the "inside" and seal it somehow. You can use undercoating, wax, or paint. When you weld your patch in it will burn the paint nearby but a weld-through primer will last better. Paint the inside of your patch too. The patch should be about 1/8 smaller than the hole so you can get a good bead of weld penetrating full thickness. Practice on some scrap first to develop your technique and try breaking the weld in a vise to test for strength. You can also cut through to see if you are welding "void free". Gas welding is easiest for beginners but MIG is preferred with TIG being the best way to go but requires the Most skill. Keep your repairs small to avoid warping and distortion. Pick up some books on welding at a nearby welding supply house. You can also get a lot of books on this kind of repair at Classic Motorbooks. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "TalksToGod" <5n-@xxxx> wrote: > I am doing a major front end replacement and I'm putting sheet metal > plates over the areas where I welded in order to stregnthen. My > question is-should I zinc primer the underside of the plates in order > to prevent small time rust/surface rust? After everythings finished I > plan on spraying POR-15 over the whole frame so it will hopefully seal > the plate welds and outside and no moisture will likely get in. If I > do this will it be necessary to spray anything on the underside of the > plates? Maybe something more then the zinc primer? To me if its sealed To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/