how to: outer sheetmetal rust repair

[SELLERSRODSHOP 13]

guys, here's a quick tutorial on how to repair the small rust holes that are prevalent in the lower doors, fenders & quarter panels on old vehicles. naturally, any large areas would require a stamped repro patch panel, but this covers making your own patch for small isolated spots.

 

first, cut out the offending spot large enough to have clean metal surrounding the area & grind off any paint from the area. remember, the rust pits thru from the inside, so cut out enough to have thick metal to weld to. (see pic 1)

 

next, make a paper pattern of the needed patch & tranfer to metal. cut the metal just a bit larger so you can grind to fit the hole. it's easier to remove a little here & there than to get a proper fit vs. trying to fill gaps when welding. (see pic 2)

 

after the patch has been fitted tack weld a few spots to hold in place. do not run a continuous bead of weld! this will heat & warp the metal & cause lots of headaches when doing the finish bodywork. rule of thumb is to tack at 1" intervals & keep crisscrossing to different areas, do a few spots & let cool for a minute. (see pic 3)

 

after the welding is completed, grind the weld down smooth. make sure to "clean" the welds with a wire brush, you want all of the gas residue from the welder removed, or it will cause the filler, primer, paint etc. to lift later.

(see pic 4)

 

after it's clean, a light skimcoat of filler is applied (pic 5)

 

when the filler has cured, sand smooth, the spray a coat of metal etch primer or epoxy primer, then you are ready to prime sand & paint. this whole process takes about 1 hr. to perform.

[unfrozen1969 11]

Your posting will fit in well with the wiki that they are going to start for this website.

 

I hope that you are able to contribute your expertise to this and other segments.

 

Bill from Ottawa

[d.reese 13]

Yea, thats all the correct way that I was taught. One thing that realy helped me was one of those welding hoods with the auto darkening lense, they are costly but sure are nice when you work on a serious rust bucket.

I think your explanation is complete and will be quite useful to the novice out there!

I got some great before and afters, think I should post any of them?