Patching rust holes


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By timmy4 - 17 Years Ago
I am patching a few rust holes in my fender and one in the rocker pannel and I cut out a piece of metal and make it fit nicely and i rivot it to the body, have a friend mig weld it and then drill the rivots out and weld the holes. Is that a recomended way of repairing them?
By Rebelliousengineering® - 17 Years Ago
it all depends who your asking and how good you are at metal work when i was a bit younger i volunteered at one of the most known hot rod shops in socal ( no not socal speed shop) and they didn't have a lot of tools for metal work when they started off but they did amazing cover page magazine work. so basically i learned how to make awesome panels with minor tools one tool we had was like a vise grip that had a Z effect when you would grip it and you would use that so when you mount the new panel a part of it would be on the inside and the other part would butt right up to where you cut it out so you can weld a seem less weld with no overlapped metal that you are spot welding because you laid a panel on top of a panel and all you use is a magnet to hold it while you weld so i would but that tool i forgot the name of it but you can probably get it at harbor freight or so. i just made panels this week for my fairlane for an under dash cover and used this method to join to panels i also used this panel when i got rid of the fan motor and heater core hole on the firewall. hope that helped
By DANIEL TINDER - 17 Years Ago
Interesting question for those experienced with body work:



When paint bubbles appear on the lower panels, the theory is, grinding & repainting still leaves tiny pin-holes that will cause future trouble. Many say, only sure cure is a patch-panel. With modern chemical rust-converters, and advanced Bondo formulas available today, is this still gospel?
By Johnson Rod - 17 Years Ago
Rebellious, I believe you are referring to flanging pliers?? Eastwood carries them
By Rebelliousengineering® - 17 Years Ago
yes that is the name of the tool i just couldn't think of it at 2am.



as for the paint i also worked at a paint shop and i also learned painting at the hotrod shop. when ever its possible not to use bondo thats the best. The problem is majority of the people that buy bondo don't know enough about it and use it as a large filler instead of using it to be less than a 1/8" feathered a lot of people will cake it on and if you were to do this on top of like por15 if there for whatever reason was a not clean spot or a smooth surface the bondo wouldn't adhere properly and would cause cracking later if you had a nice panel with still a good amount of metal thickness on i would sand it down to get rid of all visible rust and do a skim coat of a putty glaze which is like bondo in property where its a filler, but its thinner and already mixed and that would fill all your pin holes unlike thick bondo, Then sand that smooth then prime it block until smooth then shoot your color. I was taught to use less chemicals as possible incase of a reaction so im not a fan of dipping cars because if they didnt wash that body properly you will have a film of the acid and the paint will fish eye crack and not adhere so many problems. i hope that helped as well
By PF Arcand - 17 Years Ago
Timmy: As has been suggested it might be o.k. if you employ flanging tools. If you don't as was done on my 57 car previously, you will have a situation of probably having to use far to much body filler, which is of course not recommended. And you will run into the problem we did, of where the actual body contour was somewhat lost. In redoing the job we ended up having to refer to close up photos of another car, to restore the contours close to original, by grinding & sanding out, as much of the filler as was practical.
By rexbd - 17 Years Ago
If you want to go the flanging route, punch holes in the main body and flange the patch and then hold together with sharp sheet metal screws insead of rivits.  Then weld in the holes and then weld around the edges of the patch and grind down.  Make sure you treat the patch panel with some weld through primer.  You need to do something with the flange portion as it can collect moisture and promote rust down the road so seal both sides.

Best way is to butt weld the patch into the original panel then you don't have to overlaped metal to worry about on the back of the panel.  Eastwood sells some nice clamps that will actually clamp together two pieces of metal and leave the right gap to be welded up.  If you use the same thickness of metal you can create a patch that once painted woudl be almost impossible to find. 

In either case I use either fiberglass or all metal filler for the first coat over the patch since it prevents moisture from penatrating into the repair. 

Go to the Eastwood site and look at their forum area there is some real nice information on rust repair another area to poke around in is Bautobodystore Forums good place to get answers