69 mach1 rear frame rail rust repair

[Rindelmach1 14]

I'm looking for some advise on how to repair this rear driver side frame rail with as little work as possible to avoid messing up the paint job and trunk bottom. Do i have to replace a section or can I weld in a patch on the bottom of the frame rail?

[aslanefe 346]

I would remove the leaf spring and cut the rusted section out to see the extend of damage first. You might be able to get away with a patch.

[Viperpete 39]

Agreed. Remove spring. Get an angle grinder with a flap disc or wire brush and remove the surface rust to see the extent of the rust.  Id cut out the old stuff and weld in some new steel. 

[Mike65 504]

When I acquired my 69 Coupe back in 2000 I had some rust on the side of the l/s rear frame rail that I cut out & patched with a piece I cut from a rear frame rail patch piece section. https://www.cjponyparts.com/rear-frame-rail-section-driver-side-1965-1970/p/M103L/

[Rindelmach1 14]

thaks for advise.  I will try this in a few weeks.

[bigmal 229]

That's a really difficult section to weld in situ. As you start removing the rust you'll probably find more and more. I'd buy the section of frame and replace it. For me this would be the easiest and quickest way.

[Rindelmach1 14]

reviving this topic to get some advise before i start this topic.  I want to avoid drilling out spot welds from trunk section and just cut the frame rail but leave the lip of it welded. then my new section would just weld to that lip area.  has anyone tried this before?
 

[mustangstofear 608]

That's a short cut I wouldn't even consider. 

[Rindelmach1 14]

would be good to know why?  inside trunk is finished so trying to avoid a paint job

[Kris 90]

Even if you welded it to the lip like your thinking of it will more than likely cause the paint in the trunk to peel above it due to the heat from welding. I would just drill out the spot welds and replace it properly rather than try to do a patch job on something structural. Once you cut it out I’m sure the rust is worse than you can actually see as it usually always is. Depending on how your trunk is “finished” you can always have the paint matched and blend it and a trunk mat will cover it also.