Unibody Patch Ideas

[87_Pioneers]

So I have 2 small areas of rust through the unibody on the new Comanche I just picked up. Everything else appears to be solid but this area had the carpet over it and wet mouse nest in the frame rail causing some isolated holes. I have been thinking of the best way to tackle this that would remove the rust and keep things structural. I am also planning to do frame stiffeners after the repair and coating everything as best as possible. I have drawn a very crude CAD drawing of the frame with the affected area and my thoughts. 

 

Option 1 is simple cut out the affected channel bend up a new plate and do a butt weld to put in new metal where the rust is. However I don't like I have no way to fish plate it or anything of the such.

 

Option 2 would include cutting out and butt welding in a new piece of metal but on the inside of the frame doing another plat with a fish tail on  the inside of the unibody spanning the length of the patch area out another 4" or so either side of the repair. I am just not sure if this is going to be to overkill or to much heat in an area before frame stiffeners go on as well?

 

or am I way over thinking this and I should just cut out the rusty areas as needed and put in new metal without bending up whole new sections of "rail". The truck is not going to be wheeled hard and will be mostly a driver with occasional trips to wheel or camp. 

[89 MJ]

Let’s see some pictures of the rusty spots. That will help a lot with figuring this out. Remember, the rust is always worse where you can’t see it. 

[Tex06]

X2 on needing pictures. 

 

Do you have access to a brake for sheet metal? 

[ghetdjc320]

If you’re going to remove your floor pans, you can access the inside of the channel for repair. The frame “cap” inside the cab is a significant integral part of the structural integrity. So if you incorporate a flange to repair the frame rail, be sure you can get weld penetration from that top cap all the way to your new piece. If the rust isn’t that bad though, you may be able to just get away with some patching, especially in light of the frame plating you intend to do. Just depends on where exactly the problem spots are and how extensive the hidden rust may be.