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MG MGA - Chassis Frame Rust

I have a 57 MGA and found a rust hole about 2"long and 1" high on the inside of the frame just behind the door opening.
The outer portion is intact and the floor portion is OK.
Since this portion of the frame looks to be quite tall (top to bottom), I think this is still structurally stable.
Does anyone have experience with a welding repair without taking the body off and the floorboards out.
The gas line runs right next to this area.
Thanks-
Bill from Ann Arbor, Michigan
W Chandler

Bill, a picture would help other giving advice. Factors such as what is near, how much room to work etc will be apparent.
Gas line location should not matter, assuming this hole is inside the cockpit. You should determine how far you have to go to reach good metal to weld to. Then you can either plate over or preferably let in a plate flush. the frame is 14g steel. cut the plate and file the hole for a close fit. Use magnets to hold in place across the cut. Shield sparks from the welder using drywall or sheet matal. Find a good ground for the welder. Battery ground should do.
Art Pearse

I hope Art didn't mean what he said. Do not ground the welder on the battery. A spark from the grounding clamp could produce a nasty battery explosion with battery acid blown everywhere.
Barney Gaylord

Good point Barney. I only meant that it would be a good electrical ground. So if you use it, remove the battery!
Art Pearse

Art- I have uploaded a diagram of where the hole is located. You see the hole from under the car on a lift. Thus is is next to the gas line.
Thanks for your input.
Bill

W Chandler

Oh, that's different. Has it affected the floor rails? Thats a common place to start, water from inside hanging around the rail joints. There is a lot of stuff there, cables, brake and fuel lines. They can be released fom their clips and pulled out of the way. Take a small drill and find the extent of the bad stuff.
Art Pearse

For that repair you will have to remove the floor board. the frame rot there is caused by water trapped along the edge of the floor, so the rot will go down to the floor support rail. Once you start grinding rust out of the hole it will be a much larger hole than you first see.

Once the floor is out you can disconnect the pipes and wiring from the frame, drop it all down a little throw a wet rag over it, then go ahead and weld the frame.
Barney Gaylord

Barney - Many thanks - I think that is the best plan.
Bill
W Chandler

If you have rust, its probably elsewhere on the frame. That is what I found. May be time to bite the bullet and pull the tub off the frame. I just did it, and its not too hard to do. Welding the frame it very easy with the tub off.
Tom Going

This thread was discussed between 10/02/2013 and 13/02/2013

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