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MG MGA - body rot near 'A' posts

Hey Folks, I am unable to locate a picture of what the area near the door hinge post and the inner rocker panel should look like. I have a bad patch there and want to see how it should look. Thanks, Tom
Thomas McNamara

Tom, spend some time on the Eclectic Motorworks web site. They have hundereds of photos still posted of their MGA repair work and I'm sure some of them will show you the area you're concerned with. http://www.eclecticmotorworks.com/ Check their MGA pages as well as completed British cars. Lots of good information there. Here's a shot of the side of my car with the old sill removed and the rot cut away from the A post showing the inner support piece just below the hinge.

Bill Young

Here's another shot of the repair piece installed, plug welded to the inner support piece and the outer sill and butt welded to the rest of the A pillar.


Bill Young

Thanks Bill. The shot I want is from inside the car. Tom
Thomas McNamara

Inside? I have come of those. See here:
http://mgaguru.com/mgtech/restore/pics2/3459.jpg
http://mgaguru.com/mgtech/restore/pics2/3463.jpg
http://mgaguru.com/mgtech/restore/pics2/3919.jpg
Barney Gaylord

THANK YOU Barney, just what I need. I have attached a picture of the area that I found in a "good solid car with no rust." It aparently started out black and has received several coats of red. The picture does not show the rust present or the other side, which is worse. My question is; can this body work be done correctly while the car is on the frame? I hope so. Regards, Tom

Thomas McNamara

Thomas, if the body hasn't settled around that rusted area then I'd say yes, you can save it on the frame. At least get the sills repaired which you can do on the frame and then you can lift the body if necessary to access that inner portion and the body mount. I've got some similar issues on my car that I will address now that the sills are done and the body is off.

Bill Young

That particular spot is a little tricky because the bracket backs up against the door post with spot welded flanges (outboard of the inner fender). Welding repairs can be done with body on frame. In fact when you are dealing with anything related to body alignment or mounting points it is best to use the frame as the alignment jig.

For original production the entire F-section assembly was spot welded together first (including gussets aft of the B-post). These are the flanged "U" shape box sections for sill and door posts. Front and rear inner fenders were joined with a flat panel below the door. The F-section assembly was then offered up and spot welded to the inner panels. This is of course impossible to do for repair work without breaking all spot welds and starting with all loose panels.

Replacing body sills with body on the frame requires cutting it all out and replacing the inboard flat panel first. Then install the box panel with flanges, plug weld the door posts to the sill, and the outer rocker panel goes on last.

As an alternate approach, I fabricated all of the sheet metal sill pieces and had them clamped in place for alignment before welding anything. Then I removed the entire clamped assembly from the car for spot welding, followed by filling it with a gallon of paint and rolling it around to paint inside. The assembly was then butt welded to the inner fenders along a line above the box section, followed by plug welding the door post flanges to the sill.

There is (was originally) cork packing under that mounting point, and felt packing along the rest of the length where the body flange sits on top of the frame. Welding in this area will inevitably burn out the packing material.

It is my humble opinion that anyone going to all the work to replace body sills would be nuts not to R&R the body for clean-up and painting underneath (although I have seen this a lot). There are about two dozen bolts involved, it comes off in a few hours and goes back on in a day with fresh packing all around. Time in between is well spent cleaning and painting everything underneath that would be otherwise inaccessible. If you don't paint underneath it will eventually rust out again. The difference between full body off restoration and repair with exterior paint only is about $10,000 difference in the value of the car.
Barney Gaylord

Thanks to Bill & Barney for the pictures. I spoke with Todd Clarke and he says he has the repair pieces that are required. My next question is; Is it better to attach the repair panels over the existing sheet metal or should it be "butt" welded? Please keep in mind that I will have to locate and hire a welder for this work as I do not have those skills or equipment.

What is my best choice, gas, MIG or TOG?

As a second thought, is there an adhisive that is good enough to hold the panels in place?

Once again, thanks for the opinions and education. Regards, Tom
Thomas McNamara

Thomas, usually such a repair is done in layers, the inner layer is replacd then you work your way out. I'd repair the flat panel behind the body mount bracket, butt welding it to the good metal at the top and front seam and plug welding it to the A post. I try to duplicate factory type welds were I can and in areas where patch panels are joined to existing metal that never had a seam I butt weld to keep a nice flat surface. The body mount bracket would have been spot welded to the body so use plug welds on that as shown in the photo I attached. The type of welding you use really depends on the experience of the welder you hire, but most would use MIG for such a repair as it's probablthe fastest method and you're usually paying by the hour. If the rust extends down past the edge of the frame top then the lower portion of the repair will be pretty difficult ot reach, that's the reason I suggested doing the sills first, adding a cockpit reinforcement and then repiaring this area with the body at least lifted 6 to 8 inchs above the frame for access.

Bill Young

Hey Bill, thanks for the picture and annotation. It is starting to sink in how much I need to learn. Regards, Tom (One picture is worth........oh you know).
Thomas McNamara

This thread was discussed between 23/11/2009 and 30/11/2009

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