Chicagoland MG Club
The fact of the matter is that almost 90% of the Sprites, Midgets, MGs, MGBs and so on are in desperate need of floor and sill replacement. Anyone with the desire can take a few classes at a local vocational school and learn to weld in a short time. With the rising costs at restoration and body shops you can do the work yourself with a little practice and save money to use on another restoration! For about $200 - $250, a simple welding outfit can be purchased. However, most clubs use funds to buy equipment like this, so, before you go out and buy your own, check out your local club and see what resources they already have.
At this stage, most of our cars have holes or rust developing in the floors and rocker panels. It's very important with a unitized chassis that the bottom of the car is completely sound because of the lack of support from lack of a roof. Over time, as the floor and sills deteriorate, you will notice the door gaps have changed and don't close as easily as they did while new. This is evidence of a weak floor and sills that need to be retired.
Moss supplied me with the high quality reproduction parts I needed. For most of us this is the hard part, so take your time and be sure to buy all the correct parts to replace anything that shows any sign of deterioration. Also, don't overlook replacement of the door hinges and footwell panels. The most effective plan of action is to work on one side of the car at a time, removing and carefully replacing the required panels using the untouched side as a source of reference.
Continue by removing the old rocker panels and the cross-member. After cleaning up the rusty edges all around the base of the car, then and only then, can you install the new floor-pan. Offer up the new floor into place and temporarily support it with five or six jack stands. Start by lining up the floor edge against the rear bulkhead; the front can be trimmed later. Tack-weld the rear edge to the bulkhead in front of the rear axle under the car. Before welding the front of the floor-pan and footwell sides, the door gaps must be checked again and again. It is impossible to stress how important this step is.
Lightly tack-weld or rivet replacement panels in place until everything is together; make adjustments to align doors, etc. (you will make adjustments) and then seam-weld together for strength. The best way to do this is to lay all the parts on a level surface and test fit them together. Start by tack-welding the inner rocker panels to the outer panels. Measure carefully and line up the jacking holes properly, then weld the cross-member to the floor, along with the footwell panels (if you plan on replacing them, too). After assembling the floor parts together, use a good rust preventative inside the cross-member and rocker panels.
The process of removing old panels is, in some regards, even more important than their replacement. Take careful note of how it all fits together and duplicate that as accurately as possible. Be careful not to destroy pieces you will need to reweld. Patience here goes a very long way .
Back to General Tech Tips