Floor Plan Repair

Driver's side seat frame was loose, so I finally got around to investigating. Long story made short...some floor plan rust, mostly confined to areas where rear of the seat frame bolts to floor pan. Center section of the floor pan still very solid. I have removed enough of the floor pan so that I'm sure my sill and transmission tunnel flanges are good. Haven't checked anything forward of the cross member yet, but I think it's in pretty good shape.

If I find problems up front, I'd like to attack in two steps...Rear of the cross member first, front later if needed. For the area rear of the crossmember, I'm considering cutting out the bad stuff, rust proofing the good stuff that's left, then overlaying it all with a "thick" metal plate. Might even cut out the entire rear section of the pan and replace it with a "thick" metal plate (appropriately rust-proofed).

I spent most of this morning reviewing old posts on floor pans and now (AS ALWAYS !!) I have a few questions.

If I go with the overlay plate, I want something substantial. I'm heavy and I don't like for the floor to "give" when I sit down. I'm going to have to re-establish seat frame mounting points anyway so why not go with something really solid. If it has to be 1/4 inch steel, so be it. What material and thickness would you recommend for such a plate?

I've also read on here that Fusor is a metal adhesive that works well. I didn't know there was an adequate substitute for welding, but I hope Fusor is it. That would solve several little problems with this job. Anyone have any recent experience with Fusor or a similar product?

Thanks, and I'm sure I'll have more questions later.

I'm no engineer but I would think 1/16 would be plenty. I can't see going with that heavy of material and glueing it in though.

Just another thought and I don't mean to criticise. I've shopped for a lot of cars and a huge turnoff for me is to look underneath and see a flat piece of plate where a floor pan is supposed to be. The stock sheetmetal pan is plenty sturdy enough to support some pretty big fellas. The ribbing adds strength and it is well supported by the crossmembers. It's your call though. Heck, MGAs have plywood. Just my opinion but I'd go for the replacement panels. The car will be worth more at resale time and by the time you buy the plate & have it fabricated to fit, the cost may well not be much different.

I'm in the middle of a floor pan replacement on my 72 B. I used a plasma cutter and removed good pans from a 77 parts car. Great tool, cut right through the cross member. Then to remove the old ones from 72 I (actually another guys doing this bit for me) he, took a drill and drilled out the old tack wells which allows you to remove the pan. A little time consuming but not bad. Clean up the edges on the pan to go in and tack in place.

...then drop in and tack weld into place.

I'm with Jim. By the time you are finished truing to cut, fit and attach a flat plate, you might as well just get a "Heritage" panel, cut the old one out and "con" a buddy into welding the new one in.

Just my $0.02

Larry: I have just what you need; the rear section of driver's side floor pan. It is steelcraft for MKI but I believe the difference in pans is in front of cross menber, Send me a PM if you are interested.

Bill,

I sent you a PM.

swapping a floor pan looks quite easy on an mgb, would i be right? i've done a few floor pans before like on beetles and morris minors, is there anything tricky on these? i am thinking of doing mine at some point as they have been "patched" up and although solid look ugly and de-value the car...

Mark - I am almost finished removing mine so I can only speak to that part of the process. It isn't hard at all but very time consuming as you have to drill out 100 spot welds and seperate the floor from the other parts.

Good luck!

gcan Wrote:

If you use steel plate for floors, you might as well get a vanity plate that says "DPO MGB".

I don't see any benifit of using 1/8" steel, just adds weight. The regular floors are strong enough if they are installed properly. They get their strength from being welded at so many points. I think i put 150 plug welds per side. Which is about how many spotwelds there were.

I would replace the whole floor and i would make sure that i welded it in. Not glued in. Glue is for fiberglass cars and DPO's. I think i would rather use steel rivets for a "quick fix" . This way you can drill them out at a later date and plug weld the holes. Once you glue them in you can forget about welding them without removing them and cleaning all the glue off. Just do it........correctly.

Glen

lbcnut Wrote: