driver seat broken

I have never heard of this before.

You should be able to use a piece of steel flatbard or angle iron under the floorboard. Then bolt through it and sandwich the floor inbetween. Welding would be nice, but this way would be super strong and hold up.

You can get steel from home depot and lowes. Depending on what you get, should cost less than $10 for the steel and bolts. If you have drill bits and a hacksaw, you can do this at home in a couple of hours.

It's not uncommon -- and basically welding a new metal in is the best way to go.

When I bought my car both the front seat stud and related floor metal were ripped out. It was a rocking chair. Everytime I took off, I was looking out the moonroof. I went to the hardware store and got a couple big long bolts, a mess of washers, and some locknuts and mickeymoused it right through the floor to the outside. This worked for about a month- I don't recomend it. My tech ended up welding a 1/4" steel plate, 2" wide, from the door to the tranny hump- basically the width of the seat on the floor rib where the old studs were. He welded two studs onto the plate, that sucker's going nowhere. In hindsite, I think it may have been easier and more rugged to drill out holes for the studs through the steel plate and then use two bolts instead of threaded stock for the studs up through the plate from underneath, and then weld them in- but hey, it'll last forever like this too.

I had 2 "L" shaped pieces fabbed from 16 gauge steel. I set them down on the existing channel so that they made a "[". Then they were marked and trimmed for size and fit. I drilled the stud holes and used a 3/8" fine thread aircraft nutplate in place of the missing stud. Then I used Cherrylock rivets (high strength aircraft blind rivets) to secure the new "[" shaped section in place.

I used aircraft rivets instead of welding because the end product is stronger and I don't have easy access to a welder. If anyone has any doubts about rivet vs. welding, try and find a metal airplane that is all welded. You won't find any.

If you have access to the proper tools, my fix will be really simple. If not, then maybe you can modify it to work for you. Instead of using a nutplate, you could tack weld a bolt in place of the missing stud. If you could find some steel pop rivets that did not pull the stem out when they set. You could use them in place of Cherrylock rivets. The rivet stem needs to stay in place to give strength to the rivet. The stem in the rivet makes it solid and not flimsy and easy to shear off.

It may be that welding the "L" shaped pieces in place one at a time would work. Cut and fit one "L", drill the bolt hole and the weld a bolt in the hole that is for the missing stud. Then weld it in place. The repeat the cut and fit of the next "L" and weld it in place.
__________________

I used aircraft rivets instead of welding because the end product is stronger and I don't have easy access to a welder. If anyone has any doubts about rivet vs. welding, try and find a metal airplane that is all welded. You won't find any.

Click to expand...

There are a few holes in this theory, no pun intended. First, and correct me if I'm wrong, but don't airplanes HAVE TO flex or they will come apart in the air? If every seam was welded I don't think it would stay together- but I doubt it's the welds that would come apart. The main problem though, is that you're riveting to one of the flimsiest peices of metal on the car. Welding will distribute the stress load over an area, a rivet will focalise it on that one tiny spot. it's only a matter of time before the holes elongate, and the floor tears again. You are riveting to a couple sheets of paper, not the wing on a Boeing. Slap me 10 years from now if I turn out to be wrong.

stangbear427 said:

There are a few holes in this theory, no pun intended. First, and correct me if I'm wrong, but don't airplanes HAVE TO flex or they will come apart in the air? If every seam was welded I don't think it would stay together- but I doubt it's the welds that would come apart. The main problem though, is that you're riveting to one of the flimsiest peices of metal on the car. Welding will distribute the stress load over an area, a rivet will focalise it on that one tiny spot. it's only a matter of time before the holes elongate, and the floor tears again. You are riveting to a couple sheets of paper, not the wing on a Boeing. Slap me 10 years from now if I turn out to be wrong.

Click to expand...

Aircraft flex because the metal stretches and then returns to shape, just like a spring. Joints DO NOT stretch, if they do, they eventually fail.

The 1/8" diameter rivets are set in a 2 row staggered pattern 1/2" apart, drilled 1/4" from the edges of the metal, with approximately 28 rivets a leg. The top section gets another 20 rivets or so, for a total of 76 rivets for the top and both sides. The rivets are stressed in shear mode, so there is little danger of them pulling loose. With the head of the rivet and the bulb (mushroomed other end) being about 3/16" in diameter, there is very little chance of the rivet pulling through the metal. This type of repair is approved for use in aluminum down to .024 or so. I have no worries about it coming apart anytime soon.

I never did any metal work on anything made by Boeing, all mine was done on light aircraft like Cesnnas, Pipers & Mooneys.

This is what I get for at an airline mechanic about aircraft construction . I just threw out Boeing as a well recognised word, I don't know how they do it either but I'd bet your guess is better than mine! You understand what I meant though, right? If a roughly 3/8" stud focalises enough stress on a point to rip the floor apart, how much more so is a rivet less than half the size, with no metalurgical bond to it? Now, if you riveted them to the floor and then welded the seams to distribute the stress load over several lineal inches instead of one square 1/4 inch, I'd trust it more. I still think if you drive it hard, you'll find a problem starting eventually. The floorpan just isn't inherently strong enough. Just my other $.02