i did not realize what therapy beating the crap out of a rusty floor was. dont get me wrong, its a pain in the az. my new rear passenger floor is stamped wrong on the outside. the lip goes down instead of up. There from Mustangs Unlimited. I havent tried to fit the rest of the floor yet. im sure ill run into some other misfits as well.

is the spot weld drill bit the best method for removing the spot welds? what a pain. i hate to think about how long itll take to do the cowl, which is next.

how much of the surface rust do i need to remove before using one of the rust sprays? ive been using a brush and wheel, got most of it, just didnt know if it mattered on getting it all.

 

My grandfathers panels were like that. He thought he got the wrong one and ordered another, but it was the same.

 

I'm too impatient to drill out hundreds of spot welds. I used an air chisel to remove the panels and a grinder to grind down the spots after the panel was off.

 

I just used a regular drill bit to get them out but you have to be carefull not to drill too far in or you'll go through both panels of course. I don't think the rear panel was bent wrong at the wheel well corner because everyone I've seen is bent that same way, mine included. I just finished my floors on wednesday and they were the last ones in. I'm ecstatic they're all done. But my rear panels didn't quite reach the wheel wells so I'm gonna have to add in another piece to fill the 2" gap it made. You may have that same problem fyi.
I didn't have an air chisle to help get rid of the spot welds but the ones i couldn't quite get with the bit i just used an old fashioned hammer and a sturdy chisle. A lot of elbow grease but worth it in the end.

 

is all of mustangs unlimited parts that way or just a fluke thing? because i live in georgia maybe a hour or just a little more from their place and that is going to suck if all their parts are like this because i would rather drive there than to wait for parts to be mailed to me from other companies

 

I used both the spot weld bit and a regular bit. The spot weld bit worked pretty well but went dull after about 15 spots. At 12 bucks a pop I decided to go to the regular bit and found that it works just as well. Like vine said just be careful not to go through. Are you replacing the whole cowl or just patching the hat area?

 

If you are going to drill the spot welds, center punch them and use a 5/16 regular twist bit to cut through most of the weld. A chisel or panel knife then works well to separate them. On panels where you can get to it from the other side, drill all the way through both pieces and use the hole in the remaining panel as your spot weld. This keeps you from having to drill a second set of holes.

 

We used regular a 3/8 steel bit (quite a few actually) for most of the spot welds. I forget where but I have to dig out a 5/8 bit at one point though it was only for a few. As fakesnakes said.. center punch them first. After doing the first few spots you'll get a hang on where to stop. I used an air chisel in very short bursts and a hand chisel with hammer in hard to reach areas.

I bought 2 spot weld bits and IMHO they are junk! I don't use cheap tools, they were a good quality spot weld bits and a complete waste of money. If you have the cowl to do and other areas go buy 2 or 3 3/8" steel bits to start with.

 

All the floors i have order are that way. They are that way for the option of settin on to off the existing metal. I have a plasma for cutting out the spot welds and it works great but you have a hole in your inner rocker to repair.