what is the best method to a: remove floor pans and b: weld the new ones in. is butt welding better than flanging and lapping. is cutting best with a whizzer wheel?

i used a jigsaw with a metal cutting blade. cut right thru it in no time. won't reach everything but the long straight runs take no time at all. i overlapped my seams rather than butt welding. this makes for 2 welds, one inside and one from underneath. you'll have to drill the spot welds for the seat pan braces (do a search there was a post on drilling out the seat pans within the last 2-weeks). on the rocker panel side i left a one inch wide section of floor and pressed the new one right on top of it. this assured me of an almost exact same height as the original floor. i also cut around the seatbelt mounting hole so i wouldn't have to reweld the braces inside the tunnel back in. grind the tops of the welds down and seamseal everything. after prime, paint and undercoat you can't see my seams.

before cutting the old floor out lay the new floor on top of it and press down firmly all the way around and mark it with a magic marker, this way you have a reference line for lining up the new floor once the old one is out. be sure to allow an inch or so overlap from your line. the tunnel side can move up and down and be at the wrong height without this line.

just take your time and measure everything several times and only cut once. pay attention to where your cuts are both inside and from underneath so you don't cut any braces (toe board, seat belt bolt bracket etc.) make sure you can get to the seam with your welder too.

i have a spot welder so i welded my seat pan braces onto the new floor first then dropped the assembly into the car and welded the floors and remaining holes for the seat pan. like i said do a search on the seat pan thing.

take any measurments you can think of before cutting out the old floor and try to match up the new floor to those. you can trim the new floor if need be.

tools required or suggested:

jigsaw with lots of blades, tin snips, hacksaw, grinder, hammer and dollies, spot welder, mig/stick welder, safety items (gloves and glasses)

it's not that hard just think ten steps ahead so you don't run into a jam.

best of luck!!! graemlins/thumbsup.gif

thanks for the info. some great tips. would it help to flange the new pieces so they fit better?

Hey Doc, if you are installing just a pan, and not the complete floor, then flanging is the way to go. But, bear in mind that when you do this, you will still have to tack it in place, hammering the edges as you go. How bad is your floor? Just bad in sections, or the whole side rusted through?

Scot

If you have the car apart, the best way is to replace the entire floor pan (fewer seams). To remove it, the ideal way is with a plasma cutter. Be careful not to cut through the under structure. In the front and rear you want to cut a little shorter so you have some overlap. Drill 1/4 inch holes around the edges of the new pan so you can plug weld along the rockers and the edges. You can also do some seam welding for added strength. Also, drill holes where the pan contacts the under structure in the front and rear so you can reweld to it. Replace the seat platforms or install new ones, grind the welds down a little, prep and paint it.

With the car apart it is an easy task and sure makes the underside of the car look like it was done by a pro.

more great info thanks. the new pans i bought dont have the knockout holes just a stamping to look like the original. what was the purpose of the original glued in knockouts? :confused:

when you weld the new pans in, do you weld a continuous bead at the joint between the new and old? or do you just spot weld spaced every 1-inch and use seam sealer?

I myself, used a complete pan. I agree that the complete pan is the easiest way to go. I spot welded just like the factory, and if you look at my website, you will see that it looks good so far. All I have to do now is seam seal and paint. I just installed a new trunk pan also. Pics soon. I removed the old 2 piece floor pan a previous owner installed, very shoddy if I do say, with a spot weld bit and a cut off wheel. Then I ground off the leftovers. Made a really clean area to weld to. Pics of my floor pan progress are on there too. If you need any further help email me, I think I have more pics on my puter. Maybe helpful.

Scot graemlins/hurray.gif

67 Cruise, Those are excellent pics of your work. You will have a solid and neat clean looking body when you are finished. Good Luck with the rest of the project.

Thanks 69X. I checked yours our too, fantastic. I know mine will be just as good looking as yours is when I'm done. Our obsession, eh?