Who has experience cutting out floor and trunk pans??

[1969vert500]

Okay guys I have finally got some good metal rounded up in 2 parts cars and I need to cut out a trunk pan and floor pans. I had really wanted to do the floor pan as a one piece pan and trim up the back footwell as it is going into a vert out of a 4 door so I should have that extra inch and a half.

My question is are their spot welds ALL over the place I will have to deal with? I have access to a plasma cutter so I can cut well but can you just zip along the sides and unbolt it or is it spot welded all over the place? Never cut a pan out so I am looking for help from someone that has.

Also would you suggest doing it as a one piece pan on the floors or cut it side by side and then splice it along the tunnel as my tunnel is very solid and the spot where the seats mount is solid too. I just picture cutting the whole pan out of the vert and bracing it in the doors and still watching it fold up like an achordian. ANY input would be great. Thanks

 

[65sporty]

Yes there are spot welds, invest in a spot weld cutter

 

[1969vert500]

is that different than a spot weld drill bit? I have seen those and heard you burn through them like butter getting a floor out

 

[DasBoot]

This is what I used on my sons Duster trunk and taillight panel:

http://www.blairequipment.com/Spotweld_Cutters/Spotweld_Cutters.html

Its the only brand I've used. I got it at an autobody/paint store. Yes its spendy but for what I paid, it has lasted thru tons of spotwelds.

The cheaper way but not as pretty is to use an air chisel carefully along the frame rails. Since the floor pan sheet metal is thinner than the frame rails, the floor pan will bend and release before the frame rail metal will. Clumsy usage will result in bent flanges which you then have to straighten by hand (hammer/dolly, or pliers) which will take more time to mess with but thats why its the easier way, not the better way. If you're trying to save both pieces, use a spot weld cutter. If its rusty metal, air chisel.

 

[detmatt]

Blair is the best, well worth the money. You have to drill out the spot welds on the pan you plan on using. Start by using a stiff wire brush over the whole surface and that will help expose all of the spot welds. If you end up drilling out the spot welds on the old rusty pan just be careful not to drill through both layers or you run the risk of having to fill holes in both pieces rather than just doing the plug welds. Start drilling a few out on the rusty stuff and you'll get the hang of it. By the time you go around the entire perimeter including wheel houses, extensions, the tail panel and the tops of the frame rails you'll have perfected the process.

 

[1970cat]

i've had good luck with the spot weld cutter above too. as long as you keep the drill as straight as possible the teeth won't break like some of the cheaper ones. there are spot welds all along the perimeter and along each under floor brace. the tunnel has double and triple layers in places. i would either replace the tunnel as one piece or avoid it all together. the floor braces are not really as strong as they seem. the floor pan itself is what gives the car strength. as long as your rockers are solid i would suggest leaving the tunnel in and welding to it. if the rockers are bad then you are going to need to brace it so it won't hurt to take it all out. take the time to remove the old seam sealer and it will become apparent how it was constructed and where the spot welds are

 

[1969vert500]

Good to hear as the rockers are solid on this car as it just rotted in the low spots as they left it exposed and the top was torn up and the water came in and settled to the low parts of the pans and then through. So the tunnel and rockers areas are solid. I will probably just cut out patch panels then and try to save as much solid original floor as I can.

 

[1969vert500]

Here is a shot of the worst side of the pans so you can see what I am working with. I had taken a hammer to it and pounded out the pans so where the metal starts is pretty solid right up to that area as I beat them pretty good.

Here is a link to my photobucket on it if you want to see more pics. But I think patch panels should work once I cut them out unless I am missing something. Thanks

http://s1327.photobucket.com/user/vette1986/library/1969 Polara 500 vert?sort=3&page=1

 

[1970cat]

looks about like my car did when i started. you might want to go over it good with a wire brush or wheel. you'll be surprised at how many pinholes open up. maybe you could cut the tunnel out of you new floor and replace a complete side at a time. the trouble spots are where the rear foot well meets the tunnel. you'll have to either cut off or peel up the tunnel layer because the floor goes underneath it. very tough going around the pedals and column. not much room there. also the inner rockers must be galvanized or plated with something because they are tough to weld to. surprising your trunk floor is so good.