Thread: floor for channeled '30 coupe

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Need help on how to install a 16ga steel floor into my coupe that's channeled
over the original frame. If I weld in then can't remove body if floor goes past frame rail width,(door to door) or bolt into frame? If placed only acroos frame rails when door is opened the frame is visible. Car has sb 400 w/700r4. I'm 5'9 and fit just fine with the already chopped top. Currently, frame has no additional cross-bracing, but i plan on it as soon as I know what to do about floor. Oh, body is also original. Thanks to all for your help.

Weld in a grid built of 1"X1" rectangular tubing that connects to body supports, firewall, etc. Then you can attached the sheet metal floor to the tubing. You will have a stronger, more rigid body that way.

When I get home from work I'll post some pictures for you. But something you said confused me. Why can't you go clear across with the sheet metal from door to door? That is the way it's always done.


Don

As rumrumm said, you need to build a subframe to go under the floor. BTW, 16 gauge is ok, but you really don't need to go that heavy. 18 or even 20 has been used, but you will do no harm with the 16 if you went that direction.

The subframe will be metal slats that tie in one side of the body with the other. You can do 1 x1 or 1x 2 box or rectangular tubing, and weld it from one side to the other, maybe every foot or foot and a half apart. You will have to build a tunnel in the center to clear your driveshaft, but that is easy to do out of flat stock the same width as your tubing or similar.

Here are some pictures of how my '39 is done, and also how my Kids '29 is done, to give you some ideas.

Don

Dongas----When you channel a car, the floor sets on top of the frame . You have to create a "well" in the floor on each side where the door is. The sides of the "well" extend down on the outside of the framerail to where the original floor would have been before the car was channeled. When you open the door, you don't see the side of the framerail---you see the side of the "well".

I was concerned with how much interior space I would have on a 32 ford truck I am building. I am 6' even, the top Is chopped 4" and the body is channeled 5 1/2 inches over the frame. I didn't want to wind up sitting on the floor when I was done. My solution was to cut my frame in half to pick up an additional 3" of head room then add extra frame members back in for any strength I lost.
The other thing I always do is weld in my floor but make the tunnel completely removable. This helps with maintenance and room to work inside the car. You loose so much interior room when you channel these things. I hope this helps or spurs some ideas for yourself.

Nice work - all.
I do suggest that you use some steel lighter than 16ga, 20 - 22 should work fine. 16ga becomes very difficult to work with - been there (by mistake) and it wasn't fun - most reasonably priced electric or air nibblers just wont cut it and aviation cutters, well, you'd have at least one very strong hand and forearm !!!

Originally Posted by Itoldyouso

When I get home from work I'll post some pictures for you. But something you said confused me. Why can't you go clear across with the sheet metal from door to door? That is the way it's always done.


Don

the car is channeled over the frame, the doors are at the low end of the frame rails.

thanks it does. the transmisson tunnel is from 20ga. I think that by using 16ga as main floor section I can then use less 1x1's to make the sub-floor frame. then weld the 16ga piece( I made a one piece section that includes the toeboards) to the 1x1's, tunnel will be removable .

excellent suggestion. But should I still weld the 16ga piece to frame and then weld the well to the body where the doors sills are?

thanks for the pic. got the idea how the door sill area is raised to the frame's height. also see the sub-floor frame . did you plug weld the sheets to the sub?

Dongas--this is the car floor, shown with the "wells" in the area where the door would close. In this model, I didn't show any 1" x 1" sub-floor framing, but you see how the floor basically sets directly on the frame, (or on a sub-frame of 1" square tubing, which sets on the frame.) You do not weld ANYTHING to the frame!!! Everything is welded to the floorpan, which is welded to the car body all around its perimeter. In this case, I took the wells down to a point level with the underside of the frame, but in reality they only have to reach down to where the "normal" bottom of the body would be. I would use #16 ga. if I were doing it, but I know some use a lighter gauge metal. I agree, #16 ga. is a real bear to form, but if you have the equipment to form it, then you don't need nearly as much 1" square tubing sub structure.---Brian

so then the body is only secured to the frame where the normal body mounts are located (3 on each side)? May be secure the wells (blue area) to side of frame rails with bolts for additional strength? did you place some kind of insulator between floor pan and top of frame rails? THANKS for the drawing---your are a real PRO!

Dongas---Yes, you only use the normal body to frame mounts. I do not recommend that you secure the "wells" to the frame--there is no need to do that, and it will cause other issues. Whenever I have channeled a car, I don't even use the normal body to frame mounts. On one car I drilled and tapped the top of the frame every 8", and drilled directly thru the floor pan to bolt the floor to the frame. I used the 2" x 1/8" thick fabric webbing that has an adhesive backing you peel off one side and stick to the top of the framerail for an anti-squeak insulator. On another car,which had a glass body and laminated plywood floor, I was afraid od "tweaking" the floor by pulling it down to the floor with bolts---this would have caused issues with body flex, and consequently affected the fit of the doors, as it was an open top roadster. ---In that case, I set the body on top of the frame, and bolted a series of short angle iron peices to the floor (they lay tight against the inside of the frame but were not bolted to it).---Then I bolted thru the floor and the angles and drew the bolts up tight, then welded the angles to the inside of the frame rails.---That essentially gave me a good solid connection between the body and the frame, didn't "tweak" the floor in any way, and still allowed me to unbolt the body from the frame if I needed to. ---and yes, as far as the solid models go, I really am a "pro"---thats what I do for a living.
www.rupnowdesign.com

I just looked at the first picture that Itoldyouso posted (he is doing mighty fine work on both his and his sons vehicles). Be aware, that although it looks like the well area is welded to the frame, that is not actually the frame you are seeing--that is part of the "sub-structure" that the body is welded to. The entire sub-structure and body can be unbolted and lifted off the frame.