Floor pan rust repair

[agnes the dog]

I'm getting ready to replace the sections of my floorpan toe boards shown in the pics below. I plan to make my own patch panels. I'm just wondering if anyone has an tips/tricks that I should be aware of before I go cutting out the swiss cheese. Any warnings about these areas? Thanks.

http://67-72chevytrucks.com/gallery/...n-rust&cat=500

http://67-72chevytrucks.com/gallery/...n-rust&cat=500

Couldn't get the pics to embed into the post. Click the links to see what I'm replacing. Sorry.

[mongocanfly]

here ya go.....

[agnes the dog]

Originally Posted by mongocanfly

here ya go.....

Thank you! If you don't mind, how did you get that to work?

[mongocanfly]

I just copies and saved your pics...and then posted them like this...
http://67-72chevytrucks.com/vboard/s...sting+pictures

[mongocanfly]

those rotted support areas are possibly why your constantly fighting your door gaps....it would be a much easier repair with the cab off so you can get to everything. ...but your gonna have to get the cab weight off that area while you repair it...when you get the cab weight off that area your door gaps may move again so be sure and check for that before you cut but after you jack it up...you can weld bracing in the door opening where the door will still open and close...

[mongocanfly]

depending on how bad and how far the rust goes I would weld some cross bracing in there to hold everything in place before you start cutting...but what im seeing isnt bad enough for bracing though.....what's in your pics is fairly common with these ol trucks....when you get those places cut out use a rust nuetralizer in that area...

[agnes the dog]

Originally Posted by mongocanfly

depending on how bad and how far the rust goes I would weld some cross bracing in there to hold everything in place before you start cutting...but what im seeing isnt bad enough for bracing though.....what's in your pics is fairly common with these ol trucks....when you get those places cut out use a rust nuetralizer in that area...

Thanks! I assume that I'll need to access the cab mounting bolts at some point? Should I create the patch panel with an access hole or actually bolt the repair panel to the mount below?

[mr48chev]

^^^^^^^^^^ Just what I was thinking.

From experience on mine that wasn't necessarily good It is very important to make sure you have the cab sitting level be it on or off the frame, you wan to get your door gaps set before you weld anything and the bracing helps keep things from moving when you start cutting and then welding.

I didn't think to set the door gaps on my truck before doing some modifications and lots of welding and then fought door gaps from then on. If the cab isn't all level and square you stand a chance of building in an issue that it may not have had before after it is stiffer from the new metal being welded in.

Other than that, take your time plan it out and do a nice neat and orderly job that you will be proud to show the results of to us. The "I am going to do this the best I can do it" Beats out " I gotta get this much done today or else" every time.

[whitedog76]

If you're leaving the cab on the frame during the rust repair process.... I've heard of people using 2x4's as kick stands on the firewall to help keep the cab where it needs to be.

[agnes the dog]

Originally Posted by whitedog76

If you're leaving the cab on the frame during the rust repair process.... I've heard of people using 2x4's as kick stands on the firewall to help keep the cab where it needs to be.

I will be leaving it on the frame. Good idea. Better to be safe!

Thanks for all the replies and ideas.

[agnes the dog]

Originally Posted by mr48chev

^^^^^^^^^^ Just what I was thinking.

From experience on mine that wasn't necessarily good It is very important to make sure you have the cab sitting level be it on or off the frame, you wan to get your door gaps set before you weld anything and the bracing helps keep things from moving when you start cutting and then welding.

I didn't think to set the door gaps on my truck before doing some modifications and lots of welding and then fought door gaps from then on. If the cab isn't all level and square you stand a chance of building in an issue that it may not have had before after it is stiffer from the new metal being welded in.

Other than that, take your time plan it out and do a nice neat and orderly job that you will be proud to show the results of to us. The "I am going to do this the best I can do it" Beats out " I gotta get this much done today or else" every time.

I've been fighting door gaps for a long time. Adjust, then drive it for a couple months just to have to do it all over again. Is it possible that the weakness in the floors could cause my door issues too?

[_Ogre]

Originally Posted by agnes the dog

I've been fighting door gaps for a long time. Adjust, then drive it for a couple months just to have to do it all over again. Is it possible that the weakness in the floors could cause my door issues too?

old oil soaked rubber cab mounts and rust around the cab mounts probably account for any front door gap problems
top, bottom or rear door gaps are worn hinges or rusty hinge pockets
front cab mounts are ~1'' thick rubber and mounted to allow the frame to flex
the rear cab mounts are .1'' thick at most plus shims to adjust the front door gap

the big cross member under the bell housing supports the front cab mounts
if you cut it out to install an automatic you need to add some bracing to support the cab mounts
you can see how i braced the cab supports in my build thread (using chrome and the add-on)
there are braces built into the floor board extending from the step to the trans cover that need to be made whole again
these keep the floor from flexing and are welded to the floor

[agnes the dog]

Originally Posted by mr48chev

Other than that, take your time plan it out and do a nice neat and orderly job that you will be proud to show the results of to us. The "I am going to do this the best I can do it" Beats out " I gotta get this much done today or else" every time.

Sorry, I didn't see this comment yesterday. Such great advice! I've always been results driven and try to have a goal to get stuff done. I have to get better at taking my time!

[gigamanx]

I did a very similar repair in the same places. Cut out the support under the floor first and welded in a new one. Cross bracing is a great idea. I probably should have done that but I got lucky with the small amount I replaced. The passenger side had the battery box hole for me. That was probably the trickiest place to do. As for the side kick panel, I ended up buying the patch panel for that area just because it has a few nuances to the way its bent into place. Glad I did.





While I was in there, I also sprayed the back side of the outer skin with some POR15 just to try and seal it up a bit and prevent future rust through.


Probably should have used clecos for this part but I was a newbie at the time and didn't know what those clamps were for

[agnes the dog]

Well, I broke down and ordered some rocker/steps today. While I was at it, I got the repair patch panels for the floor. Probably will save me a lot of time and frustration. Hope to have them by the weekend. I'll post pics when I get it done. Thanks for all the support.

[b-mac]

+1 on the bracing. I thought I had mine braced well enough:



Now I'm having a hell of a time getting the doors back on...

[agnes the dog]

Here's the final product. The passenger side welds are much better than the driver side. Practice helps! It's going to be covered with sound mat and carpet anyway.