floor pan firewall question

[daughtersdart]

View attachment IMG-20131103-00490.jpgView attachment IMG-20131103-00490.jpgSorry guys but this is my first build.can anyone tell me what to do about my rust issue.where my floor and firewall meet is rust through how much should I cut out and what's the right way to seem it at tht point scared to go any further without some direction

 

[1968FormulaS340]

Realistically, you need to evaluate the total rust situation throughout the car. You need to evaluate the value of the car when repaired.

Is this a factory 340 car?

If the rust has attacked multiple body seams and panels, you are better off getting another car.

Other than that..... You will need good metal from a donor car. The rusted area will need to be cut out and replaced.

 

[zkx14]

You can get the floor pans new. If its just a few inches in front of that it is not too difficult to bend pieces to weld in. If much more than that you may need a firewall or at least doner section and are getting beyond a' beginners scope of work' and into the 'is it worth it' question. Also can't see in your pic where you cut side or back to know if too far for new pan to cover. Most of these can just be overlapped, since you wont see them. I usually use a pnuematic flange tool where I need to level the metal, not important on a floor pan though. I would not try to butt weld anything there unless you are a really skilled welder trying to do a perfect restoration. Be sure to seal everything from underneath. I used Black Jack neoprene for that (regular seam sealer inside)

 

[Bad Sport]

I took the liberty of flipping the pic so it's easier to see.

 

[daughtersdart]

Value really isn't an issue here my dad gave to my daughter but its up to me to fix it nothing special just 318 buckets and half vinyl top auto on column bought AMD floor pan halfs And I have a piece of a donor car for firewall piece just wasn't sure where to cut but that pic helps a lot thanks to all for the help

 

[amoparacer]

Cut where the metal is usable just above the rust Make sure to give your self enough room to flange the doner metal. I assume your welding it your self. Harbor Freight make a nice air flanger. Flange the doner metal then drill or punch hole in doner flange to weld new metal to old. It would be hard to butt weld this as the floor is very thin. Also use weld through primer before installing and welding to slow down new rust. East wood and most body supply shops sell weld through primer in spray cans. Do as recommended above seal it well both sides after installation.