Floor Pan Rot

[geordie]

I just got my newly painted car back from the body shop about four weeks ago. I was busy stripping down the dash to add the new wiring harness. Prior to the car going to paint I stripped out all the interior with the exception of some rubber matting which was stuck to the floor in the way of the foot wells.
Referring to the attached photos, I made rather a disturbing discovery yesterday evening. After removing the remains of the interior under carpet rubber mats from the drivers side foot well I discovered a glass fiber repair had been made to the floor pan. I checked under the car and the repair had been filled, sanded and painted by the PO and could not be seen. The glass fiber on the inside was starting to lift away from the floor and when I removed as much as I could I found that an approximately 1.5 inch square hole through the floor pan. The surrounding metal around the hole is pitted.

As I see it, I've got two choices:

1. Replacement of the corroded panel with new metal.
2. Make a new glass fiber repair. I've read good things about POR-15.

I'd prefer to go for the panel replacement but this is going to depend on cost.

I would like to ask you guys for an initial opinion on the way forward. Has anyone got a good idea of price for a partial floor pan replacement. Thanks in advance.

 

[68RCodeConv]

It's not a structural problem. I would kill the rust (I use phosphoric acid) and patch over it.

We use to use old license plates as patch panels. They don't rust.

 

[geostang351]

I would go with cutting out the corroded material and replace with an aftermarket floor pan patch:

http://mustangsunlimited.com/itemdy01.asp?T1=A106ERH+01&Category=&catkey=EMUSTANG

I know it says passenger but just order drivers side.

 

[Jester67]

I would go with cutting out the corroded material and replace with an aftermarket floor pan patch:

http://mustangsunlimited.com/itemdy01.asp?T1=A106ERH+01&Category=&catkey=EMUSTANG

I know it says passenger but just order drivers side.

+1

 

[suki243]

haha geordie, our projects are the exact same...

 

[geordie]

Yeah, would you believe it. The PO said my car had been in AZ for the last 25 years. I'm starting to wonder now.

 

[James Kirk]

Better check your lower cowl panel. That's usually the cause of the whole problem. Patch all you want. If the cowl is rotted you will only be prolonging the issue.

 

[geostang351]

Better check your lower cowl panel. That's usually the cause of the whole problem. Patch all you want. If the cowl is rotted you will only be prolonging the issue.

I would suggest that too, but the fact he just had the whole exterior painted, I don't think Geordie is looknig to remove the cowl cover to repair this.

 

[geordie]

It possible to inspect the lower cowl panel from underneath the dash?

If that's not possible then I'll do some water pouring tests through the cowl and find out if it's pouring into the drivers foot well.

 

[suki243]

where do you guys buy por 15? do local hardware shops have it? osh? home depot? or something? or is it only available online?

 

[BornInAFord]

Eastwood.com I think is the main (maybe only) place to carry it. They are usually pretty fast at getting things out, so you could have it to your door by next weekend...
Daniel

 

[cardude]

If you want to keep the car, do it right and cut/ replace the pannel, its not that expensive. Then if you want to POR15 over it go for it. you can go to a nearby metal place and get 18ga steel and have it bent (or bend over something sturdy).

just my 2cents

 

[BlwnGazkit]

Even if you replace the panel I'd recommend POR15 on the new metal. It will help prevent future issues.

 

[smitzer]

My cowl is pretty tight but I found my leak at the top of the windshield. Might check there too.

 

[SHIFTY101EASY]

http://www.stoprust.net/

 

[geostang351]

It possible to inspect the lower cowl panel from underneath the dash?

If that's not possible then I'll do some water pouring tests through the cowl and find out if it's pouring into the drivers foot well.

You can but you can't see around the entire vent as there is too much in the way. But obvious rust can be seen and if it is noticebale could be a bad sign. You will at LEAST see surface rust.

 

[geordie]

I spoke to the body shop guy at the weekend. I have three alternatives:
1. Lap weld in a new foot well panel, this will be visable from below.
2. Butt weld a new foot well panel, this will be dressed and will be an almost invisible repair.
3. Glass fiber repair followed by sprayed on bed liner coating of chassis and interior floor.
Right now I favor (2) but much wilkl depand on price. I'm expecting a quote soon.

 

[suki243]

Really? hmm, I decided to go with the POR 15 method

 

[Platonic Solid]

I spoke to the body shop guy at the weekend. I have three alternatives:
1. Lap weld in a new foot well panel, this will be visable from below.
2. Butt weld a new foot well panel, this will be dressed and will be an almost invisible repair.
3. Glass fiber repair followed by sprayed on bed liner coating of chassis and interior floor.
Right now I favor (2) but much wilkl depand on price. I'm expecting a quote soon.

But what were the results of your cowl leak test?

 

[geordie]

Still got to get to that. Temperatures out here in Tucson are about 105 to 110 F and I can't summon up enough energy to go in the garage during the evening.