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Floor pan rust holes

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Old 11-03-2010, 11:56 AM
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mySAVIOReigns
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Default Floor pan rust holes

I've got ~10 "pin" holes in the each of the 4 floor pans (front/rear, pass./drivers) - they're all smaller than 1/4", most range about 1/8"-1/4" in diameter. Ironically the drivers side front is in the best shape.

Other than that, there's surface rust in the pans, but they're pretty solid. What would you do to fix these? Whatever I do, I'll be following it up with POR or Rust-bullet.

Thanks
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Old 11-03-2010, 01:00 PM
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john721
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I would break out the old copper bar (as backing from the bottom) and try to fill them with the MIG welder. Maybe even braze them closed. Chances are even though they appear to be pin holes, the nominal thickness of the sheetmetal around the pin hole is thinner as well. They will open up when you throw an arc to them. Worht the effort to me to put metal back where metal was. I would avoid trying to fill them with bondo, glass, JB Weld etc. Just my .02.......
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Old 11-03-2010, 01:59 PM
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001mustang
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I agree.

I would drill them out to good metal and repair w/ mig using Cu trick; small patches if required.

I've had mixed results w/ rust prevention products.

Next time I do floor I will probably paint it and inspect every 10 years.
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Old 11-03-2010, 02:11 PM
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Coupe
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I am going to go out on a limb and suggest that a hole the size of a pencil could end up over an inch by the time you get to nominal thickness. Dont try to weld up the rust holes till you know for certain. And keep in mind where the fuel line is routed while doing this.
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Old 11-03-2010, 02:23 PM
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mySAVIOReigns
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Good thinking guys - did not consider the thickness of surrounding material. Shucks...
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Old 11-03-2010, 06:07 PM
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I would cut out the section and get an aftermarket pan section and weld it in.
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Old 11-03-2010, 07:31 PM
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hightower2011
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Originally Posted by VeroWing
I would cut out the section and get an aftermarket pan section and weld it in.
That's a lot of work for a few pinholes.


I've decided to do some brazing on the pinholes I've found. I'll be using a industrial-ish torch but some people just use a combination of propane and a form of oxygen that are combined to make the flame hot enough to braze metal. I suggest you look into that option if you don't want to go all out with an industrial-ish torch. I don't know much about it, but I think you can get the kit at Home Depot or something, don't quote me on that though.

Like others have mentions, just make sure you widen the hole a bit to take car of all the rust.

Last edited by hightower2011; 11-03-2010 at 07:59 PM.
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Old 11-03-2010, 08:13 PM
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001mustang
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Default Keep factory welds when possible

I would not replace the pans for a few pin holes.

Much nicer if you can keep factory fit, seams, and welds; they are hard to duplicate.

A pin hole can easily be finished to look like factory job.
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Old 11-03-2010, 08:35 PM
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hightower2011
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Originally Posted by 001mustang
Much nicer if you can keep factory fit, seams, and welds; they are hard to duplicate.

A pin hole can easily be finished to look like factory job.
Excellent points, I agree 100%.
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Old 11-03-2010, 08:47 PM
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All good suggestions. If you find the holes too big to fill with a MIG after cleaning them back to good metal, there is nothing wrong with welding in some small metal patches over them. Once the welds are ground, it's doubtful anyone would feel them after the pad and carpet are installed.
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