Powdered Comanche? Yes, please!

[NC Tom]

I'm the first admit that I am slow to finish a project. I had an art teacher in high school named Mabel Bullock. Mrs. Bullock once described me thusly: "Tommy, you are slower than molasses in the winter time!" I can't disagree. However, ADD had not been labeled in the 80's and I was definitely a distracted kid.

 

I mentioned this because I post project updates sporadically, or not at all. I am trying to do better because the feedback here is usually valuable and many of you are just flat-out Comanche nerds and like seeing what others are doing.

 

So, I have been following the guides and comments about floor pan repair. Mine weren't too bad. I've cleaned, coated and Bondo-ed the holes. I sprinkled baby powder this morning because we're expecting rain tomorrow. I'm really interested to see how well the Magical Powdered Comanche can magically reveal the leak locations!!! I'm kidding. I know how it works. It's just a clever idea.

 

 

[Pete M]

without the powder trick I would never in a million years found a couple of the pesky leaks

[NC Tom]

1 minute ago, Pete M said:

without the powder trick I would never in a million years found a couple of the pesky leaks

That's what I expect. I did go around with a brush and some flex seal to address tight areas like inside the rear windshield, vent windows and the antenna. Guess I'll know something Monday.

[89 MJ]

10 hours ago, NC Tom said:

I've cleaned, coated and Bondo-ed the holes

Please tell me you cut out the rust, welded new metal in, then did the bodywork over the welds and didn’t just put filler straight over rust holes because that’s a temporary repair that’s just going to speed the rust up.  
 

9 hours ago, NC Tom said:

I did go around with a brush and some flex seal to address tight areas like inside the rear windshield, vent windows and the antenna

From the inside or the outside? If you did this from the inside, the flex seal is going to hold moisture up against the metal and cause worse rust issues. 

[NC Tom]

On 9/5/2026 at 8:52 PM, 89 MJ said:

Please tell me you cut out the rust, welded new metal in, then did the bodywork over the welds and didn’t just put filler straight over rust holes because that’s a temporary repair that’s just going to speed the rust up.  
 

From the inside or the outside? If you did this from the inside, the flex seal is going to hold moisture up against the metal and cause worse rust issues. 

Well, everybody has opinions on how to do this. I read a lot, because the largest hole was fist-sized, welding was not really needed. I wire brushed the interior, coated the areas needed with KBS Rust Seal, as it's a chemical match to POR15 only cheaper. Let all that stuff dry and then used a metal Bondo patch with Bondo filler to repair the "big" hole. Small holes, pin holes, etc., just got Bondo. I used the KBS liberally, inside and out to help encapsulate the rust.

I would have preferred to just get new pans welded in. My budget doesn't allow that and I didn't want to keep driving it as it was, so I did what I did.

The Flex Seal was applied on top of the KBS and Bondo and some other rubber areas. Not against metal.

It's not perfect, however, it will easily last for as long as I own her.

[89 MJ]

Ok, as long as the rust was slowed way down or stopped with that rust seal, you’ll be good for a while. It’s not “the right way”, but it’s definitely better than before and will hold it until you decide to replace the pans, if ever. 

[dasbulliwagen]

One odd leak point I've seen on two of them is around the big electrical connector that goes through the firewall on the left side. The seal dries up and shrinks allowing water through. I've been fairly successful in adding flowable clear silicone sealant to get the leaks to stop.