Technical Strange etching from rust on floorboard?

That seems to be the prevailing theory. It isn’t that bad though so maybe happened long time ago and issue was resolved or happened more recently and didn’t get that bad.

 

Ahhh true, didn’t think of that. Thanks underside is perfect.

 

Like the last few responses. But in any case I think it looks cool like the cracks in a frozen lake.

 

I’m almost this obsessive haha! It’s a patina style truck so it’s not too big of a deal I don’t think. Just wanted to try and figure out the why and we have some pretty good theories now.

 

Reminded me of my aunt’s living room. She had my uncle put that marbled mirror stuff on a couple walls in the living room after a visit to Graceland.
I’d would have wire brushed it and applied Penetrol. Then used clear floor mats in honor of my aunt and Elvis

 

Maybe it was a flood car.
Maybe the assembler took ill,That day

 

If you get the floor nice enough you could leave the carpet out and just wear your new socks.

 

What's the age of the truck? Beginnings of varicose veins......

 

That is funny, and also a good idea haha! Penetrol!

 

Flagstone floors..... get in contact with William Shatner a good episode for his "Weird or What" program.

 

THAT'S what you get from hanging out in the Twilight Zone! Creepy!!

 

The cracked insulation pad makes sense for the pattern, but I do wonder what it was that ate the steel away but didn't make it all pitted. If it was a farm truck, lots of chemicals get used on farms/in barns that could get spilled or tracked in with someone's feet. Who knows.

That floor shape looks like a 60's Chevy/GMC to me.

 

Either a cracked insulation pad, or one with trapped air pockets formed in the lines. The sticky stuff would have protected the metal it was stuck to, but where the cracks or air pockets were, the metal was not protected. If the heater core leaked, the coolant could have ran down the firewall and into the cracks/air pockets causing the rust lines you see.

For the record, most rust belt rusted out floorboards were rusted out from inside of the car or truck. People would get in the vehicle with salt mixed snow on their boots or shoes, the snow would melt into the carpet, and the jute backing under the carpet would soak up that saltwater mix and hold the wet mix against the floor pan for as long as 2 weeks after the event. The only places the floor would rust out from the bottom up would be places the salt water was held against the floor and couldn't drop or run off. I spent 30 years replacing rusted out floorboards, 90% rusted from the top (inside the vehicle) down.

 

Metal mites.

 

That makes a lot of sense. Probably the best explantation on floor board issues we’ve gotten. It’s just weird to me that it wasn’t worse.

 

I thought about that too. It was weird though that the original carpet was in such good shape and the seat on the passenger side was near perfect. It’s a gm floor out of a c10

 

I can't believe you covered it up. Now nobody will ever see it! You coulda charged .25c to ppl at shows, a legit Ripley's "Believe It Or Not" display down the drain.

 

I’m guessing the judges at your car shows have different expectations than any I’ve ever been. However I don’t own or build AMBR or Riddler style vehicles.