What have I done… rusty floor

[olivemartini]

The rest of the bus is rust free. I mean for real. I pull up the floor to find this… is this a lost cause? Is it fixable and I’m being dramatic?? Helping me please

[rossvtaylor]

Really, the plywood is the floor structure and the metal appears to be a substrate to protect the plywood from the bottom. It's not unusual for moist wood, even slightly moist, against metal to cause rust.

If you take that crowbar and push the straight end into the metal, does it penetrate? In other words, is there still sound metal there? Regardless of your findings, this is certainly a fairly minor issue as long as the frame and ribs below it are as you describe.

Breath!

[musigenesis]

That surface rust is normal and not a big deal. You might have a few small spots that need to be cut/squared up and patched with new sheet metal, but probably not. Treat the rust with Ospho or other rust converter, prime with Rustoleum rusty metal primer and paint it, and you'll be good to go.

Check out my build thread if you want to see what really bad floor rust is like.

[Lasagna Dave]

If it were me I think I would put on a respirator and some eye pro, then hit it with a wire wheel. Look for the thin spots but otherwise I think you would probably be pretty surprised by how you feel about the floor afterwards.

[olivemartini]

Alright guys, wire brushing today and tomorrow. Wish me luck!

What would you all suggest for patching holes?

[musigenesis]

Originally Posted by olivemartini

Alright guys, wire brushing today and tomorrow. Wish me luck!

What would you all suggest for patching holes?

Wire brushing is a PITA. Use Ospho and let the chemicals do the work for you.

Best way to patch holes is to square them up and weld in new sheet metal. If you're not set up to weld, screwing patches of sheet metal will work OK, too.

[Mr4btTahoe]

Originally Posted by olivemartini

The rest of the bus is rust free. I mean for real. I pull up the floor to find this… is this a lost cause? Is it fixable and I’m being dramatic?? Helping me please

That's a pretty standard find actually... do don't panic.


First, finish getting everything out... sweep up the mess and see what you've got. Then order you some rust prep of your choice (Ospho, Coroseal, etc..) Follow the instructions. We used Ospho with good results... its ~$25/gallon at ACE hardware and goes a long way. We did 3 treatments of the entire floor... patched up some small holes and then painted with a heavy oil based paint.


Once the rust has been stopped... and a good layer of paint put down, you'll be good to go.


This is a great example of why it's always a good idea to pull up the floor. You would have never known and holes likely would have formed relatively soon.

[olivemartini]

So did you guys do ospho before scrubbing?? Or just ospho and skip scrubbing all together?

[Mr4btTahoe]

Originally Posted by olivemartini

So did you guys do ospho before scrubbing?? Or just ospho and skip scrubbing all together?

I swept everything out... then pressure washed everything. Opened the windows/doors and let it dry out for a day. Then went straight to ospho. No wire brushing or wire wheeling. The pressure washer removed all of the loose rust and junk. Each application of Ospho takes 24 hours. I sprayed it down (MUST use proper PPE when working with these chemicals).. let it do it's job. Recoated the floor 2 more times and allowing to cure. Swept the floor again and painted.

[musigenesis]

I scraped off the loose scale with a painter's tool and then brushed the Ospho on with a big chip brush. I prefer this to spraying because you don't get any phosphoric acid mist floating around (you still want to use gloves and a respirator, though) and the process takes very little time no matter how you do it. Then come back next day and scrape various spots with a screwdriver; as long as you're still scraping up brown powder (rust), you need to keep applying it. As Mr4btTahoe say you'll probably need at least three coats - my floor took twice as many in some places.

Then I wiped the whole floor down with mineral spirits and primed with the Rusto rusty metal primer. After that dried/cured (took a day or so to make sure) I painted with two coats of Rusto industrial enamel. I did this in winter barely above 50°F so the enamel really took at least two days (per coat) to cure. In summer and warm temperatures it shouldn't take as long.

[musigenesis]

Some folks recommend POR-15, but my experience with it is that it doesn't adhere at all to metal that still has Ospho residue on it - peels right off like a separate layer of rubber (it's also really expensive and absolutely foul to work with). Rusto primer has no trouble sticking to ospho-y steel.