Question about sealing the floor

[surfskool]

I tore up my skoolie's floor and, as most people here, found that the plywood was rotted out.
My approach to sealing up the floor has been a bit scattered because I'm taking advice from too many sources.
First, I used an angle grinder to get rid of *most* of the rust, but some of the thin sheet metal seemed to be more rust than metal.
Then I took the advice of a friend and used a spray paint that was supposed to convert the rust back into metal.
Then I used a thin coat of rust resistant paint. My three little neighbors (4, 8 and 9) helped me paint so it was a bit chaotic and had lots of little shoe prints/slide marks
Then on the advice of a friend I ground around the holes (where the seats were attached) and we welded up the holes (some with metal plates, some just with welding).

So now what I've got is a floor with some rust conversion spray, some rust resistant metal paint, some bare spots that were ground out and welded.


So the question is, what would you use on top of this mess to properly seal the whole thing?

I got two 6 mil vapor barriers on the advice of a Home Depot employee, but then another (perhaps more knowledgeable?) friend suggested using POR 15 instead- he said that having a plastic vapor barrier against metal was like putting plastic gloves on your hands- soon the moisture would make the whole thing wet and rust it out. So he said POR 15 then plywood, then the padding and carpet I've got.

I know there are lots of threads on sealing the floor, but I'm wondering if anyone has expertise to advise me given the fact that I've already thrown a hodgepodge of crap on this floor (see the part in bold above). I am happy to report that I think all the major holes in the floor are sealed, now it's just time to deal with leaking windows and such.

Thanks in advance for any help, I'm so excited to have found this site!

 

[Josiahdr]

So now what I've got is a floor with some rust conversion spray, some rust resistant metal paint, some bare spots that were ground out and welded.


So the question is, what would you use on top of this mess to properly seal the whole thing?

Welcome! Do you have pics of the current condition of the floor?

 

[surfskool]

ahh, well...
picture a very sloppy white paint job with children's footprints all over it
I suppose I could go take one, but that's about what it looks like at the moment...

 

[surfskool]

I'm considering getting something like this:

Eastwood Rubberized Rust Encapsulator - Black Aerosol

or this:

Custom Building Products RedGard 1 Gal. Waterproofing and Crack Prevention Membrane-LQWAF1 - The Home Depot

 

[Josiahdr]

Well if the paint job is that bad I would do another coat.

If there is no more visible rust then no point of POR15~Based on my knowledge.

If the paint job is just messy but is a good coat, then keep it and start putting in your choice of sufloor/floor.

Without seeing it that's my $0.02

 

[Robin97396]

Aren't you putting any insulation under the plywood?

 

[Docsgsxr]

I agree with robin, you should at least add 1/2" foam insulation to the floor for if nothing else, added sound insulator. Plus if you are in a colder climate, it will help tremendously with keeping feet from getting cold-er-ish.

 

[surfskool]

I'll be putting padding and carpet above the plywood. My uncle just removed carpet from his house and gave it to me. It's still in pretty good condition.

Do you think that would suffice, in terms of insulation/sound barrier? I also got some rubberized sound barrier that I'll spray around joints and cracks.

Thank you all for your opinions and help! I'm so excited to have found this site!

I think what I've decided to do is do the Por 15 on spots where the paint is scraped/ground away/thin, then the plywood, then great stuff in any cracks, then carpet padding, then carpet.

Luckily it rained yesterday so I got a good look at any spots where water was coming in, and sealed those with the Right Stuff (my neighbor swears by it).

 

[aaronsb]

Lay down as much insulation as you can stand to lose in head room.

For any areas that you converted rust, check to see how well it "converted" by using a scraper on a small spot. If the rust was too deep, it'll have the very surface converted and a layer of rust existing under. You have to remove all rust to keep it from growing.

Por15 is a pretty expensive paint to throw on the floor, and is happiest when it is touching bare metal or oxidized surfaces.

Also, every spot that you welded from the top side should get dressed, cleaned, and painted from the bottom side because those points will begin to rust as well.

 

[surfskool]

Thank you. It sounds like you know metal.
I'll get under the bus and paint those spots with POR 15 today.

I think most of the spots "converted" pretty well- I got most of the rust off before spraying. But there is one spot that I'm sure wouldn't pass your scrape test.

I'm going to do it right though---- no use being lazy now only to have to do it again in a couple of years.

I've got until Saturday to get the floor right and my neighbor has offered the use of his sandblaster.

Also…about bolting down the plywood…I'd rather not- I just got the whole thing sealed up and I see every bolt hole as another festering wound that will rust my bus floor. Can I get away with just laying down the plywood with Good Stuff around the edges? I get that the floor might not end up perfectly even, but I'd rather have that then more rust.

As far as insulation--- I wanted to save some of my insulation room for the roof. I'm thinking of putting a layer of cork board on the ceiling (to be secured by a band of metal - my dad can bend it to fit the curve of the ceiling). I'll also be staying away from cold areas, though I may be in hot areas a lot. I'm painting the roof with that special paint additive that nasa uses - ceramic beads or something? And I've got a good A/C in the back.

 

[slaughridge85]

Just remember, insulation is very important in places where the climate is hot as balls too... Keeping your conditioned air cool and such...

 

[surfskool]

Maybe I'll put a layer of insulation above the plywood instead of below--- anyone have a reason why it should be below the plywood?

 

[Robin97396]

Yeah, because insulation is soft. It will compress in traffic areas if it's not covered with a hard surface to spread out the weight.

 

[Robin97396]

Or were you joking?

 

[katix]

can i use redgard on top of por-15?

Good morning! This summer I'm removing moldy old carpet that's been in my skoolie for decades. After patching holes I plan to paint the bare metal floor with silver Por-15, then I was thinking RedGard shower sealant next, a layer of hard insulation, and wood on top, colored wood stain, and finally either clear polyurethane or epoxy. I did a google search asking if I can paint Redgard on top of Por-15, and wouldn't you know, this thread showed up! I should have looked here first!

Has anyone tried that? Can RedGard shower sealant go directly on top of Por-15?

(And if you have any questions about what breathing black mold for years does to the body, I'd be happy to go on and on about that.)