Questions about new Floor.

[FawnaFox]

Hi,
My FS-65 turns 27 this September, and I was naive enough to try to save the original floors in the bus. They were made of an extra thick rubber, that allowed skis and sharp objects not to poke holes into the floor of the bus. After I de-seated the bus and started walking in places where old seats were, I noticed soft spots.. I decided to remove the rubber floor and the original floor that the rubber was placed on top of, I discovered the infamous rotten wooden subfloor.

I need help, I have the bus down to the bare metal floor, there's rust, but no holes (besides seat bolt holes).
How do I remove the rust (Will naval jelly help?)
How and should I fill the bolt holes at the metal level?
What wood should I use for the subfloor?
Are peel-n'-stick floor tiles any good?
Is there a layer I'm missing (Yes I will put some kind of sealant on the bare metal)

 

[desrtdog]

My recommendation:

1. Strip all the old wood off the floor
2. Treat the rusted areas with a rust reformer product (lots of posts on the forum dealing with this)
3. Prime the treated floor with a product meant for galvanized metal (assuming the floor is made of galvanized steel - most are)
4. Plug all the holes … again different methods for this you can find online, but I used plastic hole plugs I got in bulk from Widgetco I believe…
5. Paint the floor with Rustoleum oil based enamel
6. Consider putting some sort of insulation down for both sound and temperature reduction.
7. Cover that with plywood or OSB, then finished flooring

Posts 5&6 of my build thread cover the demo and post 19 shows what I did for the flooring: The Dominic

 

[TaliaDPerkins]

Suggest after removing the old floor down to the metal, wire wheel/wire brush it to remove all loose rust and scaling, then vacuum and use the rust converter.

 

[FawnaFox]

My recommendation:

1. Strip all the old wood off the floor
2. Treat the rusted areas with a rust reformer product (lots of posts on the forum dealing with this)
3. Prime the treated floor with a product meant for galvanized metal (assuming the floor is made of galvanized steel - most are)
4. Plug all the holes … again different methods for this you can find online, but I used plastic hole plugs I got in bulk from Widgetco I believe…
5. Paint the floor with Rustoleum oil based enamel
6. Consider putting some sort of insulation down for both sound and temperature reduction.
7. Cover that with plywood or OSB, then finished flooring

Posts 5&6 of my build thread cover the demo and post 19 shows what I did for the flooring: The Dominic

Will be following this, thanks!

 

[nikitis]

Suggest after removing the old floor down to the metal, wire wheel/wire brush it to remove all loose rust and scaling, then vacuum and use the rust converter.

Do this ^. But additionally to do it right, you need to consider some things.

Resale possibilities. - To sell this bus down the road, and not screw over the next person that owns it, how far will you go to treat it? Do you care about the next owner?

I'll tell you the simplest and cheapest method that will give you the longest life reasonable.

Do as TaliaDPerkins suggested. Rip to bare metal. Wire wheel the floor.
Now what I'll add to do it right is to take a flat head screw driver and everywhere it's rusted, poke the floor with the screw driver. If it pokes through replace that section. Cut it out and replace with a square piece.

Anywhere it won't poke through by jabbing it into the floor is still good. This is a general automotive rust test to determine if it needs to be replaced or not. Simple to do.

Assuming that is all done and you're metal floor is in good shape now and bad parts replaced, the goal to prevent further rusting is to cover and not allow it to be exposed to air and water. Needs to be covered.

A self etching primer is good to use, and then a thick oil based paint. Thick so it covers it. If any rust areas are exposed past the paint even at a microscopic level it will spread again. Oil based paint is far cheaper than POR 15 and other preventatives. You can buy enough to do 2 coats of it, and you're done. This will make it last another 30 years. If you decided to sell it after 15 years, it's good for another life with another person for resale.

Leave the tiny holes in the floor. It allows drainage should moisture find it's way under your new insulation you'll be adding. If moisture remains under the floor it will eventually penetrate the paint so you want it to exit.

So to simplify.
1.) Remove old floor down to bare metal.
2.) Wire wheel.
3.) Do poke test all around, replace any section that pokes through.
4.) Self etching primer
5.) 2 coats of oil based black paint.
6.) repaired.

 

[desrtdog]

Agree with the comments above about wire brush/wheel on the loose rust and scale, as well as repairing obviously compromised sections of floor…also, following the instructions on the paint as far as surface prep goes.

Respectfully disagree with the suggestion to leave the “tiny” holes (from seat bolts, etc?) open to act as drains…you’re just begging for water intrusion from below (for example driving on a wet or snow covered road) to get between the insulation and bus’ metal floor…add a little road salt to that, and you have the perfect recipe for more rust to start where you can’t see or repair it without tearing apart the interior floor.

 

[nikitis]

Respectfully as well. It is my personal take that the holes can allow water in from underneath as you say but it can also exit the holes and dry out faster. If it's coated well with paint, including hole edges, it should be better than plugging them. If plugged, the first drink you spill on the floor or water tank leak, as it seeps down, it will have no where to go if plugged. Unplugged, the water won't saturate the paint as quickly because it can exit.

If you look at people who repair truck beds and other automotive rust areas, the spots that rust through the most are the spots where there is not a drain hole added and in the lowest spots in the supports. In a buses case that would be the metal floor.

Additionally most Bus C-Channels are open and water falls and dries off of them creating surface rust, but they rarely rust through like on a car or truck who instead of C-Channels use Full square tubing trapping the water in. Manufacturers put holes into the C-Channel at places but the places they rust are usually in between the holes because the water couldn't find the holes.

There's rust in both cases, but I've observed far less rust when holes are added personally on cars and trucks. I would think the principal would apply to the bus floors too.

 

[#1FordFan]

No matter what, don’t put plywood or OSB back on the floor.
Advantec Flooring is what you want to use. It is a (50 year warranty) water proof OSB. It is not much more at all compared to std OSB.