Holes in Floor

[TannerLittle]

Hello, I've finished ripping out the old floor of my bus to find many holes in the sheet metal base layer. My current plan is to clean and grind/polish the holes then apply rust converter and aluminum tape, however some of the holes may be too big for this. Please let me know if you have any advice on how to proceed.

[peteg59]

If you plan on keeping it for any length of time, your plan will leave you wishing you'd done more initially.

That rust looks fairly extensive and doing basically a "bandaid" to "fix", won't last long.

Those rust holes should be ground out to get to good non rusted metal.
Then metal patches should be welded in.

While that suggestion will take longer to do, it will buy you years of future safe use down the road.

Good luck...

[musigenesis]

Yeah, this rust damage is much worse than something you can tape over. I second peteg59 about cutting these holes away until you get to clean metal and then welding floor patches in place. Check out my build thread for a whole lotta this kind of action.

If you don't want to get into welding, you can just attach the patches with self-drilling/tapping sheet metal screws (Teks makes really good ones). If you do want to get into welding: awesome! Your bus there will give you lots of practice. You should be able to get a decent mig welder + Ar/CO2 bottle + gear for around $500; a flux core welder will be cheaper (and cheaper to operate since you don't need to futz with the gas) but a bit more difficult to use.

[BeNimble]

Is this metal structural? Isn't there structural members under it that support the floor?
Need to make sure those are not rusted.
Looks like its the door entryway, so you don't want flex there, with thick plywood it would be ok if structural members are good.

[TannerLittle]

Thanks for the suggestions. There are structural members underneath that seem to be in okay condition and there isn't much flex in the sheet metal flooring.

I ended up grinding all of the holes and any visible rust then applying rust converter over the entire surface. Then I filled all of the smaller holes with silicone and secured them with aluminum foil tape. For the larger holes and rusted-away areas, I put a bead of silicone around the holes then a bead of construction adhesive around that and screwed larger patches of galvanized steel over it.

After all of this, I just put down the first layer of Tremclad paint and primer. I will put another layer or two before putting down the insulation and subfloor.