Life in Limbo

[livinginlimbo]

The story so far:

A few months into Covid quarantine felt like the right time to start this project that I’ve always dreamed of. I got this bus (2006 Ford E350) pretty cheap ($2000) and pretty close to where I live (Ontario). After ripping out the rotting floor, I found out why it was so cheap: rust. The frame is covered in rust.

https://imgur.com/gallery/2fUjprg

I have time and elbow grease to spare, but I’m trying to keep the cost as low as possible.

If anyone has any advice on how to deal with the rust, and reinforce the frame, I would love to hear it! The plan right now involves a lot of cleaning with wire brushes and then welding in some new cross beams in conjunction with the old ones.

I would love to hear everyone’s thoughts!

[dwood443]

That is a lot of rust and if you are going to move forward with it I’d suggest using a power washer and pick up a sand blaster attachment for it. I used one on my floor to get in the corners and hard to reach places. Stay away from the windows though. I accidentally shattered one of my windows using it

[livinginlimbo]

Originally Posted by dwood443

That is a lot of rust and if you are going to move forward with it I’d suggest using a power washer and pick up a sand blaster attachment for it. I used one on my floor to get in the corners and hard to reach places. Stay away from the windows though. I accidentally shattered one of my windows using it

Oh wow, great advice, I would not have even considered the windows! I was thinking about sandblasting, my only concern was trying to contain the sand. I just have my bus parked in my driveway and I don’t want my neighbours to hate me for getting sand all over their yard!

[dwood443]

That’s what so great about the power washer. No dust. The sand blaster attachment is $20 - 50. Just keep the sand dry.

[BeNimble]

Doesn't look that bad, but hard to tell from pics. The flat top side is not where the strength is for the floor, it is the vertical sides, so if they are solid, probably ok.

To sand blast with a pressure washer requires like a 6gpm unit, double of your typical one. You can rent the big ones. You might try just straight water and see if that removes the loose stuff. It still makes a mess.

[Oscar1]

Originally Posted by livinginlimbo

The story so far:

A few months into Covid quarantine felt like the right time to start this project that I’ve always dreamed of. I got this bus (2006 Ford E350) pretty cheap ($2000) and pretty close to where I live (Ontario). After ripping out the rotting floor, I found out why it was so cheap: rust. The frame is covered in rust.

https://imgur.com/gallery/2fUjprg

I have time and elbow grease to spare, but I’m trying to keep the cost as low as possible.

If anyone has any advice on how to deal with the rust, and reinforce the frame, I would love to hear it! The plan right now involves a lot of cleaning with wire brushes and then welding in some new cross beams in conjunction with the old ones.

I would love to hear everyone’s thoughts!

The rusty cross members that supported the floor should be bolted or clamped to the bus chassis, you can weld together new cross member framework but they should not be welded to the bus frame. Welding on the frame will weaken it. Good luck with your work.
Stay safe

[livinginlimbo]

I've found a contact (a family friend) who is willing to help me out, and do some soda blasting to remove the extensive rust on the frame and chassis! So the next step is getting Limbo to their shop, which is about an hour drive. I want to put down some sort of temporary floor for the drive (for safety and so it won't be so loud). So I'm thinking I should just go out and get the plywood that will eventually become the floor, and strap it down for the drive.

I see that most conversions still have the sheet metal beneath their plywood subfloor, but my metal floor was too rusted to salvage and I've stripped it right down to the frame. I think I will probably just treat some plywood with waterproofing paint and put it down on the frame, without reinstalling any sheet metal. Anyone have any advice on how thick the plywood should be if I don't plan on having a metal floor beneath it? Any reason this is an awful plan, waiting to bite me in the future?

[JackE]

I would go with 3/4" pressure treated T&G plywood. I don't think you will have any problems down the road, at least not for many years. You can always have someone spray a healthy layer of undercoating or even truck bed liner on it when you are done with the build for added protection from the road elements.

[livinginlimbo]

Originally Posted by JackE

I would go with 3/4" pressure treated T&G plywood. I don't think you will have any problems down the road, at least not for many years. You can always have someone spray a healthy layer of undercoating or even truck bed liner on it when you are done with the build for added protection from the road elements.

I’m definitely thinking 3/4”, but I’ve heard that pressure treated doesn’t always play nice chemically with the metal. I’ve also heard others recommend Raptor Bed Liner for the underside. I’m thinking 3/4” plywood on the bottom, rigid foam insulation, and 1/2” plywood on top.

[Jolly Roger bus 223]

3/4 inch thick marine grade plywood at a minimum is my opinion? for your intentions.
my personal opinion if it were mine is different and i dont live anywhere near your area?
so take that with a grain of salt?
NO PUN INTENDED??????
wish you luck.
sand/soda/dry ice blasting will deffinetely show the problem areas to be fixed and usually more than visual if done correct?

ospho and several brands neutralise the rust and for the not so bad areas LOCTITE makes a spray on converter that seams good and has lasted on my old truck frame for 5 years now but then again i am not in your area?
workiing on my old truck i was introduced to a product by a friend that works on boats and trailers called fluid film that is widely used as vehicle undercoat in the northern states and it isnt cheap but it does what it says it does and if it matters to you every bit of it is plant based except the aerosol if you buy it in a paint can but they sell it in five gallon buckets that can be applied with a garden pump sprayer(idea) paint sprayer if you have access?
to me the stuff stink but it did what i was asking of it and that was after wd and pb or a combination but have gone to it for several other projects and it needs saturation time of course but it is starting to suprise me?

[musigenesis]

Modern PT lumber uses compounds with high copper content, which makes it bad for steel thanks to galvanic corrosion. I don't think PT plywood would instantly eat through your frame like Alien blood or anything, but it's something to consider for the long-term health of your bus. Even in house construction, PT is generally used as a way to quickly build something (quick because you don't need to prime and paint it), at the cost of its having a definitely finite lifespan.

[livinginlimbo]

I’m definitely leaning towards using marine grade plywood. Has anyone experienced any issues with marine grade plywood reacting negatively with the steel like PT plywood?

[joeblack5]

Our low floor city bus has wooden floor that are coated at the bottom side.
Then the well regarded Crowns have wooden floors .. so it cannot be all that bad.


Actually i think that having a metal floor i asking for problems unless you have real good ventilation and drainage between the metal and the wood. My though that the school buses have a steel floor for fire barrier reasons in case of accidents and that they well knew that they would rot out.. Is that not the basis of our current economy.


I would take thin plastic, as in shower wall stuff, insulate and then put a painted marine grade floor on top. The pressure treated stuff is not very flat or appealing .


Good luck

Johan

[BeNimble]

The shuttle buses are just plywood on metal grids on top of the frame rails,
My 1999 is now 20 years old, and the plywood has no issues at all from underneath.
They will dry out if wet, the problem occurs when they CAN'T dry. I would not use pressure treated, and all plywood is 'marine' waterproof glue today, the difference today is marine plywood doesn't have voids in the plys, not needed for this kind of application.
I'm pretty sure it is 3/4 inch, yep. Now note they don't put tile down on it, just rubber mat, so it doesn't need to stay perfectly flat for a kitchen table.

[Jolly Roger bus 223]

Originally Posted by joeblack5

Our low floor city bus has wooden floor that are coated at the bottom side.
Then the well regarded Crowns have wooden floors .. so it cannot be all that bad.


Actually i think that having a metal floor i asking for problems unless you have real good ventilation and drainage between the metal and the wood. My though that the school buses have a steel floor for fire barrier reasons in case of accidents and that they well knew that they would rot out.. Is that not the basis of our current economy.


I would take thin plastic, as in shower wall stuff, insulate and then put a painted marine grade floor on top. The pressure treated stuff is not very flat or appealing .


Good luck

Johan

joe. not to single you out but there is another thread i sent your way about the mercedes engine.
they are looking at buying a bus with one and i i asked them to PM you.
you are more than welcome to PM me a finger or whatever but but with you owning a mercedes motor i thought you would give the best advice.

[Oscar1]

Originally Posted by BeNimble

The shuttle buses are just plywood on metal grids on top of the frame rails,
My 1999 is now 20 years old, and the plywood has no issues at all from underneath.
They will dry out if wet, the problem occurs when they CAN'T dry. I would not use pressure treated, and all plywood is 'marine' waterproof glue today, the difference today is marine plywood doesn't have voids in the plys, not needed for this kind of application.
I'm pretty sure it is 3/4 inch, yep. Now note they don't put tile down on it, just rubber mat, so it doesn't need to stay perfectly flat for a kitchen table.

What is your source of information in saying that all plywood is marine and waterproof? I find that extremely hard to believe when Home Depot grades their plywood as exterior, exposure levels 1 and 2, structural and cabinet grade. When members are stating fact or opinion it would be nice to say so, fact-quote source, opinion-in my opinion.
Just my opinion
Thanks

[musigenesis]

Originally Posted by livinginlimbo

I’m definitely leaning towards using marine grade plywood. Has anyone experienced any issues with marine grade plywood reacting negatively with the steel like PT plywood?

Any wood that isn't pressure-treated won't cause corrosion - with the exception of the situation where wood absorbs water and then holds it against metal for a prolonged period of time (which is how the plywood floor of a regular school bus manages to rust out the steel floor underneath it). Since your plywood will be on an open frame, that won't happen.

[musigenesis]

BeNimble brings up an interesting point here. Plywood is not waterproof - if it comes in contact with water plywood will absorb it, but if it is then allowed to dry out no rot will occur. In the role of a bus floor on an open frame, the underside would always be able to dry out after a drive in the rain, and it would potentially last for a very long time without degrading (perhaps decades although this would depend on the humidity of wherever you live), even if completely untreated (like, no primer or paint or anything). In fact if you treat the underside at all, the possibility exists that the coating or sealant you use (if it's ever compromised in spots) will end up trapping water in the plywood and preventing it from drying out, leading to rot.

One material I would not use for an open floor (and I don't think anybody would, but who knows) would be OSB. One of the interesting differences between plywood and OSB is that in dry climates they both dry out equally well after a soaking, but in humid climates plywood will dry out much faster than OSB. But it gets worse for OSB: if plywood is soaked and then dries out, its ability to dry out in the future will remain unimpaired, but once OSB gets wet (a single time), its ability to dry out (called permeance) will be less than before. If it gets wet again then its permeance will be lowered even further, etc. etc. until you have just a wet pulp.

[BeNimble]

Originally Posted by Oscar1

What is your source of information in saying that all plywood is marine and waterproof? I find that extremely hard to believe when Home Depot grades their plywood as exterior, exposure levels 1 and 2, structural and cabinet grade. When members are stating fact or opinion it would be nice to say so, fact-quote source, opinion-in my opinion.
Just my opinion
Thanks

Everything I say is my opinion..if you find something hard to believe, check it for yourself..the very first page of a google search, at least it didn't take me long to reply. Having worked on my boats, plywood is something you learn about. Doesn't mean my opinions are always right, or google results either.
The fastest way to find out 'facts' is post false ones, like a School Bus is safer because its made of metal. ;)


"There can be no voids or holes hidden on the inner layers of marine grade plywood. Accordingly, it is denser and stronger than exterior plywood. The edges tend to cut and sand cleaner than the standard plywood. Marine plywood is intended for use in boat building or other marine applications."

" Marine grade uses exterior adhesive. Incidentally, this is the same adhesive as used in the inexpensive construction CD-X plywood or any other ..."

[livinginlimbo]

Thank you so much for the help everyone! I’ve pretty much decided on using marine grade plywood and coating it with truck bed liner on the underside.