The Murder Bus...

[kidharris]

Originally Posted by banman

In your case, with your bus, probably so... not so with my bus -- I'm really surprised how the galvanizing is "like new" right next to metal that is pitted.

I will only wire and paint the rusty areas -- probably no point in painting the shiny galvanized -- no reason to acid etch the good layer of zinc...

The I'll have to decide what (if anything...) to do about the zillion little holes in the floor -- part of me ponders the value of letting it breath/drain in case it does get wet in the future...

Tny holes are going to allow the water to soak thru and coat the bottom. What is the source of the water? Can you stop it?

Maybe a zinc rich paint could be of use over the slightly damaged galvanized metal after clean up.


Vinegar is such a mild acid that, on new metal, you can't hardly tell that you even washed/etched it with the white vinegar. Don't know about badly rusted metal, but the ospo should allow you to paint over the galvanized without further etching.



If you can't completely remove all moisture there are several roofing products that allow air to circulate air between layers and exit thru vents in the top layers. The products usually involve small channels made into the layer, ceramic granules, or a fibrous mat that allows the air to move. Maybe put down one of these layers before you install the plywood.

[banman]

Originally Posted by kidharris

tiny holes are going to allow the water to soak thru and coat the bottom. what is the source of the water? can you stop it?

read post #192

maybe a zinc rich paint could be of use over the slightly damaged galvanized metal after clean up.

if you can't completely remove all moisture there are several roofing products that allow air to circulate air between layers and exit thru vents in the top layers. the products usually involve small channels made into the layer or a fibrous mat that allow the air to move. maybe put one of these layers before you install the plywood.

I'll certainly try and stop any water ingress that I can find...

Pondering the future of the Murder Bus -- the nail holes in the floor would only allow water to get in if I'm driving in a severe downpour, or fording creeks... I'm not sure either of those events will actually ever happen while I'm driving. That means the holes in the floor might actually be a great set of well spaced drain holes if I ever get a bunch of water coming in from above like leaving the roof vents or one of 24 windows open or the windshields defying the ability to be properly sealed, or...?

I will probably do a ½" of dense foam for sound/temp insulation covered by 5/8" cdx plywood and a linoleum pattern for the living area. There's some fun patterns of linoleum out there now...
In theory any water coming through a leaking window would drain down and out -- it won't hurt the foam, it won't reach the ply.

The other possibility here is that with a ½" of foam sitting on top of the metal floor; the holes in the floor are covered/sealed by the foam with the weight of the plywood and the build out on top of that.

I'm just pondering that the effort of filling the holes in the floor is a potential waste of time depending on how you insulate the floor...

[kidharris]

Originally Posted by banman

I'll certainly try and stop any water ingress that I can find...

Pondering the future of the Murder Bus -- the nail holes in the floor would only allow water to get in if I'm driving in a severe downpour, or fording creeks... I'm not sure either of those events will actually ever happen while I'm driving. That means the holes in the floor might actually be a great set of well spaced drain holes if I ever get a bunch of water coming in from above like leaving the roof vents or one of 24 windows open or the windshields defying the ability to be properly sealed, or...?

I will probably do a ½" of dense foam for sound/temp insulation covered by 5/8" cdx plywood and a linoleum pattern for the living area. There's some fun patterns of linoleum out there now...
In theory any water coming through a leaking window would drain down and out -- it won't hurt the foam, it won't reach the ply.

The other possibility here is that with a ½" of foam sitting on top of the metal floor; the holes in the floor are covered/sealed by the foam with the weight of the plywood and the build out on top of that.

I'm just pondering that the effort of filling the holes in the floor is a potential waste of time depending on how you insulate the floor...

My experience, in 30 years of roofing, is that water does not "drain" from holes smaller than .25 inch. It seeps thru the holes and spreads out/runs on the surface until it hits a bump or something that allows it to drip off. I believe it is the waters surface tension that keeps it from just falling off. In addition capillary action will actually pull water uphill if 2 surfaces are close enough to each other.



If you leave galvanized sheet metal stacked up outside and allow it to get wet for an extended time so that it gets wet repeatedly the sheets will actually suck water in between them and trap it there. The surface tension keeps the water in between the sheets and the zinc will corrode to a white powder and then the steel will start rusting and ruin. I had my own sheet metal shop and I have seen a lot of metal wasted that way. My advice is seal the nail holes (top and bottom), seal the metal with paint and provide some ventilation for the wood and the metal to dry if it ever gets wet again. Not being able to dry out is the reason all of these bus floors are rusted in the first place. Galvanized (G90) will last a very long time if it is allowed to dry out quickly such as being outdoors and exposed to rain.


BTW, galvanized steel is easily soldered with a hot copper iron and 50/50 solder as long as it is not bare or rusty steel. Use sal ammoniac bars to tin the hot iron and diluted muriatic acid applied with a small acid brush for a cleaning flux. Paint the areas you want to solder with the acid. If the acid just turns the galvanizing grey it is about the right strength. If the acid turns the galvanizing black right away, then dilute it some more. Immediately apply the hot iron to the sheet metal until the metal is hot enough to melt the solder and solder guickly moving the iron along the metal, flow the solder so that it covers all of the acid/flux. When the iron gets too cool put it back in the fire to heat back up.

When done, rinse with a wet rag to remove any flux remaining There are many fluxes available that are easier to use, especially the ones with powdered solder mixed in, but they are expensive.

You can buy the copper irons (buy one with a wood handle if you can) and 50/50 solder bars on ebay or amazon. You can heat the iron with propane, natural gas, charcoal etc. When heating the iron it is ready when the flame starts to turn green (copper burning). If you are not ready, you must remove/back off the iron from the heat or you will ruin the tinning, the iron will get pits in it as the copper burns and you will have to file/reshape the copper iron surfaces back flat and re-tin it. Do not breathe fumes from the acid or the sal ammoniac block, you won't do it but once and you will not want to do it again. Worse than smelling salts. Electric irons are available but expensive.

I don't have a heating station any more, so I use an old brake drum or cast iron skillet to hold the charcoal and iron. If you have a lot to do get a second iron so that one is always hot. Bigger irons hold more heat but are more difficult in tight places/corners.

Do not use a torch to apply heat to the sheet metal. It is too hot and will cause the zinc to burn and the metal to warp very quickly. Seems everybody has to try it once to see for themselves because they think it will be faster. If you have an under coating I wouldn't try to solder the holes because it will probably mess up the under coating.


Caulk has pretty much taken over most of the soldering applications in construction now a days, except for copper work.

[musigenesis]

I don't think very much water would come up through these holes from the underside, but I think you'd get a situation where the holes would clog up with dirt and mud which would retain moisture against them. You'd end up with these little fairy circles of rust spreading outward from each hole, similar to what seems to happen with rust on chassis rails.

I bought a bunch of 1/2"x1/8" flat bar with the intention of creating a small sort of gutter around the base of the floor. I was going to drill a few small drainage holes through the floor inside this gutter, so that any water coming down the walls couldn't accumulate and damage my interior. I gave it up because I couldn't think of any way to protect these holes on the underside.

I think also if you ever power-washed the bottom, you might get some water being forced in through the holes.

[banman]

Originally Posted by kidharris

My experience, in 30 years of roofing, is that water does not "drain" from holes smaller than .25 inch.
SNIP...

Caulk has pretty much taken over most of the soldering applications in construction now a days, except for copper work.

You are very right about the capillary action and the nail holes probably being too small to be effective as drains. The bus-seat-holes are ¼" or bigger but...

As to the old school methods of tin-smithing I haven't done that since high-school-shop class...
Good write up on the method. I greatly enjoyed blacksmithing when I learned it -- another not very portable hobby of mine...

Indeed -- a dab of urethane spooge would make better sense for all the nail holes...

Originally Posted by musigenesis

I don't think very much water would come up through these holes from the underside, but I think you'd get a situation where the holes would clog up with dirt and mud which would retain moisture against them. You'd end up with these little fairy circles of rust spreading outward from each hole, similar to what seems to happen with rust on chassis rails.

I bought a bunch of 1/2"x1/8" flat bar with the intention of creating a small sort of gutter around the base of the floor. I was going to drill a few small drainage holes through the floor inside this gutter, so that any water coming down the walls couldn't accumulate and damage my interior. I gave it up because I couldn't think of any way to protect these holes on the underside.

I think also if you ever power-washed the bottom, you might get some water being forced in through the holes.

I think with the foam held down by the plywood there'd be no room for mud and debris but...

for mentioning the power-washer. That IS always a possibility -- I don't like doing maintenance on a dirty, muddy vehicle...
Guess I will seal all the nail holes... But, now for a long bicycle ride -- before it gets tooooo hot out!
Gotta earn my beer...

[musigenesis]

Originally Posted by banman

I think with the foam held down by the plywood there'd be no room for mud and debris

I meant the little hole itself would fill up with mud and then rust would start at the inner rim of that hole.

[TJones]

I think sealing the nail and bolt holes is a good idea. I think a thick layer of the appropriate foam safe adhesive between the floor and the foam would fill any voids where water could accumulate. No moisture or air = no corrosion. The factory plywood acted like a sponge and held the moisture in place.

Ted

[Native]

Ditto what TJones et. al. have said. I welded all of my holes up before putting new ones in when adding furring strips in for the flooring.

[banman]

Originally Posted by Native

Ditto what TJones et. al. have said. I welded all of my holes up before putting new ones in when adding furring strips in for the flooring.

Grump, grump, grump -- work, work, work...

[Native]

LOL... but sooooo true!

[joeblack5]

I see very little use in the steel floor. Some crowns.. Transit buses and coaches have only wooden floors. They seem to hold up longer then the almost always rusted floors of modern skoolies... My theory is that the main reason for the metal floor was a fire barrier.
I would use marine ply ..paint it from the bottom and make bigger holes in the steel floor with a hole saw.
Water will get in ..it is not if ..but when.. And it can not get out..so the outcome is clear.. 15 years from now you have the same rusty floor.

Johan

[banman]

Originally Posted by joeblack5

I see very little use in the steel floor. Some crowns.. Transit buses and coaches have only wooden floors. They seem to hold up longer then the almost always rusted floors of modern skoolies... My theory is that the main reason for the metal floor was a fire barrier.
I would use marine ply ..paint it from the bottom and make bigger holes in the steel floor with a hole saw.
Water will get in ..it is not if ..but when.. And it can not get out..so the outcome is clear.. 15 years from now you have the same rusty floor.

Johan

This bus will be turned into soup-cans waaaay before 15 years from now...

Part of why this build will be a low-budget and modular (think easily removed) design...

How long has anybody here lived in the same bus?

[joeblack5]

That is even better, then why worry at all about the holes or rust. Why did you take the plywood out?


Good luck,
johan

[banman]

Originally Posted by joeblack5

That is even better, then why worry at all about the holes or rust. Why did you take the plywood out?


Good luck,
johan

See earlier posts & pix for details but...

Plywood is moldy in spots and I will be repairing the structural rust under the drivers seat.

And once I got started...

The only way to really see if the plywood is moldy against the floor is to lift it up...

And now that it's all out I'll probably want to do the same treatment for the entire floor just to keep it all level...

I won't just leave it to rust further because that's wasteful at this point...
There are low-budget right ways to do things...

[JackE]

Originally Posted by banman

There are low-budget right ways to do things...

Hahaha! I can provide solid testimony to that statement! If I count the value of the truck I traded to my son, I'm into this bus about $2000, and I have all the main components to make it usable. My 2 largest expenses will be insulation, and raising the roof, and I think I can get all those supplies for right around $2000. As long as the wife doesn't go crazy with decorating and appliances, I'm going to be way under the projected $10K budget.

[banman]

Finally stripped the rubber off the wheel well.
I'm really wondering if every Thomas got as much spooge on assembly as mine did or maybe the R.I. school district ordered extra...?
A lot of what I thought was crusty rust on the floor is actually a goo like roofing tar that was used along the edge of the wall and the plywood and other random areas covered with rust colored dust. Under the tar is shiny galvanized steel !
It also looks like the wheel wells were built by Freightliner -- they have the same box section construction as the support channels under the drivers seat area. Then Thomas laid their 9" wide floor panels over that. Anything boxed and layered is what rotted out. It also seems that the Thomas floor was never fully welded to the wheel wells. There was a ½" or more thick bead of sealant covering all that up and gluing the floor mat down...
I'm not quite sure what i'm going to do here yet -- I'll patch and weld up the holes by the wall but it's not all worth welding. I may use duraglass (2 part fiberglass epoxy resin structural filler) as that will do a better job of keeping water out...

[Native]

Wow, your floor and wheelhouse look great in comparison to ours! I could literally see the floor under the bus in front of the wheels.

[musigenesis]

Originally Posted by Native

Wow, your floor and wheelhouse look great in comparison to ours! I could literally see the floor under the bus in front of the wheels.

Seriously. He's out of the rust club, I think.

[Native]

Originally Posted by musigenesis

Seriously. He's out of the rust club, I think.

Yeah, that's pert-near rust-free!

[banman]

Originally Posted by Native

Wow, your floor and wheelhouse look great in comparison to ours! I could literally see the floor under the bus in front of the wheels.

Like I said before -- I've been really impressed at the quantity and quality of the sealants used on the floor of this bus to keep water out from between/under the walls and the plywood... Almost all of the damage is from water running under the drivers seat floor area (still haven't pinned down the source) and into the back

Originally Posted by musigenesis

Seriously. He's out of the rust club, I think.

I can't say I'm sorry for being kicked out

I do think I've saved the worst for last. there really is very little support under the drivers seat -- I'm just not quite ready to make the bus inop...