Warped flat cars, fix?

[badlandnp]

This is a pair of Fine N Scale flat kits. They have warped up over the years since assembling them. Am not sure why, either the 'body' shrank under the brass top, or they just warp because they are resin.

Anyway, I am not sure if I can save these or not. Any suggestions are welcome.
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[ChicagoNW]

How much disassembly can you do?

Curving like that often happens when two materials have different properties. One material contracts/expands while the other doesn’t. Looks like the resin body/frame compressed as it finally cured all the way through, but the wood deck didn’t.

If you strip the body of the trucks, truss rods and any other fragile parts, then heat it up in very hot water and place it under something heavy to flatten it might work.

Believe it or not, some flats have a slight arch to them. When used with very heavy loads the car flattens. The prestressed body prevents the load from collapsing. You see this especially on flatbed trailers used by steel companies.

[badlandnp]

I guess the top plate will have to come off, as well as the trusses and trucks. Then I will have to find a way to warm it up and flex it down again without trashing the paint and lettering. Ought to be interesting. Then to find a way to stiffen the frame on the bottom so it doesn't warp again....

[bobo1160]

ya , ive seen empty flatbed semi trailers that are bowed like that . but thats pretty extreme . that sucks man .

I'd put a few ounces worth of coins or something on the bed and gently heat it with a hair dryer and see if she'll straighten back out before you go tearing it apart .

[ChicagoNW]

If you can’t flatten the cars. You could do what the real roads did. Use the arched cars as bridges on dirt access roads.

[badlandnp]

Now that's funny!! Bridges!

I did set them on my workbench last night, placing my Fast tracks filing jigs on the center of the decks. We will see if it helps at all.....

[Army-Gandydancer]

I have seen old flat cars used as ramps for loading docks too. As the old saying goes "waste not want not". So if you can't flatten those cars enough to use on the tracks you can always incorporate them into the layout in other ways.

[MRLdave]

You just need to loosen the truss rods a little.......just kidding. Heat is the only answer, but the trick is finding the right amount. Hot water will probably strip the decals and hot air (hair dryer) will probably damage them as well. You could try putting them on a cookie sheet with some weight on them and pop them in the oven at very low heat. I'm not sure there is a "this always works" solution..........and success will somewhat depend on the resin the cars were cast from.

[Moose2013]

@badlandnp

Moose has a number of Fine-N-Scale cars with the same severe warping issue. All things considered, might be better time spent fabricating replacement flatcar chassis from polystyrene or brass and reusing the Fine-N-Scale details, trucks, etc. Just a moose thought...

[WP&P]

I agree with the moose: it might be best to replace the carbody. A cheap way to go about it is to find some old Bachmann or other toy-train level cars, and just migrate over your trucks and details like the truss rods, etc. Probably would want to fabricate a new wood deck, too. Now that I'm thinking about it, this is turning into more of a scratch building project than a fix!

A problem with flatcars is the weight, especially empty. One solution would be to use a flat car body that is all cast metal. I don't know whether such castings exist, but maybe there is an option on Shapeways, since I think you can order 3-D printed metal parts there. Sorry, I'm too lazy to look it up myself, but just want to put it out there as a route to explore.

[ChicagoNW]

If you sealed the decals under clearcoats then it is tough for them to get wet. But I can’t see anything but the company name on the cars. Are there more markings?

Bridges…
https://www.google.com/search?client...&bih=267&dpr=2

[badlandnp]

They have settled down a tiny bit since last night with the weight on them. I will probably just pull the brass decking and try a bit more time and weight, and placing them on a shelf over the woodstove. If that brings them down, I will find a way to attach some brass tub or angle to the frame.

If all else fails, The sides will get cut off and a brass frame soldered together for them to attach to.

The decals are just the NP, no numbers yet. Maybe never if they aren't salvageable.

[badlandnp]

Well it is almost a flatcar again. Since I took this picture, the left car is even a bit flatter. The plan is to give it another day or two, then use a couple of clamps to hold it flat against the steel block. Set a brass bar in the JB Weld in the middle of the frame, and let it set up for a day. I have 8 more of these cars to build and such, so am glad to have discovered this issue before building them. Lets see whether or not the 'fix' fixes it.

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[ChicagoNW]

Are the truss bars still pretzeled?

[Pencil]

I have one of these kits I still haven't put together yet. I'll be following along with your mitigation fixes, and integrating them from the beginning.....

Curtis

[NtheBasement]

Never tried it but seems to me doing this in a bath of warm (maybe 120 degree) water would speed things up and end up with less bounce-back when you remove the weight.

[badlandnp]

"Are the truss bars still pretzeled?"

Nope. They are intact and loose now that I have been flexing things. This morning I took the time to do the JB Weld as they were flat. I used a flat brass bar to be a clamping block. Mixed up the JB and clamped the flats to the bar. Tomorrow will be the proof in the pudding if it holds a flat shape.

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[badlandnp]

This morning I tested the 'flex' in the cars. None, nada. Of course I didn't try too hard, but they are purty stiff. So, they got reassembled and numbered and put into service on the layout. Now for an appropriate load....
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And rolling along nicely,

[bobo1160]

nice ! I bet those cars will run better with the extra weight too .

[ChicagoNW]

I am impressed.