Easier to Bend? Gargraves flex stainless or tinplated?

@Mannyrock posted:

Hey Guys,

I am going to bend some flex -track into tighter than 027 curves.   Which track is easier to bend.  The stainless or tinplated?

Thanks,

Mannyrock

I’m sorry I don’t have an answer on bending. If you have any locomotives with magnatraction, you may want to consider the tinplate. Stainless steel is not very magnetic.

Steve

It's going to be a tough project either way. Follow @RideTheRails's lead on this one.

Do you have something matching the radius you want to bend to? That's probably going to be the best way to get there.

I have to ask - what equipment do you have that calls for tighter than 027 curves?

I would imagine that the tinplate would be easier, just knowing about the differences in stainless and plain tin plated steel.  OTOH, I have to echo the query about what you'd run on such a track???

@Mannyrock posted:

Hey Guys,

I am going to bend some flex -track into tighter than 027 curves...

You might run into some difficulty. Years ago working with my grandfather we needed a couple more gargraves 32" curves. We made a plywood jig from an existing section of store-bought 32" radius gargraves and try as we might the tinplate would start taking kinks as we got nearer to 32" radius. We went through 3 of tinplate and one remnant section of stainless before we got it without significant kinks and creasing. We kept wiggling the ties and bending carefully but even when we got 'done' the store-bought sections looked good and our tinplate looked home-made.

i hope your luck is better than ours

with a radius tighter than 27 the engine might run into the caboose!

EDIT: best suggestion i have is to be patient and go slowly with lots of tie wiggling/adjusting

I've used both, used track, had a mix.  Stainless is more difficult to bend.  Any custom bending O72 or less is difficult.

I had no problem bending a piece to O54, but it took a little longer and more moving the ties around.  The big issue is kinking the track if you rush it.

FWIW, @Tom Tee did some perfect O31 bends with Gargraves Flex, I was suitable impressed!

@gunrunnerjohn posted:

but it took a little longer and more moving the ties around.

I forgot about this part! It can be the most tedious part in my opinion.

@BillYo414 posted:

I forgot about this part! It can be the most tedious part in my opinion.

Most of my track was bent to O72 or larger diameters, and I didn't have any issues doing it with minimal shifting of the ties.  As the diameter gets tighter, there's a more fiddling to make a smooth curve and not introduce a kink in the track.

Also important, start with new track, especially if you're going to be bending it into tight curves!  Used Gargraves flex is much less cooperative!  Before I started laying track on my current layout (first time I used flex track in any quantity), I bought a bunch of used pieces to practice on.  It was a real learning experience, but when I started bending the new stuff, it was a breeze compared to the old stuff!

Tinplate is going to be easier, BUT it will be VERY difficult to avoid kinks with curves that tight.  In my experience, bending Gargraves tighter than O42 is difficult.  The method is:

1. Use only brand new track where the ties slide easily on the rails.

2. Don't try to bend the entire 37" section at once or you're guaranteed kinks.

3. Instead, slide the ties together so that they are almost touching (just 1/16" or so between them.  Bend the area with the ties.  Use a plywood or other template a little tighter than the curve you want.  Once curved, slide the ties apart to their original spacing in the bent part.  Work the ties all in the same direction, so you'll have extra ties on some unbent rails.

4. Adjust these ties on unbent rails to the close spacing and continue bending on the template.

There is a learning curve to doing this, so be prepared to sacrifice a few sections of track while you learn.  Also, the bent track will not hold the tight curve once bent.  It will want to relax into a wider curve.  You'll need to tighten the curve as you screw the track down.  You'll also need to trim the rails on each end of the bent section, since they will be significantly out of line.

Best of luck to you!

Thanks for all of the excellent advice.   The crowding together of the ties in the bend area is something I would never have thought about.

The only thing that I will run on the tight curves with be an Atlas Handcar.  Nothing else.

With something like this, I will generally go agonizingly slow on the project.  Maybe spending 2 or 3 weeks to bend it, little by little by little.     I will only buy two sections of the track.   If I end up ruining them both, I'll just toss them and scrap the whole project.

I have a thought, probably a stupid one, that if I heat the rails up to a high temperature, somewhat lower than the burning temperature of wooden ties, the rails may bend easier.   (I'll stop heating when I see the ties start to smoke!)

In researching this online, I have read about people seeing it bent to circumferences as tight as 12 to 14 inches,  but of course the internet is full of lies, and there are no pictures of these.

As far as the jig, I am the kind of guy who is more likely to take an old steel 5 gallon paint can (free at the dump), screw it down on a small piece of plywood, and just bend the track around the can.   Or, buy a small round outdoor cement step at Lowes, epoxy it to a scrap piece of plywood, and use that as the jig.  I have lots of construction epoxy lying around, and the step would be very cheap.

If my failures are comical enough, I will post pictures of them.

Thanks again,

Mannyrock

@Mannyrock posted:

As far as the jig, I am the kind of guy who is more likely to take an old steel 5 gallon paint can (free at the dump), screw it down on a small piece of plywood, an...

The paint can type of bending is effective. You're on the right track.

Good luck! Don't forget to post your results!

I have seen several tips about spraying the track and ties with WD-40 before I start bending.

Since WD-40 is flammable,  I guess it will be interesting to see what happens when I start heating up the rails.  :-O

I thought about putting the track in our gas oven for a minute or so with the Broil flame on, but I can see where that may lead to a divorce.

So, I will look for one of those mini-type butane torches, that spurt the tiny blue flame, and run it up and down along the particular short sections of rail that I am trying to bend at the time.

Mannyrock

@Mannyrock I'm still not convinced about heating up the rails. I haven't worked in metallurgy in a while but I think steel doesn't change properties much until 700F. I know it changes above 1900F. Obviously you should go for it if you want to. I just think it's going to be difficult to do without damaging the track. That would be my biggest fear.

I worked a lot in casting and forging, not high service temps. We always started with a heat treat at 2700F-3000F so I could be totally wrong with my info above.

Mannyrock,

I don't think the heat will do anything except maybe discolor the rails if you use an open flame. Heat helps with die cast metal bends such as straightening a steam engine cab roof but not the tinplate material used for rails.

First, mark out your desired curve on your roadbed or plywood tabletop using a large compass or a pencil, string and a nail for the center of curvature.

Bend carefully around your paint can moving ties as you go. Keep placing your curved track on the template you drew to see how close you are to the right curve and to spot any kinks.

Expect to lose the last couple of inches of each section you are curving. You can never get a smooth curve right to the very end. Cut the ends off. For the sharp curves you want, you will be able to do a 90 degree curve (or maybe even a 180) with a single section of flex track even with the loss a few inches on each end.

When you are close to the desired curvature, lay the track along your drawn curve using a track nail or screw every six inches or so around the curve.

Jim

I have not had an issue bending the flex trak.  It takes patience,  perseverance and practice!

I have bent one reverse loop insane crazy tight...probably about o-24.  It can be seen on my YouTube channel.