Large Scale Central

Casting One-piece Standard Gauge Ties with Tie Plates

Modeling
#1

…because I can. :smiley: I thought this little project was a bit out-of-the-ordinary (if not a little nuts) and worth sharing here. No Big Point, it’s just something I’ve been working on and am getting a bit excited about. Background. About a year ago, when I started planning my first railroad, I decided I really just had to have: code 250 rail, nickel silver, and standard gauge. I was unable to find ready-made flextrack with these specs, or maybe I just didn’t like what I was able to find at the time. In any case, I’ve been struggling with the hand-laid track decision ever since, especially with spiking. For the past year, I’ve played with a number of ideas, including the stamping of one-piece rail retainers from sheet metal, milling tie plates from the solid, and solder-assembly of sheet metal pieces to form what would look like an extrusion to be cut into short pieces. After getting some casting experience, I thought I’d try going that way. The master pattern, made from a total of 14 pieces of styrene. Two pieces were laminated for the tie itself, then each cleat is made from 3 separate pieces skillfully hand-crafted to get the shape I felt would hold the rail, allow the rail to be easily inserted, and would release the mold without tearing it up.

This is just a fuzzy closeup of one end of the tie:

The master was used to make an initial mold, from which 10 castings were made. The castings were then cleaned up and used to build the master for a 10-cavity mold shown here:

The 10-cavity mold was then used to pour the ties, and in this case I used Smooth-Ons Task 7 moisture-resistant urethane plastic, dyed with both black and brown pigment:

This shot shows two of the finished ties with my rail gauge attached, just to show how the ties will work in practice–should I decide to go forward producing these for myself.

So far, I’ve pounded out about 100 or so ties, and the demold works well. Task 7 is more ‘adherent’ to my styrene backing plate than the Smooth Cast 300 resin I’ve been using until now, and that seriously slows down production. Cleaning up the backing plate prior to the next cast is taking way too much time. The Task 7 product has a good pot life–close to 7 minutes–which is good in this case because my only available method for clearing bubbles from the cleats is to probe each cavity (4 times each). Plenty of time to do that with this resin. The downside is, the demold time is about 30 minutes, vs the 8 minutes I was seeing with Smooth Cast 300. What I need to find is a long pot-life short demold plastic, but the two kind of go hand-in-hand.

#2

Kirk, what scale track is this?

F scale 1/20.3 standard gauge?

Gauge I - 1/32 scale standard gauge?

or ???

Looks nice so far!

#3

Thanks Vic! This is intended to be standard guage, Guage1, 1:32, and roughly 30s era. So, the ties were intended to be about 8" x 10" ties which I thought would represent your medium-to-heavy ties for standard gauge of the time–my ‘research’ and my modeling were separated by about a year and by my complete lack of documentation. In any case, they are .25" x .31" actual, and 3.3" long (just under 9 ft). My plan is to use 15 per actual foot, which comes out to just over 22" scale spacing, roughly, per PRR mainline standards. I’ll go 18" spacing ‘in the yard’, also per my understanding of PRR specs.

This could be a short-lived experiment–I don’t know how it’s all going to go down.

#4
Kirk Fleming said:
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So far, I’ve pounded out about 100 or so ties, and the demold works well. Task 7 is more ‘adherent’ to my styrene backing plate than the Smooth Cast 300 resin I’ve been using until now, and that seriously slows down production. Cleaning up the backing plate prior to the next cast is taking way too much time.

The Task 7 product has a good pot life–close to 7 minutes–which is good in this case because my only available method for clearing bubbles from the cleats is to probe each cavity (4 times each). Plenty of time to do that with this resin. The downside is, the demold time is about 30 minutes, vs the 8 minutes I was seeing with Smooth Cast 300.

What I need to find is a long pot-life short demold plastic, but the two kind of go hand-in-hand.


If your using an open face mold, don;t use a backing plate at all! pour the mold level and be done with it. IT will b the bottom side of the tie that is hidden in the ballast anyways…after a couple 100 pours ya should be able to achieve a relative level go. If not. run it across a belt sander! When I’m castinglarge batches of things I generally do it in conjunction with something else…pour go work on a project…come back demold and pour again!

#5

That’s crazy talk, Bart! :smiley: Like ordering a burger without fries!

But seriously, I’ll try that simple idea (that I never would have thought of). Should speed things up considerably. Plus, I notice that if I get the mold nice and level, I can actually pour with a positive meniscus, which would be very cool.

#6

ITs always the obvious that I miss too. WhenI moved my shop I had to relevel all the benches because the building itslf wasn;t level when delivered! I design a lot of my molds so that I don;t have to use a backing plate…One of Murphy’s Law of Castings…Mold Release DOESN’T! ( Well, not always)

#7

And yet another ‘obvious’ solution that wasn’t is to use…what?..silicone. Duh.

I took the masters out of the mold box, reassembled the mold box, and poured it about 1/4" deep with silicone, providing a thick, heavy sheet with a flat, smooth-textured surface that works perfectly as a backing sheet. What’s also cool is that it can be easily cut into smaller pieces to match several of my small molds that are only about 1/2" x 1" or so in surface area.

#8

While your ties look great, I was just wondering why.

You said you couldn’t find anything.

Llagas makes 250 NS 1:32 tied SG track in 6-foot flex sections.

Has for years.

Also, he adds some kind of UV stabilizer to the stuff, if yours is going outdoors, have you ever found such a product to add to the mix?

TOC

#9

I THINK this is what happened to me, as best as I can reconstruct it.

When I was looking for a code 250 solution a year ago, I think I was really hung up on NOT using plastic ties (e.g., flextrack). I’m pretty sure that’s all it was (that, and maybe I was shocked at the price)–I really wanted to hand lay the rail. Besides wanting to, I also felt it was inevitable, since all of my turnouts would be hand-made as well. I bought about $800 of NS rail, and hand laid a bunch of it, at great effort, agony and frustration.

During the one-year period, I came up with a half-dozen or so possible solutions to the main problem: keeping the track in gauge and holding the rail down without relying on nails–all the while using wooden ties. This long chain of ‘solutions’ brought be around to casting the entire tie.

So, looking back, what I did was reinvent the same solution that someone else had come up with many years before, but at greater cost and consumption of time. Perfect! Very often, I learn things the very hard way. In this case, I don’t have any regrets, though–I think I learned quite a bit about the reality of hand-laying track.

As for UV stabilization, the Task 7 resin (or maybe I have it confused with the Task 9 product) from Smooth-On is supposed to be UV resistant.

Just for curiosity’s sake: buying the resin in small quantities (2 lb at a time), the cost of these ties works out to $11.25 per 6ft of track. Add in say $18 for the rail and amortize the cost of the mold, this track has a run rate of $20 per 6’ section.

#10

Your figures look okay except for one thing.
You need to add an hourly dollar figure to your time.

#11

Yes, unfortunately I’m already running at capacity, and am selling all the time anyone is apparently willing to buy.

But, it’s an interesting calculation. A lot of my work is actually done during time that’s ‘on the clock’ in the sense that, the software system we’re building for ourselves is such a piece of *&(# that, while I wait for it to respond to my simplest of requests, I can actually process a run out of the mold. So the scenario is kind of like this:

  1. Access the system and log in
  2. Navigate to the proper page, and select the function required
  3. Select some user preferences, then submit the query
  4. Clean mold and prepare resin
  5. Mix in coloring pigment, check the system to see if it has responded (no, of course not)
  6. Pour resin into mold, de-bubble the pour, place the backing sheet on mold
  7. Clean up any paper towels, spilled resin, etc. Check to see if system has responded (duh…no)
  8. Check email for any important (yeah, right) messages
  9. Go downstairs and pour a fresh coffee, put a few things in the dishwasher, go back to the office.
  10. Watch the page refresh with the results of the query–total elapsed time–about 9 minutes.

Works out great. I believe I was ‘thinking’ about the project during the entire time I was pouring my resin, so I think my ‘bill rate’ is fair.

#12

Hard to tell, but how many ties per pour?

I have a couple of guys local who did dual-gauge ties like that.

I think six per pour.

I think in 1:20 Narrow Gauge it’s like 64 per 6 feet.

That takes a long, long time, and 1:32 has to be triple that.

I mean, it looks good, no problem, and in my younger days I figured hey, my time is free, but assign the dollar amount per hour you make when you work…

It’s like doing your own bodywork on a streetrod.

You could get it done cheaper and faster if you farmed it out, but this way, YOU did it.

How many feet you got laid so far?

TOC

#13

It’s a 10-cavity mold, and the rate is 90 ties per 6 ft section to approximate 22" spacing for mainline ties. I haven’t laid any yet–I’m just collecting them in bags. I’m reluctant to pull up the existing wooden ties if I can get them to work for me–right now I just want to get a choo-choo running around the Big Loop.

#14

On a perverse note (or contrary?), had a bloke stop by yesterday all excited about the article he’d seen on TREX ties.

I was somewhat shaken.

That stuff is awfully brittle and flexible at the cross-section of a tie…

#15

A few hundred of my ties are a very similar material–basically a composite deck material of identical appearance. They are, for the most part, oversize for scale, and so I didn’t have too much trouble with spiking rail to them, although if the spike is off-center by much it will distort the tie. As far as stiffness/strength though, they seemed more than adequate, but then, in my case at least, the outer 3/4"-7/8" of ends of each one is fully supported by the ‘ladder’ structure. So, you’re only working with a span of about 2" or so. After struggling with the composite material for a year or so in attempting to get smooth curves laterally and no curves (i.e., waves) vertically, I can’t recommend the material and personally won’t ever use it for anything again. It behaves about like rubber and needs to be supported about every 2 ft at least. It splits and breaks easily when you try to use drywall or deck screws on anything narrower that a full-width board, and it doesn’t glue for #$&%, either. These are just my experiences–other folks have had good luck I guess. Actually, for the Narrow Guage man, where the ties are physically larger, this may still be an option. This shot shows my oversized (for SG) ties, and they could be build to look pretty good for ng, I think. What I and others have found is that the material is ‘slippery’ as far as hold a spike, however. The little burrs you see on the left edges of these are due to taking a belt sander across the installed ties to make ‘adjustments’.

I DO want to highlight an issue with hand-made ties–those corners are sharp as they come off the saw. I’ve dragged my ankles across them several times before I learned to be a LOT more careful. I’m talkin’ blood now, not just a little surface scratch.

#16

Holy smokes.

I just saw your photos of the PT ties over on the site not as good as this one…

Ouch.

TOC

#17

Fellers, you sure like to be in the labor intensive projects and I just can’t see the ends justifying the means ?
Of course one must do what one must do and if you haven’t tried it then it will always just be an idea.
I do applaud you for making the effort tho…

Cheers,

#18

Yup. The point is well taken, Darryl. Lessons learned–I hope.