Large Scale Central

Polymeric Sand for ballast?

Track and Trestles
#1

I just ran across some info on this Polymeric Sand. It’s designed to use with pavers instead of regular sand that you put in and brush off, kind of like grout, when you put down pavers for a walkway or patio. After you put it in, you lightly sprinkle it with water and the polymers activate and lock it all together. It won’t blow away, but it has some flexibility for ground movement.

There is more information at http://www.groundtradesxchange.com/pavers/polymeric_sand.htm

Those with more experience might want to comment on this. Does it look viable for track ballast? Has any one tried it yet?

Just wondering.

#2

I remember reading about someone using it for ballast.But it does bond,so it may have to be chiseled or scraped off if you want to remove it.
It also seems to be very fine.
Ralph

#3

Don"t do it. Polymeric sand has a metallic component to it and is attracted to magnets. Just a little bit of it in a motor could chew it up in no time. You can buy the organic binder separately. I do use it for roads/paths mixed about 50/50 with stonedust as seen in the work yard area here -

(http://i113.photobucket.com/albums/n214/altterrain/forums/workyard.jpg)

-Brian

#4

Brian,

Do you have a name (trade name, material name) for the organic binder?

#5

http://www.pavetech.com/paveChem/sand.shtml

-Brian

#6

It makes great roads but poor ballast.

#7

What about mixing it in with rock dust? Would it hold it in place?

#8
Quote:
... Polymeric sand has a metallic component to it and is attracted to magnets. Just a little bit of it in a motor could chew it up in no time.
I'm not disagreeing with the potential magnetism of the product, nor the destructive results that could occur if particulate matter were to get into a bearing. I do wonder if it's that significant of a danger in this particular application. The magnetic field would have to be pretty strong for it to draw up the particles. Since the idea with this product is that it forms a very solid base, you'd have to have a magnetic field capable of not only attracting loose particles, but loosening them in the first place. (I'll accept that the weight of the train moving over the track could release [i]microscopic[/i] particles from the roadbed.)

When our motors are near the track where the magnetic field has the greatest potential of being remotely close enough, they’re usually in sealed cases, keeping the nasty stuff on the outside. The motor’s magnets might attract it, but it doesn’t give the particles a roadmap on how to navigate through the plastic case. On other locomotives without sealed motor blocks, the motors are typically mounted above the frames, which puts them between 1 - 2" above the ballast. I question whether that’s close enough to attract anything. I can’t get a magnet to fall towards the fridge at that distance. I seriously doubt the magnets at that distance would have the strength needed to separate particles from the roadbed.

Also, there’s the simple fact that if a magnetic particle is attracted to the motor, it’s going to be attracted directly to the magnets on the motor. The law of attraction doesn’t allow for detours, so the particles will most likely attach themselves to the outside of the case, away from the bearings. Larger particles–whose potential for damage is greater–are by nature heavier, and would need a stronger magnetic field to draw them up. Particles small enough to make such a voyage would cause no more damage than the dust in the air around them.

Obviously there’s the potential for damage, but I seriously doubt it’s any greater than the risk posed by other nasties we deal with. The oil and grease we put on the locomotives will attract far more dust and debris–magnetic or not–than any large-scale motor ever will. That stuff’s right next to the ballast, in the open with nothing getting in the way. If you’re worried about particulate matter contamination, magnetic draw from our motors is pretty far down on the list of causes.

Getting the binder separately and mixing it yourself with non-magnetic media is an ideal solution. At that point, though, are you just as well served mixing a bit of cement in the ballast and wetting it down? That’s a solution that’s worked for a number of folks over the years, too. I don’t see the sand as posing enough of a realistic threat to worry about its use in the garden.

Later,

K

#9

I’d like to get some of the binder and experiment with using it for roads. I’ve got so much rock and concrete on my layout, being able to make roads with a porous material would be beneficial.

I wonder how it would look to mix the binder with some of that black volcanic sand that is sometimes used in lobby ashtrays? Seems like that might give it an asphalt appearance.

#10

Ray,

It seems to me it might be easier just to use “cold patch” asphalt repair. It would really look like asphalt.

#11
Kevin Strong said:
Quote:
... Polymeric sand has a metallic component to it and is attracted to magnets. Just a little bit of it in a motor could chew it up in no time.
I'm not disagreeing with the potential magnetism of the product, nor the destructive results that could occur if particulate matter were to get into a bearing. I do wonder if it's that significant of a danger in this particular application. The magnetic field would have to be pretty strong for it to draw up the particles. Since the idea with this product is that it forms a very solid base, you'd have to have a magnetic field capable of not only attracting loose particles, but loosening them in the first place. (I'll accept that the weight of the train moving over the track could release [i]microscopic[/i] particles from the roadbed.)

When our motors are near the track where the magnetic field has the greatest potential of being remotely close enough, they’re usually in sealed cases, keeping the nasty stuff on the outside. The motor’s magnets might attract it, but it doesn’t give the particles a roadmap on how to navigate through the plastic case. On other locomotives without sealed motor blocks, the motors are typically mounted above the frames, which puts them between 1 - 2" above the ballast. I question whether that’s close enough to attract anything. I can’t get a magnet to fall towards the fridge at that distance. I seriously doubt the magnets at that distance would have the strength needed to separate particles from the roadbed.

Also, there’s the simple fact that if a magnetic particle is attracted to the motor, it’s going to be attracted directly to the magnets on the motor. The law of attraction doesn’t allow for detours, so the particles will most likely attach themselves to the outside of the case, away from the bearings. Larger particles–whose potential for damage is greater–are by nature heavier, and would need a stronger magnetic field to draw them up. Particles small enough to make such a voyage would cause no more damage than the dust in the air around them.

Obviously there’s the potential for damage, but I seriously doubt it’s any greater than the risk posed by other nasties we deal with. The oil and grease we put on the locomotives will attract far more dust and debris–magnetic or not–than any large-scale motor ever will. That stuff’s right next to the ballast, in the open with nothing getting in the way. If you’re worried about particulate matter contamination, magnetic draw from our motors is pretty far down on the list of causes.

Getting the binder separately and mixing it yourself with non-magnetic media is an ideal solution. At that point, though, are you just as well served mixing a bit of cement in the ballast and wetting it down? That’s a solution that’s worked for a number of folks over the years, too. I don’t see the sand as posing enough of a realistic threat to worry about its use in the garden.

Later,

K


Kevin, Polymeric sand was engineered for gaps no greater than 1-to 1-1/2 depending on brand, exposed over a larger area the sand is bombarded by rainwater, which softens/loosens the bonding agent, which then realeases anything it’s bonded to, Splatter from the raindrops then scatter the materials EVERYWHERE, and then dry and attach to it. If your like Curmey and you run all weather, then it is more plausible to come to the conclusion that the polysand, and the magnetic particles therein can and will get anywhere and everywhere via the wheels spinning and throwing it all over the place, then it dries and basically is glued inside wheelsets, gears, and pickups, and so on…

Why would you risk all that for a ballast that isn’t even close to being prototypical??

#12
Quote:
... the magnetic particles therein can and will get anywhere and everywhere via the wheels spinning and throwing it all over the place, then it dries and basically is glued inside wheelsets, gears, and pickups, and so on..
Yes, but so do non-magnetic particles, which is the premise of my argument that the magnetic particles pose no more danger than any other ballast. I had a flat car sitting outside for a week just as an experiment. A few rain showers and routine watering of the railroad, and the trucks were covered with dirt and debris. No magnets, just physics.

Using the above example of one of TOC’s infamous operating sessions (how does he keep his cigar lit?), the hard rain would splash more unbonded ballast up onto the equipment than it would bonded ballast. Even with the bonded ballast breaking loose and splashing up, it’s heavier (because of the water), thus more resistant to magnetic attraction. Those particles, like their non-magnetic travel partners, will attach themselves to whatever surface they hit first. The surface tension in the water will keep them in place.

None of the particles can magically travel inside sealed gearboxes or up into boilers and fireboxes. In both situations, the surfaces most prone to damage will be the oiled and greased surfaces, not motors and gears which are in sealed cases or out-of-the-way locations. Magnetism has nothing to do with that. The physics apply equally to magnetic and non-magnetic particles.

Quote:
... Why would you risk all that for a ballast that isn't even close to being prototypical??
That's another issue altogether. Aesthetics is a purely personal choice. But it is--in my opinion--a perfectly safe option if that's the look you want.

Later,

K

#13

I’m not proposing this sand as ballast, but I’d like to register my agreement with Keven. I was steered away from bagged crusher fines because of the magnetic properties (a magnet buried in it would come up covered with stones and dust). But I already had a ton of it down and had noticed no ill effects. I came to the same conclusion. The motors were just to far away for there to be any potential to lifting the ballast.

It’s been over 5 years since I started using it and no ill effects at all. I didn’t even bother to magnet test my new source of crusher fines. With the make up of local rock I wouldn’t be surprised if there was some iron in it.

#14

The magnetic particles are not so much the issue as is the fact that they have a BONDING agent that sticks to anything and everything. Crusher fines don’t “glue” onto surfaces, they wash off with just water… Polysand glues itself to whatever it comes into contact with. THATS the ISSUE the fact that it’s glueing magnetic particles only adds to the "Why the hell would you be willing to take the chances"question

#15

You lost me there. If water loosens the binder on the track so that the particles splash on the equipment in the first place, then it stands to reason that water would loosen the binder on the equipment when you go to wash it off. If it’s the bonding agent, not the magnetism, that’s causing the issue, then Brian’s suggestion to mix the binding agent with non-magnetic rocks instead is equally risky.

Later,

K

#16

A lot of water loosens the bonding agent, once on something you have to scrub it off with a brush and water, just rinsing it will not get it off.

You planning on soaking your motor blocks or wheelsets to loosen any binder that works its way into it?

#17

Guess its adding cement to the crusher fines, then! Anyone know a good ratio?

#18

All:

Every one of the several RRs I’ve seen where cement was used to ‘bond’ the ballast have eventually suffered severe cracks in the resulting mix. The resulting unreinforced ‘concrete’ structure just doesn’t have any strength.

The end product is a really ugly surface that has all the appeal of a broken concrete sidewalk. Someone posted pix of this on MLS a year or so ago. These broken chunks then require that the track be lifted in order to remove them. After disposal of the ‘concrete’, re-ballasting is required. IMHO, bonding with cement is not really a viable solution.

If bonded ballast is really wanted, I think some folks have had good results using diluted mixtures of wood glue applied with a wetting agent. This is just like doing small scale indoors. I haven’t tried this.

Happy RRing,

Jerry

#19
Quote:
... A lot of water loosens the bonding agent, once on something you have to scrub it off with a brush and water, just rinsing it will not get it off.
If that's the case, then the bigger issue isn't so much the stuff getting on the equipment and not wanting to come off, but the stuff getting on the tops and inside of the rails themselves, making it impossible for the trains to even run without going and scrubbing the track. If that's happening, we're not hearing about it. Those who I've talked to who are using it (primarily for roads, not ballast) have had nothing but good things to say about it.
Quote:
... You planning on soaking your motor blocks or wheelsets to loosen any binder that works its way into it?
Er, yes. I do that with regular ballast. A thorough scrubbing with a wet tootbrush (and occasionally degreaser) is routine maintenance when stuff gets that dirty. Binder or not, dirt and dust don't play well with oiled bearings. If you want to get rid of it all, you need to give it a good cleaning.

Obviously Mark’s and my opinions of this stuff differ. Simply put, I see it as posing no greater danger to an operating railroad than ordinary ballast. No point in this horse getting flogged further. When someone who has been actually using this stuff on the railroad–as ballast–chimes in, we’ll have a better understanding of what actually happens.

Later,

K