Spokane & BC Railway Circa 1955

Modelling what might have been in southeast BC and northwest Wasington

Tag: Track

Ballast adhesive research

Now that we have the ballast neatly placed between the ties and not on top of them, we need to fix it with some sort of adhesive.

The traditional material is good old PVA white glue, diluted with a bit with water. You mist the ballast with so-called “wet water” and then dribble on the solution to soak the ballast and then let it dry. Various tools can be used to apply the mixture, but the slickest is a rubber ear syringe as it holds plenty, and is very easy to control.

Wet water is another area of great debate, as the traditional wetting agent is dish washing liquid, but Isopropyl alcohol (IPA) or Kodak Photo-Flo can also be used. The simplest for me is the automatic dishwasher drying agent liquids, as it is just a surfactant and does not contain and real cleaning agents. I use 1/4 teaspoon in 32 oz or one litre, based on an article online somewhere by Joe Fugate.I did try to mix white glue with IPA and it formed a gooey blob and did not dissolve at all. I am not sure how well it will dissolve in a water – IPA mixture, so I don’t use that.

In recent years the press has been talking about using artist’s acrylic matte medium instead of white glue, as it is not as water soluble after it dries. This all sounded good to me, and I had been using it to fix the main ground foam scenery on the layout. When it came time to do the track ballasting, it was supposed to work there as well, so I used that. Well, at least for me, this was a big mistake. No matter how much I tried to soak the sand to make sure the solution penetrated throughout the material, it ended up very fragile and crumbled very easily. Not what you want on your track work! So, of course, more controlled tests.

I tested fixing small piles of sand on a wood base without any track to prove a point. Even with the sand completely soaked with wet water and then mixed thoroughly with matte medium mixture to the point that it was a slurry, it still didn’t hold.

By the next day, after it had completely dried and look good with no visible glue residue, it still easily crumbled with the press of a finger.

So, back to try the old trusty Elmer’s While Glue and water. Cutting to the chase, after repeating the exact same process, this time it resulted in a very strong bond that could not be broken with a finger. There was no hint of a white residue as some have reported with white glue. As for any residual shine, I did another controlled test to see how shiny the white glue really was. When using matte medium, it is recommended to mix it with water and then let it stand for about a week to let the white powder settle out. This is reported to be talc that gives the medium its flat finish, however it can also leave a white residue behind, which we don’t want. The interesting thing is that once you separate out the white powder, what remains is just the clear acrylic medium, and it is glossy. So as a friend said, why not just start with gloss medium and save the extra decanting step. So, I tested both decanted matte and gloss medium and found both to be weak at bonding the ballast. As to their shininess, I let puddles of all three materials dry on a dark coloured plastic lid.

Surprising to me, the decanted matte medium was the shiniest, followed closely by the gloss medium, and then the white glue. The glue looked positively matte in comparison to both of the acrylic mediums. 

I then did a small section of track to prove out the white glue approach, and while it looks awful when wet, it dries perfectly clear with no residue nor shine.

So, I am concluding that the white glue approach is still the best, in spite of more modern materials. 

One caveat that I should mention is that the glue I am using is the original, standard Elmer’s “Glue-all” white glue. I have no idea if the results will be the same with any other brand of white glue. I’ll leave those tests to someone else.

Ballast application technique

The tools

I am finally getting to ballasting the track on the layout. Much of it has been down for a few years now, and has been well tested during various operating sessions, so it is now time to ballast it and make it look complete.

Ballasting track seems to be such a simple process that there should be no need for any great details nor research. But, alas, such is not the case it seems. Everyone has their way of doing it, with better or worse outcomes, so this is just a small treatise on what I have figured out that works for me. If you have a different way and are happy with it, just keep on doing it. There are oodles of “how to” videos online that show all sorts of techniques. This is just what I do. I have no patience for using a small brush to push individual grains into place to make it look “perfect”. I need a technique that is simple, easy, repeatable, quick, and good enough for photography, and this fits that bill.

The basic process is pretty simple, but the details is where it gets interesting. I am using commercial track, so the rails are already in place when the ballast is applied. If you hand lay your track, then it gets easier because the ties can be ballasted before the rails are spiked down, which makes it much easier to do a neat job.

After the track is installed and tested, and has had some time to settle and reveal any issues, ballasting involves simply spreading the grains of material between the ties, and soaking it with some sort of glue.

f only it were that simple.

The first big question is what to use for the ballast. Commercial products range from crushed walnut shells (or something similar), to real crushed rock. Colours are all over the map, and as usual should match what you are modelling.

A long time ago I thought I would use Woodland Scenics ballast, as it seems to be the most popular and readily available. My first attempts with it were less than satisfactory, and cutting a very long research story short, I have changed to using some form of real sand instead. The biggest problem with the WS product is that it is not actual rock, but I’m told is ground walnut shells. While it looks nice, it is very hard to apply it so that it will lay down between the ties as it should. Being something other than rock, it is very light and tends to float once the area is wetted with water and glue mixture. Even misting it with water tends to easily disturb the particles, resulting in a lot of clean up work afterwards. And, the dye used to colour the material seems to soak out a bit and leave light coloured stains on the tops of the ties if the grains are removed.

Based on visits to friend’s layouts where they had used real sand and it looked great, I decided to experiment with that instead. I weighted equal volumes of WS ballast and sand and found that the real sand was 2.5 times as heavy as the WS stuff. It tends to stay put after application even when it is wetted and glued.

Cost is not really a factor, because this is a hobby after all. I did find the sand to be much cheaper, with the best deal being from our local landscaping centre were I got a 5 gallon pail full that I could barely lift for under $2.00. Such a deal! Another source is paver sand from a home improvement centre. It is all quite different in colours so it helps to search a bit and then get enough to last a while.

I also experimented with some other commercial products that are real crushed rock, but I found them to be far too uniform in colour, which may be suitable for some railroads, but certainly is not for where my prototype was. Also, it seemed to have a kind of unnatural sheen, almost translucent, under some lighting, that I didn’t care for.

OK, so how do I install it?

Instead of a spoon, or other open container, I use a small squeeze bottle with the tip cut off to pour it over the ties. After a bit of practice you can estimate how much to pour so that it will fill in between the ties without overtopping them. To spread it, I first use just my dry fingers to run back and forth along the tops of the ties. If there is too much to nestle neatly between the ties, I use a coarse paint brush to move some of it along. With the brush held vertical, the bristles will sweep down just a bit between the ties to remove some material. This will leave some grains on top of the ties, so a finger is again used to push them off into between the ties.

Most prototype track of the transition era had the ballast just a bit lower than the tops of the ties, rather than right up to the top. By working to arrange the ballast this way, a bit of room is left to easily push errant grains off the tops and into the space between the ties.

The one problem with your finger is that is is rounded, and does not completely get into the corner between the rail and the tie. For a final tidy up I use a cosmetic wedge sponge that I trimmed to just fit between the rails. This slides along the tops of the ties and pushes the last few grains into the inter-tie spaces.

Some videos show tapping the rails to settle the ballast off of the ties, but that doesn’t seem to work for me with the sand, I suspect due to its weight. It may work with the lighter materials. Try it and see how it goes.

Once the ballast is all nicely applied where it needs to go the next step is to fix it with a dilute glue mixture of some kind. Again, the issue of what to use comes up, so guess what, more experiments!

But that is the subject for the next post.

Here is the final result.


November 16th work session

The gang continued on on a number of fronts, refer to the captions for details. Thanks guys!

  • Colin adding supports to the fascia at Carson.
  • Tom improving the scenery transition below the upper level staging.
  • Brian cleaning freshly painted track at Curlew.
  • John working to install LED headlights in an Atlas/Kato GP7.
  • Colin and Tom cutting the fascia for the stream bed.
  • John and Brian checking the LED polarity for correct operation before soldering it in place.

Noxious fumes

Now that all of the new track at Carson and Curlew had been tested by VanRail and other operating sessions, it was time to paint it before we start on the scenery.

I have been using a spray paint made by Rust-Oleum called Specialty Camouflage – Earth Brown. It is very flat and covers well, and seems to stick to the plastic ties.

I clean the tops of the rails after it dries with a special tool I made from a simple piece of aluminum with one end sharpened with a file. The aluminum is softer than the rail, so it does not scratch it, but the paint peels right off with very little effort. The tool needs to be sharpened a few times, as the rail wears a groove in it. I found that if I tried to wipe the paint off while it was still wet, I would manage to hit the ties as well, messing up the nice finish. Also, by carefully using the tool, the tops of non-running rails such as guard rails can be left brown.

Rail cleaning tool.

I have not bothered to try to paint the rails a different colour, as I just don’t have the patience for that. I find that the dark brown colour of the paint seems to make the track just recede from view, and once it is ballasted, it looks fine to me.

Mainline track at Grand Forks after ballasting.

The only problem with this painting method is the fumes. You can’t really take the layout outside to paint it, so the room quickly fills with noxious fumes. I close the door to my workbench area which closes off both it and the layout room from the rest of the house, and I use a respirator when spraying. Afterwards, I run my paint booth exhaust in my workbench area for about 24 hours to clear the air. One window elsewhere in the house is left open a bit to let in fresh air, and it seems to travel through the heating ducts to the train room to replace the air that is being exhausted. This works well and we don’t smell the paint elsewhere in the house.

Curlew masked and painted.
Carson done as well.

While the spray paint works well, I really need to find a suitable acrylic alternative and learn to spray it before I need to paint future track additions.