Articles, information, how-to manuals, tutorials and instructions written to be

JS Geare
Mike Militello
Articles, information, how-to manuals, tutorials and instructions written to be
both entertaining and informative and, occasionally, even accurate or useful.
A Guide to Making Realistic
Coal, Ballast or Aggregate Loads
We Show You a Simple Method to Make Realistic Loads
Using Ordinary Tools and Inexpensive Materials
Why We Wrote this Article
Call us cheapskates, but often there are very simple,
quick and inexpensive ways to create visual features
for your railroad that are as good or better looking than
the commercial versions. Here, we explain a quick and
easy method, using ordinary tools and inexpensive
materials, to build up coal (or ballast, gravel or
aggregate) loads.
Our star performer is good old meat tray foam, the
stuff that holds your burger, chicken and steak at the
super market meat section. In addition to what you
salvage from your trash, you can also ask for it at the
meat department - and don’t be surprised if they just
give you some.
Try our techniques and materials - we think you’ll be
pleased by the end result and the savings.
Tools and Materials
Above, right, you’ll see the basic material and main
tool, a razor blade. These sit on a self-healing mat
(from Testors) which is marked with a grid to assist in
alignment for accurate cutting. The mat makes your
work go faster, but is not essential.
From left to right:
A mixture of 70% rubbing alcohol and 30% water in a
pump spray bottle Ratio is not critical, that’s just the
brew that works best for us. This will be sued when we
apply the aggregate to the form will first build to give
the load a basic shape.
A pump spray bottle of “Insta-set” CA accelerator, to
Making Realistic Coal or Aggregate Loads, page 1
make the CA in the bottle with purple label set faster.
This particular CA is BSI #107 Insta-Cure Gap Filling.
It is a general purpose CA glue that is slightly
thickened so you can control the application. You
could use anything else, even good old white glue, but
it would take longer for the bond to set up. Note that
this CA will attack the foam. The Insta-set accelerator
(BSI #151) will harden the CA so quickly, though, that
the foam will not be terribly affected by the CA. But
even if you don’t use the acclerator, the attack will not
make the foam simply melt away.
Some Woodland Scenics medium ballast, which in this
case will be used to give a coal texture. But you could
use it as ballast, gravel, or maybe even taconite ore.
Nothing magical about this product - use sand if you want.
An old sour cream container, to use as a mixing pot for
the white glue next to it. You use anything handy.
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We’ve chosen Aileens Tacky White Glue for this job
because it is thicker than regular white glue, but here,
again, it is a minor point. Elmers should work just fine.
This glue will hold the granules of ballast onto the
basic form of the load.
A mustard bottle with adjustable flow tip. It contains a
mixture of white glue and alcohol, about 50-50. This
mix will be used to saturate and bond the ballast to the
load form. Very similar to ballasting roadbed.
In the center, front, a foam meat tray. This one is a #4S
which we like because it is mostly flat and thick
enough to easily handle, cut and sand. Luckily, we had rectangle whose sides and ends, respectively, are
it in black, but it comes in white and yellow as well.
exactly parallel. This is where the grid on the cutting
But don’t worry about the code or color.
mat comes in handy, as you see above. But if you
On the foam, a new, sharp razor blade. It is perfect for don’t have a mat, then use some graph paper, or
perhaps a draftsman’s triangle.
this work because it will slice through the foam
without snagging it. But keep several at hand; at the
first sign of becoming dull, switch to a new blade.
Hobby knives, utility knives, etc, will work if very
sharp and thin, and a scalpel should do well, but the
razor blade is the instrument of choice.
Not shown is a bottle of cheap acrylic black paint
(craft department), some paper towels, a 1/2” artist’s
brush, a small container of water to wash the brush, a
carpenter’s rasp, a charcoal briquette, a utility knife and
a sanding sponge,
So, grab a coal or open hopper car, and let’s get started
on this project.
The Procedure
Next, as seen above, we place the side of the car to
match the long edge of the foam and lay the straight edge
along the other side to establish a parallel cut line. Owing
to the thickness of the car body, this will produce a piece
of foam that is a bit too fat and a bit too long.
But this is resolved as illustrated below. Lay the foam
Step 1: Cut your first piece of foam:
We place the target car on the foam simply to estimate
where we’ll cut the foam to the length we need, and mark
the foam accordingly. The idea is NOT to ride up the
curved slope of the foam tray - you want a flat piece. But
if the foam is too short, then butt together 2 pieces, and
bond the edges with CA to get the length you want.
Cut the foam a bit longer than needed, drawing your
blade along a straight edge as a guide. Now that you
have one edge perfectly straight, use cut as little as
possible away the other three sides to produce a perfect
Making Realistic Coal or Aggregate Loads, page 2
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in the car, one long edge tight against the inside of the
hopper. Mark the opposite, slightly over-hanging edge
with your blade, to match the interior of the car, then
pull the foam away and cut away the excess.
Use the same approach to trim the ends of the foam,
then try a test fit:
and thick in combination. We suggest, however, that
the thin foam sections be glued together BEFORE
cutting them to fit. We did not do this with the #4S
because handling and precisely cutting all the layers at
once would be more difficult. Point being: there is
nothing hard and fast, here - use whatever different
methods get you where you need to be.
So, let’s now move along.
Step 2: Cut foam for the remainder of the load form:
Using our first section of foam as a template, we cut
out pieces which were identical to the first. If your
clones are too big or too little, it really doesn’t matter,
because only one need fit snugly in the top of the
hopper - and that one you have already produced. The
other two will be conformed to the final shape when
you whittle and sand the slug later on, anyway.
You’ll now have 3 sections of foam, ready to be
laminated into the sandwich.
Step 3: Adhering the foam sections into one piece:
Perfect! But suppose you’ve removed too MUCH
material? Not really a problem; later you can apply
some masking tape to the edges to achieve a friction
fit, or perhaps but something in the car below the load
to hold it in place. But if you’ve really made the foam
way too thin - start over.
This step is conceptually very simple, but somewhat
tedious to implement, because you’ll need all 3
sections to matched end to end as closely as possible.
By now you will have noticed that one side of the
foam is embossed with the tray type, which forms a
depression one one side of the material. The other side
Before we move on, let’s pause to explain where we’re is perfectly flat. For best results, you’ll want the flat
sides to be glued together.
going with this. Now that you have one “perfect fit”
piece, you can increase the thickness of the foam by
making a sandwich of 3, using the first piece as a
template for the two more you’ll need. These will be
clued together with CA to produce a “slug”that you will
subsequently whittle and sand into the basic load form.
Recalling our earlier discussion of the types of foam
trays in common use, you’ll remember that we opted
for the #4S. It works well, but it was also what we had
around when we started taking pictures for this article.
In fact, your meat department has much thicker trays
available; the ones they use when the load they bear is
especially heavy - such as a thick steak or a maybe
some cut up chicken. This extra thickness means you
may only need TWO layers of foam to achieve the
final thickness you need, to project slightly beyond the
top of the hopper. So, if you are going to check the
meat department for some free trays, consider getting a
variety which includes the thick trays.
That said, you can also make a multi-layer “Dagwood”
sandwich out of much thinner foam, such as the kind
used for disposable picnic dishes. Or, you may use thin In the picture above, you’ll note that glue will be
Making Realistic Coal or Aggregate Loads, page 3
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applied to one piece, the accelerator applied to the
other (top section in the picture above). And you will
see a screw driver whose blade lies near the end of the
section at the bottom of the photo.
The screw driver is there simply to indicate that you
want to apply NO glue between it and the near end of
the foam section. The reason for this is that you will
need a glueless area to hold with your finger tips when
you bond the two pieces together. Without this dry
area, you will look very odd with foam sections
sticking out from your fingers! You don’t need an
actual tool to designate this dry area - we just put the
screwdriver there to illustrate the point.
Here is the actual set-up:
You will now repeat the procedure, this time applying
the flat side of the third section to the top of the stack,
which has the embossed side exposed. Restrict your
bead of glue to the material which is not depressed.
Again, remember to leave a dry handling area for your
fingers. When done, you have your 3 layer sandwich,
which is the slug.
Step 4: Shaping the slug:
This step is basic whittling, much as you would do
with a pocket knife and a stick, but using the razor
blade to form the slug into a sloped shape, broad at the
bottom, narrower at top. This is probably best
accomplished by holding the slug in one hand, and
drawing the blade through the foam toward you, so be
very careful. Peel away material, to make the bottom
of your slope fall just below the top of the walls of the
car, as illustrated below:
Apply a serpentine bead of the CA to one of the
pieces, leaving one end “dry,” as indicated. Spray the
entire flat side of the other piece with the accelerator.
With the glued section remaining on the workbench,
place, by hand, one end of the sprayed section
(sprayed surface facing down) on the dry end of the
glued section. For now, AVOID CONTACT of
accelerator with glue, while you line up the ends
square. Because the foam is flexible, this is fairly easy
to do. Once the ends are matched, lower the sprayed
section onto the glued one, making sure the long sides
of each are also matched. Press down firmly along the
entire length. The bond will be nearly instantaneous.
You will notice one of the outstanding qualities of
foam - it is very easy to cut and shape. You will also
notice on the of the qualities of hardened CA - it will
resist you!
Now and then, place the load in the car to check
your work.
If, by any chance, a bit of glue on your fingertips
encounters the accelerator, you’ll notice a sting. This is
from HEAT, because the reaction of the CA and
accelerator produces heat. The sensation may startle
you, but should do no harm and will quickly pass.
Because the reaction is virtually instantaneous, the CA
will form a bond before it can attack much of the
foam. If your alignment is slightly off, no need to
worry. You now have a 2 layer sandwich.
The first foam section you cut out should be on the
bottom of the stack; if not, then flip the stack to this
orientation. The embossed side of the top section (the
one that had the spray) should face up toward you.
Making Realistic Coal or Aggregate Loads, page 4
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Don’t work too hard at this; we’ll come back in a
moment to give the finishing touches. And you will
notice that we have not yet cut a slope on the ends of
the slug; but that will come in a moment.
For right now, let the artist in you come out. Grab the
sanding sponge, and smooth away the rough cuts from
your blade work producing smooth sides to your
sloped load.
Sanding sponges may be purchased from any hardware
or home improvement store. Basically, they are a fine
sponge with an abrasive surface on one side. Select a
fine grit. Because they are very flexible, they are easy to
maneuver. Normally used to sand joint compound
smooth, they are perfect for this project and many other
modeling tasks. Draw the sponge back and forth to
smooth out irregularities and impart a smooth surface to
your load. After a minute or two, you’ll have nicely
smooth sides and a realistic angle of repose.
Now is the time to cut your slopes at each end. This
can usually be done in just one or two passes, because
the distance is just an inch or so. After establishing the
The final result should look something like this:
slope, come back with your sponge to round off the
sharp edge between your side and end slopes.
Optionally, and as a final step, you may want to indicate
the gentle peaks of a load which has been dumped by
multiple tipple chutes. Consult the picture at above right
to see how to cut away wedges of foam at roughly one
third the length of the car, from either end.
Make a plunge cut one direction, then to the opposite,
and remove the wedge. Next fold your sponge as
shown in the photo at right. This will allow you to
more smoothly shape the spaces between the mounds.
When you are satisfied with the results, it is time once again
to place the load in the hopper and judge the appearance.
Making Realistic Coal or Aggregate Loads, page 5
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Actually, the above example needs a little more work.
The side slopes should be sanded away a bit more, to
suggest a more probable angle of repose of the load.
And we also need to sand away some more foam at the
near left edge, where the straight edge pokes above the
top of the car.
Matter of fact, that’s exactly what we did. But,
otherwise, this is looking pretty good; the load
descends below the top of the car walls, nicely
contained. We’re now ready for the next step.
Step 5: Applying the texture:
your bench or cutting mat. Some ballast will fall away
and spill to the side. Not to worry - just make sure that
every glued surface gets some ballast.
Because you may need to manipulate the load form to
catch a portion of ballast, your finger tips might mask
a small area from receiving any ballast at all, leaving a
“blank” spot. Not to worry - we’ll come back to these
orphans areas, later.
In general, it is better to apply too much, than too
little, ballast (or sand, or whatever). Let the excess
fall away, as long as the load form is fully coated.
What’s left behind may be swept up and used for
the next application.
In truth, if you were to apply black paint to what we
have thus far done, you’d have a credible load, as seen
We use a trim brush and our own version of a dust
from a distance. But now, we want our work to stand
up to the test of close examination in the foreground.
pan, as pictured below to capture the escapees and
And that means we need to coat the surface of our load return them to the main supply.
with something that could really BE coal (or whatever
else you may have in mind).
In this case, we are going to use Woodland Scenics
medium ballast to represent coal. But you could just as
well use sand.
The end result of this effort should produce a load
similar to the one appearing below.
Above, you’ll see some key ingredients (in addition to
the ballast itself, which is not pictured). We’ve put a
few tablespoons of the tacky glue in the sour cream
container, and stirred in some cheap black acrylic to
darken it. This gives us a thick, gray, glue.
With an artist’s brush, coat the load with this gooey Next, apply a mix of white glue and alcohol over
stuff, covering all but the sides of the edges that fit everything. We use equal parts of each. The idea is to
achieve something thick enough not to freely run, but
into the sides of the car.
thin enough to spread out and fill the voids between
Once you’ve coated everything, sprinkle on the ballast
the particles of ballast. As you can see from the picture
liberally, to all coated surfaces. This is best done over
below, it appears as a kind of milky thick fluid in the
a piece of old cardboard, or something else to protect
Making Realistic Coal or Aggregate Loads, page 6
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consistency of a thin syrup. Be generous in your
application. We find the adjustable nozzle of a mustard
bottle to be the perfect applicator, but you could just as
easily spoon it on or drizzle if from a container.
production line, there is no reason you can’t knock out
a dozen or more loads in an hour or two.
Before we move on to the finishing touches, return to
your work after it has thoroughly dried, and fill any
voids created where you held the load, or spots that
simply were left bare for whatever reason. Brush a
small spot of glue in those areas, and with your
fingers, drop on pinches of ballast and lightly press
them down with a sliver of foam or some similar clean
flat object - or even your finger tip - but very carefully
so as not to make the ballast and glue stick to you.
These repairs will dry much more quickly than the
watered down general application used originally, so
you may come back to finish in a few hours.
A word of caution: do NOT brush it on, or you will end up
Make some coal: Prefatory to the finishing touches,
pushing the ballast around and worse, picking up ballast
make some coal by scraping away material from a
and glue on the brush. Let the mixture flow or puddle in
charcoal briquette (or an actual lump of coal, or very
small globs that gradually ooze into the ballast.
charred piece of wood). Work carefully with the utility
Finally, to achieve maximum spread and saturation,
knife to scrape and gouge the charcoal, and alternately
generously spray the load with a mix of alcohol and
scrape with the wood rasp, working over an open
water (about 70% alcohol). This mixture makes the
water thinner, so it will liquefy the previous
application of thin glue and flow it among the particles
of ballast.
Set your sprayer to produce a wide misty cloud of the
alcohol and water mix. If you set it to shoot out a thin
jet, you will blow away the ballast. Hold the load
perhaps 10” or a foot away from the spray, you that
you are basically hitting it with a thick fog.
Feel free to dangle the load between your fingers,
grasping it along the edges, so you can make a straight
horizontal shot with the spray. There is enough
adhesion of the ballast to the foam to keep the particles
from falling away.
You may be tempted to immediately go to the final
step - finishing touches - right away, but don’t. Set
your work aside to dry overnight. Optionally, now that
you’ve done one load, set yourself up for production of
as many more as you need, stockpiling foam pieces to
be glued together. The description of the procedure
takes longer than the actual doing of it. If you set up a
Making Realistic Coal or Aggregate Loads, page 7
container to catch the dust and particles, as you see at
top left of the next page. You won’t need very much,
because it will be used as a kind of dusting over the
otherwise finished load. But you will need to have a
pile of it handy so you can apply it quickly when the
time comes. Note that some of the coal particles are
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shiny - just like some of the faces of an actual lump of
coal. This is exactly the appearance we want for our
coal load - it should sparkle, here and there.
Then squeeze some flat black acrylic (the cheap stuff
from the craft department) into a suitable container as
shown above.
Of course, you could prepare the coal at any point
ahead of time, perhaps make a batch and set aside until
Use a somewhat stiff artists brush (about 1/2” wide) to
much later.
brush off any loose particles from your loads. Then,
This is dirty work, by the way, so be dressed
accordingly. Fortunately, it is just that - dirty. There
should be no permanent staining of fabric or your skin.
Soap and water clean up.
Step Six: The Finishing Touches: With your load
now thoroughly dried, and any patches made, we can
proceed to painting and applying the coal dust.
If you haven’t already done so, move your coal dust to
a shallow bowl which is easy to reach into with your
fingers to grab a pinch of the dust, as shown below.
with the same or similar brush, start painting the loads
working from one end to the other, and applying full
brush loads. A semi stiff brush will allow you to work
Making Realistic Coal or Aggregate Loads, page 8
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the paint in between the particles of ballast and evenly
cover everything. No need to rush, but work quickly so
you finish in about a a minute or so. Immediate pinch
some coal dust between your fingers, and sprinkle it all
over the load. Repeat 4 or 5 times for each load,
distributing the dust as evenly as you can, but not
completely coating the load. The dust will readily stick
to the wet acrylic paint. Tap the load on its side to
remove any dust that doesn’t adhere, and set aside. The
finished work should have this general appearance:
load, which keeps coal dust from blowing into areas
through which the train will pass on the way to a
power plant or a seaport terminal for export. But don’t
over do the spray, or you’ll end up with a load that
looks like plastic which is exactly the appearance you
want to avoid.
(As a side note, you may wonder why, then, coal dust
continues to accumulate in neighborhoods or
commercial districts through which the coal trains
move. The answer is that the dust comes not from the
loads, but from the empty cars being returned to the
mines or tipples. Although the fall-out is much less
than it would be from an untreated load, it is still
present and over time will settle on roofs and interior
walls and furnishings.)
Step 7: Installation and Adjustments:
Your next move should be to inspect your loads for
any areas that may still require a bit more ballast to fill
any voids or places you missed previously. Patch these
as you did before, and paint. No further coal dust
should be needed.
Next, you’ll install your loads into the hoppers.
Inevitably, there will be fragments of ballast which
have become attached to the edges of your loads, and
The dull areas above are where the coal dust settled,
block an easy insertion into the hopper. Use you
the shiny areas are the still wet acrylic. Below we have sanding sponge to trim the edges back for a proper fit
7 loads we made for a customer, and which served as
into the hopper.
models for this article.
Sanding the edges will also remove some of your
black paint. Touch up exposed areas as necessary, they
should be dry in 15 minutes or so and ready to place.
If you’ve removed too much around the edge of your
load, it may fall into the hopper. But it will be caught
if the ends of the hopper are angled, as many are, and
the final appearance may be perfectly acceptable. If
not, then build up the edges with masking tape which
is applied to the edge of the load, then folded to the
When completely dried (about 2 hours) the paint will
have become dull, but here and there you may see a bit
of the coal dust sparkling - very much as it appears in
the real world .
Later, optionally, you may enhance the sparkle effect
by applying a thin and uneven mist of cheap hair
spray, which, because it is actually a kind of shellac,
will reflect light. Raw coal, as loaded into hoppers
appears for the most part as flat black. However,
carriers typically apply a thin spray of oil over the
Making Realistic Coal or Aggregate Loads, page 9
You may also note that your loads have acquired a
slight bow or warp, owing to the drying out of the glue
used to adhere the ballast. No problem - just bend
them back to straight. This may cause tiny cracks to
appear in your load - fill with paint, or just leave them
alone. In the real world, the same thing happens with
the coal load, which shifts unevenly as car move along
the track. Just use your visual judgement in deciding
what to do, if anything.
Alternatively, put standoffs inside the hopper to
elevate the load to the desired height, or apply thin
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shelves to the walls to do the same job. There are
other ways to solve this issue - let your imagination
guide you.
We hope you have found this article to be both
inspirational and useful.
Rest assured that, once you get started, you will find
that it takes longer to read the article than it does to do
the work involved.
Making Realistic Coal or Aggregate Loads, page 10
Most certainly, modelers who undertake this project
will discover methods and materials that make the
work go faster and more conveniently, with improved
results. We hope you will share them with us so that
revisions of this article may include your discoveries
and recommendations. Contact us at:
[email protected]
so we may include them in future revisions of this material.
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