Installing The Track Power Buss

Wow!!  At last!  We've got the module deck completed.  We started out with some

• Bits-and-pieces of wood
• Installed some T-nuts
• Assembled and painted the bits-and-pieces
• Installed a chunk of Styrofoam
• Painted and finished things off

Before we lay any track on the module deck, there's two things we have to get out of the way first -
1) Install the track power buss;
2) Install the LocoNet and telco jacks/ UP3/5 panels.

This will save us a lot of time and headaches later on.  There's nothing worse than having the module flat on its back with the underside face up and the trackwork laying on the work surface.  We usually compromise by stringing the track power buss on the surface of the gussets and middle cross member which leaves the wiring vulnerable to tearing out, or on its side which results in a lot of sag, wire staples, and hanging track feeders.  If we can work on the wiring now, we can get it nice and snug to the surface of the Styrofoam so that wiring the track feeds will be a piece of cake.

For the record (cause I know there`s gonna be discussion on this issue), I use a minimum of 14 AWG stranded copper wire for the buss and a minimum of 20 AWG stranded copper wire for the track feeds.  Connecting the two, I'll use either 16 AWG or 18 AWG stranded copper wire "pigtails"  to join the track feeds to the power buss.  Once the track power buss has been installed (at the end of this blog), I don't ever touch the track power buss when I'm installing track feeds.  All track feeds are connected via the "pigtails" - which results in a wiring job that's almost flush with the surface of the Styrofoam.  No "saggy pants" on this job.

All wire connections are soldered.  Plug connectors (Jones, trailer, power pole, 4-wire, 2-wire, etc) at the module ends are soldered to the buss.  I don't use suitcase connectors.  I don't use any spade terminals.  I don't use terminal blocks.  I don't use any brass screws.  I don't use house wire.  There are no mechanical connections from one end of the module to the other.  I only use stranded copper wire that is soldered together and covered in shrink tubing because it's what I believe is the best. 

I find the best wire source is the automotive supply store that carries trailer hook-up wire.  It comes in 18, 16, 14, 12, 10,  8 AWG wire sizes, 25' and 100' rolls, and in 7 colours - white black, red, green yellow, blue, and brown.  It's the same stuff that's used by the trucking industry to light up the trucks and trailers on our highways.  If it's good for them, it's gotta be good for my modules!  In North America, the major manufacturer is Grote Industries. Here in Canada, Princess Auto periodically puts the stuff on sale in 25' or 100'  rolls for about 25¢-30¢ a foot.

I use two colours when wiring so as to keep the wiring job simple with one colour for the front rail and the other colour for the back rail..  If there's any problems, it's a simple matter of tracing two colours.  In this case, I'm going to use black and white throughout - black-and-white track power buss, black-and-white track feeds, black-and-white "pigtails". 

When soldering 14 AWG wire you need a soldering iron or soldering gun with a high wattage.  A 20-watt pencil soldering iron won't do the trick.  A 40-watt iron might do the job but it's going to take a lot of patience.  On the heavy-duty 14 and 16 AWG wire, I use a soldering gun.  The first click of the trigger gives me 100 watts.  The second click gives me 140 watts.

There are two kinds of solder - plumber's solder and electrical solder.  Plumber's solder is readily available at your local building supply store, along with acid flux.  It's the kind of stuff you use on the copper pipe in your house.  DON'T EVER USE THAT STUFF ON ELECTRICAL WIRE!  It will cause you great grief!  It's easy to tell if plumber's solder has been used by the green corrosion on the wires and on the soldered rail joiners.  The corrosion starts to show up real quick.

Rarely will you find the name "electrical solder" on the label of the electrical solder.  You have to look for the word "rosin" on the label. Rosin is the flux used to complete the soldering operation on electrical wires and circuits. It comes in various mixtures and "thicknesses".  In any heating operation, oxygen in the air reacts and forms an oxide so that the solder forms a "blob" rather than flowing into and through the work.  To keep the oxygen off of the work, we need a flux - in this case rosin - to do the job properly.  While "rosin core" solders are advertised as having flux in the solder, there isn't enough to do the job on our 14 and 16 AWG wire.  Which is why we need some extra rosin flux. Rosin fluxes come in two states - paste and liquid and several kinds of dispensers - bottle,  pen, jar, etc.  Each is equally as good as the other. 

A soldering job isn't complete unless the solder "flows" along the two pieces being joined, whether it's rail joiner to rail, rail to track feed, track feed to pigtail, pigtail to track power buss, or track power buss to plug.  Using a combination of flux, solder, and the right amount of heat applied for an appropriate length of time, we can produce a connection that will last a lifetime.

My father used to say that we have to "cook" the solder.  That is, once the solder starts to heat up, leave the soldering iron on the wire for 4-5 seconds more (Count "one-thousand, two-thousand, three-thousand, four-thousand, five-thousand".)  This ensures the solder will flow into every strand of wire and around the joint.  (Don't try "cooking" the solder on a printed circuit board!)  Otherwise, we will end up with a "cold" joint that will give us problems months, even years, down the road.  The combination of flux, heat, and solder will ensure that we have a reliable electrical connection. 

If you aren't familiar with the soldering process, practice on a few pieces of wire before tackling the track power buss. There are all kinds of instructions on the web which tell you how to solder. 

Here's the material, supplies, and tools we'll need to install the track power buss.

1. 1 pc - white 14 AWG stranded wire 6' long (one half of the buss)
2. 1 pc - black 14 AWG stranded wire 6' long (the other half of the buss)
3. 2 pcs - white 16 AWG stranded wire 18"' long (to fasten to the white 14 AWG buss and which we'll connect to our track feeds)
4. 2 pcs - black 16 AWG stranded wire 18"' long (to fasten to the black 14 AWG buss and which we'll connect our track feeds)
5. 4 pcs - 6mm (1/4") shrink tubing 1 1/2" or 2" long (to cover up the exposed soldered joints)
6. 2 pcs - wire staples (to hold our buss in place at the module ends)
7. Rosin Core solder
8. Rosin Core flux
9. 100/140 watt soldering gun (or equivalent)
10. BBQ lighter or other heat source (to shrink the shrink tubing) 
11. Duct tape (to temporarily hold the wires in place against the Styrofoam when we apply polyurethane glue).  We can also use a pair of T-pins stuck at a sharp angle into the Styrofoam to hold the wires in place.  
12. Polyurethane glue (for gluing the wires to the Styrofoam)
13. 2 C-clamps (to temporarily hold the buss in place against the module ends when we apply polyurethane glue)
14. 2 blocks of wood, 1"x 4" and 4"-6" long (or something similar) (to temporarily hold the buss in place against the module ends when we apply polyurethane glue)
15. Spray bottle of water (to speed up the reaction of the polyurethane glue)  
16. 6"-8" piece of telephone cable (to keep the buss wires separated in the notch of the middle cross member).  

1) Mark the mid-point of 14 AWG wires with a marker, etc (at the 3' mark).
2) Mark the mid-point of the 16 AWG wires with a marker, etc (at the 9" mark).  
3) Measure 12" from the mid-point of the 14 AWG wires on both sides of the mid-point.  Mark the spots on the wires with a marker, etc.

4) On each of the 6 wires, strip about 3/4" of insulation so that you are looking at bare stranded copper wire.

 5) String the 14 AWG wire under the notch in the middle cross member.

6) Wrap a piece of 16 AWG wire around one of the bare spots of their respective 14 AWG wire as shown in the photo below.

7) Apply some rosin flux.  Apply the soldering gun and solder.  Once the solder starts to flow, "cook" the joint (ie leave the soldering gun in place) for 5 seconds.

8) Roll on a piece of shrink-tubing so that it covers the bare soldered joint.  Shrink the tubing with the BBQ lighter or your favourite heat source.

9) Repeat Steps 6) to 8) for the other 3 joints. 

10) Centre the pigtails on each half of the module (ie the 1' and 3' "mark").  Make sure you twist both the white wire and the black wire so that you have about 6-8 twists from one end of the module to the other.  (This is particularly important if you belong to a module railroad club where total module lengths are longer than 30'.  Twisting the wires together prevents "ringing" which can result in distortion of the DCC signal that goes down the track power buss.  For more information on the phenomenon, Google DCC Ringing.)

11) At one end of the module, using a C-clamp and a block of wood, anchor the two buss wires in place against the module frame.  The two buss wires should be touching each other. 

12) At the other end, pull the wires tight using the block of wood and the C-clamp as a lever.  When tight, clamp the buss wires in place. Again, the buss wires should be touching each other.

13) Insert the 6"-8" piece of telephone cable into the notch in the middle cross member and between the two buss wires.  The objective here is to ensure we have enough space to insert the 6-wire telephone cable when we install our LocoNet cable.  You may have to use a "poker" (eg popsicle stick, ruler, etc) to cut a shallow channel under the Styrofoam so that the cable can slide through. 

14) About every 6"-8" or so, place a small strip of duct tape or a pair of T-pins across the two wires so that the buss wires are flat against the Styrofoam and touching each other.   

15) Drizzle some polyurethane glue in between each strip of duct tape and over the two buss wires.  Spritzer the glue with water to start the reaction.  If necessary where the wires are lifting a bit off of the Styrofoam, put some weights (eg clamps, etc) across the wires. 

16) Once the glue has set and hardened, remove the duct tape.  You may have to apply more glue to the stuff already set to cover the wire. 

17 ) Set the module on end.  Using the pliers to hold the wire staple, hammer a wire staple between the two buss wires and into the end of the module frame so that the buss wires are secured to the module frame.  It's not necessary that the staple be driven in next to the Styrofoam as the polyurethane glue and the stiffness of the wires will hold them in place.  

Voila!  Buss wire installed.

Except for soldering our plugs (Jones, trailer, power pole, etc), we'll never have to touch the buss wire again.  It's nice and snug against the Styrofoam and we have a very neat package.  All of our connections with the track feeders will be done through the pigtails (which we'll cover in a later blog).  Simple, eh!?

Later on, we'll show you a trick for keeping the plugs and LocoNet connections out of the way when we transport our modules.

Next, we get ready to install the LocoNet.

(If you've stumbled across our blog mid-stream instead of from the start, you might want to start off with a previous post where we trimmed the size of the telco jack as it came right out of the box down to a slimmer trimmer package.) 

PS - Here's tip that will help you thread those stubborn track feeds through the Styrofoam or any deck

Installing The Styrofoam - Part 4 - Finalizing A Masterpiece

In a previous episode, we finally installed the Styrofoam deck using polyurethane glue.  The glue set up nice and fast and we're now ready to finish things off.  It may take us several months (or even several years!) before we get every square inch of our modules scenicked and structured. 

IMHO, there's nothing worse than seeing the pink (or blue or green) of the top deck of a module with huge gaps between the wooden frame and the Styrofoam.  It completely detracts from any scenicking we may have done - and we certainly don't want that to happen. A few easy steps will make sure that our visitors focus, focus, focus on our nice scenicked vignettes.  


Trimming The Beaded Polyurethane Glue
In less than 12 hours the polyurethane glue has set nice and hard.  If you've taken the option of taping the interior underside of the module, we only have a few beads of polyurethane glue to pull off the underside of the module. 

However, if you haven't used the masking tape, we've got a bit of work to do.  OR, you can leave the beads where they are as you're the only one who's going to be spending any time looking at the underside of your modules.

In this latter case, I take a utility (or other kind) of knife and slice these beads off simply to make the underside look a little neater.  An Atlas snap saw or a razor saw will also nicely trim the beads.  You can leave them on if you want to.  (You might not see the difference between the photo below and the photo above but the glue bead has been cut off, making quite a difference. 

We've put on two or three coats of paint plus glue so we want to make sure the threads in the T-nuts are clear.  Take a 5/16" bolt and screw it into the T-nut with your fingers.  If the bolt sticks, gently use a wrench to tighten the T-nut.  Make sure you don't strip the threads!  The black paint has covered over the red paint I had on the blind T-nuts so I've freshened up this paint.  (You may have to use a "tap" to clear the threads.)

Finishing The Top Of The Deck
Turn the module over so that we're looking at the top.  Here's the tools and supplies we'll need to finish off the deck of the module.

 I first sand the glue off the wooden edge of the module frame.  DON'T sand the Styrofoam! (Yet.)

I next cut off any dried beads of polyurethane glue with the utility knife, making sure that the Styrofoam is flush with the edge of the module frame.

We next have to deal with holes, scars, scratches and scrapes on the top of the Styrofoam.  We also have some large gaps between the module frame and the Styrofoam.  I use spackling compound on all of my module work because it is much lighter than any other plaster product.  I also have several hours before it starts to set compared to the 5-10 minutes for hydrocal or plaster.

When you first open the pail from the store, the spackling compound will be very dry-looking.  It needs to be revitalized.  I spray some water into the top of the pail and stir it all up with a paint stir stick.  With the spray bottle, I add a small amount of water at a time and stir the paint stick until it resembles Cool Whip dessert topping - light and fluffy but very spreadable (the technical term is "plastic").  It only takes a few squirts to go from "plastic" to "soupy" so watch how you add the water.  

I fill all of the imperfections and gaps with the spackling compound using a wide putty knife to produce a smooth surface.  This first coat usually takes 24 hours to dry. 

Once the first coat is dry, a light sanding gets rid of any ridges left by the spackling compound.  Make sure you vacuum or brush off any crumbs from the sanding as they will mar the surface of the Styrofoam in subsequent sandings.  A few more coats of spackling compound (with light sanding in between) and we can produce a top deck that looks almost like one continuous sheet. 

Painting The Module Deck (Getting Rid Of The "Pink")
While I might be able to put some railway track on the module in quick order (and get the modules included in next setup), it will be several months before I have a completely scenicked module.  The pink (or blue or green) Styrofoam deck will detract from the other modules in the setup.  A couple of coats of flat brown or grey latex paint gets rid of the pink.  Make sure that it's latex and and not alkyd (oil) paint!!!  Alkyd paint will turn the Styrofoam into a sticky mess.

After the first coat of paint, other scars and scratches may become apparent.  It's a simple matter of applying a bit more spackling compound and covering up the white with some paint.

And voila!  One completed module.  Not bad, eh!?.

Jusr for the heck of it, I put the module on the bathroom scales.  It weighed in at 8lbs (3.2kg).  Now that's what I call "very lite", eh!?

In our next blog, we install the track power buss.  After that, we install the telco jacks (UP3/5 panels).

Installing The Styrofoam - Part 3 - Applying The Glue

On our previous posts, we cut the Styrofoam.  Then we got the materials we're going to need together (this part can get messy so we want to make sure we're not scrambling for a spray bottle, cleaning rags, etc).  
Now we're ready to apply the glue and install the Styrofoam.  Make sure you have a flat work surface, particularly if you aren't going to use the clamping method.  

If any of the T-nuts are going to be covered by the Styrofoam, place a square of masking tape over the washer end of the T-nut as the polyurethane glue will expand into the T-nut.

Make sure you have the shop rag soaked in varsol close by.  I put my soaked shop rag in a shallow plastic container so that the rag stays soaked.  You will need your spray bottle of water close at hand, primed and ready.  Your garbage pail should almost be at your feet ready to discard the two 18" strips of masking tape.

Spreading The Glue
1) Place the Styrofoam on the two blocks on the floor so that you are looking at the 22 1/2" edge.

2) Squeeze a thick bead (or two thin beads) of polyurethane glue along the length of the 22 1/2" edge as shown in the photo below.

3) Spread the glue over the complete surface of the Styrofoam with the putty knife.  The idea is to spread the glue along the length of the edge of the Styrofoam with the putty knife much like you would thinly spread butter on a piece of toast.  It doesn't require a lot of glue as the glue will expand quite a lot as it absorbs the moisture. 

4) Rotate the Styrofoam 180 degrees so that you are looking at the other 22 1/2" edge.  Apply and spread the glue. 

5)  Rotate the Styrofoam 90 degrees so that you are looking at the 46 1/2" edge.  Place the Styrofoam on the module frame so that it is resting on the two 18" strips of masking tape.  Apply and spread the glue. 

6) Rotate the Styrofoam 180 degrees so that you are looking at the other 46 1/2" edge.  Rest the Styrofoam on the two strips of masking tape. Apply and spread the glue. 

You should now have all 4 edges of the Styrofoam buttered with polyurethane glue.  You have a very sticky mess on your hands.  This is where having the varsol-soaked shop rag close by is very handy.

7) Pull the two strips of masking tape off of the module frame and discard them in the garbage pail.

"Spritzing The Module Frame;  Inserting The Styrofoam; Duct-Taping The Top
8) Liberally spray the interior of the module frame with water.  The water should almost be running down the inside of the frame.

9) Insert the Styrofoam into the module frame.

10)  On the top of the module, cover the gap between the module frame and the Styrofoam with duct tape.

11) If you aren't going to clamp the Styrofoam down with clamps and spruce strapping, go to Step 13.

Clamping The Top Deck
12) If you have the clamps and spruce strapping, clamp the Styrofoam down to the module frame on the 4 corners and then in the middle as shown below.  If you have extra clamps, you can add them if you wish. 

Babysitting The Polyurethane Glue (Very Important!)
13) Turn the module over so that you are looking at the underside of  the module.  You will see that the polyurethane glue has already started to expand and is oozing out of the gap between the Styrofoam and the module frame.  

14) If there is a large cavity that is less than 1/8", dribble a bit of polyurethane glue into the gap.

15) If the cavities are greater than 1/8", slice some pieces from a chunk of scrap Styrofoam.  Dribble some glue into the gap.  Insert the slice of Styrofoam.  If any part of the slice sticks above the surface, trim it flush with the underside with a utility knife.

16) Liberally spray the Styrofoam with water. 

17)  By this time, the polyurethane glue is oozing nicely out of the gap between the Styrofoam and the module frame.  Notice the difference between the photo above and the one below taken 30 minutes later - lots of glue oozing out of the gap.   Scrape the glue off of the Styrofoam with the putty knife and stuff it into any cavity where the glue hasn't yet oozed out.  Repeat this process for the next hour.

Here's a close-up of the foaming glue where we've masked off the underside of the module with masking tape.

18)  If you've taken the option of taping the interior underside of the module, as the polyurethane glue bubbles up, scrape the excess glue off of the masking tape with your spatula.  Wipe the excess glue off of the spatula with a rag, shop towel, or paper towel.

19) Periodically clean your hands, the glue bottle, and the spatula with the varsol-soaked shop rag.  

20) Throughout all this time, the polyurethane glue is reacting with the water and foaming in the gap between the Styrofoam and the module frame, even though you may not be able to see this reaction.  Our objective is to ensure that the glue will ooze out of the underside of the module and form a nice bead between the Styrofoam and the module frame all around the perimeter of the module.

As we can't see what is happening between the thickness of the Styrofoam and the module frame, the bead is our indicator for ensuring that the glue is expanding along the full thickness of the Styrofoam.  This bead will start to harden in about 2 hours.  It will be completely set in 18 hours, after which, we can trim it flush with the Styrofoam.  Here's a closeup of the hardened bead.

Removing Masking Tape, Clamps & Duct Tape/ Preliminary Cleanup
21)  If you've taken the option of taping the interior underside of the module, peel back the duct tape, working the tape from the top and outside of the module frame and the Styrofoam back to the edge where the polyurethane glue has oozed out. Using the edge of the spatula or other semi-sharp tool, as you lift the edge of the maksing tape off the module, scrape the still-gooey bead that remains off the Styrofoam and module frame.

22)  After 2 hours the glue will have set up, is no longer oozing out of the gap but it's still soft.  Turn the module over so that you are looking at the top.  If you've used the clamps, remove them.

21) Remove and discard the duct tape.  The glue on the top of the module has been held in check by the duct tape but there may be a bump around the perimeter of the module where the polyurethane glue has tried to ooze out of the top - more pronounced if you didn't use the clamps. 

22) Glue will have oozed out underneath the duct tape and onto the module frame.  As you remove the duct tape, you will find that most of the excess polyurethane on the Styrofoam has peeled off with the duct tape.  However, the glue on the module frame stays in place.  This glue may be slightly soft.  You may be able to scrape it off the wood with the putty knife or with a chisel.

23)  You may be able to peel any excess glue on the Styrofoam by rubbing it with your fingers.  However, if it doesn't easily come off, DON'T try to remove the glue on the Styrofoam as you will tear out chunks of Styrofoam with the glue.  After the glue has hardened, we can trim it off with a utility knife tomorrow.

24) There may also be gaps between the Styrofoam and the module frame.  Don't try to fill these gaps with polyurethane glue.  The glue has sufficiently expanded along the thickness of the Styrofoam so that it is well fastened to the module frame.  We'll fill these gaps and any gouges in the Styrofoam later on with some light spackling compound.  

Voila!  We have just permanently glued the Styrofoam into the module frame.   

Next up.  We trim the polyurethane glue bead from the underside of the module and finish up with a masterpiece.

Installing The Styrofoam - Part 2 - Getting Ready To Glue

The next steps deal with VERY sticky glue.  Before you start down this path, read this and the next 2 posts. 

From our previous post, now that we have the Styrofoam cut and snugly fitting into the module frame, we now get ready to permanently glue it into the frame with polyurethane glue.  It is manufactured by most glue manufacturers (Elmers, Lepage, etc) and you probably know it best by the catchy brand name of "Gorilla Glue".

Polyurethane glue is an expanding foam glue when it comes in contact with moisture (ie - water).  It expands almost like spray foam insulation that you get in the aerosol can.  It takes a bit longer than spray foam to set up so we have time to place it into the module frame and work with it.  It has the look, consistency and spreadability of corn syrup.  It can be spread very thinly while still a liquid.  A very, very thin layer of glue will expand to fill the space between the module frame and the Styrofoam.  It starts to set up in about an hour and starts to harden an hour later.  It will be hardened in about 12 hours and we can work on it in 24.   

If we aren't prepared, it can be very, very messy which is why we want a shop rag soaked in varsol before we start gluing.  While still a liquid it can be washed off your hands with varsol followed by hot soap and water.  Once it sets up, it will take about 10 days to flake off your fingers. 

Tools & Materials
Which is why we need the following tools and materials close at hand: 

• polyurethane glue
• 1" - 1 1/2" putty knife (for spreading the glue)
• spray bottle of water set to a fine mist (to speed up the reaction of the glue) 
• masking tape (to reduce the mess)
• duct tape (to stop the glue from oozing out the top of the seams)
• varsol (turpentine, paint thinner, etc) (for cleaning up before the glue sets)
• shop rags (for cleaning up)
• 2 blocks of wood (to reduce the mess)
• garbage pail (to quickly dump the masking tape and shop rag into)

Clamping the Top Deck
 The following materials are for a recommended practice if you have them, but are not necessary to glue the Styrofoam into the module frame.  They do, however, make the work a lot easier.    

• 2 pcs - 1"x 3"x 48" spruce strapping (or any size to form a 48"x 24" rectangle)
• 2 pcs - 1"x 3"x 20" spruce strapping (or any size to form a 48"x 24" rectangle)
• 6 pcs - 12" wood clamps
• 4 pcs - 1"x 3"x 4" spruce strapping

The polyurethane glue will expand and ooze out of the top and bottom seams between the module frame and the Styrofoam as it sets up.  In all cases we'll tape the top of the module with duct tape to limit the amount of oozing coming out the top.  Once the glue has set up, we simply trim the excess glue from the top of the module.  If we can clamp the spruce strapping to the top of the module, we can almost stop any oozing coming out of the top of the module so that all we have to focus on is the bottom (underside) of the module.  It also ensures that the top of the Styrofoam is relatively flush-and-even with the top of the module frame.  Here's a photo of my "dry run" for this install to make sure that it all fits together. 

And a close-up of how we'll clamp the corners.

Taping One Corner; Blocks On The Floor
For all installs, I place two 18" strips of masking tape in the middle of the end plate and the middle of the side plate.  I tuck the 4 corners of the tape into the sticky side to act as a tab when I want to remove the tape.  This is where we'll place the 46 1/2" side of the Styrofoam while we apply and spread the glue. 

I next place the two blocks of wood on the floor about 18" apart parallel with my feet.  This is where we'll place the 22 1/2" side of the Styrofoam while we apply and spread the glue.

Huh!  What's this all about??

Think it through.  We're going to spread glue on one side.  We then rotate the Styrofoam 180 degrees to spread glue on the other side.  But we have a problem.  The side we want to set down has sticky glue all over it.  Where do we set it down!!??  On top of the masking tape for the 46 1/2" side and on top of the wooden blocks for the 22 1/2" side.

I learned this little trick with the blocks and masking tape the hard way when I glued in my first piece of Styrofoam with polyurethane glue.  I had glue spread all over one 22 1/2" side and one 46 1/2" side.  I went to apply glue to the other sides.  Where in the heck do I set this down!!??  Yup, I had one hell of a mess!  It took 10 days before I shed all of the glue off my hands and fingers.

Taping The Underside Inside
The following is another one of those options.  The polyurethane glue is going to expand and bubble up on the underside of the module on the edge between the Styrofoam and the module frame to form a bead of dried polyurethane glue.  We can either leave the bead of dried glue where it is, trim a lot of it off after the bead has dried, or take steps in our prep work so as to minimize the size of the bead.

If we take this latter option, it's a simple matter of taping the inside edges of the module frame and the Styrofoam as shown in the photo below.

 To give you a better idea, here's a closeup of how I've taped one of the corners.  We simply proceed to do the same all around the inside perimeter on the underside of the module.

As we proceed with the gluing, we'll show you the next steps to take.     

In our next blog, we apply the glue and insert the Styrofoam into the module frame.

Installing The Styrofoam - Part 1 - Cutting

Styrofoam is available in many shapes, sizes and colours, depending on where in the world you happen to live.  Technically, "Styrofoam" is extruded polystyrene.  You'll only find the word "Styrofoam" on the blue stuff as it is a registered trade mark of Dow Chemical used to describe their building insulation version of extruded polystyrene.  I don't know who manufactures the green stuff as it isn't available in my neck of the woods.  The pink stuff is manufactured by Owens-Corning.

The building-insulation kind comes in various thicknesses (1/2", 1" 1 1/2", 2", 4"), sizes (2'x 8', 4'x 4', etc) and insulating R-values.  The denser and thicker the product, the more expensive it is.

Since the inside of my modules are 2'x 4' (and sometimes 30"x 48"), I'm interested in the Styrofoam that is 2'x 8' and which is readily available at local building supply stores.  When I build 30"-wide modules, I simply glue two pieces together.

There are usually two types of 2'x 8' Styrofoam boards - butt edge and "shiplap" edge.  As the name implies, two sheets of butt-edged Styrofoam simply butt up against each other.  The edges of two sheets of shiplap edges will overlap each.  While I prefer the butt-edge sheets as I have to cut off the overlap-edge on shiplap, you'll have to use what is readily available to you.

As Styrofoam is an oil-based product, the price will vary greatly.  You can save quite a bit of money if you buy your Styrofoam at your local contractor's building supply store.

Styrofoam cuts very easily.  You can score it deeply with a utility knife and snap it in half.  You can cut it with a hacksaw blade or hand saw.  It cuts really nice on a table saw if one is available to you.  I'm going to cut my Styrofoam using a hand saw.  Styrofoam can be very messy when cut with a saw so I'm cutting it outside on my picnic table.  Measuring the inside of the module frame, I need a piece that is 22 1/2" wide and 46 1/2" long.  Love that pink! (Or is it blue?  Maybe it's green.) 

I stored my Styrofoam outside in my tent garage and the chipmunks decided to make a home in it.  So I'll have to patch some holes for the second module.

Rub the edges of the cuts with your hand to make sure the crumbs stay outside and aren't brought into the house.

Dry-fit the Styrofoam into the of the module frame to make sure that it fits snugly in place.  I like to put the lettering topside on the module as I'm going to paint the module deck.  This will leave a nice"clean" look on the underside.  Where there is any "friction fit", trim the sides of the Styrofoam. 

Don't be concerned if there are gaps between the Styrofoam and the module frame.  In our next blog, we're going to use some expandable polyurethane glue (you might know it as "Gorilla Glue") to glue the Styrofoam in place.  Later on, we'll smooth out any other gaps with some spackling compound.

Check and make sure the Styrofoam doesn't poke above the edges of the module frame.  If they do, score the Styrofoam underneath the gusset and shave a slice or two out of the Styrofoam.  This won't weaken the Styrofoam in any way as the Styrofoam isn't glued to the gussets.

Up next, things start to get kind of messy as we get ready to apply the polyurethane glue.

Carry Plates - Boxing The Modules Together

One problem we face when transporting our modules is protecting the track and scenery from damage.  This problem is readily overcome if we can "box" our modules together in pairs with the track and scenery facing inwards and the undersides of the modules facing out.  We can readily box the modules together by bolting a rectangular piece of plywood, which I call "carry plates" on the ends of the two modules.  To give you an idea of what I'm talking about, here's what my carry plates for Bancroft & Irondale looked like after I had just finished them.

The carry plates are fastened to the module ends with eight 5/16"x 1 1/4" bolts and washers.  Notice the hole in the middle of the carry plate - the "hand hold" holes.  With another person on the other end, it's very easy to lift and move this boxed set of modules.

The carry plates are made from 3/8" poplar plywood that is used as flooring underlay for tile floors in the house.  I find it has the same density as 1/4" fir plywood at half the cost but with that extra ply which provides added stability.

I regularly cruise the building supply stores and keep an eye open for sheets or pieces of plywood that are either in the cull bin, or have been damaged on the edges.  I can usually pick up a 4'x 8' sheet of plywood for about $8-$10 and, once again, use their saw service to cut the sheet up into rectangular pieces.

I have the plywood cut up into pieces that are 25" long by about 18" wide.  The width will depend on what kind of scenery and structures I'm going to put on the modules and whether I will have a backdrop.  While the width of the modules is 24", I add an extra 1" to account for the thickness of two pieces of 3/16" Plexiglas or Luan backddrop and "finishing" washers that I use to fasten the Plexiglas/ backdrop to the module.  This keeps the Plexiglas off of the floor/ carpet and reduces the amount of scratching when I load them into the car.

Poplar plywood can be a bit rough so I usually give each rectangle a good sanding on both sides and fill up any cracks with filler - body filler, wood filler, even spackling compound - anything that will hide those cracks.

The first step is to locate the middle of the plywood.

My next step is to locate the "hand holds" where I can insert my hand to lift the boxed set.  After much experimentation with different sized holes, I settled on the following - simply two 1 1/2" holes (ie 3/4" radius) drilled into the plywood, the piece between the two holes cut out, and the edges rounded with a file.  Here's the diagram for locating the two holes.

 Using this diagram, I locate the centre for drilling the two holes.

 And drill the holes out using a 1 1/2" Forstner or spade bit.

Once I have the two holes drilled, I draw two lines between the holes.

In order to get my hacksaw (or sabre saw) blade right next to the edges of the circle, I file the edges square with a file.

 Then, using a hacksaw blade or a sabre saw, I cut along the two lines between the two circles.

 With the small piece of plywood between the two circles cut out, I can now round the edges of the hole on both sides with a straight and half-round file. 

 And here is what the final result looks like.

Since I'm buying a 4'x 8' sheet of plywood, I can usually get 6 carry plates out of one sheet which I then complete all at once (a bit of "mass production").  I next give the carry plates two coats of paint (pick your favourite colour).  I'm now ready to drill 4 holes that match the location of the T-nuts for the carry plates.  This we'll do later on.

For the moment, we're going to get ready to install the Styrofoam deck.  As these steps are going to be quite different from anything we've done so far, we're going to do it one step at a time.  So, before you race ahead, read all of the instructions first.