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Make Your Own Homasote Roadbed

I made a ton of homasote roadbed for a fraction of the commercial price, and you can too!Cut it yourself on a Table Saw and save a ton of money

By Craig Bisgeier

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The choice of roadbed, or the material that we lay our track down on, is an interesting and complicated one.  there are lots of types to choose from, including Cork, foam strips, pine lathe, Micore and many others including Homasote, my personal favorite.  Homasote is a sheet-goods product sold in 4' x 8' panels like plywood, 1/2" thick.  It is excellent for spiking track down onto (holds spikes really well, not difficult to drive into), it holds its shape and is easily worked with most cutting tools we have on hand (jigsaws, utility knives).  It's biggest downside is that most people find the dust generated when cutting it objectionable, and that's hard to argue with.  A lot of folks also object to the 1/2" thickness of homasote and prefer to use something thinner.

Many opt to purchase homasote strips already pre-cut into a useful roadbed shape (thin cross-section with beveled edges).  This eliminates the mess and waste of doing the work yourself but at a very steep price - You are paying a lot of money for the convenience of skipping the cutting and dust.  While I liked the product and have actually bought it in the past, the last time I ran out of it I started getting ticked off at how much it cost me to buy something I could easily make for myself in an afternoon.  As a woodworker and home improvement buff I already had a tablesaw, so I decided to give it a try - the worst that could happen was I'd be out $20 for a sheet of homasote, and I wouldn't be so mad about handing over my money for the product any more.

Well, I got convinced all right, but not to buy the overpriced stuff any more!  That afternoon I took that $20 sheet of Homasote and turned it into over 200 feet of roadbed equivalent to the commercial product, worth a retail price of about $170 before shipping. Plus, because I cut it to thickness on my tablesaw I also netted another 175 or so feet of 1/8" Siding-height roadbed worth about another $150 or so on the street. Not bad for about 5 hours work on a sunny day outside the garage.

It was not very hard to do, no special jigs or anything, just some hard work and dust. Most of it was collected by my dust collector (which I had to empty two times) and the rest by my shop-vac after the fact (emptied once). And the results were just as good as the product I've purchased in the past. To net over $300 worth of roadbed from a single sheet of homasote that cost me about $20 sounds like a pretty good investment of time to me.

Tools Needed

bulletJigsaw for cutting kerfs (A Band Saw is better if you have one, but a thin blade on the jigsaw works fine)
bulletCircular Saw for breaking down large panel (helpful but not critical)


bulletone 4' x 8' sheet of 1/2" homasote

Basic Roadbed

First, get yourself a good dust mask to protect yourself. Also, try to do this outside as much as possible to maximize your ventilation and minimize the mess you'll need to clean. Homasote makes a LOT of dust, as if you didn't know that.  If you do it on a windy day Mother Nature will help you clean (but your neighbors won't be really happy).

Take an ordinary 4' x 8' sheet of 1/2" homasote and cut it into three sections 32" wide x 48" long, on the tablesaw if you must but I used a Circular saw because it was easier and safer. The smaller sections are easier to handle while cutting, and the 32" length is ideal for handling the strips after cutting (they won't break under their own weight as they are handled).

NOTE:  I model early period railroading in HO scale, so my exact cuts might not be the same as yours.  Determine your own measurements from the size and scale of your own track, or take them from an existing piece of roadbed you have and like.  Don't be afraid to experiment before you cut up the whole sheet. 

Also decide now if you want to include beveled edges on your roadbed or not.  Beveling the edges doubles the number of cuts, and also reduces the number of strips you'll realize in the end by about 20%.  Ballast profiles can be easily added with joint compound and a putty knife after laying the roadbed down quickly and for little cost.  It's up to you, I did the beveling step because I was trying to prove to myself I could do it, but if I were to make more roadbed later I'd skip it.  Unless of course you are making a split roadbed, in which case it's pretty simple and doesn't add any cuts.

For my own roadbed I cut the panels along the 32" length in strips about 1-3/4" wide.  If you are going to make a split roadbed (separated down the center) add another 1/8" to the cut width to account for the blade kerf when you need to split it later (assuming your tablesaw blade cuts a slot 1/8" thick). When you are happy with the width, cut all three panels up into strips.

Now set up for milling the strips to thickness. First check to make sure your fence and blade are both set to 90* to the table. Accuracy counts here if you want a good result.  I use a plastic drafting triangle to check and adjust both things. Another good safety device to use here is a zero-clearance insert around your blade.  This will help support the thin strips next to the blade and keep them from being drawn down into the space between the blade and the table.  If you have one, use it.

For my roadbed I set the fence 1/4" away from the blade, and raise the blade to just over 1/2 the height of your strips when standing on end (so if your strip is 2" wide, raise the blade to 1-1/8"). If you have a featherboard to help push the strips against the fence, install it now.  Cutting half the height twice (as you'll see in a moment) is much safer and will work just fine.

One by one, run each strip through the blade, using a push stick when you get near the end of the cut. Take the strip and flip it end for end vertically -- not horizontally -- and cut the strip again, which will complete the cut for thickness, and should yield one strip 1/4" thick and a second cutoff strip about 1/8" thick. Cut all strips to thickness them. 

NOTE: I found that there are two distinct sides on a sheet of homasote, one side with defined grooves like tire treads and one with mushy grooves. The side with the defined grooves is flatter and should be kept against the fence when thicknessing, it will give you a more consistent product in the end. Let the cutoff have the uneven side.

So now all your strips are cut to width and thicknessed. If you are not going to cut the bevels into the edges of the roadbed, you are now done with the majority of the cutting!  Have a soft drink and skip down to Kerfing for Curves.

Split Two-Part Roadbed

If you are making a two-part roadbed, tilt the blade on the tablesaw to 45* and set the fence about half width of a strip away from the blade. Make a test cut of an inch or so into a strip, and see if the width of each peice is the same with a ruler. Adjust the fence as necessary until the two strips are about equal in width, and then cut all your strips in half.

Note:  In a conversation with website reader Phil Gulley who tried to make N-scale roadbed using this two-part  method as described above, he told me that the cut side of the roadbed was too rough for him to use. (When you cut the roadbed this way, only one half of it with the 'nice' face stays upwards.)  I would say try it and if you have similar results, you may want to consider making a roadbed in one piece as described below.  Or consider making a two part roadbed without beveling the edges, roughing the ballast profiles in later with joint compound or wood putty.  Certainly in N-scale a one-piece roadbed is very practical, but less so in HO (though I've done well with it) and probably impossible in S or O.  Phil was considering using a sanding disc to try and smooth out the roadbed he made, if he tries it and lets me know how it worked out I'll pass that data on.

Beveling The Edges

For one-part roadbed, install a sacrificial fence on your tablesaw if possible.  I strongly suggest also using a zero-clearance insert for this operation, if you have one.  Tilt the blade to 45* (or even 30* if you want the shallow ballast profile) and move the fence almost right against the blade. Stand a strip on end and hold it to the fence and make a test cut. The blade should not be taking off more than the full thickness of the strip (fence too close), nor should it be leaving a shoulder on the strip (Fence too far away). Adjust as necessary, then mill all strips to establish the profile edge, flipping each strip vertically and making two cuts on each. 

Please be very careful performing this dangerous operation, your fingers will be very close to the blade.  A special push jig that rests on the tablesaw surface that has a cutout to go over the blade but also press the strip against the fence like a featherboard might be a good idea to make if you try this.

Kerfing for Curves

Finally, tape the roadbed together in groups of five strips with masking take. If you have a thin-kerf blade for your tablesaw, use it now. (DeWalt makes 6-1/2" finishing blades with 1/16" kerfs and a 5/8" arbor hole, which will fit on a normal tablesaw arbor.) Or if you have a Jigsaw with a thin blade or a bandsaw, this will work even better there. Set the blade tilt to about 20* and set the height to about half the width of your strip. Place the strips down on the tablesaw on edge, and using the miter gauge on your saw run angled kerf cuts through about half of your stock at about 1" intervals. This will make the roadbed easier to curve around -- curves. For split roadbed make half the cuts on the flat edge and half on the beveled profile edge, this will make it easier to use.

The reason the kerf cuts get angled is so when you go to lay your track down on the roadbed, the ties won't fall into the kerf slots.  If you cut them on an angle, the ties can't fall in, they will mostly straddle all of the cuts.  Pretty neat, eh?

Why you put angled kerfs in the roadbed!

And that's about it. You too can turn a simple $20 sheet of homasote into hundreds of dollars worth of high-quality homasote roadbed in just an afternoon's time. I know not a lot of you have access to a tablesaw of your own, but if you know someone who does you could get together with them and make enough to fill both your needs.

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