Spline Roadbed Construction

[tohowalk]

I have seen many refernces over the years to laying a roadbed (or sub-roadbed) using the spline method of construction, and I am considering using this for at least part of my next project. I recently saw an article about that mentioned making the splines out of homasote. My questions: How do you make the spline pieces - ie: cut them from a large sheet of homasote, and what do you use to cut them without creating acres of fluff? and: to what curve radius can homasote splines be used before the splines start snapping? I have used homasote in every layout I have built, primarily in the cookie-cutter method, so I have some experience working with it, but I had never heard of using it for splines before this.

Any ideas and suggestions are most welcome!

Thanks!

Tom

[ndbprr]

There is a blade like an electric knife blade from I have read that makes less dust and can be used in a sabre saw. Personally I'd drag a radial arm or bench saw outside and cut them that way. I'd also vary the splines which will happen naturally at the first curve so the joints weren't near each other. I would think as long as you were gentle when bending it it would take a 30" radius easily. You may have to experiment. If I was going to use homasote only I would also consider sealing it.

[johncolley]

See Joe Fugate's video #2 for 1/8" masonite spline construction tips. He makes it look so easy! It seems a lot better than Homasote!

[TomDiehl]

I don't know that I'd recommend making the splines out of homosote. Years ago, a club I was in made the main part of their roadbed from wooden splines. These were cut from pine, then formed the curves by gluing and clamping the splines together. If the club still exists, they probably would be still standing. The other thing to consider if you're concerned about dust, is the sanding you have to do after the splines are assembled and glue dried. This is needed to get a smooth surface to lay track or roadbed.

BIG drawback, if you want to make modifications, the trackbed section is pretty much trashed.

[Anonymous]

I have tried the knife blade and it won't cut straight and is pretty much worthless except for small cuts. I would agree with other posters that Homosote is not the best spline material. Pine or masonite would be stronger and a lot easier to cut and work.

[dgwinup]

I am a big supporter of foam. I love the stuff, so easy to work with and exceptionally light!

I tried an experiment once, cutting thin (3/16") strips of 2" foam and gluing them up as a spline roadbed. It was fantasticly easy to do, and amazingly strong! But after some time, glue joints became a problem. They didn't want to hold very well and actually pulled the foam apart in some places. (The glue held, the foam didn't, especially on long curves.) I may experiment some more with it sometime, try different glues, stagger the joints more, be more careful in the construction process. I think it's a viable alternative to other materials, I just don't have the correct procedure for it yet. And I'm not convinced that it is a better way to go than just using the foam itself as roadbed. I was just looking for a way to maximize a sheet of 2" foam, and splining seemed more economical than big blocks of the stuff.

Wouldn't be the first time I was wrong about something. (Second or third, at least!! LOL)

Darrell, being quiet...for now

[Anonymous]

Perhaps it would be better to use cork or foam. These traditional methods work quite well, and they are easy to assemble as well. However I am interested in the idea of Homasote, such as what are it' s advantages? My knowledge of Homasote as a roadbed is somewhat limited, so i would love to hear the advantages of it.

[Anonymous]

Homasote is made from pressed paper. It was in favor for many years as a roadbed material for handlaying track because of its superior spike holding capabilities. My current layout uses a homasote roadbed glued to a 3/4" plywood subroadbed. In working with the homasote I have to say that it is a big hassle. It varies in thickness, is very messy to cut (produces a fine, furry type of dust that sticks to everything) and must be sanded to make a smooth surface. It does take spikes like a dream however. I wouldn't reccomend it unless you plan on handlaying your track. Or check out Homabed (presanded and shaped Homasote)

[dehusman]

I have helped build several layouts from Homasote spline. If I were building a layout where I had reasonably large radius (30" plus) and handlaid track, that's what I would use.
I have helped cut about 5 4x8 sheets of Homasote into 2" strips. We attached a canister wet-dry vac to a radial arm saw and ripped away. It helps to cut the 4x8 into 2x8 pieces. We could cut about 2x8 of a sheet before the canister filled with grey fluff. Ended up with 2 garbage bags of it.
Once you get past that its a great material. Use drywall screws to attach the spline to each other. Fast and no mess like using glue. The best part is when you are done you have a dead smooth surface to lay track on. No sanding and smoothing the surface no uneven homasote surface like wood spline. Just glue ties and lay rail.

Dave H.

[cutting]

What IS Homasote? I live in New Zealand, and I've asked at several hardwares and no-one has heard of the stuff. Is it similar to pinex? We use this for wall linings, and it is good for kids' notice-boards, it takes drawing pins well. While I'm asking, what is Masonite? Unknown here too. Maybe it's similar to hardboard, which is dark brown and comes in thin sheets; if you try to drive a nail into it the nail usually bends before you get through even a thin sheet ... And another thing, does anyone ever use MDF or chipboard for roadbed instead of plywood?

[Jdepot]

I have used table and radial arm saws to cut Homasote but found it very hard to control the 10' long sheets, even with help. The method I use now, attach an 18" long piece of aluminum angle with two C-clamps to make a fence on a 7" Skill saw. Set whatever width you want, I use 1 1/2", and cut outside on a calm day. I use four saw horses and several speed clamps to support and hold the sheet.
I have read warnings about Homasote swelling and shrinking with humidity changes but never talked to anyone who actually built a layout and had problems. Of course here in the Arizona desert that may reduce the problem. I have built three layouts using Homasote splines and only had trouble with the first one. I didn't leave large enough gaps between track sections and contraction caused hand laid rails to come loose and almost reduce the gauge to zero. I relaid the rail leaving .040" between each rail and haven't had a problem in the intervening 35 years.

[Anonymous]

Homasote is compressed paper board. I have not seen anything exactly like it. A sheet made from compressed paper, wood fiber, wax, tar or what ever is sometimes used for the exterior sheeting of houses and is an inferior product when compared to Homasote. Home Depot carried it for a short period of time in Canada but it was intended as a floor underlay. If you can not get the real stuff stay away. Ceiling tiles tend to crumble, holds nails poorly and gets soggy when wet.

Yes, hard board is a generic name for Masonite.

The use of MDF or chipboard or particle board has had mixed reviews as roadbed. In order to maintain a smooth grade, these materials require much more support (shorter span). In time they will sage and the roadbed will take on a roller coaster appearance. Spend the extra and use plywood.

Cutting Homasote is a challenge. I have used utilty knifes and the arm strong method. It is not nearly as messy but it is slow. I like the idea of going outside and using the shop vacum. Also consider wearing a dust mask while cutting.

[Anonymous]

I onetime used a material called crazy wood to construct a large section of roadbed that had to be self supporting. It was supplied by a member of the club that I belonged to at the time who worked in a furniture shop. It was 5 ply plywood that when cut into cross grain strips 1.5" wide (the wood was 1/4" thick) was extremely flexible and easy to work with. After gluing it into a 60" radius triple track spline of about 300 degrees curvature it was strong enough for some one to stand on and stiff enough radially to stay in shape for the pass 20 years with minimal support. I wish I knew where to get this material because I have lost track of that club member and need to do lots of unsupported track work again and desire to use that material, what ever the cost.

[daddy8rene]

I just read about away to reduce the dust created when cutting homasote. Credit goes to Boone Morrison in The Narrow Guage and Shortline Gazette. Grind a saber saw blade for metal to a knife edge and have at it. The shop vac can't hurt.
I'm presently building an outdoor spline On3 layout using Composit boards (plastic and sawdust) sold as decking boards. Living in the hills east of Tucson, wood on the ground quickly transforms to termite casings. I can rip three sections 1 1/4" wide plus one section 5/8" thick (used as spacer blocks), per board. Sections of the spacer block strips cut longer than the blocks are driven between the splines into the ground to hold the roadbed in place (also used to adjust height). My spline is an open grid of split 1 1/4 sections aprox 3/8" thick and 2 and 4" blocks. These boards are 12 feet long that I have cut in half, attach the blocks to one side, I space them at 8" and stagger the spline sides so they over lap the opposit joints in the middle. At 6' there are 3 four inch blocks (each end and 1 in the middle) and the rest 2". I join them with 1" drywall screws and finish washers (stamped sheet metal half donuts). Without the washers the self countersinking heads split the splines. When working indoors to prep the sides with blocks and the AC is on, I warm the blocks in the oven to about 120 degrees so I don't have to drill screw holes, otherwise they split! Learned this by starting initial assembly outdoors under a balmy 110 degree sun... but my old body demanded creature comforts! Avoiding glue makes alterations a snap, unscrew, reshape, rescrew. Have 180' so far just for the mainline, a spur with switchbacks and a Georgetown loop will climb to a Creosote 'Mine' (actually a creosote bush) tank cars will interchange with the G guage (nephews' layout) in the front yard. I used 5 1/2" roofing nails to hold half splines (w/ blocks) in the general trackplan, next day they came out as the sun had molded the curves into the strips. Allow for curvature differences; inside/ outside radii, easiest having the blocked halves on the outside and trim the other half to fit, a couple of pistol clamps and a marking pen and a number on the piece of spline kept the proper order, allowed drilling clearance holes in the shade.
Once the splines are done I'll run a belt sander along it to level (side to side) for the ties. At this time I;m planning on filling the center gap with Cement-All to conserve ballast. Just for the mainline I figure $500 for flex track! Unsure of the lifespan of plastic ties, I'm going to hand lay the rails on sealed wooden ties, good thing I have the rest of my life, eh? Flex conduit on the uphill side will carry the wires and be covered with backfill dirt. Already I have a narrow guage roadbed that I could never duplicate indoors, few tangents and undulations based on actual topography. Can't wait to see that new MMI K-27 at work!

John

[bobjgroton]

I'll defer to other postings regarding cutting of Homasote. I can tell you from experience that even a FINE blade in a jigsaw creates a TREMENDOUS amount of grey fluff (perhaps a 100:1 expansion ratio, although that may be a bit low)!

I'm a bit confused by the mention of use of Homasote as SPLINES. It does okay for a top surface but the actual splines need to be rather strong and stable in varying climatic conditions (unless you have a RIGIDLY controlled climate in the layout room AND have let the Homasote aclimate to the climate to settle on a final water content). Homasote is pressed paper and tends to absorb moisture, particularly along unsealed edges, and that means it WILL change shape, not a good trait for smooth trackwork. I think you want to use wood (or something similar) for the splines and, if you wish, use Homasote for the top surface.

The club I'm currently in (Nashua Valley Railroad Association, 9/02 issue of MR) used 1/4" lattice board on edge for roadbed (7 layers of it sandwiched together with 2" drywall screws to hold everything together once bent into place). The result is incredibly strong and won't move anywhere, regardless of the weather (our layout room is NOT climate controlled other than some heat in the winter and windows/fans in the summer). Side note: we disrupted the entire lattice board supply for eastern Massachusetts when we bought 15 or 20 THOUSAND feet to do our mainlines in the late 1970's, but that's another story. There are many ways of doing spline roadbed that take less material than we used (use short spacers every foot or so between alternate layers of spline so your roadbed is not solid wood the way ours is). Whatever you use, when the spline subroadbed is done you will probably want to CAREFULLY go over it with a belt sander to smooth and level the surface for the final roadbed (Homasote, Homabed [commercial product mentioned in an earlier update], or something else). I stress the "careful" use of the belt sander so it doesn't dig dips into your subroadbed top. In our case we handlaid our track directly on top of the spline roadbed after the belt sander pass and running a rounter with a chamfer bit to cut the top of the outside splines to a 45-degree angle for roadbed "shoulders." We had very little trouble getting spikes to go into the pine and hold -- most of the spikes have been in place for 25 years without working their way back out.

My experience is that the main obstacle to spikes is the glue you use to glue your ties to the roadbed -- I've run into this on the narrow gauge trackage on our club layout where I used Homabed and have frequently bent spikes trying to pu***hrough the glue. Most of the spike "penetration" problems we had on the standard gauge happened at turnouts where we used a hot glue or other "filler to fill the gaps left where splines from the diverging route joined the mainline.

Bottom line -- Homasote is okay for a TOP surface but terrible for a subroadbed. Try to seal it somehow to stabliize things from a moisture standpoint or your track may shrink and swell enough to cause problems (paint and/or normal tie and ballast glue may meet this need).

[dehusman]

bobjgroton said:
"Bottom line -- Homasote is okay for a TOP surface but terrible for a subroadbed. Try to seal it somehow to stabliize things from a moisture standpoint or your track may shrink and swell enough to cause problems (paint and/or normal tie and ballast glue may meet this need)."

In my experience it is just the opposite. Homasote is actually pretty bad as a top surface, especially if you are handlaying. It isn't uniformly thick and has a wavy surface so you don't get a smooth surface if you use it flat. I have laid track on flat Homasote and i have laid track on Homasote spline. Spline is waaaaaayyyy smoother.

The layouts that have used Homasote spline have as smooth a surface as I have ever seen on any track. It is also way easier than wood spline (did that also). The layouts that I have seen use it only attached the spline to the risers every 8-12 feet or less. In between it just sits on the risers. Granted they are in basements that have fairly good temperature and humidity control (nothing extraordinary or "rigid", just normal home heating and AC, one guy had a dehumidifier). All three layouts ran for years. And none of the Homasote was sealed in any way (the top was coated with white glue when tied and ballasted). None of the layouts experienced any significant changes in alignment or kinking of track. The only place i know that there was an expansion problem was where in a fit of prototypicality the owner used code 40 rail soldered to PC ties and it took him a couple tries to get the heat right so the rail didn't pull off the ties when it cooled.

Homasote is more stable than it is given credit for.

Dave H.

[mikemorey]

I was part of a major rebuild of the Naptown & White River Model RR Club.
http://www.naptownrr.org/
Take a look at the photo tour of the North End Rebuild:
http://www.naptownrr.org/northend.html
The sweeping turns with automatic easements and smooth rises and falls of spline roadbed is hard to match with other methods:
http://www.naptownrr.org/NorthEnd/08-24-03%20North%2006.JPG
The results are spectacular but there's a catch, it's MUCH more labor intensive than regular cookie-cutter ply and Homasote.

I'm willing to post details of the construction method if people have an interest. The details would be lengthy and I don't wi***o annoy with such a LONG but uninvited reply.

Mike Morey

[cefinkjr]

QUOTE: Originally posted by dehusman
... in a fit of prototypicality ....
Dave H.

Wow! I thought I was the only one who dreams up words like that! [swg]

But you're right on in your other comments on Homasote, Dave. I used it years ago on open wood spline roadbed (1/2" spacer blocks every foot or so) and the result was incredibly smooth track (and a wife who didn't speak to me until I got all of the Homasote dust cleaned up a couple of months later). I'm not sure it's possible to lay bad curves and rough track using that technique -- even for me. And, BTW, I did not sand the top of the splines before laying the Homasote.

I have seen a small railroad in this area done with both wood and Masonite splines with Homasote roadbed. Both look great. I'd think the Masonite would be harder to work with but the builders of this railroad say it wasn't.

Chuck

[tohowalk]

Thanks for all the input folks! For what it's worth, I have read that Homasote is made of pulverized newspaper, water, and a bonding agent - glue of some sort. I have built a couple of smaller layouts using open grid benchwork, and nothing but 3/4 Homasote (cookie cutter style) for roadbed - no plywood underneath.Unfortunately, this can waste a lot of a sheet of the stuff. I have found it to be very stable over 2-3 foot stretches between joists with no sagging or buckling after installation. The last picture posted by Mike Morey is just the kind of thing I have been thinking of - thanks for the picture! And, to judge from the wisdom of other modelers, it appears there is no good way to cut it, just more and less messy ways of doing it.

Thanks again for the help!

Tom

[mikemorey]

QUOTE: Originally posted by tohowalk

And, to judge from the wisdom of other modelers, it appears there is no good way to cut it, just more and less messy ways of doing it.

We used a small, portable bandsaw. That made it easy to do the cutting outside. It's not as precise for straight cuts but the thinner blade makes half the dust and half the waste.

Mike Morey

[Anonymous]

No need to cut any wood or Homasote product. Go to 84 Lumber and purchase 10' individual pieces of wood lattice. Works great. Only need to be cut to length. Use small wood glue blocks between the two strips of lattice. The riser cleats will be glued to the bottom of the lattice pieces just below one of the glue blocks. Put glue blocks every 8". My whole layout, the Oil Creek Rail Road ( 12' x 30') was constructed this way. Underlayment 5.2mm wood was glued to top of risers for sub-roadbed. Then Homabed used as roadbed on top of that.

For more information, e-mail me at [e-mail].

Doctor ***
Editor and Publisher
Rochester Model Rails
Victor, NY

[Anonymous]

Hi cutting in New Zealand. As far as I can tell our pinex is the closest thing to homasote and our hardboard is similiar to masonite. As far as MDF/customwood is concerned, my present layout uses 9mm MDF for the subroadbed. Construction is cookie cutter style with support at 300mm spacing on the elevated area. Roadbed is 3mm closed cell foam glued to subroadbed and flex track is glued to the foam. All goes together really quickly. On this forum you will see that most people don't like MDF and prefer plywood but if you compare the price of plywood with MDF (in NZ) you will see that MDF is worthy of consideration.

[Anonymous]

F.Y.I. The RONA LANSING HOME BUILDING CENTRE on Martingrove Rd. north of Highway 409 carries 4' X 8' sheets of Homasote in stock. The Price last Fall was $35.00 per sheet. They will make several cuts for free if you have the sizes for them. This would be fine if you just need a few pieces cut to a specific size.
NOTE. Martingrove Rd. Runs North/South and is the first major road East of Highway 27.


[8]

[selector]

Doctor ***, your e-mail address is not recognized by this forum; I can't seem to send you a reply.

[Anonymous]

Using a bandsaw to cut Homasote is brilliant! Nearly any size saw should be adequate. I would recommend a 3/8" or 1/2" blade with a moderate tooth size (say 3 TPI) in a skip-tooth pattern for faster dust clearance and less heat buildup.

If you need to cut a lot of strips, it's probably worth the time to rig a larger table for material support and a longer fence such as the aluminum angle mentioned previously would make long straight cuts easier.

When using a portable circular saw or a table or radial arm saw, a decent thin kerf blade (3/32" thick vs. 1/8") will reduce dust, conserve material, and allow the saw to cut with more power due to the reduced drag on the motor.

[tomikawaTT]

What goes around, comes around!

The first reference I found to Homasote spline construction was in the January 1955 issue of MR. Irv Winer had his splines cut by the building supply house where he bought it (for about 10% of the present price) I did the same when I used that construction technique in the 1960's. 2-inch splines glued together with Elmer's glue-all worked down to 24-inch radius. Unfortunately, that layout was abandoned (due to military orders) before I could reach any conclusions about longevity - but it sure was easy to spike into it.

A little trick for yards and junctions - continue outer splines along extreme edges, step the next splines down by the thickness of the flat material to be used, then cookie-cut a flat filler to support the turnouts and intermediate trackage. This eliminates edge-joints that can cause problems with spiking specialwork.

[Anonymous]

I have built two 0-Gauge layouts, the most recent one is 18' X 33'. I use Homosote exclusively instead of plywood or other material. I can cut it easily in any configuration using a skil saw. It does create a little fluff, but no more difficult to clean up than sawdust. I find that over time it does not warp as long as it does not span too great an area without support - not nearly as bad as plywood. It is dense enough to hold nails or screws. It is also somewhat sound-deadening, although I still use cork roadbed on top of it. Homosote is a densified paper product whose main enemy is water. It comes in 8' X 4' sheets and I just bought some for $30 per sheet. In some parts of the country this comes under the name of (or maybe just a similar product) Upson Board.
I have been overall very happy with it.

Tom Duker
Mt. Angel, OR