Hi,
I would appreciate some advice. When building spline roadbed, is it possible to use 1/4" plywood, or should I use masonite?
PD
Masonite will be much more flexible and less inclined to splinter or split along grains and across glue plies.
Don’t overlook 1/4" MDF. I used it and have had excellent results…ease of us, performance, and stability over time.
If you are going to use spline and are handlaying, using Homasote spline is really a great way to go. Perfectly smooth roadbed that is ideal to spike into.
Dave H.
Guys,
Thanks for the advice. I appreciate the help!
PD
Hmm… Now that I have seen Dave’s interpretation of your question, I wonder if we are all on the same page. By spline roadbed, I mean thin lengths of masonite or MDF that are glued together to form the roadbed. Otherwise, are you talking about cookie-cutter style, where you take the material and trace your centreline, then make your cuts approximately 1-2" on either side of your centreline?
By spline roadbed, I mean this:
It’s that curved chunk of roadbed immediately to the rear of the white ruler. The MDF was cut in 8’ lengths 15/16" wide, turned on their sides, and six of them were glued side-by-side, curved around nails or screws driven into the centreline point of risers meant to support the roadbed. The photo isn’t the greatest, sorry, but you get the idea. This is not cookie-cutter.
Hi Selector,
Thanks for the clarification. I do understand the difference between spline and cookie cutter construction. I am planning to use the spline method because of the natural easements on curves that it provides and because there is so little waste with this method.
PD
One material not mentioned is pine spline. It is extremely strong and stable. My club uses this method as well as cookie cutter. This is a pic of the underside.
Pine roadbed can be seen in this one.
And an overview showing the spline/ handlaid and cookie cutter
Next to using the pine I feel that the masonite is also a good material to use. Joe F. uses the masonite and has great success with it. I believe his web site shows his methods as he built the latout.
Having just built my first spline roadbed, the choice is really between pine (1/4 in.) or masonite - to a certain degree depending upon the curvature being used. I’d be concerned about plywood delamination given the stresses involved. Thin MDF might work as well.
In a brief test I did using something like pine lattice I wasn’t able to get to conform relatively easily to the typical radii I was using (21 - 24 in), but masonite was really easy - so that’s what I used. Another construction consideration is between multiple layers (6-8) or spacers blocks (or as a friend noted ‘are you making a piano or a railroad?’). I used a double spline layer at the center, spacer blocks and outer spline layer - still very strong and flexible. Roadbed then went on top - if you’re working with flex track it will even work with WS foam roadbed material (with some care of course).
Oh yeah, its sort of like handling really long spaghetti!
Charles
A related question – in the 3 very helpful shots of bogp40’s club layout, what is the material (greenish?) being used as the “retaining wall” (for lack of a better term) on both sides of the roadbed, to prevent derailed equipment from falling to the floor? It looks thin enough to curve, but sturdy as well. I am at this point in my own layout construction – needing to add some sort of retaining wall to my benchwork.
Thanks,
JAJ
I am talking about the same thing with homasote. You cut 2’ wide strips and set them on edge. Attach them with drywall screws. No glue. No drips, no waiting to dry. Clamp the strips together and screw in drywall screws every 6-8 in. Nothing cookie cutter about it.
Then just lay track down on the homasote. No sanding or covering it with another layer of something else.
Dave H.
The material is 1/4" MDF. We use the MDF for backdrop and finished facsia. The scraps are ripped and added to any unsceniced areas of the layout. Screening both nylon or firerglass is also used to stop any equipment from falling through the benchwork. It’s not a pretty sight to see a loco travel to the concrete floor below. It doesn’t need to be painted for such a temparary use but all the 1/4 MDF is primed and painted with at least 1 coat of the finished green that you see.
This screening is a safety net, some think it’s a base for scenery
Note the diamond, one leg is dual guage extending to the HOn3 yard
Forum…
One of the big guys (like Koester) is using Homasote Spline in like 1" strips for his roadbed. It was in Model Railroader. I Emailed Model Railroader and questioned this. Their reply was yes…it is Homasote. I thought Homasote was not strong enough for roadbed unsupported. But these guys are starting to use it. Everything I have seen todate says Homasote should be suported by 1/2 to 3/4 plywood. I love Homasote, it takes spikes very well and holds them strong.
Don
Modeling Conrail 1991, 24 x 28 single deck w/lower deck hidden staging, Digitrax
I think you could use wet tissue paper for spline roadbed if you had enough plies of it. I still get the uneasy feeling that we’re not on the same page…forgive me, fellas, but…even this homasote roadbed, if it is spline roadbed, will indeed be long strips of it, each turned on edge, and then its broad side glued along the full length of the previous ones. In cross-section, it would look like a square, not a thin rectangle. Otherwise, I don’t believe that homasote can be used without something else under it to support tracks if held aloft as true splines usually are.
What am I missing…?
Right, Homasote Spline Roadbed…4x8 sheet cut into 1 to 1-1/2 inch wide strips 8 feet long, 1/2 inch thick, 4 pieces standing on edge, glued together making a road bed 2 inches wide. See January 2004 Model Railroader pg. 112, Allen McClelland (not Tony, Sorry). Open grid benchwork with standard 1x2, 1x3 risers supporting the spline. The reason I mention it is… the Plywood doesn’t bend as well as the Masonite, The Masonite being the cheapest, is hard to drive spikes into, you probably need to glue the track down. Now, if Homasote spline could support the track and not sag, it would make the best spline. Anyone else try this… Allen, how about you, any problems with your roadbed?
Curious minds want to know,
Thanks
Don
Gotcha, Don. Thanks for straightening me out.
This is the main reason my club uses the clear pine and pine roadbed. No track is glued down it’s all handlaid or spiked down Walther’s flex.
I would never consider Homosote as any supporting member no matter how it was positioned. Good spline and maybe topped w/ Homeoste will do the trick for you.
Don, et al, Check out Joe Fugate’s method of spline roadbed and tracklaying. I believe either material would do the job as long as the method is the same. However…He uses grey paintable latex caulk to mount his track, rather than spikes. Bend the track to the shape desired first so there is minimum strain on it when layed, then use cans of food to hold it in position for 24 hours. It is set, but still easily removable with a putty knife if you want to make changes in the future, like adding in a turnout or realigniment. jc5729 John Colley, Port Townsend, WA