I'm considering utilizing Homasote splines for roadbed but need to know what the minimum radius the splilnes can form. Searching on the forum and internet has proved fruitless.
I should have been more specific in my question. I would like to cut splines from 1/2" Homasote (ie. 2" X 1/2") and screw the splines together with drywall screws vs. gluing. This would be for N scale roadbed so only two splines would be needed per track. Would that thickness of a spline be able to make an 18" radius curve?
When I think if splined roadbed, I think of something like this [photo from http://www.trackplanning.com/splines.htm ] with strips, so am having a hard time envisioning how your 2 Inch dimension might apply in a spline. The site's author sensibly suggests that with N, the open spaces between splines can be omitted. I apologize for not quite grasping your question. I'm interested in what you have in mind, as I am interested in splined roadbed on my next N Scale road.
The 2" is usually the width if horizontal, so turning the strip on it's side means the roadbed is a laminate of 2-4 strips/splines, each 0.5" wide (from left rail to right rail) and 2" high (from track to timber framing). No idea how tight you can curve homosote: it doesn't exist down here! Damp homosote curves tighter, I hear. But wet homosote disintegrates. And you can score it vertically to get a tighter radius, before gluing / screwing the splines together.
I'm not sure about using HOMOSOTEfor the splines. I would go with MASONITE. Masonite can be curved pretty sharp, will need less support and won't come apart when it gets wet.
With vertical cuts on the inside of the curve ("kerfing"), I have had the local "Masonite" like 1/8" thick hardboard bent down to about 8" to make a curved fascia. Without scoring, it tends to explode somewhere tighter than 12" radius You will need more splines to hold up n-scale (3/4" to 1" = 6-8 splines of 1/8" Masonite) and you don't want to be trying to glue too many splines at once I suspect homosote would be better for starting / ending a gradient than Masonite, however. Hardboard isn't too flexible on the long side
As an experiment I'm thinking about getting one of these http://tinyurl.com/lz9cbar to test. It sounds like the same basic material as Homasote and the ante isn't too high to get in the game. The plan would be to split it down the middle to make the spline (about 1 1/2" x 1/2"). I'm making a helix with Masonite now but don't like gluing all the lawyers together. Using a power drill to screw the Homasote/Homex together as seen online looks much better.
I prefer homasote for roadbed also. I started my layout over 30 years ago hand laying code 70 track and turnouts and used a product called Homabed. It has about the same contour as cork roadbed and holds spikes extremely well. The company has changed hands since I bought my Homabed, but as you can see in the photo, the Homabed already has kerfs cut into it. It holds ballast extremely well. There are other alternatives available, but I am very happy I chose Homasote.
