Hi all. I am just in the construction phase of my first permanent layout. The benchwork is complete so next is the roadbed. I will have approximately 150" of mainline. Of this there will be approximately 75’ of spline roadbed where there will be grades. The rest will be cork on foam. I have understood that when doing spline roadbed the idea was to just put the track directly on the spline. Recently though I have seen more and more photo’s of people putting cork between the spline and track. Any thoughts on this would be greatly appreciated. And once again thanks for all your help.
I honestly don’t think it really matters. Many use cork because it is an easy way to elevate the track above the other terrain for a realistic roadbed profile. Others say it deadens sound. Some use it for both reasons. Obviously with spline roadbed, you’ll already be able to get a realistic roadbed profile, so the only possible reason is for sound deadening. That may be true as one way to deaden sound is to have a sandwich of materials with different densities. I guess I’d temporarily lay some track on your spline without cork and then with cork to see if it really makes a difference and decide for yourself if the purchase of the cork is worth it.
I’m in agreement with machinist, I really don’t think the extra cost and work would have any benefit. You also could have addional problems with irregularities and delamination in the trackwork/ subroadbed.
One other thing to consider is the transition from spline roadbed to “flat” roadbed (plywood, homasote, foam, etc.). I am in the design phase and was planning on using cork on the spline simply because in my mind the spline roadbed would join the flat roadbed (in yards, for example) at the same height so that the surface for laying the cork would be level. However, after hearing others opinions and doing some research, it does seem like the cork on the spline roadbed is unnecessary and just an extra expense. BUT…this will affect the way I construct the spline-to-flat transition since the top of the spline will need to be level with the top of the cork in the yards. Jamie
One other thing to consider is the transition from spline roadbed to flat .
I have taken that into account and so will adjust the top of the spline to meet up with the top of the cork on the foam on the flat surfaces. Thanks for the input guys. I think it’s track on spline for me.
I would omit the cork. One of the great benefits of wood spline roadbed is it takes nails and spikes well. Cork is really too soft to hold fasteners well so spiked down flextrack can flex and move on you. I like nails rather than sticking track down with caulk because it’s easier to fix track laying boo boos like kinks if the track is just nailed down.
The only thing cork road bed does is simulate the raised ballast bed of the prototype. With spline, you can do that by putting the terrain a quarter inch below the surface of your roadbed.
I will not tell you what to do or not, just tell you what I did.
I had some problems to get the top if my masonite splines even. I talked to Lee Nicholas, one of the guys that ‘invented’ spline roadbed. He had similar problems but they went away when using cork on top of the splines. For me it did a lot more then even out the spline roadbed. I got the 45 degree angle for the ballast and the track is very quiet. Look at this picture and compare the splines with and without the cork. I’m very satisfied and will continue using cork on top of the splines.
I really don’t think you can go wrog either way. In Joe Fugate’s SP Siskiyou Line video series, he shows how he rips a spline at a 45 degree angle and gles it to the outside of the roadbed splines to yield the correct ballast shoulder. It’s really just a matter of decisions regarding preference and cost. For example, I think I will not be using cork, but when I actually get to building, that may change. Jamie
I don’t know if it was Joe’s video or one of the other ones that I saw but they showed that you can level out any imperfections on the top with a little wall spackle for dips or use a wood plane or a sander to level the bumps out. It’s all part of the learning curve I guess.
