As my benchwork progresses, my thoughts are turning to the sub-roadbed. I happen to have a pile of OSB (“chip board” but NOT particle board!) in either 7/16" or 15/32" (at these thicknesses, I don’t think the 1/32" matters).
Anyway, has anyone used this stuff for sub-roadbed? How well did it work?
Caveat: I am working in O, and some of my engines exceed ten pounds in weight. I can put joists at every 12", if necessary. I suppose I could also try ripping up the pieces of OSB for splines. Has anyone tried that?
That thickness for splines is too much. I could be used as subroadbed, and you could go with 12" centres for supports if you wished, and probably a bit more, say 15" for that thickness. After all, those engines don’t weigh seven or eight pounds.
Never heard anyone bragging on it, the usual first question is : What is your humidity like? The stuff is only as stable as the glue that binds it and it’s ability to stretch and shrink with the wood.
If you insist on saving a buck with your acquired pile, consider gluing a strip along the underside for a ‘T’ cross-section. This will help reduce sags. 10 # loco’s will test even proven methods. Consider the cost of your loco’s and the cost of them diving to the floor, don’t skimp on trackwork, especially now, the foundation. Use a material that sands easily, smooth out transitions add superelevations, etc…
John
Splines need to expand uniformly with heat/moisture to maintain raduis, assorted chips may not allow that.
Selector: I have three engines that exceed 9 lbs, and one that exceeds 11. That one pounds the rails in a most realistic manner, too. Many are over five. You may very well be right on the thickness for splines: I haven’t tested it.
daddy*rene: My humidity is under control, as the layout is in an air-conditioned room, not a musty basement. The temp is held to a constant range, thought the room usually isn’t kept quite as cool or warm as the rest of the house. I could use some 1" x 2" scraps to form the web of the T: I have plenty of them, and 1" x 2"s are cheap enough. I don’t want to skimp, but it seems a shame to waste the pile and buy some (very expensive these days) plywood. OSB ssands well enough with the belt sander [:D]
I am using 1/2" OSB for sub road bed with cork on top. Using 16 " o.c. for HO. I put a bowling ball and found that 16" deflected 1/4" 12" NOTHING. Since I am bot running bowling balls I went with 16" o.c.
Hope this helped.
Wow, those are heavy engines. I guess I should have cubed my HO scale weights, and not doubled them (forgot my Gr 11 Physics, I guess). Thanks for putting me straight.
I stand by my expectation that you will have no sagging to speak of with that thickness of sub-roadbed and 15" centres, riser-to-riser. I imagine your engines are near that length anyway, and since they are stiff-framed, their weight will be accommodated nicely with that span.
Perhaps you could experiment with a mock-up section and measure the deflection downward as you increase the span. I think you would begin to measure downward deflection when the span neared 1.5 X the length of your wheelbase if your bigger engines are in the 19 lb range.
Thanks for the experimental data, claycts. That’s useful. I’m not running bowling balls, either [:D]
selector, given that experimental dat, you’re probably right. I may have to look at shoring up the outside of curves when they fall between joists. I will try some preliminary testing when I’ve got the benchwork almost ready for roadbed.