This is my third post and have got some really great feed back so here goes again. I’ve been modeling for 40 years but am starting my dream layout (I hope) and am considering using 1/2" MDF instead of 1/2" ply as sub-road bed… I’m a cabinet maker/wood worker by trade but am going back and forth about this subject. Both are readily available to me at a discount price but MDF I feel might transfer less sound than plywood and can be easier to work with. Your thoughts?
I’m not a fan of MDF for almost anything: it doesn’t take nails or screws readily, and when it does, they don’t hold well at all. When glued to other materials, it will de-laminate under stress, and, especially cut into narrow widths for sub-roadbed, will sag under its own weight unless extremely well-supported. I also find it more difficult to cut than plywood, and the dust and fumes (from the binders used in its production) are irritating.
1/2" plywood, if well-supported, will do the job, although I opted for 3/4". The difference in cost is minimal and the added thickness makes it easy to use it in conjunction with dimensional lumber (1"x3", 1"x4", and 1"x6") as sub-roadbed. The added thickness also makes leftovers suitable for use as risers.
Wayne
I agree with Wayne. I have used a lot of MDF in my wood shop for purposes other than a model railroad and I’ll use good plywood any day. Also in some instances MDF is not very good with moisture and will expand and weaken and last of all it is heavier than plywood of the same thickness. Doug
Stick with plywood. There are many articles in Model Railroader about using various materials to dampen the vibrations in the track. Ones that I’ve seen include using floor padding as roadbed (or possibly underneath cork), using homasote between the plywood and the cork roadbed, and various other ones that I can’t think of right now. You might want to look up how Pelle Soelberg did his roadbed. It was featured in an issue of MR about 6 months ago. Most complex roadbed I’ve seen, but apparently it worked very well.
S&S
My plywood subgrade is cookie cut, and takes some stress where grades change and curves are superelevated. Simply stated, I’ve seen too many cases where similar stresses caused MDF to fail - and not one case where plywood delaminated.
If you want quiet, put a layer of thin foam on top of the plywood, and laminate it and the flex-track ties with latex caulk. The result approximates stealth.
Chuck (Modeling Central Japan in September, 1964)
Great feed back as always guys. Thanks. I also liked the comment about 3/4" ply transferring easily to dimensional lumber easier. I never thought of that and recently resided to extend my layout to include a staging yard for my HO standard gauge and am thinking of 3/4" material recommended by a modeler friend who’s be in the hobby for 50+ years. Lots to consider and as always great feed back. Thank you everyone
The disadvantages sure outweigh any advantage using MDF, as a carpenter/ woodworker I’m rather surprised that you would even consider it’s use as subroadbed. Even to fully “deck” the benchwork MDF will allow sound transmission as if you are using a speaker. Yes there are certain uses for the product such as backdrop, and facia panels, but not much else. MDF cut to strips (cookie-cutter) will sag under it’s own weight. Initially it is a solid, smooth and relatively flat surface but as others mention just can’t compare to a decent grade of plywood. I do love using pieces on the workbench for assembling structures and the like, but that’s about all.