MDF for a base

Jerry Potter Apr 30, 2013

  1. Jerry Potter

    Jerry Potter TrainBoard Member

    Anyone ever used MDF ( medium density fiberboard ) for a base. This may have been asked before but search didn't find it.

    Would it be too hard of a surface to work with. I'm wondering because it is usually perfectly flat and stable.

    Just starting rebuilding my layout that is now on particle board.
  2. Arctic Train

    Arctic Train TrainBoard Member

    2 issues come to mind re. MDF. 1. It's heavier than he##. And 2, if it gets wet it'll swell up. You'd best plan on using foam to completly cover up the MDF if you're later going to use wet water to ballast your track. Otherwise its going to swell up. If foam isn't in your plan, you may avoid the swelling issue by coating the heck out of the MDF base with some sort of water repellamt. Personally, I'd just use some really good quality plywood. You can be picky and sort throught the pile at the box store, or pay a bit more and get the good stuff (ie. birch, oak, etc.) I went the cheaper route and picked through the ACX pile to find a number of really flat, good quality sheets. Very happy with result.

  3. RatonMan

    RatonMan TrainBoard Member

    Very heavy!
  4. Jerry Tarvid

    Jerry Tarvid TrainBoard Member

    A note on using birch or oak veneer plywood, the slightest amount of water will lift the veneer from the plywood. Seal with an oil base product and your good to go. I would personally seal any wood product if it will be subjected to water.

  5. traintodd

    traintodd TrainBoard Member

    Heavier, harder to cut, nail and drill through, but it will work. I put a Z scale layout on foam over mdf because I had tables made out of it and didn't want to pull it off. It worked, but if I had a choice, I would use foam over 1/4" ply. It is working fine for me for large flat areas and the 1/4" ply holds Tortoises just fine.
  6. Doug A.

    Doug A. TrainBoard Supporter

    I would say avoid it if you can. The rest have offered this and other sound advice.
  7. rsn48

    rsn48 TrainBoard Member

    I have used MDF as a base and I don't regret it. My MDF is one inch thick, is heavier than....., but it has held up well. First let me give you one real positive, the material, when it is one inch thick doesn't shrink or expand in "challenging" environmental conditions, hot and humid to cold and dry. MDF is mostly glue so no expansion and contraction issues. My MDF is laminated with an oak veneer (a contractor ordered this stuff in, then walk away from it, so I got a great price).

    If I were to use MDF knowing what I know now, I'd still use it, but if it had no veneer, I'd paint it with an oil based polyurethane, about 6 coats, easy to do, a bit smell for a few days, you can paint six coats on in two days with a few hours in between. Contrary to instructions you don't need to sand between coats. This bit of advise will guarantee that no water based scenery and ballasting techniques affect your MDF.

    Have a friend help out bringing it home and cutting it.

    For road bed, I have used AMI which doesn't exist any more. This is a sticky product that I love as you can remove and re-apply; in fact I've done this so much I don't know what people do with glued down road bed, I would have had problems. What I would do is google AMI and you will run into some threads with other recommendations of alternate products out there.

    So some pics of my MDF:


    Here you see the area more finished, by the way the dirt you see is real dirt, Fraser River Silt taken from the banks of the river. I had to use a lot of water based material to glue this dirt down, so the veneer saved the day for me:

  8. robert3985

    robert3985 TrainBoard Member

    Personally, I stopped building my model railroads on table tops when I was under 12 years old. I don't think of building a module or model railroad any more on a "base". I think of providing subroadbed for my cork roadbed and flextrack, and I've built L-girder benchwork with cross members and risers supporting splined Masonite subroadbed for over 30 years now. When I need a "table top", like in a yard or large industrial area, I use sanded-one-side CDX 3/4" plywood, supported by 1X4 premium pine risers, screwed and glued to redwood 2X2 baluster cross members sitting across two premium pine L-girders. I fill in the areas around my subroadbed with extruded Styrofoam, which gets carved to the proper topography, but it doesn't function as a structural element to support my trackwork.

    Yeah, I know LOTS of "model railroaders" build their railroad empires on table tops and doors, but y'know, geography mostly isn't flat, and having that table top there just makes it more difficult to make drainage ditches, ravines, streams, rivers, gulches, cuts...anything lower than the bottom of your "ballast", especially if it's MDF, plywood or a HCD.

    The one exception to my previous paragraph is using 2" extruded Styrofoam as a table top, and providing a support structure under it, such as L-girders or whatever (I personally don't trust 2" Styrofoam as the primary support for my trackwork). 2" gives you a scale 26.67 feet of material to carve all of those lower-than-subroadbed features into, and since railroads were generally (not always) near waterways...the lowest point in the local topography, that should be enough to make your scenery look much better than just a flat table top. Gluing extra layers to the top of your 2" foam table top is easy to do for hills and mountains too.

    If you want a gulch or riverbed that's lower than 2", it's very easy to just glue another layer or two on the bottom of your sheet where you want something deeper than a scale 26.67 feet.

    But, if you really don't care and want your model railroad to look like it's in Kansas or the Bonneville Salt Flats, then a table top is the just the thing!

    Just sayin'....

    Bob Gilmore
  9. rsn48

    rsn48 TrainBoard Member

    Who says you can't have mountains with table top construction. A long time ago I used to post here frequently about nolix's, well I have finally got all of my nolix in and it is a mountainous area. A nolix is a modified helix, a helix being a giant slinky to take your trains up or down, well a nolix does the same thing but not round, could be L shaped, peninsula, V shaped, etc.

    On my nolix, there are four levels going from bottom to top it goes like this, 1) is first level and won' be visible 2) second level will be visible from the front with its siding 3) single tracked and visible from the front 4) top level won't be visible at all.

    When I have showed these photographs before there was some confusion as to how it is to work. The inner levels along the wall with the background pics won't be visible, the purpose of the pics is to give a peek a boo look through the tops of the mountains that will be made. The tall ribs are the ribs for the mountain.

    It should be noted that using very wide angles with the camera gives the appearance of a roller coaster but I have used helix construction techniques and the grade is roughly 2.2 throughout.

    In this first photo the nolix isn't finished but where the trains are, will be the visible area on the mountains with a river between the two levels:


    So many couldn't understand what I am trying to accomplish, I took this crappy picture with paper to give a rough idea of the mountain and how only the two front levels will be visible:




    This photo is taken with my smart phone camera, wonderful wide angle lens, but it really delivers that roller coaster appearance. Notice no level is the same as the level below it, makes for an interesting building challenge. With a helix each turn is identical, but with a nolix no turn may duplicate the turn before it. So all roadbed and track in and I think most if not all the wiring in:


    So you can have "toy like" table top construction, what I learned from MR's Wisconsin Central project layout, and still have a good looking railroad.

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