Replace Warped Hardboard With???

Discussion in 'HO Scale Model Trains' started by riverotter, Apr 25, 2008.

  1. riverotter

    riverotter Midwest Alliance Rail Sys

    Jun 9, 2005
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    After two years of using hardboard as a [seemingly] humidity- and
    temperature-proof subroadbed, all of a sudden, on my new, "big"
    layout, I've got a world-class case of rollercoaster track! 90 feet of
    @#%&*! Now what do I do? This stuff was attached to a 2x4
    framework attached to the walls with cross-bracing every 2', just
    like the smaller layout I had before I undertook this expensive
    upgrade. Now I have an expensive piece of @#%&*! Fortunately,
    the hollow-core doors I used for the free-standing dominoes are
    flat as the prarie, so at least I can run a short train back and forth
    about 42'. Woowee! So do I replace the hardboard with (a)
    equivalent-thickness plywood, (b) 1" foam, (c) take out the cross-
    bracing and attach HCDs to the shelf benchwork with my trusty nail
    gun, or what?!?! Maybe I should (c) just chuck this HO stuff and lay
    some G gauge track outside. Couldn't be much worse than this
  2. doctorwayne

    doctorwayne Active Member

    Sep 7, 2005
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    The term hardboard is usually associated with Masonite, a hard material composed mainly of sawdust and glue-like binders, and usually comes in 1/8" or 1/4" thicknesses. I can't see you using this, so perhaps you're referring to particle board (often called MDF or HDF - medium- or high-density fibre board). This is also composed of sawdust and binders, and comes in thickesses ranging from 1/4" to 1". Masonite is thin and flexible, ideal for backdrops and layout facia, and I've also heard of it being used for spline roadbed.
    In this photo, the curved backdrop at the corner is Masonite, as is the layout facia:

    Even supported every 2", Masonite on-the-flat will sag - it requires continuous support. :rolleyes: Thicker MDF or HDF will also sag, even with support every foot or so - none of these materials has much in the way of structural strength, and they are not suitable for use as layout support. The latter material is also quite susceptible to moisture. Likewise, 2"x4" is not a good choice to support sub-roadbed - most dimensional lumber has far too high a moisture content to maintain its shape or trueness. In the photo above, you can see that I've used 2"x4" legs to support the benchwork, with is built from 1"x4" pine - dried and very stable when assembled into a gridwork on 16" centres. For a layout, I would suggest a minimum of 1"x2" pine, #1 or "Select", or #2 1"x4" pine - not particularly cheap, but much better than 2"x4". I used 3/4" plywood for my subroadbed, cut into strips and curves, but I plan to use 3/8" sheathing plywood over 1"x2" framing when I build the second level of the layout. Don't skimp on the quality or the workmanship of your layout's base - it's what everything else is dependent upon.
    Sorry to have to be the bearer of bad news.:-(

  3. Santa Fe Jack

    Santa Fe Jack Member

    Jul 20, 2006
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    I'm really sorry to hear about that, riverotter. Damned shame, warping on you like that. I would strongly suggest using foam for the refit. It's just sooo stable during changes in humidity and temperature.
  4. sgtcarl

    sgtcarl Member

    Jan 12, 2008
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    Santa Fe,
    What type of foam and where do you buy it? I am going to start my layout soon, I hope. I had planned on using MDF.
  5. 60103

    60103 Pooh Bah

    Mar 25, 2002
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    sgtcarl: the foam is house insulating styrofoam -- comes in sheets of 2x8, sometimes 4x8, in 1/2", 1", and 2" thicknesses. May not be available in states that don't admit to having winter.
    This is extruded styrofoam, not the little beads type. May be available at your local lumber/hardware store. Comes in pink and blue, maybe another colour -- that's just branding. Some people seem to get it with a protective coating that has to be peeled off. It's compatible with Woodland Scenics stuff, including their glues and hot wire cutter. (disagreeable gases warning). Not quite the same as WS's foam risers and stuff.
    Not self-supporting, but reasonably stiff. Will dent.
    Lots of threads around about it.
    Caution: this stuff contains material known to the state of California to make modeling easier. :mrgreen:
  6. CNJ999

    CNJ999 Member

    Aug 21, 2004
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    It would seem that DocWayne and I differ on just what consitutes "hard board" and "masonite", which may be causing confusion among readers. Out my way hardboard was always recognized as a compressed sawdust-like composite board with a paper covering. It was either white or wood-colored, typically had a thickness in the order of about 1/2" and was very stiff. It was available for many years and used mainly as a residential siding material. I haven't seen it available anywhere locally for quite a number of years now. The hardboard product, I can state from personal experience, tends to absorb moisture over time unless sealed and over time will warp unless heavily secured.

    Masonite, on the other hand, is a much thinner, slick face one side/rough on the other, dark brown composite of some sort. That found in home centers around here is typically 1/8" thick (1/4" is available on special order). As Doc points out, it's good for backdrops but not for a layout subsurface.

    In either case, it is probably best to replace the your material entirely, since the degree of warping you describe sounds like a hopeless situation. I'd suggest that replacing it with 3/8" plywood, sealed all sides with paint before anything else is done, is your best bet.

  7. DeckRoid

    DeckRoid Member

    Apr 28, 2007
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    You know, this sounds alot like what happened to me. In my case, I had mistakenly gotten the wrong foam (beaded) on top of 3/4" leftover tongue and groove flooring Chip Board. Overkill? Just a bit, but the beaded stuff was moving my track all over the place with our wild swings of temps.

    I was bemoaning of my woes one day at our club when a member who has been building layouts 20 years before I was born (I ain't no spring chick, neither!) gave me his book on building benchwork. I made a trip down to our local Box Store and couldn't find a single piece of 1x4 or 1x2 straight. I went to the other Box Store and found the same thing. Heck, even our 2 local lumber yards chuckled as I was looking thru the #3 bins for straight wood. They showed me some 1x2 and 1x4 MDF (particle board) boards they use for building supports for kitchen cabinets and the like and they were cheap as all get out. 3 bucks for 17 feet!

    But, I decided that I had already done 1 stupid, err, silly benchwork mistake, I didn't want to do another. I girded my loins and bit the bullet. It was an expensive bullet to bite, but I figure in the long run, I will be thankful.

    I mean, I plan on doing this hobby til the day they put me either in the ground or the looney bin.

    So, I did buy the #2 1x4s and #1 1x2s and 2 sheets of 3/8 birch plywood, the kind with the patched holes and goes for 25 bucks a sheet!!!! It hurt going thru the checkout line, but so far I am extremely happy I did what was in the book. It has gone rather quickly and for some reason easy. Like I told my wife, I must have done something wrong. If something I am involved in is going too well, I must be doing it wrong!

    Good luck with which ever way you choose to go. I, for one, tore up my old layout and am currently in the process of finishing up the benchwork so as I can get some track laid and hear my NP freight blow his horn thru the tunnel agian. (God I love that sound...)