Wall Brackets and Foam Construction Questions

Discussion in 'HO Scale Model Trains' started by riverotter, Oct 17, 2007.

  1. riverotter

    riverotter Midwest Alliance Rail Sys

    I have an opportunity to build a new HO scale layout, basically starting over from scratch. I'd like to build it around-the-walls, but the cost of "traditional" benchwork is outside of the available budget, so I'm considering using "L" brackets attached to the walls every 18" to 24" to support 24" wide, 2" thick blue foam board.
    My questions are:
    1. How can I attach the foam to the brackets so it doesn't slide off onto the floor? ;-)
    2. How far apart should the brackets be to support the foam board (and trains, track, scenery, etc.)?
    3. Any recommendations about make or model of brackets?
    4. How can I join the foam board segments end-to-end?
    Please feel free to ask me any questions for clarification, via either public post or private message.
    Thanks in advance for your ideas, experiences, etc.
  2. jr switch

    jr switch Member


    You might consider using a thin plywood like Luan under the foam to help keep it all level and ridgid, plus the Luan could be fastened to the brackets with small screws and the foam glued to the wood. This would work well with the spacing you are thinking of using. Give us some photos after you get started-----John H
  3. Gary S.

    Gary S. Senior Member

    My thought is as above. YOu need something under the foam such as 1/4" luan or a good grade of birch plywood or the like. This gives you something to attach things underneath such as switch machines and wiring. Now, there are those who use only the foam, perhaps inside a wooden frame.
  4. nolatron

    nolatron Member

    I'm building a similar layout to this in n-scale, but not using foam exclusively. I have shelf standards and 12" brackets mounted to the wall studs (on 16" centers), a 15" 2x2 attached to each bracket, and then 15" deep plywood on that. I plan on adding 1" or so foam to some of the lower level areas for a waterway and ground contours. That'll just be glued to the plywood base.

    So far (almost 6 months), the benchworkd has been rock solid.


    I then glued 1/4" strips of wood to the brackets, and glued/stapled aluminum trim coil to that to act as my backdrop.


    And then a coat of sky blue paint and lighting:


    For my shelf hardware, I'm using Knape & Vogt brand, and bought them all online from this Amazon.com dealer:

    Woodworkers Hardware Store @ Amazon.com: Woodworkers Hardware

    You can find more pics/info on my blog in my sig. Any questions, lemme know.


    Good luck!
  5. rhtastro

    rhtastro Member

    RR, I had considered using lightweight brackets or adjustable height hardware for my layout. My trainroom is a finished temp. utility building outside of the main house and the trains were to be around the inside perimeter of the room. I experimented with the above materials and found them to have too little strength. I wanted something I could lean on or even stand on if necessary. The stronger the better is my motto. Also, I didn't want any benchwork underneath. I thought about putting foam directly on brackets, but that was too flimsy too. So I used wood book shelf material, 4ft x 15 inches wide and regular 12 or 15 inch shelf brackets. It's strong. Then I glued onto that material, 2 inch thick art foam purchased from Micharls Art Store. It's not cheap, but it's strong. Also, you can cut and mold it using one of those hot wire cutter tools. For glue, I used Liquid Nails adhesive called "projects & Foamboard". It's a laytex glue and great for putting down the foam and for filling all the cracks afterwords. It takes a day to dry so you need to put weights on the foam as it's drying. When dry, you can't get it off, it's permanent. Then color with laytex paints. Check out some of my pics on this forum labelled "pics of Equity Junction". It has worked very well and I have even extended the width in some places using the same material plus brackets and screws. Be sure to use screws for your wall brackets that go into the studs in the wall past the wallboard several inches for the best support. It will support anything you put on it and won't sag. Good luck. bob
  6. MasonJar

    MasonJar It's not rocket surgery

    If your home follows standard construction practice, the wallstuds are 16" apart, leaving you witha choice of 16" or 32" apart. You could go (for example) at 0", 24", and 48" - but you would have to find a method of securely attaching the bracket at the 24" point, as it would only be in drywall. 24" on centre is the maximum spacing I would recommend for 2" foam with only a perimeter frame (as per our modular standards at www.hotrak.ca).

    You will have to laminate it to some wood, or use a frame, that can be screwed to the brackets.

    See above.

    Home Depot sells "Monster Brackets" in a 20" size, which would be ok. But at $12 each, it would be cheaper to make your own from dimensional lumber, or even plywood ripped to size.

    Use adhesive caulking or no-more-nails that is foam safe. If you wrap each 4 to 6 foot section in a wood frame, you can clamp, bolt or screw the sections together.

    Hope that helps. You should look up Gary S's thread on how he built his shelf layout with brackets and foam. I'll post the link when I find it.

  7. Santa Fe Jack

    Santa Fe Jack Member

    I would not use the underlayment of a thin sheet of plywood (mahogany and birch were recommended above) since in fact they will not provide much support to the foam--they are too flimsy. They may be useful for attaching things, to, but that would be it. And you CAN attach things to the foam. (See my web site pix about how I attached Tortoise switch machines).

    In order to stiffen the foam, and take care of the end-to-end joint problem, I'd suggest that you laminate several (2 or 3) sheets of thinner foam (like 3/4") together with offset joints to make a sandwich of foam that is 2-3 inches thick. With the offset joints, everything will be smooth on top when you are done.

    Attach the foam sandwich sheets to the mounting brackets with screws (with some glue like liquid nails to hold them in place) or by simply gluing the foam to the bracket directly.
  8. Gary S.

    Gary S. Senior Member

    I will respectfully disagree. I am completely happy with the 1/4" birch I used for my shelf layout. I built 1" x 2" framing with cross supports every 24" to support the plywood, then glued 2" thick foam on top of that. The plywood is not so much for support of the foam. It is more for the attachment of under layout infrastructure such as switch mechanisms, wiring, electromagnets, relays, terminal blocks.





    And more pics and commentary at: http://forum.zealot.com/t109555/
  9. Gary S.

    Gary S. Senior Member

    oops. I didn't realize there were two similar threads going on at the same time. Excuse me for my pseudo-double-posting.
  10. Russ Bellinis

    Russ Bellinis Active Member

    Foam is one of the stiffest products made. In fact, back in the 1970's GM built a prototype sports car using Vega components that used foam sandwiched between an inner and an outer fiberglass shell. That fiberglass & foam sandwich was the body & frame of the car and all of the rest of the mechanical components were bolted to it. That fiberglass/foam sandwich was stiffer than any frame GM had built up to that time.

    My point is that the foam does not need support for rigidity. It needs support to resist breaking, because it will break rather than bend. Something as thin and light as luan when glued to foam will make an extremely lightweigh but rigid benchwork base.

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