Benchwork constuction for foam??

Discussion in 'FAQs' started by spitfire, Dec 12, 2004.

  1. spitfire

    spitfire Active Member

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    What's the difference in benchwork construction if you're using foam instead of plywood? For plywood my BW is all 1x4s with support pieces every 2 ft. The plywood sits on top.

    With foam, I assume it sits inside the frame. Is this right? What size wood should I use for support pieces and how far apart should they be?

    Thanks in advance!

    Val
  2. Ralph

    Ralph Remember...it's for fun!

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    I don't see why the foam couldn't sit on the 1X4s like the plywood Val. You could cover up the sides of the foam with your facia later....it'll let you include scenic features at the edge of your layout like rolling hills and drainage ditches and the like.
    Ralph
  3. seanm

    seanm Member

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    How close do the supports need to be to support foam? I would suppose it has to do with the thickness of the foam, but some rules of thumb would be helpfull.
  4. Matthyro

    Matthyro Will always be re-membered

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    Val, I use 1/2 inch pink foam and support it every 12 inches. You saw it in action on your visit here and it works well for me.
  5. CN1

    CN1 Active Member

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    I use plywood for the foundation (conventional construction) and lay (glue) foam on top. I find it easier to carve and to change elevation of the topography and roadbed with foam than cutting the plywood and installing risers (cookie cutter method).

    But than again, I use all available technique to get what I am after, but I feel more comfortable having a plywood base than just foam. But that's me....
  6. spitfire

    spitfire Active Member

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    Thanks Robin - that's exactly the info I was looking for!!! :) :)

    Val
  7. 60103

    60103 Pooh Bah

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    Val, I would go with the 12" support spacing. Are you going to use foam under your track as well? You might need a bit more there, as HO can be heavier than N. Aim to have the longitudinal support under the track area.
    On my last layout, I used L-girder supporting Homasote trackbed and dropped the foam scenery pieces on the supports or glued some of them under the trackbed.
    If you're just supporting scenery and buildings, you may only need a few supports.
  8. billk

    billk Active Member

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    I'd put at least 1/4 plywood under it to prevent misplaced elbows, etc, from going all the way through the foam.
  9. SteamerFan

    SteamerFan Member

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    ok, 1x4 for the general frame(4" is vertical), using same 1x4's lay one horizontial slat (1" vertical) every 12" flush with depending on your standard (build the frame a bit bigger than 4x8, you flush bottom to set foam in, frame exact 4x8, flush top to set foam on top).
  10. spitfire

    spitfire Active Member

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    Thanks folks. I'm a little nervous about using only foam for the layout. Have so far used traditional plywood and homasote. Track sure spikes easily into homasote, but that method is kind of expensive, so I'm looking at alternatives. The jury is still out. Any pro's and cons toward the foam method? What about elbows etc?

    Val
  11. Matthyro

    Matthyro Will always be re-membered

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    At this point, I have had no accidents but then my layout level is 56 inches above the floor and no way for me to lean on my elbows. As a safety measure it will probably be better to have some plywood under the foam. !/4 or 3/8th thick plywood should do the trick. Doesn't have to be the good stuff, just get construction grade that isn't finished on either side.
  12. spitfire

    spitfire Active Member

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    Thanks Robin!

    Val
  13. neilmunck

    neilmunck Member

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    Hi Val,
    My layout has a 2 foot by 3 foot grid of 1/2 inch by 3 inch pine on edge on 2' centres and flat across the way with the foam sunk into the grid, flush with the front and back.

    I use the white bead type of foam as I couldn't get the extruded type. It has joints in it because it came precut into 18" by 4' bits for roof insulation so there are joints in it all over the place.

    The layout is only 2' by 12' and definately does not follow recomended practice when it comes to redundancy in support but I have had NO problems with sagging in 2 years.

    The track is laid on cork underlay, glued to the foam. It is all solid but I don't like to lean on it! Being the best part of 5' off the floor helps reduce temptation.

    Neil
  14. bigdonnie

    bigdonnie Member

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    What I wouldn't give to have a space like this for a decent sized layout!

    So, when do you expect to have your first operating session.........? :D

    Don
  15. spitfire

    spitfire Active Member

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    First comes the tracklaying party, then the operating session!!!

    Val
  16. CN1

    CN1 Active Member

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    Bingo! :cool: