Foam stacking for mountains and hills

Discussion in 'FAQs' started by Tim K, Jan 22, 2006.

  1. Tim K

    Tim K Member

    Do you use liquid nails to glue the stacks of foam together ?
    How does it hold up while shaping and sanding?

    Is plaster the best for the rock on the mountains ?

    Tim K
  2. ezdays

    ezdays Out AZ way


    I have used white glue to hold sheets of foam to a base of MDF or plywood, but have also used liquid nails, especially when buiding a base for mountains. It holds much better than the white glue.

    I have covered my hills with paper soaked in plaster, then used joint compound to shape the rock formations. I like it better because I don't have to mix it and it takes a long time dry. I've gone back and detailed rocks eight hours later and found it still was workable. You can buy a 12# pail of joint compound at Home Depot for a few dollars.
  3. Tim K

    Tim K Member

    When using joint compound can it be applied directly to the foam ?

    I am building a mountain that has a path cut right through it so it has a lot of rock on both sides of the track , I will need a lot of compound and I have never done this before.
    So any help or suggestions are apreciated.

    Tim K
  4. ezdays

    ezdays Out AZ way


    You could apply the compound to the foam, but if you get it too thick, it will not only take a long time to dry, but it will crack. Like I said, I used paper towels dipped in plast to give me the basic shape I wanted and afterwards I used the joint compound to get me where I wanted to be.

    A 12# pail of joint compound will go a very long way in N scale, and half a long way in HO.:D :D

    A few years ago I did a step-by-step of making rock formations using joint compound and a putty knife. I never put it on the Gauge though. I'll see if I can find it and if I do, I'll upload it if it still looks worthwhile. (A lot can change in two years).:rolleyes::rolleyes:
  5. Tim K

    Tim K Member

    Thank you EZ.

    Tim K
  6. 60103

    60103 Pooh Bah

    you have to watch plasters because a lot of them shrink as they set. Hydrocal is one that doesn't, but it becomes extremely hard and paint doesn't penetrate.
    If you have a shrinker, you need to use small amounts of it at a time.
  7. ezdays

    ezdays Out AZ way

    Well I found it, and I never finished it, and I can see why. Some of the pictures are sub-par and it would be more of an embarrasment than a learning aid..:oops: :oops: :oops: :oops: Maybe next time. :D
  8. Herc Driver

    Herc Driver Active Member

    FWIW...I used Liquid Nails to glue the 1" boards in place, already pre-cut to approximate the hill I wanted to create. Then after they were dry, I finished cutting away with an Xacto the foam board I didn't want and also was able to cut a sloping hill where needed without too much fuss. Of course, the danger is, if you cut's already glued in place and harder to work around. Also, I tried not to get too smooth an edge on the cut foam board so that the result would look like a hill that had some grading work done to it (sorta like what highway departments do to hill sides near roads). The imperfections (textures) made when you pre-score then break apart the foam board resembles an escavated hillside when you paint it.
  9. John Hubbard

    John Hubbard New Member

    I've used Elmer's to glue foam together with good success, but in my latest effort, I've used hot glue and it has been excellent. My wife had the hot glue gun (and glue sticks), so I simply "borrowed" both from her.

    I have found that glued-up slabs of foam can be shaped very nicely with a Stanley Surform tool - sort of a 1x3 inch grater with a handle. It's a little messy, but quite easy to use. Keep a vacuum cleaner handy.

    My best experience so far has been to use the Woodland Scenics plaster cloth draped over my foam terrain to form a hard shell, then hydrocal or other scenic materials over that.
  10. Tim K

    Tim K Member

    I have read that you can simply cover the foam with paint

    were the ground cover will be and use plaster only were you want the rocks exposed.

    This will make it easy for planting trees and moving them around to get the desired look.

    Has anyone tried this method?

  11. ezdays

    ezdays Out AZ way


    No, I wouldn't. I've even got flat areas that I've covered with plaster mainly to get a bit more texture than if I just used blue foam. I would also think that shaping mountains and hills would be a bit more difficult.

    I have a woodworker's awl that I use to poke holes through the plaster to plant trees. A nail works just as well. Moving trees around isn't a problem either since it's easy to fill in a hole with a rock or shrub or just about anything else you'd find on the ground.

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