Cutting and modelling foam baseboards

Discussion in 'FAQs' started by scotterdavid, Jan 30, 2008.

  1. scotterdavid

    scotterdavid New Member


    I'm currently building a model railroad using a styrofoam baseboard. I've decided to go for a baseboard made out of DOW Floormate which is basically the same as the blue/pink foam board that you guys use in the US. It's pretty tough stuff which is why I decided to go for it, and should make an excellent base. I'm really looking for some advice from any modellers who use foam bases, please.

    What in your opinion/experience are the best tools to (a) cut the foam board to the correct size, and (b) cut features (river beds for example) and holes in to the base? I guess that a hot wire isn't really going to be that useful (for other than cutting the base to the right size), and so, for example, I wondered if anyone had bought a hot knife that they could recommend?

    There isn't much of a market for such tools in the UK, and so I've been taking a look at suppliers in the US. So, for example, is there anyone that could recommend the tools supplied by the Hot Wire Factory (Hotwire Foam Factory), or any other company please?

    Thanks & Regards -- David.
  2. rogerw

    rogerw Active Member

  3. railwaybob

    railwaybob Member

    At Ottawa Valley HOTRAK we use styrofoam as the decking for our modules. You can see some of our construction techniques on my website.
    Module Construction

    Depending on what you are cutting, a sheet of styrofoam can be cut to size using a saw - a hacksaw blade, a cross-cut saw - a utility knife, or any other kind of sharp cutting instrument. I've cut square sheets of styrofoam, irregular pieces of styrofoam and even shaped blocks of styrofoam using a hacksaw blade and a knife.

    If you are making blocks of scenery, whether they are hills, valley, or riverbeds, the best instrument to use is a hotwire. There are a couple that are available commercially. You are only limited by the shape of the wire in terms of what you can cut. If you are so inclined, you can make your own hot wire out of a transformer, a fuse and a dimmer switch. You should be able to find something on the Internet.

    And then there are the techniques for gluing the styrofoam down. I use a polyurethane glue which works very well.

    I could write a whole book almost on the techniques of doing scenery in styrofoam but right at this moment, I don't have the time.

    Bob M.
  4. MasonJar

    MasonJar It's not rocket surgery

    You can use a hot wire cutter to cut and/or shape your foam, but it is one of the more expensive ways to do it. You can construct your own hot wire - "nichrome" wire is the key - for much less. The warnings about ventilation and appropriate masks applies whether wyou make your own or not...!

    I cut the pink (Corning brand) extruded foam with a Dollar Store "snap-off" utility knife extended all the way. Making multiple passes works better than trying to hack through in one pass. Similarly, landforms can be shaped with a sharp, longish knife: either the utility - but beware of the tendency of the blade to snap off when lateral forces are applied - or something like a bread or boning knife. I recommmend that you wear hand protection like this:,42407,33246 when cutting.

    The other option, although it is far messier, is to use a saw - hacksaw with the "extended" blade, handsaw, or fine tooth keyhole/drywall saw. This creates a lot of crumbs that can (somewhat) be tamed by a shop vac and possible light mist of water (stops static). I have also heard (but not tried) that anti-static dryer sheets rubbed on clothing can prevent the crumbs from sticking to you...! :)

    One tool that is messy, but very effective, for final (or close to final) shaping of landforms is a wire brush. You can use as big or small a one as appropriate for the job. Have your shop vac close by, and simply "scrub" away the foam until you have what you need.

    Hope that helps.

  5. Doc Holliday

    Doc Holliday Member

    I made my own hot wire cutter from an old soldering gun. I removed the soldering tip and inserted a piece of #12 copper wire. You can bend the wire to any shape you want, just make sure it doesn't touch itself. I made different "blades" such as a long thin knife for basic cutting, a tunnel shaped one for excavating tunnels, a wide, flat one for general contouring, etc.

    Attached Files:

  6. 60103

    60103 Pooh Bah

    Preliminary shaping can be done by cutting partway into the sheet and then snapping it like plasticard.
    If your foam is tough, it may not be the same as we have. :mrgreen::mrgreen:
    I use the hot wire tool for contouring and a long knife for non-straight cuts. I avoid serrated edges (incl. hacksaws and breadknives) because my wife won't stand for all the fine particles.
  7. doctorwayne

    doctorwayne Active Member

    For straight cuts, a panelling blade in a Skilsaw works well. ;):-D

  8. roch

    roch Member

    I like Doc Holliday's idea. That I can handle. :thumb:
  9. Jim Krause

    Jim Krause Active Member

    I have used everything from my pocket knife to utility knives, hacksaw blades and xacto knifes and have seen that others use bread knives. Whatever your budget will allow. I would like to try a hot wire cutter sometime but don't want to spend the money. Medium grit sandpaper in a sanding block works well for finishing but don't use heavy pressure. Learning from your mistakes will develop a good procedure.

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