How Do You Cut Foam?

[Anonymous]

Hello Everyone,

I have a few of questions regarding foam. The first is what is the best way to cut 2" Foam?
The second question is how do you run your wires for turnouts, signaling, etc. thru the foam? Do you drill a hole or cut it with a knife all the way thru? I also have a turntable that needs to be installed, how does that get cut?
Also, please correct me if I'm wrong but I will be using yellow glue to secure my foam to my benchwork and clear caulk to use for my cork roadbed to foam and track to cork. Is this correct?
Is 16" joist enough support for foam or should I space them closer togther I'm attaching the foam directly to the benchwork no plywood.

Thank You all for your help with this,

Louie

[johncolley]

let's look at supports first. If the foam is 1 1/2" or 2" thick then 16" spacing is OK. If thinner you will want plywood under it.
Second running wiring...use a 1/8" drill, ice pick, or heavy coathanger wire.
third..cutting messy with a lot of crumbs, but a good job, especially if a straight cut is needed, lay a 1x4 on it mark your line and keep the 1x4 there to guide your old serrated bread knilfe or hacksaw blade. I also use the old bread knife for my river banks, road side ditches, raised roadbed grades, dips, etc. For precision cutting you could get a hot-wire cutter but make sure to do it outside as the fumes are very hazardous! If necessary practice on scraps first until you get the feel of it. Use a pantyhose leg in a dustbuster or vacuum cleaner hose for cleanup...It collects the crumbs for use in scenery, or disposal.

[SpaceMouse]

I use the 12" wood blade from my Sawsall reciprocating saw--just the blade. It cuts about as smooth as anything and I was able to cut an even 1/4 inch layer 6" wide and 42 inches long (to fix a boo-boo) off a chunk of 2" foam with it.

[cwclark]

I use a hacksaw blade (just the blade) to cut the foam, to create the rock formations, i use a seragated kitchen knife and a hobby knife and carve out the rocks..(I have a lot of old brass rail and use cut pieces of it it to hold the foam together if the need arises)...I also use the old brass rail to punch holes through the foam if i need a hole through it...I get my foam free but it doesn't come in flat sheets...it's old pipe insulation that we have here at the plant i work at and i have a lot of cutting to do to make flat square pieces...that's why i use the traditional plywood roadbed and put the foam rock formations around it..if i try to use the pipe insulation foam for subroad bed i'd have way too much cutting to do...Chuck

[Anonymous]

I use both a hot wire tool from the Foam Factory (but as indicated above, use ONLY out of doors) and a knife-blade on my jig saw.

Glue: I think Ailleen's Tacky Glue is superior to carpenter's glue (and cheaper) for gluing foam-to-foam or foam-to-wood. But I too use caulk for gluing track.

[Anonymous]

OK, I'll add my two cents...

To make straight cuts, I cut it with a utility knife. No teeth, so it doesn't make the mess. I go as deep as I can with it, and then I line up the edge with the edge of a table and snap it the rest of the way - kinda like you do with a sheet of styrene.

I sometimes have to clean up the edge w/ a hot wire.

John

[Big_Boy_4005]

I've had good results with a utility knife so far, but I haven't been cutting anything over 3/4" thick. I like the style of knife that uses the snap off blades. If done carefully, it should be able to handle foam up to 2" thick. I have the Woodland Scenics hot wire, but I find it slow and tedious.

I have found that Elmer's white glue works very well bonding the foam to wood and itself. It really takes very little glue to do the job. I just spread it very thinly, and my gallon jug has gone a very long way.

I would worry about using any caluk type adhesive, just from the standpoint that it is thick and may cause your roadbed to be uneven. The white glue should work just fine for that application too. Remember, when it comes to glue, less is more.

[Anonymous]

i can say that i used a jig saw it cuts llike butter with a hot knife

[tigerstripe]

I use a Woodland Scenics hotwire tool. For me it gives the best results with no mess. As for the smell leaving a window open with a fan on I think is enough.
For long straight cuts like ripping a 4X8 sheet , I use a razor blade to cut a line then simply snap it like styrene, then go back with the hotwire to trim it up, Clamp down a piece of 1X4 lumber as a guide to get a smooth straight cut. The trick is you have to have the wire extremely tight to get good results. Let the tool do the work.
As for attaching foam to your benchwork. Mine just sits on top of joist on 18" centers, no glue, plywood base or anything. Its been up for almost 3 years with no problems.

Tacky glue is the coolest!!!

[grayfox1119]

I use a saw for some shaping and Woodland Scenics hot wire to do other detail work. As for wires, Sear as long shaft drills of all sizes that I use for this purpose.

[Anonymous]

Serrated bread knife . . acts like a gentle saw. Works great on any thickness.