A few questions for those of you who have layouts on pink insulation
1) How do you handle the elevated track areas? Do you glue more foam
on top and cut it with a hot wire cutter into the grade that you want?
It seems like doing that would be a bit of a pain. Any tips?
2) What do you put the board on? It seems like one of the advantages
to using foam board is you wouldn't have to build all that benchwork,
but if you just slap it down on a card table or sawhorses it's not
going to be closer to eye level which looks better. Also, how do you
handle all the wires coming out through the bottom of the board
(related to what you set the layout on)?
a) On a small, portable layout, just add layers of foam. You could use
Woodland Scenics foam risers between these and the base. O'wise,
calculate the elevations at 4" to 8" intervals, and glue risers (small
blocks of foam) at those locations. You'll have to slope the top of the
riser slightly, but that's easier than sloping a long piece of foam. Use
the shorter span for 1" foam, and the longer for 2" foam. BTW, your
track should not be laid directly on the foam. Use cork strip between
the track and the foam, even if you use the kind mounted on plastic
b) Medium sized layouts (up to about 4x8ft) can be built as above, or
else fully supported on benchwork.
c) On a larger layout, you lay the track on track boards (subroadbed)
mounted on risers which are fastened to the L-girder or boxframe forming
each section of layout. The foam is used mostly for scenery.
Well, actually you do have to build some benchwork, but it can be a lot
lighter. A shelf layout for example can be supported on shelf brackets,
with the foam supported on or inside a boxframe made of dimensional
lumber or light plywood. I used 1x2 to make a boxframe for a 24"x30"
proof-of-concept N gauge layout recently. I glued 1/4" luauan plywood to
it, and glued a layer of foam to the plywood. The track support was a
double layer of foam cut about 1-1/2" wide (I'd use 2-1/2" to 3" for
HO). The glue was acrylic latex contact cement (water based). Then cork
was glued to the foam, and the track to the cork - I used pins to hold
it in place until the glue held.
If you use a boxframe, you just drill a hole and thread the wires
through. MR showed a neat trick recently: push a wide straw through the
hole in the foam, thread the wires through the straw from above, and
then pull out the straw from below. You can also cut grooves for the
wire to lie in alongside the track base, etc. Be careful with your
soldering iron around foam - it can melt a big hole pretty quickly (and
the fumes are toxic.)
If you are building a micro-layout, bring the wires out to the side.
I've seen such layouts framed with plywood all round, 1/4" is strong
enough for mounting things like switches and plugs. (A micro layout is
about 8 square feet or smaller: a really samll one can be built on a
2"-4" slab of foam with any further support.)
Thanks for the info there, Wolf. I've worked with L girder
construction but I was thinking of going to foam for this smaller
layout I have in mind.
I was looking at those Woodland Scenics Risers, and they do look pretty
convenient, but how do you slope the top of the Risers to get a grade?
Like going from 0" to 2" in four feet or whatever. What do you cut
Well, you could put a yardstick on each side and use the hot wire foam
cutter to cut them along the edges of the yard stick...
But it would be easier simply to buy the risers that are already cut as
grades. I know they have at least 2% and 4%... I think they've got 1% as
i> A few questions for those of you who have layouts on pink insulation
i> foam board:
i> 1) How do you handle the elevated track areas? Do you glue more foam
i> on top and cut it with a hot wire cutter into the grade that you want?
i> It seems like doing that would be a bit of a pain. Any tips?
I'd use a sure-form tool, but otherwise yes you add foam and carve it to
suit. Yes, the sure-form tool creates a lot of mess, but that is what
your shopvac is for. The shreds could possibly be used as loose filler.
For major foam removal a serrated bread knife works well. One can fine
tune things with other 'abrasive' tools: wire brush, sandpaper, etc.
i> 2) What do you put the board on? It seems like one of the advantages
i> to using foam board is you wouldn't have to build all that benchwork,
i> but if you just slap it down on a card table or sawhorses it's not
i> going to be closer to eye level which looks better. Also, how do you
i> handle all the wires coming out through the bottom of the board
i> (related to what you set the layout on)?
You still build the benchwork. It is just a lighter weight benchwork.
You use a *lightweight* (sparse) 1x4 frame under the foam. Much of the
weight of a 'traditional' benchwork was with the plywood and the
relatively 'dense' framing needed to support the plywood. Because
the foam is actually *more* rigid than plywood (assuming the thinner
1/4 or 3/8, rather then the thicker 1/2 or 5/8), you can use somewhat
wider joist spacing. Warning: you probably want to avoid too much
'heavy' scenery, since the benchwork is not as strong as with the
traditional heavy plywood type benchwork. You run the wiring, etc.
under the foam, as usual.
Robert Heller ||InterNet: email@example.com
But you are actually adding angles, rather than the tangents thereof. It
won't make much difference at reasonable grades. Ten 1% wedges stacked
equals 10.7% grade. The error would be less with fewer larger wedges.
But a 180% grade is 61 degrees. 180 1% wedges would be 103 degrees. That
is only slightly upside down.
Oops I goofed with the first post!
Actually what I've done is to use a door as the bench work. Then I "cookie
cutter" my subroadbed shape into the foam layer (I use 2" foam). Between
the foam layer and the door benchwork I place a series of shims in 1/16"
increments. The foam maintains a smooth gradient that also transitions
smoothly since it is always 2" thick plus whatever the shims are. For a 1%
grade the shims change every 6 1/4" for a 2% grade every 3 1/8" etc. The
foam is rigid enough to handle these spans especially since I bond 1/8" door
skin to the top of the foam so that the resulting structure will hold track
nails. I like to use track nails because I find that I tinker with the
track plan quite a bit before I get to scenery since I do not have the
patience to come up with a rigid plan before commencing construction.