I'm thinking of eschewing foam, and just redoing my benchwork with a frame of 1x3's or 1x4's with homasote as a base for my subroadbed, because you can stick T-pins in it just like with foam.
But what I'm wondering is what kind of glue can I use to secure my roadbed, among other things? I know that you CAN screw into homasote, as well, right?
What I'm thinking of doing is to create an outer frame of 1x4's or 1x3's (waiting on the Wescott benchwork book to arive) with cross beams or joists or whatever you call it going through the middle, and screwing the homasote into the beams, from the top. I'm not happy with gluing down foam to a sheet of plywood, as thats given me problems, and I can be completely ready to go by just screwing the homasote to the benchwork frame.
It is best to put a sheet of 1/2 in plywood (or thicker) under the Homasote.
Any glue that is used with wood can be used with Homasote.
Dave H. Painted side goes up. My website : wnbranch.com
Greg
I used white glue and carpenter's glue and the powdered hide glue (hard to find nowadays) with Homasote. I never screwed it to the plywood; just glued it. Homasote without plywood support underneath needs very closely spaced supports to avoid long term sag. The joists would have to be on the order of 6"-8" to avoid sag. Cheaper, better, easier to put 1/2" or 5/8" plywood underneath with joists every 16" or so.
On this latest layout, I am using 2" foam on top of 1/4" plywood. The Homasote roadbed goes on top of the foam. Like you, I'm rapidly becoming disenchanted with the foam. I'm beginning to wish I had gone with the old standbys - 1/2" cookie cutter plywood on risers, Homasote roadbed, and some sort of shell in the open spaces for scenery.
In the past, I've laid 1/2" sheet plywood and sheet Homasote glued to it directly on the joists. After laying some of the track, I took a jig saw and cut out the ply and Homasote around the track, then raised the track on risers.
A final thought - you could screw from the plywood to the Homasote through the foam with long screws. This would sandwich the foam between the ply and Homasote, both of which will hold the screws. Just don't tighten so tight that you compress the foam.
my thoughts, your choices
Fred W
Any wood glue (I use Elmer's) will work because homasote and plywood are both made from wood. Nevertheless,.... the homasote needs to be held securely to the plywood while the glue is curing. I use short finishing (small head) nails for that purpose.
Mark
fwright Like you, I'm rapidly becoming disenchanted with the foam. I'm beginning to wish I had gone with the old standbys - 1/2" cookie cutter plywood on risers, Homasote roadbed, and some sort of shell in the open spaces for scenery.
Like you, I'm rapidly becoming disenchanted with the foam. I'm beginning to wish I had gone with the old standbys - 1/2" cookie cutter plywood on risers, Homasote roadbed, and some sort of shell in the open spaces for scenery.
I'm with Fred on this one - I think I've used foam board for the last time. I'm very hard pressed to see it's real advantages over homasote roadbed on plywood, and cardboard lattice work for scenery.
For the homasote, I've found yellow carpenter's glue to work quite well as a binding agent.
I'm trying to model 1956, not live in it.
You must have something under the Homosote to support it -- 1/2 inch or thicker plywood or some such, because Homosote is just compressed paper and it has no strength. Without wood under it, Homosote will sag between the supports.
More than a moisture barrier painting keeps the dust down. Unpainted Homasote almost pumps out dust, seemingly forever. A coat of cheap latex paint largely solves the problem.
Good luck!
The last "under the tree" N Scale layout was a 4' x 4' homasote on a 1" x 4" wood frame with an additional support underneath that provided a box benchwork of (2) 2' x 4' wooden sections. The four legs were each two 6" "L-shaped" 1" x 4" wood. No plywood was necessary under the homasote.
Rock solid for a 2-track mainline and some sidings.
The layout lasted 30 years with never a concern about the weight of the Christmas tree resting in the middle of the 4' x 4' layout.
My first Jr-High - High School HO Scale layout was on a 4' x 6' piece of homasote with a similar box-grid underneath of (3) 2' x 4' sections. No plywood underneath, and it easily supported my weight during scenery construction. The four "L-shaped" 1" x 4" legs were three feet in length.
White glue worked just fine on the homasote in each case.
Conemaugh Road & Traction circa 1956
Well said there Fred W! well said!
This is the way I have been doing it for most of the past 25 years; I don't use 1/2" ply but rather 3/16 with 12" joists. For me the ideal is a sandwich of 3/16" ply and 1/2" Homasote® and cork roadbed. I cookie cut my subroadbed and Homasote® and suspend it on risers screwed into the joists.
From the far, far reaches of the wild, wild west I am: rtpoteet
I haven't abandoned the foam - yet. As far as I can see foam has 2 primary advantages over cookie cutter plywood and plaster shell. 1) It's light weight. 2) You can "plant" trees into foam much easier than into plaster.
Unless the layout is deliberately intended to be portable, the difference in weight between the 2 material sets really doesn't matter. Even a sectional layout is that moved once every few years - the weight issue just isn't that important. Again, if you are moving a layout module or section several times a year - than weight matters and you need to use foam along with a lightweight support system.
For a flat top layout, foam is probably more flexible than plywood. It can be easily carved and stacked for scenery both above and below track level, and again you can stick things into it (like trees).
But trying to approximate a cookie cutter plywood/plaster shell layout with foam exposes some of foam's weaknesses. Whether the foam is cookie-cuttered or stacked, it's much thicker than plywood plus roadbed. This thickness has to be allowed for when one track is over another - which I forgot to do in my planning. In order to keep grades reasonable with the required clearances, a thinner material has to be substituted where the track passes over or straddles another. Changing and joining materials at overpasses or straddles sets one up for abrupt grade changes. One of the beauties of the cookie cutter system - foam or plywood - is that you can't make grade changes too abrupt as long at there are no joints in the grade transition section.
The thickness of the foam "shell" also makes access to hidden track much more difficult, and makes under the track mounting of switch machines and uncoupling ramps more difficult. Finally, many folks end up putting a layer of plaster on top of the foam to get better topography and/or for a medium that is easier to carve/cast scenic detail into. The plaster coating negates a lot of the weight savings, and takes one back to drilling/punching holes to plant trees.
So if I am not building a flat top layout, I don't see any real advantages to foam. Since the layout I am currently building with foam will have to be moved perhaps once a month, I am adapting to using foam to keep the weight easily handled. But because the track has several elevations and has a 36" long hidden section with track passing over it, traditional plywood cookie cutter would have been easier in many ways.
just my experiences