Foam on the Palmer Industrial Park

I finally got back to working on the N scale Palmer Industrial park this weekend.  The focus was getting the backdrop supports in and the foam down.

The backdrop supports came first.  I've decided to go with a 10" high backdrop.  Since the plywood is at 48" above the floor, that puts the top of the 2" foam at 50", and the top of the backdrop at 60" - just a bit below eye level for me.  It seems to be high enough to make a nice backdrop, but low enough to leave the room more open feeling.  I wanted to keep the backdrop thickness down, so instead of building a more complicated frame I opted for using my favorite fastener - the pocket screw - to fasten 12" high pieces of 3/4 ply vertically along the backdrop center line.  The paper plan now has cut outs for the backdrop supports, the theory being that once the foam is glued in and painted I will drop the paper plan back down over the supports and trace through onto the foam.  We'll see how that plays out in practice later.

The backdrop supports pocket screwed into place.

The photo also shows what I'm going to try for a backdrop - 10" wide vinyl flashing.  The total length of my backdrop is roughly 30 feet (15 feet from the wall to the end blob, then back), so the 50 foot roll will let me have no seams, and give me a little to experiment with before I start to glue it in place.

The next step was cutting the 2" foam sheet to fit.  I tried a serrated bread knife, but that quickly got stuck.  I bought a cheap fillet knife, which worked much better but also eventually gets stuck.  So I ended up using a 6" or so sawzall blade mounted in a handle I got somewhere for the purpose.  The sawzall blade cuts on the upstroke and it's got relatively fine teeth, so it makes a decent, fast, and easy cut.  By doing all the cutting on the other side of the room on a couple saw horses and vacuuming each piece before bringing it to the layout I kept all the little blue foam dust away from the layouts.  The backdrop has several angles and curves in it, so each piece of foam required some careful layout.  I balanced the 2 foot wide sections of foam in place on the layout as shown below (the gooseneck thing is for weight to keep it from tipping off), made sure the front edge was parallel to the front edge of the layout, and measured in from the backdrop the same amount as the front edge overhung the layout to transfer the back edge marks.

Transferring the back edge line to the foam.

The worst piece to lay out was the one where the lead will go - it's got odd angles on both edges.  But everything ended up fitting OK.

Test fitting the foam.

I'm considering several possibilities for the scenery at the end of the peninsula.  One is modeling the Swift River that follows the real park track, which would cut down into the 2" foam.  Another is building up the terrain a bit so the sharp curve is a bit concealed in a cut.  While I could still do it, I traced the outline of the end foam onto a 1 inch foam sheet and cut it to match.  Not sure if I'll use it yet, but it was easier to cut it now than later.

A 1" sheet cut for raised scenery at the end.

With everything ready, I glued down the foam.  I used Liquid Nails projects construction adhesive, which is safe for foam.  I had assumed one tube of it would be enough, but ended up having to make a quick trip to the hardware store for a second tube.  A motley collection of stuff from around the basement served to weigh down the foam.

Foam glued and weighted down.

Watching glue dry is, if anything, less fun than watching paint dry since you can't even see it.  So I decided to test bending the fascia around the corners.  One corner on the peninsula is a 4" radius, the other is 6".  I don't remember why they ended up different - that was a number of plans and several years ago.  Lance Mindheim's book "How To Build A Switching Layout" (an excellent book) recommends using 1/4" MDF for fascia.  I used 1/8" masonite on the O scale layout, and avoided the warping problems I've seen other people have by gluing and nailing it to the 1x4 at the front edge of the layout.  But the top edge is a little thin to lean on, and I've noticed that people like to lean on the layout.  Preventing leaners seems to be impossible (I catch myself doing it sometimes), so with a 1/4" fascia the top edge should be considerably stronger.  My one reservation about the 1/4" MDF was whether I could get it to bend to the 4" radius corner.  I bought a 2x4 foot sample piece, ripped a 6" strip off it to try.  If I do end up using that 1" foam to raise the scenery at the end I'll need to use a 7" strip, but that's not today's problem.  I soaked the bend area using a garbage can lid and a dripping wet towel, and then tried to bend it around a roll of flashing I had hanging around that's about the right diameter.  Very awkward trying to hold everything in place and clamp it.  Eventually I gave up and clamped it directly to the layout - a little damp won't hurt that corner.  Surprisingly enough, the 1/4" MDF does seem to bend nicely around the 4" radius.  I guess I won't know for sure if it will work until it's thoroughly dried out and I remove the clamps.

Test bending fascia to 4" radius.

I'm eagerly looking forward to the next steps - gluing the backdrop in place, and painting it and the foam.  But that will have to wait for the glue to dry.