After making a move which required the demo of my 10 year old plywood based layout, I have decided to give the foam benchwork a go. Seems like most folks who have tried it like it. As I begin the initial planning my question is this:
I am going to include grade changes, so are their any tips in making the grades with the foam base? What’s the best way?
Thanks for any help here,
Mike
My plan thus far is to set the foam to a height that is the END point of the grade and put a ramp on top leading up to the preceeding section. For example, the current baseline is 48". On the next section I am going to have a grade down 4" for the first drop down to staging underneath. So the next section will be built to 44" height, and the grade put on top to bring it back to the original 48", using either riser blocks I cut myself, or the Woodland Scenis risers and inclines.
–Randy
I’d use the Woodland Scenics foam risers for your grades. I use foam base for my layout, and do NOT think that you can use the ‘cookie cutter’ style of grade rises that you can use with plywood. Not nearly enough strength. The Woodland Scenics risers are available in 2%, 3% and 4%, and they contain charts on how to combine risers to almost any percentage of grade you wish. They provide a good, even rise in elevation, I’ve used them for 2%-2-1/4% grades without any problem at all. They’re pretty foolproof.
Tom
I used an open-framework to give me a number of level changes. Then I use cookie-cutter style for the foam. For inclines, I make T-shaped risers and fasten them to the benchwork below, and glue the foam to them on top.
I did try one incline which I built by cutting a ramp out of foam. I had a hard time getting a level cut, though, and it took a lot of shimming to get the ramp even. After that, I switched to T-risers and found it much more satisfactory.
My favorite method is to avoid grade changes completely. If that’s not feasable, I use an underlayment of 1/4" Lauan plywood under the 2" base of foam, and cookie cutter out the whole structure as neded. I build up the surrounding area with scarp foam and blend it all together with lots of carving. This method may take a bit more work, but it’s 10 times cheaper and smoother than using the Woodland Scenics risers.
I will be trying a slightly different technique. I am using two layers of 1.5" foam, one for the base and the other for the track layer. I will cookie-cutter out the top layer to create low areas like stream beds. But I will also create ramps by shimming up the roadbed using scrap pieces of foam between the base layer and the top layer. When it is all correct I will glue the two pieces together. This method retains the benefits of all-foam construction, in particular the ability to poke holes all the way through.
I was going to use L girders with joists with my wall mounted layout. But I realized that the foam technique allows me to get rid of the joists.
My switch machines will be actuated through a crank wire run through a tube, which can be offset from the throwbar if required, so thickness of the foam should not be an issue there, nor should there be an interference problem with the L girder.
1" foam for one or both layers might work as well or better with this technique.
I use several layers of foam glued together and then using a surfoam file just work the foam ramp from the lower layer of foam up to the top layer. It makes quite a mess but having the small shop vac close by keeps it under control.
One disturbing thing I have found is that the Liquid Nails for Projects does not really hold the layers of foam. At least on mine it doesn’t as I am able to use a putty knife to separate the layers and the top piece just pops off leaving the glue spots, which I can then just peal off. And this foam has been down for 2 years or better!
Although this maybe better this way as I do end up making too many changes to the foam scenery and this allows me to salvage and reuse the foam.
BOB H – Clarion Pa
I used a knife, or carpet cutter, and carved out long wedges from my sheets of foam. I glued the wedge pieces, side-by-side, as needed to get the width I wanted. When they had dried, I simply used a wooden wire brush and took long strokes up and down the ramp, including right over the top, to get the transitions I needed. At the botom of the ramps, so as not to gouge out the bottom foam layer, I added shims to the thin foam at the bottoms of the wedges to get the lower transtions.
If using snap track, the transtions sort of ‘happen’ as best they can once the pieces are laid over the ramps. With flex (which I didn’t use), the ballasting over the ramp will provide a natural transition if the shimming doesn’t quite do it.
There are several methods that I have used in the past to make grade changes on my N scale layouts using 2" foam.
For very consistant grades, cut a riser from a sheet of 2" foam. The 2" dimension works perfectly for N scale. Larger scales will need pairs (or more) of risers made with this method. Determine your grade requirements (1" in 100" = 1% grade). Since the foam sheet is 96" long, it is close enough to 100" to use as is. I mark my height on one end and draw a straight line to the corner of the other end. Cut along this line and you will have an 8’ long riser for your grade. Mount the piece with the factory-edge facing up because it is difficult to make really smooth cuts through 2" foam. (Do your homework before going to the home center. Usually free or for a small fee, they will cut the panel into smaller pieces. Just have them cut of long rectangle as wide as 2 times the height you need. Split the piece from corner to corner and you have TWO risers with the proper gradient!)
To carry the grade through turns, simply make fairly deep vertical cuts and alternate the cuts between the inner and outer edge of the riser. This will allow you to bend the riser. Don’t worry if it breaks in a few places when bending. Just keep working it into position. I secure these risers with Liquid Nails for Foam and use florists pins or bamboo skewers to hold in place until the glue dries. You can lay your roadbed directly on these risers, but I found it was better to cover the riser with plaster-soaked paper towels to prevent ballast from falling into the cuts in the riser. A light sanding after the plaster dries will give you a nice, smooth base for your roadbed. (Sorry I don’t have a picture of this. It’s all covered up with scenery.
Another method I used utilized 1" foam in a cookie-cutter fashion. I cut pieces of foam to fit an area that was to have a gradient, then used various thicknesses of foam to raise the piece a little at a time until I reached my upper h
Duh, I forgot all about the WS inclines and risers. But agree they are expensive. Folks, thanks for the tips. I sure there’s other things I;ve forgotten in the past 3 years since I modeled.
Mike