Grades Using Foam

Hi everyone! Long-time lurker, first time poster.

I'm about 6 months away from starting construction of my "dream" layout. In the past, I've used laminated lauan on 1x3 risers for my sub-roadbed. Now, I'm CONSIDERING using 2 inch foamboard. My question is, how do I build up the grades? Do I build up my usual 1x3 risers, then glue the foamboard to that, or is there a better option? How far apart should my risers be for 2 inch foam? I'm looking at a climb from a 40" base level to a 66" highest point, so there'll be grades aplenty.

I'd appreciate any advise out there. This is a great site and I look forward to exchanging ideas and experiences with everyone.

 

Just treat it like plywood. Use foam risers under the roadbed and use the cookie cutter method. i havent tried this out yet, but am confident it will work. My next layout will hang from the walls on 12" shelf brackets, with 2" foam used for all the benchwork. Should be real light......Mike

 

MPCaboose, the only thing to keep in mind is to provide some means of holding YOUR BODY weight. I had an unfortunate incident that will sooner or later happen to you if not already. You or someone will loose their balance, or slip off of a support, and one hand will come to rest on the layout instinctively to keep from falling. Mine was repairable, (there is now a lake there), but had I caught myself closer to the edge, it would have broken out a chunk and I would have gone to the floor. As it was, My arm pit happened to cross a 1x4 stringer which supported my weight. I got a bug's eye view up close and a mouth full of tree, but with the help of the 200 ton wreck crane, the Giant survived. (Test to see how close to place supports under your foam, by placing 2x4's on the floor, foam on top, then push down with one hand like a push-up and support your weight. Keep moving the blocks farther and farther away until the foam cracks or breaks. That would be just at the maximum, but do start with only 6" space between the 2 by's. It isn't far. Remember, you will heal, your brass engine will die when it hits the floor when "(If it CAN happen, it WILL happen), and did!

 

<BLOCKQUOTE>quote:</font><HR>Originally posted by mpcaboose:
Now, I'm CONSIDERING using 2 inch foamboard. My question is, how do I build up the grades? Do I build up my usual 1x3 risers, then glue the foamboard to that, or is there a better option? How far apart should my risers be for 2 inch foam?<HR></BLOCKQUOTE>

MPCaboose - I glued 1"x3" blocks of 1/2" and 3/4" foam together (side-to-side) to make risers every 12". The blocks are laid on their sides, on top of a flat base surface, plywood, or foam sheet, or whatever. Then a "cookie-cutter" sub-roadbed of 3/4" (or thicker) foam is glued to the top of each riser. The result is strong enough to support trains and scenery (but NOT Watash's hand ).

Increase riser height by 1/4" every 12" to make a 2% grade, as shown below.

At 12" from start of grade, use 1/4" shim of wood, cardboard, or whatever.
At 24", use 1/2" foam
At 36", use 3/4" foam
At 48", 2 pieces 1/2" foam
At 60", 1 piece 1/2" and 1 piece 3/4"
At 72", 2 pieces 3/4" (or 3 pieces 1/2")
At 84", 2 pieces 1/2" and 1 piece 3/4"
At 96", 4 pieces 1/2"
.......... etc.

Just continue combining 1/2" and 3/4" blocks until you reach the height you want. If you want (need?) a steeper grade, place the blocks closer together. For example, 9" apart for a 3% grade, or 6" apart for a 4% grade.

I found this technique much easier and it made much smoother grades. When I screwed risers to framework my grades always looked like a roller-coaster.

Hank

[ 22 May 2001: Message edited by: Hank Coolidge ]

[ 22 May 2001: Message edited by: Hank Coolidge ]

 

Watash, that's exactly what I'm concerned about. I've experimented with foam, and it seems I continually end up with a series of sinkholes that match my elbows perfectly.

Another concern is that if I put any excess weight on the foam roadbed, would it collapse cells where it is in contact with 1x3 risers, creating a dip in the roadbed? That's why I was wondering if that is the best support method.

I like a lot of what I hear about foam, although I've learned that carving it with a surform creates electrically charged pieces that cling to everything. I'd like to be sure of it BEFORE I start, because this will be a major investment in time and money.

Thanks for your help!

 

Hank, that sounds like it might be the ticket. I'm planning on using 2 inch foam for the roadbed, because I come from a long line of overbuilders, but I think I'll try your idea with various thicknesses to test the relative strength of the bed. My heaviest engines are 1st generation P2K and the old Athearn super power F7's, so I don't have any real crushers like brass. Thanks for your idea!

 

I am a very quite person but this post really got me going….I used a piece of ½” plywood for the base and then went to a home type retail place. Bought a couple of pieces of 2’ x 8’ 2” insulation foam for about five bucks. Measured out what I needed for grades. Usually about 2 to 2 ½%. Ran the pieces for the angle on my bandsaw. Waw-laa preformed grade and all the filler you need for hills and valleys. Followed through from that with medical plaster wrap (2.50 for a 10’ roll about four inches wide. Sprayed or misted lightly and you have what you need. Easily changed and if using a little imagination can be moved from place to place until you get your scene.
The main thing is to remember to have fun!!!!

 

Squirrelrun, if I understand correctly what you are saying, you created wedges of foam that you mounted on edge to make a 2 inch wide roadbed. Is that correct?

Wow, that's a pretty cool idea. Have to ask, though, how did you bend the foam around curves? My experience is that foam will snap in half with not a lot of bending.

 

Don't rule out Woodland Scenics' new line of foam products. I have experimented with their prefab inclines and I like the results. They are designed to go around corners and will probably handle a curve sharper than you will ever use.

 

To form a bend in your wedge of foam, go back to your band saw and slice 3/4 into the foam on the outside edge about every inch. Doesn't have to be exact, just 'eye-ball' it. You end up with flex foam roadbed support on an incline. I got several sheets of 1/4" thick cell foad (beeded kind) and cut out the curve by laying this foam sheet on top of my incline, and mark the under side with marks-a-lot, turned it over, cut it out, turned back and glued it. That smooths out the bandsaw cuts, fills the gaps, and the bandage hides the rest. This thinner sheet will flex quite a bit but will give you a gentle lead into your incline from the flat table top, like plywood. You can even use the hot wire and put a slope on the edges to make a fill. Cut scollops in the incline, glue paper on the side that is seen, trim it to fit, paint, and you have a viaduct! Foam is better than balsa wood for carving. Experiment and enjoy!

 

What the process is for me is to cut the foam into manageable lengths and a useable width.. Usually about two inches wide and maybe three feet long. Determine your grade. I tried to make mine about ¼ “ to the foot. That, with general mathematics will give you a 1” rise every four feet. Then come the radii. Determine a centerline on the 2” width and on that edge cut a ¾” wide tapered slot just past the centerline. This should be done every 3” to 4”. Then you can get a nice 19” radius without the foam shattering. As I said before I use my bandsaw, but there are some nice electric hot cutters that the insulation installers use.

Sorry for the delay in response, it seems we had one heckofa thunderstorm and it knocked out the power.
Remember to have fun while you are railroading!

[ 22 May 2001: Message edited by: squirrelrun ]

[ 24 May 2001: Message edited by: squirrelrun ]

 

I've never used 2" thick foam. Is it strong enough, when supported every 12", to survive the mis-placed hand or elbow?

Hank

 

Hank, if you make an open 1x4 frame with cross members, only the 3/4" width supports the foam, and could be dented if you happened to lean on it. This can be prevented by laying a 1/4 or 3/8 thick flake board or plywood strip 1-1/2 to 2" wide glued to the top of any member the foam would rest on. This spreads out the support area. You would have to stand on it to do any serious damage to the underside. A 12" spread along with the support strip I mentioned should be suffecient for 2" foam, closer for the 3/4" foam.

I use a small 8x18, 12x12 and a 8x24 piece of 1/2" plywood to rest my elbows on to prevent denting the upper surface of any foam I have to lean on. These usually reach any support underneith, so I don't break through again. I sanded all edges smooth and slightly rounded to prevent mashing a line across the foam. Then I glued a pad of 3/4 thick polyurethane foam to prevent hurting my elbow for long periods of leaning my weight on it while spiking down track, painting, or planting trees, etc.

REMEMBER THAT THE FUMES FROM THE HOT WIRE CUTTING ARE HIGHLY TOXIC!! Be sure you have a fan blowing the fumes away from your face. I have to use a long hose on our vacuum sweeper to draw the fumes out of the room, by sitting the sweeper outside. I don't need the fan this way, and can work longer at a time before getting sick. Now days, any hotwire work I do, is done outside, then brought in.

DO NOT DO HOTWIRE WORK AROUND PET BIRDS, OR BABIES, IT CAN BE FATAL!!!

 

Watash, your "leaning" board sounds like a good idea, I'll try it. Fortunately, I'm 6'2" with l-o-n-g arms, so I haven't needed anything like that ... YET! (When an "oops" shows that I should have used a leaning board, I'll name the newly formed geological formation "Lake Watash" )

Regards the foam block grade supports ... I have them resting on 3/4" foam supported by 1x2s spaced in a 6"x6" grid pattern. So the support centers are no more than 3" from solid footing, with the ends being much closer. I now think it would have been better to have used 2" foam laid on a 9x9 or 12x12 grid. Oh well ... too soon old, too late smart

Thanks for the info, Hank

P.S. I use a standard utility knife for cutting the 1/2" and 3/4" foam ... quick and no fumes .... OK, an occasional blood stain on the foam, but that gets covered up

[ 23 May 2001: Message edited by: Hank Coolidge ]

 

You are in good shape Hank, 6" is ok for 3/4 foam, but do use the 'leaning board' if you do lean right in the middle between the supports. I use the pads because it gets my back after a few minutes. (Old back injury from the Marines.)

I used Elmer's wood glue to mount track about six or so years ago on my other layout, and just noticed last week several places have released. The track is still in place, but the glue is not a 'tear bond' to the plastic ties. I can't use Gorilla, or any of the polyurethene glue, so I'm looking for something else to bond track on my new layout. Any advice?

 

Watash, I'm using AMI roadbed and so far I like it. Occassionally the track releases from the AMI, but a minute or so with a hair dryer and a little finger pressure solves that. A hair dryer also allows you to super-elevate curves, but getting exactly 6 degrees is a little tough . I have also used cork roadbed with Liquid Nails (Foam) for both foam/cork and cork/track joints, but AMI is quicker and easier.

In either case, gently using a putty knife (~1") will release the AMI or cork from the foam base, and the track from the cork. You may have to use a hair dryer to release the track from the AMI in places.

It might be a good idea to strip the plastic face layer off the foam before applying Liquid Nails, but I haven't confirmed that yet. Occassionally the Liquid Nails has released from the foam, but that could be dirty foam. (My neighbor remodeled his house, and I have been known to pick through trash )

Hank, COO,
Saucier & Southern Railway, a wholly-owned subsidiary of the Boston & Maine (I like B&M Maroon & Gold on first generation diesels )

[ 23 May 2001: Message edited by: Hank Coolidge ]

 

You are a scavenger like me Hank! I used to drive a 140 Jag drophead coupe to work, until one day I saw a full sheet of plywood blow up in the air and sail off to the side of the innerstate. (I was able to find it after work and brought it home in my pickup.) So I started driving the pick up to work. I found and got: all kinds of foam, 1x4,2x4 2x6, plywood of all thicknesses, full box of 8 penny nails,10 pound sledge, a two-wheeler, and all kinds of tools, pliers, claw hammer, bolt cutters 30"ers, and a package of 1/8" cork gasket material. So far I haven't purchased anything to build this new layout. So far the Elmer's woodglue has held the roadbed OK, but does not seem to bond to the plastic ties. One club member said he used Silicone rubber adhesive. It does bond to plastic, but you have to wipe the underside of the ties with alcohol first to remove any residue of mold release agent. I will try this on a piece and see how well the bond is.

 

Silicone rubber will hold rail, Watash, but therein lies the problem ... it holds forever!!! That's why I like something less tenacious like Liquid Nails or AMI. I'm an Engineer who is prone to "improving" the design occasionally

Any "good" modeller worth his/her Salt has a very large box of "Stuff" hidden under the layout behind the drop cloth so others can not scavange its contents.

Arrrgh! A 140 (or 120) drophead was always my dream, but I had to settle for an MGA, then a TR3A, then a family. Now it's a Miata ... (I'll trade you the Miata for the Jag ... even up, of course )

Later, Hank

 

Watash,
Try a spray adhesive once I have done this on a few diarama's in the past and they still are together and nothing has left go yet and if my memory serves me right they are at lest 8 years old so far and still in the same shape they were when I built them! I used 3M spray adhesive and it seems to hold onto the ties and the Blue styrofoam real good. The styrofoam that is used on the outside of homes to insulate works great for scenery and is good for shaping and forming into different things such as rock cuts and isn't like white styrofoam, that has a bad grain to do that type thing with! The blue styrofoam has a thicker, and tighter grain to make that type scenery. It done a fine job for me! I sprayed the adhesive onto the syrofoam and then layed the track into the adhesive and it worked great I thought about spraying the adhesive onto the track then I though about it getting onto the rail heads and causing problems with electrical flow so the loco's would run on it to a point tho being they were only display diaramas, so the running capabilities were short not alot of running you can do on small displays anyway but it was the idea of the smallest bit of running though on them that I was thinking of.

[ 24 May 2001: Message edited by: 7600EM_1 ]