Tapered Wedges of Extruded Foam

[olequa]

QUOTE: Originally posted by JanekKoz

Ref the recommendation from George (OLEQUA). I tried to create smooth wedges to support my track on grades but no matter how hard I tried to make the subroadbed level across its width, or smooth along its length, the worse it got. Now I cut out my subroadbed from 2" thick foam (or 1" where vertical space is tight) cookie-cutter style, then cut my wedges using several of the techniques mentioned above and place them beneath the 1" or 2" subroadbed. In this manner the wedges need not be perfect - just close enough. I glue the cookie-cutter subroadbed to the wedges with Liquid Nails and I'm set. This gives me a very, very solid roadbed (I have a hard-to-access section of my layout and can walk to it over my foam scenery/roadbed with no problem), smooth vertical transitions, smooth grade and dead-level subroadbed across the width.

Janek

Huh? I think you misattributed me. My recommendation for creating grades in foam is to cookie-cutter it, just as you ended up doing. I think your post demonstrates my technique very well.

George

[kenkal]

Sears has them. Like 2 for 2.79 or so. Use a variable speed saber saw for best control and fast cutting.
Ken

Where did you find the sabre saw knife-edge blade? I've looked at Wal-Mart, Home Depot and Lowe's. They don't have any.

Darrell, quiet...for now

[dgwinup]

QUOTE: Originally posted by mpcaboose

If you use a sabre saw, use a knife edge blade. Even the finest tooth blade will create a mess. The knife edge does a pretty good job, although there's a fair amount of melting. I literally scrape that off the knife edge saw blade with a utility knife.

Where did you find the sabre saw knife-edge blade? I've looked at Wal-Mart, Home Depot and Lowe's. They don't have any.

I've used those disposable hobby knives with the snap-off blades. They seem to do the best job. Haven't used a hot knife yet, but I think that would be better at carving shapes rather than straight cuts. I did experiment with a hot knife trying to cut thin strips of 2" foam. The strips didn't come out very straight, but I was able to glue them together to make 2" thick spline roadbed. Seemed to be pretty strong stuff after the glue had set. It was only an experiment, so it never got installed on the layout.

On one section of my layout, I used 1" foam in layers. I used spacers of different heights to create a grade. Here's a picture:



In another area, I ended up with a dip in the trackwork using carved 2" foam. To correct the dip, I sliced into the foam and inserted small pieces of foam or cork roadbed to correct the dip. Here's a picture of that area:



One of the reasons why I like foam so much is because changes are so easy to make. I'm working on a plan to make an around the room shelf-type layout using foam on shelf brackets. When I get into construction, I'll post pictures of my successes (and failures!).

Darrell, quiet...for now

[JanekKoz]

Ref the recommendation from George (OLEQUA). I tried to create smooth wedges to support my track on grades but no matter how hard I tried to make the subroadbed level across its width, or smooth along its length, the worse it got. Now I cut out my subroadbed from 2" thick foam (or 1" where vertical space is tight) cookie-cutter style, then cut my wedges using several of the techniques mentioned above and place them beneath the 1" or 2" subroadbed. In this manner the wedges need not be perfect - just close enough. I glue the cookie-cutter subroadbed to the wedges with Liquid Nails and I'm set. This gives me a very, very solid roadbed (I have a hard-to-access section of my layout and can walk to it over my foam scenery/roadbed with no problem), smooth vertical transitions, smooth grade and dead-level subroadbed across the width.

Janek

[axeheadsq12]

when your all done cutting the big pieces, i use a drywall rasp/plane to finish and vacumn the mess.

[Anonymous]

Thanks to everyone who responded. Now I have numerous good ideas which may help to cut my wedges.

Fred

[mpcaboose]

If you use a sabre saw, use a knife edge blade. Even the finest tooth blade will create a mess. The knife edge does a pretty good job, although there's a fair amount of melting. I literally scrape that off the knife edge saw blade with a utility knife.

[sansouci]

Anybody ever try a saber saw on the blue/pink extruded foam? The saw would keep the profile at 90deg (no super elevation wanted on my incline) I've got 2" thick blanks I want to cut into wedges. This thread has been very helpful.

[Anonymous]

You can get a battery powered hot wire at Michaels for about $14.00. At that price if it does'nt work out for that you on that project you could certainly find another place to use it on your layout. Jerry

[Anonymous]

I just finished doing this for myself. I used an electric knife. It was that easy.

Brian

[Anonymous]

Fred
I just used my radial arm saw on2in. foam worked better than I thought it would
As for taper make a jig out of 1/2 in. ply to go against saw fence, place foam
on ply, tack in place with small nails,at desired angle, push ply agenst fence
run thru saw .DO NOT PUT NAILS IN LINE WITH BLADE!
I learned this trick makeing tapered table legs.
good luck
jshack

[mgruber]

A hack-saw blade works just fine. Just wrap one end to protect your hand.

[olequa]

If you are making a grade why not just cookie cutter it? It bends enough for that and the result is as smooth as the original surface with a perfect transition between level and sloped sections.

george

[Anonymous]

I used a piece of foam that I didn't taper at all. I used supports underneth it to get it to the correct height and slope. At the Zero point I cut out a section of foam to make room for my Ramp.

[MisterBeasley]

I'd go with Selector's scribe-and-snap method. Scribe it as deep as you can.

I did try doing this to create a grade. It was difficult and I ended up with a lot of shims and fill-in pieces. After that, I just went with a flat piece supported from underneath using open-framwork methods. That gave me a much better and more easily controlled grade.

[selector]

Draw your intended slope on the foam board with a fine pencil, then scirbe down that line with a sharp utility knife using a straightedge for support. Snap the board and you will have your slope...in rough. To shape it once it is where you'd like it, use a sanding block with a coarse grade of sand (80-100), or use a wire brush. Both will create a mess, but that is what shop vacs are for. To get it to a finer transitioned grade, use a finer grit of sandpaper, say 120-160. This will require time and patience, so plan to do it right.

[fiatfan]

Use an electric knife. It will even cut the beaded foam without a mess. Thanks to my wife for this tip.

Tom

[tohowalk]

I have had pretty good success using a sawzall to cut the tapered pieces - using a 4" or 12" blade as necessary. It isn't easy to cut an exact line, but if I cut slowly, I can get it pretty close. I never thought of using a bandsaw - will give it a try!

[Anonymous]

I've built two layouts with foam and I've learned to not worry about being too precise. Hack it down with a knife so that its reasonabbly close to what you want, then use Sculptamold to form the final slope. Don't bother with those hot carving knives/wires. As far as I'm concerned they are a waste of money.

[ondrek]

band saw was my best results.
I took the piece i needed to cut, drew the line to be cut, and just free handed it on the band saw. very little mess....and that was using the white beadboard foam(the messier kind) not the blue or pink....that stuff should cut clean on it.

the band saw i have is a 14" wood bandsaw


Kevin

[simon1966]

I used foam wedges, but not in the way you are planning to. I needed to make a shallow grade on a curve going from about 1 1/2" to zero over about 2 feet. I used 1/2" bluefoam and created 4 wedges that I could them curve and run next to each other in a sort of "spline" effect to create the slope. The difficulty is getting the cut to be perfectly square, but with some practice I got it down. I used one of those sharp bladed knives, the kind where the blades can be snapped off to give me a long sharp cutting knife.

[ARTHILL]

I will follow this thread because I could not figure how to do it. I had best luck with the Radial Arm saw, but the mess was impossible. I tried the band saw and the belt sander. I tried the hot wire. I had the best luck with the steak knife. It is my tool of choice for all my foam work. It carves rock the best. If I need any more inclines I will do Woodland Scenics.

[Anonymous]

Does anyone have a special technique to taper a wedge of foam (blue or pink foam) other than shaving it and creating tons of debris? What I want to do is cut a 2 inch thick piece of foam so it tapers from 2 inchs at the edge to zero in about a 6 inch wide strip , a foot at a time. I do not have a hot wire knife.

It should give me a moderate slope.

Cheers,
Fred