cuting insulation board

[shlbygt500]

what is the best way to cut insulation board so that i can get a nice clean incline

[selector]

Straightedge and a box cutter or razor-type blade.  If you merely want to shape a surface, such as a concave or convex slope, use a serrated knife or a fine-tooth saw, and then shape the surface with either a sanding block or more roughly with a wire brush.  A more expensive solution is an electric "hot knife" that actually melts its way through the foam.  You'll still have to hand finish in most cases, and that is with the sanding block.

[dsmith]

Here are photos of how I shaped an incline through 3 layers of 1" foam insulation.  I used a combination of serrated knife, fine tooth saw, hacksaw blade, rasp, and sanding block.  I kept checking the curved incline with a flexible metal straightedge.  In areas where I cut a little too deep, I filled with "light" spackling compound.  It does take care and planning to get it right.

 

And after lots of hard work, here is the layout so far..............

 

[tinman1]

I am just using 1.5" pink (much cheaper than 2") on edge for the track bed and then placing flat foam around it as needed. I am using a 2" x-acto blade and a long straight edge to get any grades I need. I then use a decent bead of construction adhesive on the bottom and use a straight edge to "bed" the foam on the table. A piece or two of flex-track layed on the foam and a car run up and down it will indicate any problem areas .  Keeping the razor sharp is the key, or the foam will tear instead of being cut. Doing it this way makes it easy to make super-elevated curves also. To lay the foam around curves just use the razor and make cuts 3/4s of the way through the foam on the outside of the curve, about 3/4" apart. Just try to make the cuts vertical or the resulting bend will try to force the foam upward. real broad curves can have the cuts further apart. After the foam is where I want it I will take a tube of latex caulk and put a blob inside the cuts around the curve. This goes a long way in stiffening the foam if you have a tall section ( Im talking many inches tall, not really needed for only an inch)

[Medina1128]

Your hard work has paid off handsomely! Very nice!

[MisterBeasley]

I tried making a nice ramp shape by cutting the foam with a hot-wire cutter,  It's really not designed to give you nice straight edges, and the results were less than spectacular.  So, for my next ramp, I simply cut a flat, straight piece of foam and supported it from below on the benchwork, raising the height of the support structure instead of cutting the foam to shape.  This is much faster, and gives a much better slope.

Dave - your work is meticulous and very well done.  Two thumbs up, from someone who's all thumbs when it comes to stuff like that.