Tehachapi, BC

[ednadolski]

They were concrete lined ca. 1915.

Ed

[GaryHinshaw]

More great feedback.  You guys always come through.

I did some hack-saw tests last night and the results were very encouraging.  I ended up using a hacksaw blade in my jig saw at the slowest setting and it produced perfectly acceptable cuts with a completely manageable amount of dust:



(For the record, I did need to vacuum up some dust, but it didn't fly everywhere.)  Here is a quick shot of the first test piece in place:



For me, getting to this stage without creating a holy mess is a big deal.  I suspect Chris' leather blade will be even better.

-gfh

[Chris333]

no teeth = no dust 

[basementcalling]

Gary, if you need to cut thicker slabs, grab a set of these from Amazon. I bought a pack thanks to @peteski recommendation. I'll actually cut foam indoors with these in my jigsaw. Not on your life with a regular type blade.

https://www.amazon.com/Festool-493656-Foam-cutting-Jigsaw-3-pack/dp/B0033LBOJY/ref=sr_1_4?ie=UTF8&qid=1481835633&sr=8-4&keywords=foam+cutting+saw+blade

[peteski]

Gary, if you need to cut thicker slabs, grab a set of these from Amazon. I bought a pack thanks to @peteski recommendation. I'll actually cut foam indoors with these in my jigsaw. Not on your life with a regular type blade.

https://www.amazon.com/Festool-493656-Foam-cutting-Jigsaw-3-pack/dp/B0033LBOJY/ref=sr_1_4?ie=UTF8&qid=1481835633&sr=8-4&keywords=foam+cutting+saw+blade

I'm glad that I could offer helpful advice (although by now I forgot that I did). 

[C855B]

I stand corrected. The Festool "bread knife" blade is the bee's knees. I think I figured out what I was doing wrong before to lead me to conclude it had a binding problem, so I did this just five minutes ago:



A long curved cut in 2" 25psi pink foam (the denser stuff), effortless, and best of all, TOTALLY DUSTLESS.

The problem, it turns out, was trying to use it with the shoe against a straightedge. The blade wants to seek its own direction a little bit, and while you can correct it freehand, with a guide it will push against the guide and bind. Straightedge is no problem with a conventional toothed blade, so for precision straight cuts I will still deal with the dust.

[Ed Kapuscinski]

That is a thing of beauty.

[GaryHinshaw]

Agreed - it looks great Mike.  Sounds like plenty of good options here.  Now I just wish I were home to try them out!

[GaryHinshaw]

The Festool "bread knife" blade is the bee's knees.

Indeed it is!  I found a local source for these blades on Christmas Eve and bought myself a present: a pack of these blades and a new sabre saw to go with it.    Since then I've been experimenting with foam and here is what I've come up with so far:



It turns out the technique I like best is to work in vertical slabs that are cut into basic block shapes with the saw (no dust!), glued to the next slab and carved with a long blade to get the final shape.  This process is repeated until a particular section is complete.

On the Loop shelf, there are a number of plywood "beams" that were cut to the basic profile I was aiming for, and I'm using those as guides for carving (along with a boatload of prototype photos).  Here is an example of a section that is basically complete, removed to show the forms I am working towards:



And here is the same section resting in place:



There is still some fine tuning to do on the contours, especially along the track cut, and the section on the right is still in progress, but I'm loving the material and the fact that the process is totally dust free.  (I do have a rather large pile of foam chips left over from the carving though!)  Creating believable landforms is one of my favourite parts of the hobby (geek) so I'm thrilled to be getting to this stage finally.

Thanks for the blade tips! That made all the difference.  I'd still like to find a more flexible long blade for carving. Right now I'm using some Woodland Scenics long hobby blades and some thin snap-off utility knives.  The latter have pretty good flexibility, but they'll snap if you're not careful.  Any tips?

[Scottl]

Nice to see you channeling your inner geomorphologist    It looks great, especially put together in blocks like you are going.  It will make for a clean build and ease of alteration.

[jagged ben]

That cut below the loop is looking good.  I was going to post some links to proto photos, but I bet you already have them, and my kid just woke up from a nap.   

[Scottl]

There is something about this that reminds me of Sheldon Cooper 

[C855B]

... Since then I've been experimenting ...

That's some mighty fine "experimenting", Gary. You've made quite the argument in the vertical vs. horizontal debate.

[ednadolski]

Looking really good there Gary!  What kind of glue are you using?

Ed

[Bendtracker1]

The overall use of the foam is looking real good Gary.
Glad you found the special blades for foam.  They make it real easy and clean.  Nice job on the fitting!