Foam cutting tips?

[Anonymous]

I have a few questions that hopefully someone here can help with.

I have seen people cut white, pink, and blue insulation foam with Hot Wire cutters. But I am curious if the same methods can be used for cutting the expanding insulation foam that come in cans. One of the brands is called "Great Stuff". You spray it from the can and it expands. When it drys it looks like blobs of yellow lava. I have noticed that it has a bit of a different consistancy from the other foam. It has a more rigid shell. Would a wire cutter work on this or not.

Another question is related. I have several places that I want to have high hills and valleys in foam. Should I glue these areas together then cut with a hot wire or cut then carve. I prefer the first option because it would seem more naturalistic but I am worried about the effects (messing up the cutter, ...etc.) of cutting through the glue.

My last question is similar but more on based on technique. I want to make four scenes that are exactly the same. I mean the same topographey to show the same location over time. I would like to do this in foam. Any ideas on a simple trick to make four exact copies?

Thanks for the help.

[Buckeye Riveter]

I have cut the expanding foam, but I don't like the stuff. The product I used took several days to harden and then was mushy.

A good cutter goes right through the glue if you are using something like Elmers

[Roger Bielen]

Another tool you can use for cutting foam dates back to my days fooling with model planes, a Weller soldering iron with a tip made from a piece of 12ga, or 10, solid copper wire, bare of course, bent to the shape you need. You could probably also use brass.

Another trick I found using the wire type cutter that comes with a fixed voltage transformer is to use a regular train transformer to give better control of the temp.

Lastly, do your cutting with good ventilation, the fumes are toxic and may be carcinigenic.

[BR60103]

One thing I have found is that the hot wire doesn't cut through latex paint. I think it may have to do with fire resistance.

[FJ and G]

I used to cut foam with a drywall saw but that got old pretty quick.

Now, i fire up the sawzall and it makes quick work of any chunk of foam.

[Anonymous]

As far as making 4 of the "exact" same hills in foam. If you are going to use the expanding foam the best way would be to make a mold. This can be done with latex or silicone, and there are a number of products out there.

The foam you mentioned will expand to fill the mold. All you have to do is make 1, then make a mold of it, then fill the other 3. That's the best way if you want to make 4 or 5 or 50 or 500 of the same thing.

[Anonymous]

Thanks everyone for the help and advice. I feel like I really need to know what my options are here before it takes up too much time and $. Again thanks.

[Anonymous]

Someone in another area gave me some good advice on the last problem. To make multiple copies of the same shape to stack the foam so it is vertical like cards in a card catalog at a library instead of horizontal like a wedding cake. Then make the shape I want. His advice was to use thinner sheets of foam like 1/2 inch to get closer to a smooth shape. Then before I glue this together, separate the layers and copy them by tracing and cutting the layers of the other versions. The final smoothing of the shapes would still have to be done individually but the profile would be more uniform which is what I am looking for. This is the best solution so far.

Thank you again for the advice.