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.

[Anonymous]

When we built a series of "high" terrain, we used a mix of left-over pink/blue foam from the base and some of the woodland scenics white foam. We cut each layer of the "cake" into a basic size/shape, with each higher layer being somewhat smaller (in most areas). We glued the layers of the "cake" together with a both the woodland scenics flam glu and the low temp hot glue.

Afterwards, we shaped the countours of the cake with a combo of a foam knife in spots, but mostly used the woodland scenics hotwire knife. It seemd to work fine, but some advice....

- Let the hot wire knife/cutter do the work for you.... don't push on it too hard

- The blue/pink foam seems to cut slower than the white foam, again, use a little pressure, but moreover, let the heat do the work

- When you hit the glue, you will need to apply a bit more pressure, but it the hot wire will go through it, and we didn't see any damage or other affects to the wire. A liitle sawing action through the glue might help, or atl east it helps psychologically

Best advice I can give (other than letting the knife work for you) is to buy an extra hot wire for your cutter. Nothing worse than breaking your wire 2 hours after all the hobby shops have closed.... extra wires are cheap and help with those breakages.

As for making the same terrain, that may take some work. Best suggestion I would have is as you make the layers of the "cake", you trace each layer on another sheet of foam, and then carefully glue the layers in the same way for each one.

Unless you are an accomplished sculpture artist, I think it would be tough to carve the foam to be identitcal... at least i wouldn't be confident in my skills to do it. But what I'd try is to smooth the contours out with wadded newspaper balls on each, then plaster over the whole thing. They won't be exact, but close.

[Anonymous]

Thanks for the help and good advice.

Someone in another area gave me some good advice on the last problem. The advice is similar to yours with some slight variation.

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 horizontally like a wedding cake. Then make the first version that becomes the pattern and 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. This is the best solution so far because the profile is fairly uniform which is what I am looking for.

Thank you for the advice especially the wire tricks. I've not done this before and look forward to beginning outside this weekend.