How to cut large thin slices of Insulation foam?

[LouieN]

Hello,

Let me explain the set up.  I have sheets of 2" thick, 12" x 12" pink insulation foam I use in terrain making. 

I want to cut 1/8" slices from this and still keep the 12" by 12" footprint.  My Proxxon canont cut a piece that tall. 

I was wondering what tools, or technique, I could use to achieve this?

Thanks for any help.

[ColonelMutumbu]

the only thing I have been able to come up with for cutting things too tall for my proxxon(with a clean cut) is with a sharp knife drawn through gradually, given the size of your cut this probably wont work, I dont think there would be any practical way to keep it straight all the way through. I have seen people cut it with a powered saw but the cleaness of the cut will vary wildly between saw I would imagine.


If you work something out I would love to know what works .

[zemjw]

I watched a YouTube video recently where the guy cut 2" insulation foam with one of those craft knives with the snap-off blades. He basically extended it enough that he made it through in two cuts.

However, I agree with the Colonel on the difficulty of keeping it square. I'm cutting 10mm foam just now, and keeping the ruler from moving, while trying to cut vertically, has been a challenge

[Daeothar]

I watched a YouTube video recently where the guy cut 2" insulation foam with one of those craft knives with the snap-off blades. He basically extended it enough that he made it through in two cuts.

However, I agree with the Colonel on the difficulty of keeping it square. I'm cutting 10mm foam just now, and keeping the ruler from moving, while trying to cut vertically, has been a challenge

Speaking from experience, this method has never, ever resulted in square cuts (for me). Not even with a metal ruler to cut along; the blade is simply too flexible. perhaps a more solid blade (such as a large kitchen knife), honed to a very, very keen edge might do the trick, but even then it'll never be perfectly square.

I'm afraid that for cuts 12" tall, you'll need a bigger boat cutter, as not even Gert Boom has solved that particular limitation of the Proxxon.

So I think you best bet would be to source sheets of the required thickness (perhaps foamcore?), or settle for 2 sheets of 12"x6"...

[FifteensAway]

Boy, you don't ask for much, do you? 

Probably pretty expensive but maybe getting a hard rod - maybe from welding supplies? - and heat it up 1/8" away from a very rigid vertical surface and then - very carefully - run the block of foam straight down the surface.  Challenges almost certainly outweigh the advantages.  Chief challenge is not burning the guiding surface since 1/8" is very, very thin.  And I'd guess any rod capable of doing this at a useable temperature would melt 1/8" foam.

Vastly easier to just source 1/8" thick foam, probably the foam core idea is best. 

Good luck.

[zemjw]

I re-read the original post after Daeothar's comment, and I had the thing oriented completely wrongly in my head

Cutting essentially 3mm slices, rather you than me I'm changing my answer to "buy", although I'm struggling to find anything thinner than 5mm

[DS615]

Seems like pieces that thin would be really fragile.
Is there another material to use, or another method of doing what you need?

[_Si_]

What's your end goal? XPS can hide a multitude of sins, could you not get away with cutting the 12x12 into 3 12x4, then ripping those to 1/8? If you're cladding or surface texturing you could hide the seams.

Failing that I'd suggest looking at underfloor insulation, comes in much thinner gauge and you'll save yourself a lot of pain.

One thing to bear in mind, as I'm sure you know as a proxxon owner, that to cut thicker depths of material you need a hotter wire, which means drift or pausing will massively scar your finished surface. If you're only going for 1/8 thick it'll be hard to hide.

[FifteensAway]

Not going to solve the problem discussed here but saw a possible tool today when out shopping with the wife that might work to cut a nice straight line into foam - a 'long' pizza cutter.  The tool was over 12" in length and looked like it would cut at least an inch deep and probably deeper - not sure if it would go all the way through a 2" thick piece but maybe 'attacked' from both sides would work?  No idea how well it would work but wondering if anyone has ever tried this and how it worked out?  A bit of thinking outside the box.

[LouieN]

Hello,

Thanks for the discussion.   I did think it would be a challenge. 

I wanted to make simple terrain tiles.  For example for woods, rough areas, etc. 

I was trying to avoid chipboard and foamboard as they tend to warp after glue. 

[Major_Gilbear]

Have you tried EVA foam perhaps? It's flexible, so you'd need to attach it to a rigid backing material with some zigzags of superglue or such. But it's cheap, comes in lots of sizes, thicknesses, and colours, and you can do most of what you can with your insulation foam, including painting it.

[fred]

. 

I wanted to make simple terrain tiles.  For example for woods, rough areas, etc. 

I was trying to avoid chipboard and foamboard as they tend to warp after glue. 

I’ve used 3mm MDF for these - and they haven’t warped