How to score thin foam

so : if perhaps you made a little sliding foot device that holds the soldering iron to a set depth, then it could only cut xyz deep.

or : you could push a single edge razor blade thru a stiff piece of postboard, epoxy it in place, and it would do the same thing.

either way, you going to probably want to build yourself a guide/tool/jig sort of a device that keeps the tool from going too deep.

or : if you have a table saw, you would set it to cut only xyz deep, and run the foam across the top of it.

or : maybe you could heat a metal straight edge (like a framing square) hella hot, set some blocks up to limit the depth, and it could melt you a very sweet indentation line.

consult the nearest model builder at work for any questions such as this. model builders can invent ways to make almost anything. you'll need cookies. they love cookies.

cheers,
v.

Two metal rulers put together with an open slit between them, and a box cutter with the blade retracted some?

I know you said folding on itself won't work. But have you tried folding it on itself and then leaving a heavy weight on top of it for a day or two? I did that with 3/8" foam a year back to make a torso pad fold nicely and it's worked very well and held up great.

You may want to try something like this :

I heated two pole sections (no cord inside…) and then placed them over the mat putting some pressure there with a brick.
The scoring is about 2-3 mm deep but you can get more or less .
It was done very quickly so it is uneven bit you should get the idea.

Sweet.

Thanks for all the ideas. My brain was stalled but the "idea-juices" are flowing again.

Man, ask and ye shall receive.

I was thinking about that the other day for a backpack backpad- I think I'd try a cheap aluminum yardstick- chop an inch off each side for a "stop" then heat an edge and set it down.

That said-
I occasionally sew foam- that in and of itself does a decent job of giving you a break, if not a full fold. I have done it with 3/8" foam on the center of a hipbelt to get a bit of curve in it.

I think you should just get a gun and shoot it at the foam.

He shoots! He scores!

(yeah, sad. well it's late so leave me alone).

If you cat/saw a thin line into it ,when you then fold it (concertina style) the cut will become deeper and eventually completely separate.

Bill,

For a backpack backpad I'd really recommend just folding it carefully the way you want it, then leaving a heavy weight on top of it for a day or two. I left a crate full of climbing gear (probably 40-50 pounds worth) on top of mine and it worked great and didn't leave any weaknesses in the pad.

"If you cut/saw a thin line into it ,when you then fold it (concertina style) the cut will become deeper and eventually completely separate."

I kinda figured that this would be the result of cutting, but I am assuming a heat scored/melted fold will act more like a living hinge and be resilient to repeated bending back and forth.

Something I failed to note with regards to the "fold and weight" technique for my particular needs is that my score lines will be intermittent and not a continuous line across the material. I'm working on a crazy idea. If it works, I'll post. If it doesn't, this never happened. I have a lot of "never happened" in my work shed.

"I think you should just get a gun and shoot it at the foam."

I was actually expecting at least one person to suggest a pick-up line. LOL!

Is it wrong I go into every thread expecting chaff-drift!

Would something like this work?

here

Hmmmm, if I help you score does this make me a pimp? A foam pimp?

Has kind of a magical Christmas sound to it. “Cue the foam pimp to dance in from stage left…….wearing the traditional red and green holiday colors used by the ever popular channel markers in the Strait of Juan de Fuca.

Thanks Daryl.

I was just assuming a rotary tool would result in tear-out. I have all the required pieces, so I'll have to give this a try!!!

… and I think you have the "foam-pimp" title all shored up. You are afterall the only one with a white shiny foam coat.