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foam for custom cases

PeterT

Ultra Member
Premium Member
I'm lurking on Amazon for ideally 1/2" & 1/4" but this seems rather expensive on a $/volume basis. I want to make some foam cut outs from sheet stock for instrumentation type protection. Would this be better sourced at a local plastic supply store, or is the material just plain expensive? I usually keep scraps from shipping boxes if its the right stuff (not really sponge foam , its more of a denser material, I suspect polyurethane flexible foam?)


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I've been using EVA foam interlocking floor mats. They are about 2 foot square. Got a whole slew of them from Princess Auto a couple of years ago when they were only about $5 for a package of 4. Don't see them at PA any more but someplace like Walmart might still have a good deal on them.
 
Like this stuff from uline?

@Johnwa good thought & I've used that product, but my parts are kind of small & weird outlines. But I've good luck cutting profiles with fine scroll saw blade. I have ordered from Uline before & checked their other plain sheet products. Some potential candidates but big qty I'll never use.

@Tom O Yes, I've purchased some different foam in the past from place in NE. I'll have to bring my sample & see if/what they have. This stuff is kind of shiny & denser but not rigid. Hard to explain. All I know is a 50$ electronics item usually has a square foot of it in the box, my scrounge stock is out LOL.
 
go to your local Kia or Hyundai dealer and ask them for some of the foam rubber sheets from the engine crates. Its really good stuff. Its very dense, super strong. I have machined some of it before too.

They pack the engine crates with it, so should be free for the asking. I have machined some of it before too.


IMG_20240119_235636.jpg


Kinda hard to see but its the only pic i have. Its the stuff underneath the lathe
toolholders
 
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Kinda hard to see but its the only pic i have. Its the stuff underneath the lathe toolholders.

Holy Crap. Sure is hard to see anything under all those pesky tool holders!

Some really cool ones there. We could have a whole thread on some of them! I especially like the dual TNxx. Did you make that?
 
I am not an expert in this at all but I have been looking at options for case foam similar to you. I just built a diode laser cutter to do some custom cases and some gasket work.

I find that when looking for things that I am unfamiliar with learning the proper name is the toughest part. Once you know what something is called finding it becomes a lot easier.

I think what you posted above might be polyethylene foam. Do a search for that and see if that matches what you are looking for.

EVA foam as mentioned above is another good option. Readily available in foam floor tiles. That might be what the Hyundai foam is too but hard to say from the photo.

Polyurethane foam is generally softer foam used in pick and pluck foam or eggcrate foam for example.
 
I just bought some foam rubber mats at Dollar store to create a deadening mat for under my shotshell loader for when shot spills happen ' that shit bounces and rolls everywhere when it hits a hard surface.
The stuff i bought is only 1/4 in thick but they did have some 1/2 in stuff also 50" x 24" chunk was $2.95
 
I am not an expert in this at all but I have been looking at options for case foam similar to you. I just built a diode laser cutter to do some custom cases and some gasket work.

I find that when looking for things that I am unfamiliar with learning the proper name is the toughest part. Once you know what something is called finding it becomes a lot easier.

I think what you posted above might be polyethylene foam. Do a search for that and see if that matches what you are looking for.

EVA foam as mentioned above is another good option. Readily available in foam floor tiles. That might be what the Hyundai foam is too but hard to say from the photo.

Polyurethane foam is generally softer foam used in pick and pluck foam or eggcrate foam for example.
I believe the softer polyurethane foam is the dreaded disintegrating foam often used by Mitutoyo. EVA is a little harder and more durable.
 
I think what you’re looking for goes by the trade name of Ethafoam. It’s expanded polyethylene and it comes in a range of densities. Google Ethafoam and you’ll get a bunch of links.

You choose the density based on the weight of the object you want to protect and the shock load the package is expected to see. I would consult the manufacturer rep when I needed to design a package for a specific application (MIL-STD Etc.) and they would specify density and required support area to meet the shock spec.

U-Line lists one formulation on their site:

U-Line link

You might get a better price from a distributor.

It’s rigid enough to cut with a sharp knife or saw, maybe hot wire too but I haven’t seen that.

D :cool:
 
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