Foam cutting hot wire?

[BradKW]

Looks like I got a nice memory foam mattress off CL for $100...it's a Cali King and 12" thick, so plenty to make a bed and seat cushions from.

I picked up an electric knife, but I think I'd also like to cut the thickness and a hot wire would seem best for that. I remember awhile back someone rigged up a DIY hot wire to slice up a bunch of thick, rigid foam chunks they got for free, but I can't turn up the thread...

I'm trying to think how that even works DIY... search Amazon turns up lots of fairly expensive solutions, but seems to me that if I maybe got resistance wire I could just stick one end in + and - 110v. Or that may just trip the breaker. And there's lots of choices in resistance wire, not sure what to try...

 

[eDJ_]

Here is a set up you can build almost entirely from salvaged parts.  If you know some HAM Radio operators who know of local HAM Fest (HAM Flea Markets)  you could go there and see if these parts are available.  Ask the vendors if you don't see them....they may have this stuff at home.  (they can only bring so much)

INSTRUCTABLES:   HOT WIRE FOAM CUTTER

http://www.instructables.com/id/Hot-wire-foam-cutter/

As for the Hot Wire....NiChrome 80  (Nickle Iron and Chromium)  can take tremendous heat in an application such as foam cutting.

 

[SternWake]

I've not done it, but the EPS surfboard blanks are generally cut from a larger block of foam using a hot wire.

http://bgboard.blogspot.com/2011/01/i-spent-over-8-weeks-trying-to-find-all.html



Seems like one would have to experiment to find the right voltage amperage and wire thickness for the specific foam  being cut.

http://www.swaylocks.com/search/goo...54383327:zhdzlosyzti&cof=FORID:11&sitesearch=

Sounds like a job for a adjustable voltage dc power supply.

 

[WheelEstate USA]

Would an old train transformer work? Might find a used one at the flea or a hobby shop.

 

[Optimistic Paranoid]

Or, you could just make a simple frame with a tight wire, as described, and get it good and hot with a propane torch.

The US spent a gazillion dollars inventing the space pen so our astronauts could write in outer space.  The Russians gave their cosmonauts pencils.

 

[BradKW]

BradKW, Does the Banana Bread Man still sell at the sunsets? It was 35 years ago but I remember his warning "Don't blame me when it's all gone!".

Pretty sure he passed years ago...been a long time since heard him mentioned, and certainly haven't seen him in recent memory. 

I could go for some banana bread for breakfast...

 

[highdesertranger]

when I cut nylon material or webbing, I have an old knife that I get hot with a propane torch. this seals the nylon as it's cut. Weller makes a hot knife to fit their pistol grip solder gun. if I need to make round holes for grommets I take a bolt heat it up and burn through the material. highdesertranger

 

[ccbreder]

Hot wire is used on rigid foam. not used in any upholstery shop i have visited. They all use saws. I used a electric knife. Practice with the electric knife.
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