Let's talk Kerfs (curving your foam)

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A few test's;
This did make 1 V

V for R.jpg (108.44 KiB) Viewed 2734 times

The second and third, where I pushed didn't

[GPW]

Personally , I think Heat bending is the way to go .... No kerfing (stronger) , no mess, and it keeps it's shape when cooled ...

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Personally , I think Heat bending is the way to go .... No kerfing (stronger) , no mess, and it keeps it's shape when cooled ...

I have made two roller’s one 5’ wide, and could still use it, the rollers are not heated, &
I need 75”.
My thoughts I can epoxy, easier then building a oven that big.

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I was offered a job at Smucker's; Because I had rebuilt equipment like their's
Part of it was Steam heated Rollers
Wish I had Accesses to their's on the weekend

[Pmullen503]

That of course is the problem; building something big enough to properly heat bend a thick piece of foam at home isn't something most people want to tackle.

I've always though more doable approach would be two thinner layers of kerfed foam glued together with the kerfs facing each other. You'd probably have to build a plywood form to clamp the foam to while the glue was drying but you'd end up with smooth surfaces inside and out.

[Pmullen503]

Here's an example of what you can do with heat forming foam. But this is only 3' long and the foam is only 1/4" thick.

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Those wouldn't fit in my Toaster oven

Piece I posted prior on the left side was sliced; Ready For Epoxy?
1/2" thick with the snappy stuff just cut off

[tomhawk]

I think I used a combination of most of the ideas here for my curved foam. I never used a soldering gun though.

I wanted 2" curved segment on my cabin.
I tried to heat bend foam and failed to bend pieces any thicker than 3/4". When I kerfed foam, it kept breaking when I bent it. I ended up shallowly kerfing (1/3"-1/2") 1" foam with this hot cutting tool.


This could be bent without breaking with a heat gun.

I glued together two pieces with the kerfed sides facing each other to give a nice smooth surface on both outside sides.

I am pretty happy with the way it turned out.
viewtopic.php?f=55&t=75248#p1297194

I used a old "dumb" 12V battery charger as a power supply for hot cutting. Using ghcoe's idea, the length of the wire modulates the resistance and the heat of the wire. I tried some arbitrary lengths to find the right temperature.

They don't market these chargers anymore but maybe you could find one on line or at a yard sale. There are several web sites and utubes that show you how to make a DIY one.

Tom

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My next attempt is a hot wire Curve
large Radi may work.

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I have more then a handful of programs I use for my CNC
I have drawn and tried to test auto generating G codes for this
They Know and call me out for it. Don't support it;
Need a Module; ($- Download) Wire addon Exc.
On to a Pendulum 3" foam
Hot wire cutter up to 48" wide.