Rounding an edge on a cushion foam.

[regalman190]

Just wondering how you would cut a radius on the top edge of cushion foam.

[MinUph]

You can order foam with a buffed edge (best way) or you can sand it off yourself with a disk sander (more work) gently.

[cajunpedaler]

One of my old time mentors said the way he rounded or shaped foam was to wet it, then freeze it, THEN shape it...
I never tried it, but it makes sense to me.

[byhammerandhand]

Outside my scope of work, but has anyone ever used a Surform?

http://en.wikipedia.org/wiki/Surform

[MinUph]

There used for sheetrock . I doubt they would do well with our foams.

[byhammerandhand]

Like I implied, I'm not sure.   I use them for wood shaping.

[BlueFlamingo]

I use an electric carving knife.  It works GREAT!!!!!

[fragged8]

when covering in vinyl  i wouldnt bother making a radius on the foam edge, the cover will pull the foam into shape.

[regalman190]

Thank you.

[Judy_Boat]

if you have strange rounding shapes you can try this
After the foam is fixed in place:
you can glue thin material(cotton or muslin) to the foam leaving the material loose over the area you want to shape. Then cut foam if necessary and pull the material down until you are happy with the shape and staple to the frame.
Then other padding and good material are put on.
Mid-50's upholstery textbooks are great for this kind on info.

[seatbuilder]

on some cushions I cut and grind with a grinder. On some I cut out a notch around the foam, anywhere from 1/2" to 3/4" depending on the radius I want. Spray in glue and join. When this method is used you can add a strip of cloth over the finished edge for added security.
It makes a beautiful rounded edge with no grinding. If you want a much larger radius the other method is probably better

[bobbin]

Great discussion.

[Mike]

It its just a knee bolster i do as ri h the cover will round the  edge. If it realy had to be round  then i rough cut it with a knofe then add a layer of 1/2" coam to smoothe things out

[JuneC]

If patching a damaged section, I glue in a new chunk, rough cut with a foam saw, then grind smooth with an angle grinder and 60 grit sandpaper.

For new cushions, I do like Mike - cut a smaller-than-necessary section and glue either 1/2 or 1" foam sheet over the section needing rounding.  Works great and looks pretty-much perfect. 

June