you can put copper wire (e.g. 12g) of any shape into a soldering gun to cut a grove using some thin wood strips on top of the foam as a guide and to limit the depth.
bend the contour you want, 1"x 1/2". at the top of the 1/2" edges, bend the wire wider than 1". after that, bend the wires to fit into the soldering iron.
with the wire hot, plunge it into your foam up to the wood guides at one end. slide it to the opposite end and pull is straight out.
greg - Philadelphia & Reading / Reading
MisterBeasley Can you first cut the foam with regular once or hot knife, and thengo back and cut the plywood with the saw? Using power tools to cut foam is messy.
Can you first cut the foam with regular once or hot knife, and thengo back and cut the plywood with the saw? Using power tools to cut foam is messy.
It takes an iron man to play with a toy iron horse.
Have a friend aim the shop vac at the jig saw. Wear masks. It going to be messy.
Henry
COB Potomac & Northern
Shenandoah Valley
Get a jig saw with dust extraction port and use a coarse blade
My response falls into the category of "thinking out loud", so it may not be very good.
When cutting plywood, many will run masking tape along the cut line to keep the top layer of veneer from sharring off into little chunks, making a nice clean edge. Taping the top cut line and underneath if neatness matters on both sides.
I would assume that since your foam is securely sandwiched, that it would tend to cut neater than if it was exposed and allowed to flex around.
I think that I would worry about cutting the wood and not so much the effect on the foam, but a finer blade would be better than coarser.
- Douglas
IDRick..Probably want to try some different blades as I'm thinking an aggressive blade might make more mess...
That's why I suggested the blade for metal, as many of them have finer teeth...they won't cut as fast, but should make a neater cut.
Wayne
Okay, thanks, Wayne! Think I'll search for a longer jigsaw blade and try cutting all in one fell swoop (drilling guide holes first). Probably want to try some different blades as I'm thinking an aggressive blade might make more mess...
Extruded foam can be cut with just about anything (I've been cuttting some of it today, using a keyhole saw). Your jigsaw, with a wood- or metal-cutting blade will cut the plywood and the foam, too.
You did mention...
IDRickDoes not need to be a finish surface as these cut-out sections will be hidden.
I need to cut several 3" long x 1" wide x 1-1/2" deep sections out of my finished benchtop (construction = 1" foamboard + 1/2" plywood). Does not need to be a finish surface as these cut-out sections will be hidden. Any suggestions?
My thought is to use a jigsaw but different blades are needed to cut plywood versus extruded foam. Came across an interesting video showing jigsaw blades for foam that give a finish cut with minimum dust but these blades would not work for cutting plywood.
https://www.youtube.com/watch?v=U8Po8NoM7g4