Which is preferred for sacrificial cutting material...

[bluecpu]

I plan on doing some Festool Plunge Saw Cutting soon and was wondering which do you prefer as the sacrificial cutting
material under the project plywood?

For this discussion, let's assume that I do not have an MFT or I do not want to cut into the top.

I saw 2" 4 x 8 foam (~$25) and 3/4" 4 x 8 MDF (~$24) at a local big box store, basically a wash for cost.

Please comment, Thanks in advance.

Bluecpu

 

[peter halle]

I love using the foam.  Light weight, long lived.

Peter

 

[EcoFurniture]

I personally don't want any off gassing foam in my shop. It also can't be recycled.
Therefore, I use a shop grade sheet of purebond ply underneath that I got to a really good price. That sheet saw at least 30 sheets on top of it and still has a lot of live left.

 

[Brice Burrell]

I've used all sorts of material for a cutting table. If I only have a few cuts to make I just use saw horses, when I plan to do a lot of cutting or want the best quality cut I can get from my TS55 I make a cutting table. I use saw horses with three 2x4s on edge and then some sort of sheet good on top of that screwed down, generally a cheap piece of 1/2" ply. This makes a sturdy cutting platform perfectly supporting my sheets. I make sure the screws are counter sunk deeply to avoid cutting into them.

 

[danrush]

Blue,

I have used a 2" insul board on my assembly table for two years ( or more) .  I split the board in half lengthwise, to form (2) 2 x 8 sections, then taped the back together to form a hinge of sorts.  When I'm not using the foam backer, it easily folds and packs away into a nook in the wall. 

I like 2" board because it's still quite rigid, and ok for occasional use on sawhorses, and much more maneuverable than mdf.

Dan

 

[gkeas]

I use a piece of foam board on top a hollow core door on top of saw horses (assuming I don't just drop the foam right on my concrete floor).  I prefern not to cut into another layer of wood, if nothing else, just to prolong the sharpness of the blade that little bit longer.

 

[Rick Christopherson]

I prefer the 2 inch pink foam. It holds together and can support weight while cutting.

 

[JeromeM]

Expanded Poly every time

 

[woodshopdemos]

I have been using 1" foil faced sheets for the last 200 cuts or so. Set saw depth of cut to cut 1/4" into foam. Cuts on top and bottom are perfect. To me this setup is so good, I havent stopped to consider other materials. I like the 2" pink boards with the tape hinge...that I will try.

 

[Bob Marino]

I am going to be using 2" foam - it's on the way from the lumber yard right now.

Bob

 

[VictorL]

For  sheet material I use several short 2x4s (1 - 5 foot each).  Works fine and doesn't take a lot of space.

 

[mike1967]

I sometimes use old hollow core doors for this purpose.

 

[Daviddubya]

I use a cutting platform - photo and plan available here:

http://www.woodstore.net/cutplatsheet.html

Between the sheet and the platform I use two or three long scraps of 2X6 so the platform does not get cut.  Foam would work just as well or better.  The setup is fast and the platform amd sawhorses store in very little space.

 

[richard.selwyn]

When I can I like to completely support the cut with foam underneath as it seems to greatly improve the dust extraction.
Cutting with nothin underneath allows more dust to escape.

 

[woodguy7]

Richard,

does it really make much of a difference to the dust extraction with foam underneath.  I have never tried foam but i like the idea & am all for better dust extraction.
I also like Dans idea about splitting the board in half with the "tape" hinges.  This is the thing i like best about FOG, the great ideas that are shared.

Woodguy.

 

[JeromeM]

Richard,

does it really make much of a difference to the dust extraction with foam underneath.  I have never tried foam but i like the idea & am all for better dust extraction.
I also like Dans idea about splitting the board in half with the "tape" hinges.  This is the thing i like best about FOG, the great ideas that are shared.

Woodguy.

Dust extraction with foam underneath makes a world of difference it becomes about 95% (this includes tape over the disk change port).
FWIW the foam I have needs 3 pieces and I have being using  100mm cloth tape hinges for the last couple of years.

 

[clev1066]

Richard,

does it really make much of a difference to the dust extraction with foam underneath.  I have never tried foam but i like the idea & am all for better dust extraction.
I also like Dans idea about splitting the board in half with the "tape" hinges.  This is the thing i like best about FOG, the great ideas that are shared.

Woodguy.

Not only does it improve dust collection, it also gives a cleaner cut on the back-side of the panel. A sacrificial cutting substrate is a win-win situation; be it foam, MFT top, or the next sheet(if perfectly measured and aligned).

 

[Corwin]

does it really make much of a difference to the dust extraction with foam underneath...

Yes.  Dust will also escape when you are making a cut over the kerf from a prior cut.  Eliminate this by either moving your cut line over an unchartered area, or cover the former kerf with tape...

On Edit:  Covering all of an existing kerf in your sacrificial cutting material is not necessary.  Since the saw throws sawdust forward beneath the cut, you only need to cover the existing kerf that extends beyond the far end of the material you are to cut.  When ripping a full 4x8 sheet that is sitting on a 4x8 piece of foam little if any of the sacrificial material is exposed -- but covering the existing kerf in the edge of the foam will greatly reduce stray sawdust.

 

[festocracy]

Have a cutting table (box beam construction with cafeteria table style legs) with a sheet of mdf sitting on top. Over that, I use 4x8 sheets of corrugated cardboard that the lumber yard gives me as a truck liner with each load of plywood I buy. Set the saw depth to score, but not cut through the cardboard (25mm for 3/4 ply). If I screw up and accidentally cut deeper and hit the mdf, no big deal. A sheet of cardboard usually lasts for several dozen sheets of ply. I suspect that its abrasive texture may dull my blades more than foam would, so I may try the foam, but has anyone checked into potential health risks of foam dust. I normally don't wear a mask, as very little dust escapes the saw.