Large Finish Cuts

[alex grams]

I am coming up on a project with a desktop that is a trapezoid 32" wide at the front, and expands to 53" wide at the back over a depth of 26". This will be cut from a veneered top, so the cut will need to be a smooth cut of finish quality.

I have a full size tablesaw, but that would still constructing a substantial sled for a single cut.

My only thought is to clamp a straightedge along the board and use a router to make the cut? I would probably use a spiraled downcut bit as to make sure I do not damage the veneer top. I only have a 1/8" spiral downcut bit at the moment, but this will probably call for at least a 1/4" bit with enough depth to be able to cut through the 3/4" material.

Any other ideas or methods?

[Richard M. Wolfe]

I would probably use a circular saw with a fine tooth blade. You might tape the cut beforehand which should help with any chipout. Make sure the downcut is on the top.

[Stephen Cherry]

I think whiteside sells a spiral downcut- upcut.

[Prashun Patel]

I hate 'cutting' with a router.

I'd use a circular saw with a good blade and a good guide.

[Chris Tsutsui]

If you have a router, itr doesn't have to make the full cut it can be used to clean up a cut and remove minimal material.

[alex grams]

Maybe it is me, but i feel I would get a better cut with a router w/ spiral downcut bit and good straight edge vs circular saw. One thing i wouldn't like about a circular saw is that in order to cut the finished/exposed surface on the downcut of the blade, I would have to run the saw on the backside of the piece, which would make alignment a real pain in the but, and I wouldn't be able to see anything going awry until the cut is finished and i turn it over.

Stephen, CMT has solid carbide spiral downcut 1/4" shaft diameter, 1/4" cut diameter, and 1" cut length (http://www.woodcraft.com/Product/2008218/15329/Downcut-Spiral-Bit-14SH-14D-1CL-212OL---CMT-Part-19200811.aspx)that would be my choice for the job.

Chris, I would do the cut in probably 3 passes or so with the router bit, taking about 1/4" in each pass. True I could use a circular saw and cut within about 1/2"-1" of the finished cut and then finish the cut off with the router and straight edge.

I have seen people use a router and straight edge for edge jointing, and that is the same level of precision I am working towards, but never seen anyone do edge jointing with a circular saw. Odds are I would get an 8/4 piece of maple, joint its edge flat, then use that as the straight edge reference.

[Victor Robinson]

I made a long finish cut yesterday with router and flushtrim bit (after rough cutting first with a jigsaw). I didn't have time to make a large crosscut sled to accommodate the workpiece and I don't trust my circsaw + straightedge. Worked like a charm. Just make sure (obviously) that your straightedge is straight and its surface is flat.

[alex grams]

Victor posted while I posted. As said above/simultaneous to your post in regards to the straight edge, I would joint the edge of a piece of 8/4 hardwood, then use that as the reference.