Dust Cut Procedures

Woodworkers describe how they make initial cuts on sheet goods to establish straight and square edges. July 27, 2008

Does making a dust cut on a slider require that you cross cut first, then rip a small piece? If so, that doesn't leave much room for sheet optimization, does it? What are most of you doing?

Forum Responses
(Cabinetmaking Forum)
From contributor C:
A dust cut refers to making an initial slice off of an edge of the panel (rip or cross cut), to provide a reference edge. The very edges of a panel are often damaged anyway. Then you use your initial cut as a straight reference edge to continue cutting.

From contributor O:
What contributor C said, plus all of my sheet goods are generally 48.5 x 96.5, which allows enough to square up and still have a full sheet.

From contributor M:
If I am using 49 x 97 stuff, just make a 1/4" dust cut and be done. If using 48 x 96, I make a small (1/32") end dust cut then set my crosscut fence on 47 15/16 to 47 31/32 and make a long dust cut. That gives me an edge that is straight, and if still a little rough, I'll turn it to the wall and then it's fine.
From the original questioner:

So when I have been using a dust cut, I crosscut first and then rip a little off one edge. Now I can rip to whatever width I need. It sucks to have to make two cuts before even starting on the cabinets. Sometimes I will just make one crosscut, and measure from end to end checking for accuracy. If I'm dead on, then I will just rip, but most of the time I need to make my own clean edge. This is definitely time consuming and I wanted to check and see if others were doing the same. Thanks for your responses.

From contributor J:
So why do you cross cut first? I just make one dust cut (or one straight line cut), then start ripping. Then I turn the material 90 degrees and start cross cutting. Dust cutting must be a southern east coast thing. I always called it a straight line cut. I'm not cutting dust, I'm cutting plywood.

From the original questioner:
I believe I got this from the Altendorf or Stiles website on how to square a panel. I do believe that the crosscut was performed first, then a small rip would square the plywood. I do see how just one rip cut would work, though. Maybe I will try this tomorrow.

From contributor M:
Make an initial cut, usually a crosscut on 4x8 sheets. This cut should have material on both sides so that your blade does not deflect. You should be fine if you have about 1/8" on the right side of the blade.

After you have done this, your panel is straight on this edge, or "fresh." Now swing your panel around so that your fresh edge is against your crosscut fence. Repeat the same process... Make a rip that leaves about 1/8" on the table. Your sheet is now square. Now you can make your rips.

"Dust cut" refers to making a cut that just leaves dust... no strip left on the table, just dust. But when you do this, the blade does have the chance to deflect. If you edgeband, you may notice a void. If you have material on both sides, instead of panel on one side, air on the other - your blade will run more true.

From the original questioner:
I spent a few hours yesterday tuning up my saw, and it was painful. I started out moving the fence and then ended up back where I started. I can't explain it, but maybe I was getting some deflection. I kept ending up 1/16" off both ways until I finally got it right. I did try just ripping once, then flipping the sheet over so the clean edge is now up against the flip stop so my clean edge is on the good side of the blade. This didn't work for me, so I went back to crosscutting first.

From contributor M:
I have tried to train several guys to use a slider accurately. It is harder than it looks. Probably the first thing you need to do is a 5-cut test. This will tell you if your carriage fence is out of alignment.

Next, reread my post. It sounds like you are taking your fresh edge and putting it against your stop. That does little good if your piece is not square. I am not sure what you mean by the good side of the blade. A slider is designed to cut pieces so that good parts come off both sides.

When you square a panel, make a fresh cut across the width of the panel (the 4' side). Now rotate, don't flip, leave the panel flat and the same side facing down, the edge you just cut and put it against the back side of your crosscut fence. If you were to use your stop as a guide, you would now have a factory edge against the stop, your fresh edge against the crosscut fence, and a factory edge facing the blade. Trim this edge. You now have a fresh edge against a 4' and 8'. You are now ready to start cutting. If you want your panels to be square, you must do this with every sheet.

I would suggest that you economize your movements and begin ripping your pieces to width. Then go back and crosscut to final size.

From contributor J:
Cross cutting first is a waste of time. Slide on a sheet of plywood or melamine, rip a dust cut or straight line the factory edge. Rip to width using the fence on your right. Then cross cut at will, square up the first cut, flip and cut again, or slide back your fence (on the right), cut a few, then cut the last one from your fence (on the left). It's so easy. If you're worried about your melamine slipping while ripping a full length 8' straight edge, set your fence stop on the left side to 48 3/8", then start ripping - you'll get a straight line.

From the original questioner:
Contributor M, that is exactly what I was talking about, but I wasn't clear. Crosscut the width, move that against the fence, now rip a clean edge. I was talking about taking the clean edge (leaving the trued up crosscut width piece against the fence), and then flipping it over to put the clean edge against the stop to get your exact cut dimension. Now I am done with that piece. Using the other piece, just slide it over to the stop and now you will be ripping the factory edge. If this is still wrong, please let me know, but the way I see it, I am using all cuts that I made, not relying on a factory edge.

From contributor H:
I have a Tiger rip fence on my slider and I mounted a small laser on the dust shroud that points down the length of the rip. It is easy to see when making my dust cut. If my optimization allows it, I prefer to make a 1/4 inch dust cut so that I do not have to blow the dust off the table before the next rip. I have an air gun hanging from the ceiling just above and ahead of the cutting area for this if needed. My Casolin rip fence has a small air feed that is supposed to keep the fence clear, but it is not very useful in practice. Using a slider is easy when you think of it as doing the tango; just keep moving and think ahead to save steps and it flows well.

From the original questioner:
I am a little confused as to making a crosscut cut. Seems that some don't do it and some do. This seems pretty easy to me when you think about it and it would seem to work both ways. First of all, if you first crosscut, move the clean edge against the slider fence, now rip a dust cut. Your panel is now square on one side. Move your sheet over to the rip fence, which is set at your preferred dimension, say 23 1/4". Move the rip fence back off the table away from the blade. Using your slider, rip your first clean sheet. The portion to the right of the blade is now true and cut to 23 1/4". Now that leaves you with the other half of the sheet which has two clean edges, one against the slider fence and one against the rip fence. Now to cut the factory edge using the slider, flip the sheet over and put the clean edge against the flip stop on the slider and now the factory edge is what is going to be cut. No factory edges left except for at the width on one side. Now look at not using the crosscut dust cut. If you rip one edge leaving the factory edge against the slider fence, now use the rip fence to the right of the blade, cut to dimension, and you have one true piece with the factory edge left on the left side of the sheet. Now flip this sheet so the factory edge is by the blade ready to be cut. Cut this and you have completed the full sheet. When cross cut, all you have to do is start off by cutting a little off one side of the sheet.

This is the way I interpret this argument. If I am wrong please let me know. I have tried every way and just want some consistency out of my saw. If I can skip a step and still get a perfect panel, I will. I spent a lot of money on this saw and I expect a lot out of it and it damn sure better cut straight.

From contributor H:
I make one long dust cut, then use the rip fence to make my first long rip. I then use the rip fence only to push the other half of the sheet through in the case of a 23 1/2 panel, or continue ripping for 4 pieces of 12". I often band these long lengths as my helper is offloading and my bander is in line with my saw. While he is waiting for the next piece from the saw he is banding the first one. We have a 7'x24" rolling table that receives these panels. It is later rolled back to the crosscut table and we crosscut it all, starting with a dust cut. This way there is one long dust cut and 4 12" dust cuts for a typical panel cut into 4 pieces of 12x96. Turning the full sheet to make two dust cuts of 48" and 96" takes more time and when you cross cut, the piece is there anyway and the short crosscut is faster. I have a permanent mark on my crosscut fence for 48, 49, and 61" sheets for registering the dust cut. I also attached a small laser to my blade shroud that directs a line down the cut line like the gang rip saws have. This laser cost me $10 at a drug store and gives me a line of sight for any odd size pieces that I want to make a dust cut on.