Making kerfs/dados with Table Saw blade

[Don Morris]

I saw an add for a KM-1 Kerfmaker and thought about tools and techniques like that. Very accurate kerf size making devises or techniques on the TS. I use a Forrest WW11 blade almost exclusively. A good blade, sharp cuts, but it doesn't leave as flat a bottom as when I stop, break out the Amana stacked dado set, go through all the PITA set up, trial and error with shims, to get the exact dimension I want, if I want an exact dimension. That's why I don't find myself using the TS to create wide kerf dados. I use the stacked dado set...the bottom fit is better. Or am I missing something? Maybe a different TS blade that creates kerfs that leave a flat bottom. Is that the answer? What do you guys do that use Table Saws to create wide kerfs do to get that flat bottom. How do you do that?

[Mark Duksta]

I use a Forrest Woodworker II blade with a number 1 grind (WW10401125).

It cuts a kerf with a flat bottom.

Mark

[Prashun Patel]

I usually just use a regular cross cutting blade to do it. I like the control and ability to finesse the size.

As for the bottom, I use a chisel (and some day a router plane!) and a sanding block to clean up.

It actually goes pretty fast, because even if you leave between 1/16 and 1/8" between the kerfs, you can knock out the residuals with a chisel.

[scott spencer]

I either use my stacked dado for wide kerfs, and grab a flat top (FTG) ripper for narrow ones. The FTG grind is the only grind that'll leave truly perfectly flat bottoms...any other configuration has teeth that are intentionally set at different depths, so the bottoms aren't "perfectly" flat. I'll also occasionally use a router with a straight bit.

[Dan Bowman]

I use a homemade kerfmaker calibrated to a 5/8" stacked dado. It doesn't matter if the dado isn't exact, as long as the kerfmaker is, and the bottoms come out flat

[Doug Shepard]

Why not use the stacked dado set and skip all the shims? Stack up as many blades/chippers as necessary to get to a thickness less than your target thickness then use the Kerfmaker and set the cutter size to that thickness? 2 cuts would get most or your dado needs vs multiple cuts using a single blade.

[Don Morris]

Doug, that sounds like a neat solution. Does require breaking out the stacked dado set though. I've also used router bits for certain standardized sizes, but if I needed sizes that weren't that standard exact size of the router bit, I was stuck. The FTG grind I guess will give a flat bottom, what about the sides...tear out? I've never used an FTG blade, why don't people use that all the time? There must be some pros and cons to its use. Have to go to the Forrest site and/or some blade sites and read. So far it looks like I have to end up with chisels, sanding blocks, separate FTG blade or the two step dado + kerfmaker. Choices, choices....

[Doug Shepard]

... The FTG grind I guess will give a flat bottom, what about the sides...tear out? I've never used an FTG blade, why don't people use that all the time? There must be some pros and cons to its use....

I think most dedicated rip blades are FTG (at least mine is). I dont think they're optimal for crosscuts and/or especially on something like veneer plywood due to some chip out on the edges.

[Ralph Barhorst]

Don - Check out this post. http://www.sawmillcreek.org/showthread.php?t=77289

[Don Morris]

That's a great solution and just uses a "standard table saw blade". OK, now I just have to look and see if I still have a standard table saw blade. Thanks for the post!