Dado Blade

[Mark Bear]

Hi all. I've been browsing this place for a while but now I have a question. I have a Freud Dado blade, 8"er and it seems to be leaving a small groove in the corners. Is that a standard thing for this blade? Is there another out there that does not do this? I'm looking for something that cuts a flat 90 with no grooves or funny stuff.

Thanks

[Charlie Doret]

It's pretty common for a dado set to have teeth on the outer blades with an angle so that they score the outside of the cut, helping to prevent tearout. This causes the groves in the corners to which you're referring.

There have been some dado reviews on FWW in the past; one point they cover is the flatness of the dado. Take a look if you're looking for a suggestion. I know there are also some finger joint sets that are intended to cut extremely flat bottoms, but don't have chippers enough to reach a full 3/4" in one pass.

[Alan Schaffter]

Hi all. I've been browsing this place for a while but now I have a question. I have a Freud Dado blade, 8"er and it seems to be leaving a small groove in the corners. Is that a standard thing for this blade? Is there another out there that does not do this? I'm looking for something that cuts a flat 90 with no grooves or funny stuff.

Thanks

The Forrest Dado King leaves little ears also.

[glenn bradley]

You don't mention which model you have but my SD508 is pretty flat. If you really look you can see the ears but they are so slight that they vanish with a topcoat film. The outer blades should score the surface to assure a clean cut in veneered woods (plywood) but they should be pretty minor. My old set left them big time; nothing would hide them but sawdust mixed with finish and they still looked "fixed".

[Leo Graywacz]

You'll miss those tips when you cut cross grain in a sheet of plywood. Most high quality dadoes will have the scoring points on the outer blades.

[Jason Hallowell]

They do exist, but as others have mentioned have some limitations, mainly tear-out issues. Rather than buy a finger joint set, I use the router for the rare cases I can't live with the "ears" in my dados.

[scott spencer]

Very common due to the reasons already explained. You'll read lots of comments from people getting perfectly flat bottomed dados that really aren't perfectly flat...those "bat ears" are usually pretty minor. Some sets have a flat raker to minimize the bat ears even more, but upon close inspection you'll still notice the tiny grooves.

[Fred Hargis]

You can buy some router bits that are designed to perfectly clean up those lines, but it's fairly inconvenient to have to cut dado's in multiple steps. Even so, they work really well, and flush cut to the side of the existing dado. MLCS is one maker of these bits, called, strangely enough, dado clean up bits (I think).

[george wilson]

Can you go back with a shoulder plane to clean up the bottoms of the dados?

[Frank Drew]

Can you go back with a shoulder plane to clean up the bottoms of the dados?

Only if you had a plane at least slightly narrower than the dado.

[Alan Schwabacher]

If you want to clean up the dado with a hand tool, a router plane is perfect for cutting to a specified depth and leaving a flat surface.

[Frank Drew]

Very good suggestion, Alan.

[Cliff Rohrabacher]

I have an old craftsman that makes a dead flat slot.
It doesn't fit my Hammer arbor.
If Craftsman could do it ~ ~ ~ ~ ~ ~

[Mark Bear]

Thanks all, for confirming my suspicions. Since touching things up with a plane or router isn't an option I've had the blade reworked to fix the problem. Also found a company that can custom make a blade if the "rework" doesn't work. Roberts Saw Company in FL. Wanted to share.