FYI Dado Set Sharpening

[Jim Talbert]

Hello,
We sharpen on average 40 carbide stacked dado sets every month. I know most woodworkers understand the importance of sending both the outer blades along with all the chippers that belong with a set. We have about 10% of the sets we get missing chippers. The reason we find for most missing chippers is that the chippers most used are the ones sent to be sharpend, and the woodworker did not realize the ones left at his shop would not work properly if he ever needed to use them once the sharpened set is back.
When sending or taking dado sets to your sharpening service you want to make sure you have both outer blades as well as all the chippers in the set. The whole set needs to be sharpened at the same time to keep the set matched to work properly.
Just something that newer woodworkers might find useful when having their first stacked set sharpened. Thought this might be a good place to pass along alittle info.

Had a set come in today with just the outer blades and a note saying the chippers still seem fairly sharp and did not need to be sharpened at this time.
Thanks
Jim Talbert
Cardinal Tool Sharpening
www.cardinaltool.com

[Paul Kunkel]

:D

[Todd Burch]

Hey Jim, quick question about dados just sharpened.

When getting a stacked dado set back from sharpening (assuming I sent in ALL the chippers!), how flat should the bottom of a dado be on a test cut thereafter? I would expect that with the naked eye, I should not be able to see any "tall" (or "deep") chipper cuts and that they should all be just as good as new.

Is this a correct assumption? Or, should I expect some variances in depth across the width of a dado with all chippers installed?

Thanks, Todd.

[Jim Talbert]

Todd,
If properly sharpened you should not see any strips or uneven areas across the cut if using all chippers. The individual chippers should all be exactly the same after being sharpened and all cutting the same depth into the wood.
Thanks
Jim
Cardinal Tool

[Todd Burch]

Thanks.

Back when I had my Sears Craftsman saw (R.I.P. 1997), I bought my first "real" stacked dado set, installed it, and the cut was TERRIBLE!! It looked as if I had run several passes with a 1/8" flat top blade, moving the blade height each pass just a little bit, up and down, up and down.

I called my blade supplier to come look at the junk $220 dado set he sold me. He had never seen anything like that with SYSTEMATIC "FINE" dado sets. He had brought with him another set, and we loaded it up and by golly if it didn't do the same thing. We checked the arbor on the saw and it was undersized. I had never thought to check it since it was the first saw I ever owned. A few months later, the motor mysteriously burnt up and I was forced :D to buy a powermatic. No arbor problems now. No jagged dado cuts.

Todd.

[Ron McNeil]

Jim, Thank You for this information I would have not known to send all the chippers.

[Kevin Gerstenecker]

Jim, I can see the importance of sending all the components of the Dado set to be sharpened at the same time, to keep the depth of cut consistant. What about a set that has never been sharpened that doesn't cut to a consistant depth? Is there a way that the blades and chippers can be ground to correct this condition? I have a Freud Set that is as close to perfect as it gets, but I have another set that is not as high quality and it doesn't cut quite perfect as far as depth of cut goes. I use it mostly for rough work.......like Cedar for deck railings and the like, but it would be nice if it could be ground to cut the bottom of the dado smoother. Just curious...............

[Dale Sherman]

Jim,
I have an older Freud dado set that has very high outer blade teeth. I was told by the vendor that this was for glue squeeze-out. But the outer blades cut a 'V' groove about 1/16" deeper than the chippers. If the end of the dado is exposed, it looks terrible.

If I sent the set out for resharpening, would this pronounced 'V' groove be reduced so I can get a clean, square dado?

I've been using router bits for most dadoes, but once in awhile I use the TS when I have a lot of cutting to do. I get my best results using a wobble dado and cleaning it up with a router bit. I hate the wobble dado, but it does hog the wood out.

Dale

[Jim Talbert]

Kevin,
Yes your dado set can be sharpened to cut smoother in the bottom of the cut. There are older poorly built sets out there that even with excellent sharpening just will not cut exactly perfect.

Dale,
You are right some dados are designed and come from the manufacturer with the outer blades 1/32 to 1/16 of an inch longer for purposes of a a glue groove. They produce a small triangular shaped groove in the outer edges of the cut. Your set can be sharpened to reduce or eliminate the small groove altogether if that is what you need and specify to your sharpener that is what you want.

Thanks
Jim Talbert
Cardinal Tool Sharpening
www.cardinaltool.com

[Bobby Hatfield]

Jim, does anyone make a set of bushings for the Sears arbor and bore the dado set hole oversize, to fit the bushing to eliminate the "Sears Dado", that you know of ?

[Jim Talbert]

Bobby,
Iam not aware of any but that does not mean there might not be one out there somewhere.

Thanks
Jim