Flat bottom cutting dado blade recommendations

[Dominic Greco]

Hi everyone,

About 5 months ago I spent some time and built a finger joint jig for my tablesaw. I had just purchased a Delta Dado set on close out from the now defunct Woodworker's Warehouse (got it for 50% off) and thought the addition of the box joint jig would compliment this blade set.

While I was impressed with the cut, I was not too happy to see the little "v-grove" that the ATB (Alternate Tooth Bevel) blade made at the side of every dado! This pretty much renders this dado set useless for decorative joints.

Anybody have a recommendation for a dado blade set that will cut true, flat bottom dados? And not break the bank? I figure I'd like to stay in the $100 to $150 range if possible.

I posted this on WoodCentral and someone there suggested speaking to a blade sharpening service and having them grind the blade flat. While it's a good idea, I'd rather not do this. 1) I don't have a sharpening service nearby. And 2) I understand that this blade geometry was set up to do perform just this way. I'd rather just get another dado.

Thanks in advance.

[Scott Parks]

FWIW, if you are shopping around, I have the Craftsman Excalibur dial stack. ($189, I think, so a little over budget). It won't quite cut flat either, but it's close. It is very close to flat, just scores the outer edges. The ATB scores the sides to prevent tearout when crosscutting, but it has flat chippers. I've used it many times for cutting raised panels and dovetail pins without much problem, so it might be better than the Delta. A quick pass with a plane or sharp chisel on your box joints will clean it up. When I get home next week, I'll post a picture of dovetails I cut with this dado blade. (if I remember). I'd hate to see you buy one though for trial and error only to find out that it isn't quite what ou expected. Maybe you could talk Sears into giving it a test run?

Also, I was in Home Depot yesterday and saw a Freud stack that was $89. I didn't look at it, but might check that out.

[Dave Wright #2]

I have the same dial dado blade as Scott. It works quite well. There is a teeny bit of play in the blades, as there is with all blades. Sometimes it happens to set up giving me very slight grooves. Sometimes it sets up perfectly smooth and flat, except of course for the faint corner marks.

[Jim Becker]

I tend to believe that any of the reputative dado sets will leave a slight score, although some more than less. What you might consider is just using an inexpensive set for box joints and have it sharpened/ground to your specifications for that job.

[Michael Stafford]

I find it hard to beat the fit and finish of box joints cut on the router table. I have jigs that locate from my miter slot for 1/4, 3/8, and 1/2" box joints. I presume you could cut larger joints than that but I would not recommend it.

[George Tokarev]

Most dado sets will leave a couple of v-grooves, and it's tough to make them go away entirely. Remember the outsides are severed with the v-shaped teeth, and the insides are chipped out with flat-top grinds. Tends to leave a rougher surface that you can knock down with some sandpaper on a board, shoulder plane or such, or if the work permits, squeeze to vanishing with clamping pressure. One of the many reasons for stopped dados - can't see the imperfections.

Otherwise, router. Makes grooves flat, square, and anywhere. Router Workshop show on PBS, and their books from the web are chock full of jigs and techniques. Their box joint jig is an incredibly easy, accurate, and reliable one. I actually bought a set for myself, though they're easy enough to make for the kids at school who aren't always careful with their setups.

[Dominic Greco]

I find it hard to beat the fit and finish of box joints cut on the router table. I have jigs that locate from my miter slot for 1/4, 3/8, and 1/2" box joints. I presume you could cut larger joints than that but I would not recommend it.

Mike,
When I first built the finger joint jig, I cut up enough pieces for (2) jigs. One was for the tablesaw, and the other was to be used on the router table. When I completed the first I found I had made a horrible mistake and ruined one of the main pieces. Guess which one got sacrificed so the other could "live"? :>)

I'm thinking that it will take me about a days worth of work in the shop to retrofit this finger joint jig to work on my router table. Then I need to buy a set of nice sharp high quality straight bits (the ones I don't have at least). Maybe I end up spending about $100. I think this is the most economical, and logical solution.

Thanks for your advise.

[John M. Cioffi]

Sorry, I don't know how to copy the discription, but this is the set I've been using for 6 yrs. now & it is still cutting clean & flat & beautiful.
Amazon has it for around $94.00. Lowes, HD,Rockler,Woodcraft,ect. all have them.

Hope this helps.
John