# Dado Blade Leaves Grooves



## chandler48 (Jun 5, 2017)

No blade is perfect so you will encounter boogers in your cuts. Look at the business end of a blade in the light and you will see that the tip is not flat. It can't be and perform well. Thus the striations. In your instance, I would not worry about them. The only alternative would be to use a beveling (wobble) dado blade, or even a router with a fence. Both will give really flat bottomed dadoes.


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## m_ridzon (Sep 29, 2017)

Thanks for the feedback. After poking around the internet, it seems folks prefer stacked dados over wobble blades. With that in mind, how do the master woodworkers deal with the ridges left from dado cuts when making fine furniture? When I look at rabbet joints or other dado joints on high quality woodwork, I don't see the tiny misfit that can result from these ridges. Instead, everything comes together very tightly.


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## ZTMAN (Feb 19, 2015)

How many passes did you make to get to the width of the cut in your pic


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## m_ridzon (Sep 29, 2017)

ZTMAN said:


> How many passes did you make to get to the width of the cut in your pic


One. I stacked the dado chippers to the width I needed and passed the wood through the blade once. If I merely repeat the pass back-n-forth over the blade, it doesn't change the outcome.


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## ZTMAN (Feb 19, 2015)

m_ridzon said:


> One. I stacked the dado chippers to the width I needed and passed the wood through the blade once. If I merely repeat the pass back-n-forth over the blade, it doesn't change the outcome.


You would probably get a better result by narrowing the blade and making more passes for a cut that wide.


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## Drachenfire (Jun 6, 2017)

You did not indicate what type of table-saw you were using. Normally an 8" dado stack set requires a table-saw with at least a 3-horsepower motor. If you have a budget model bench top saw, a 6″ set will cut dadoes deep enough for most home projects.

Providing you have a robust enough saw, I suggest you try feeding the wood slower and make the cut in two passes, the first at half the final depth.


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## SeniorSitizen (Sep 10, 2012)

Fine wood workers use a wood chisel that we could shave with to correct that if those ridges are offensive to them. Ladies, don't try this on your legs.


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## hkstroud (Mar 17, 2011)

The stacked dado blade is designed that way to give you the sharp internal corners. After cutting the dado you get out your sand paper and stick to sand the bottom smooth. Has to be that way because the teeth of the internal chippers are wider than the body of the chipper. That allows you to add paper shims to obtain the desired width. 
The wobble dado lets you dial it to the precise width you need but leaves a rounded or concave bottom. 

Just the way life is. Called woodworking.


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## Nealtw (Jun 22, 2017)

Exactly why most people will use a router if they can. The dado blade is just an improvement over 6 saw cuts and cleaning it up with a chisel.


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## Marson (Jan 26, 2018)

Not really sure if a more expensive stacked dado would be better, but I will say that Avanti blades from HD are not high quality blades. You get what you pay for.


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## SeniorSitizen (Sep 10, 2012)

Nealtw said:


> Exactly why most people will use a router if they can. The dado blade is just an improvement over 6 saw cuts and cleaning it up with a chisel.


 I'm glad you said "if they can".


When the plywood manufacturers decided they need to screw around with the thickness they pizzed me off and I avoid the router method when possible.


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## chandler48 (Jun 5, 2017)

Hopefully you aren't making these cross cuts on a table saw without a sled. A radial arm saw would be a better tool if you have one.


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## Nealtw (Jun 22, 2017)

SeniorSitizen said:


> I'm glad you said "if they can".
> 
> 
> When the plywood manufacturers decided they need to screw around with the thickness they pizzed me off and I avoid the router method when possible.


Yeah, you have to get into a double fence


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## m_ridzon (Sep 29, 2017)

Drachenfire said:


> You did not indicate what type of table-saw you were using. Normally an 8" dado stack set requires a table-saw with at least a 3-horsepower motor. If you have a budget model bench top saw, a 6″ set will cut dadoes deep enough for most home projects.
> 
> Providing you have a robust enough saw, I suggest you try feeding the wood slower and make the cut in two passes, the first at half the final depth.


It's a mid-grade homeowner table saw. It doesn't bog at all when making the cut, so I have no doubts about having enough power. Slower feed doesn't change the outcome. Multiple depths doesn't change the outcome. Bottom line is that the chipper diameters are not exact with the outer blade diameters, leaving tiny ridges in the groove.



Marson said:


> Not really sure if a more expensive stacked dado would be better, but I will say that Avanti blades from HD are not high quality blades. You get what you pay for.


Yup, I knew what I was buying when I bought it. Entry-level. My inquiry though, is if paying more money for a better stacked dado will improve the results and lessen the ridges. From reading replies here, it seems the answer is No.



chandler48 said:


> Hopefully you aren't making these cross cuts on a table saw without a sled. A radial arm saw would be a better tool if you have one.


Safety 101. Of course, I am using a sled. It's the one that came with the saw. It does just fine. I understand the implications of a free-hand cut. I rarely make free-hand cuts, but for sure I never would try free-hand with a dado blade. No, I do not have a radial arm saw, but am accepting donations for anyone who wants to give me one.:wink2:


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## wooleybooger (Feb 23, 2019)

Yes more money will get you a better dado set. Most stacked dados will leave such a surface in the groove. One of the best is the Forrest Dado King. Be prepared to spend beaucoup dinero if you plan to buy one.

The current odd thicknesses of plywood is not a problem with routers. Router bits are also made in the appropriate width for it. 23/32 instead of 3/4, etc.

As for the Forrest set I suspect only professional woodworkers and very experienced hobbyists would want to buy one. Notice prices at the bottom of this page in the link.

https://www.forrestblades.com/dado-king/


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## SeniorSitizen (Sep 10, 2012)

wooleybooger said:


> The current odd thicknesses of plywood is not a problem with routers. Router bits are also made in the appropriate width for it. 23/32 instead of 3/4, etc.


It certainly isn't a problem for me because I ain't buying a another router bit for a specific job because of a industry change. I'll stack my dado set until it fits whatever even if I have to use onion paper.:biggrin2:


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## wooleybooger (Feb 23, 2019)

SeniorSitizen said:


> It certainly isn't a problem for me because I ain't buying a another router bit for a specific job because of a industry change. I'll stack my dado set until it fits whatever even if I have to use onion paper.:biggrin2:


Yup, my Freud stacked set does just fine for me. The rough grooves don't bother me.


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## SeniorSitizen (Sep 10, 2012)

wooleybooger said:


> Yup, my Freud stacked set does just fine for me. The rough grooves don't bother me.


I see the grooves as more glue surface.:biggrin2:


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## Scottg (Nov 5, 2012)

I use a Freud Diablo dado set. They're about $90.

The resulting grooves are perfectly smooth. No sanding or anything necessary.

So maybe a bit expensive, but the real question is how often you need to do them. If it's a lot or building higher quality furniture, then it's probably worth it. The only challenge is when doing 3/4" depth or so, you have to take care with the arbor nut; there's not a lot of room left for it.

I've built all kinds of shelves/bookcases with this thing. So for me it's worth it, but it's also not something I use all the time, so yeah, you've got to suck it up on the price a bit. But it does work well. Oh, it it matters, I'm using a Bosch 4100 portable table saw with the set.


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## m_ridzon (Sep 29, 2017)

Scottg said:


> I use a Freud Diablo dado set. They're about $90.
> 
> The resulting grooves are perfectly smooth. No sanding or anything necessary.
> 
> ...


Very interesting. You're the first one in my thread to say that a stacked dado exists that doesn't leave small ridges in the cut. Everybody else basically said, "ridges are going to be there and it's the nature of the beast." Thanks for sharing this information. $90 is not really a bad price either.


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## SeniorSitizen (Sep 10, 2012)

m_ridzon said:


> Very interesting. You're the first one in my thread to say that a stacked dado exists that doesn't leave small ridges in the cut. Everybody else basically said, "ridges are going to be there and it's the nature of the beast." Thanks for sharing this information. $90 is not really a bad price either.


I hope you aren't disappointed to - _possibly _- find a new blade of yesterday's quality isn't the same. Here's hoping you find satisfaction in a new blade purchase and hope that Frued quality is still there. They've had excellent products for a long time.


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## Scottg (Nov 5, 2012)

m_ridzon said:


> Very interesting. You're the first one in my thread to say that a stacked dado exists that doesn't leave small ridges in the cut. Everybody else basically said, "ridges are going to be there and it's the nature of the beast." Thanks for sharing this information. $90 is not really a bad price either.


I've never noticed any such thing. (Not even the little side ridge things that some say are common.) I've even used the dado stack to cut... I'm not sure what they're called... crenelations I think, in a designed top for a castle bookcase. Now, in this case if taking a full depth cut, you can get some tear out on the sides.

https://scottgermaise.smugmug.com/Woodworking/Castle-Bookcase/i-pvWb62J/A

The side panels of this are held in with dado joints and everything in the groove was so flat I didn't need to sand at all.
https://scottgermaise.smugmug.com/Woodworking/Arts-and-Crafts-Bookcase/i-fhFLDbD/A

It's likely that at some point, as with any saw blade, I'll need to have them professionally sharpened. The problem you describe seems to happen sometimes. I checked on Lumberjocks and here's a post that may be of interest that talks a little about this potential problem.

https://www.lumberjocks.com/topics/224225

-Scott


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## Scottg (Nov 5, 2012)

Found this...

https://www.table-saw-guide.com/dado-saw-blades.html

This is the set I've got and the pics on this review are the same results I generally get. I didn't know about any of these problems when I first got into doing this stuff a handful of years ago. I'd seen the dado stack in use in a YouTube video and I guess I was luckier than smart in just learning about one of the more problem free options.

Two keys seem to be - if you're not doing this already - is use a featherboard attached to the fence for consistent hold down pressure, and use a zero clearance insert on your table saw. (Having the blade and fence well tuned and square is a given.) The tool to use to solve unevenness might be a a shoulder plane, but these aren't cheap either, and may work for lap joints. But for actual full dados are not likely to be the exact same size as your joint. And then of course you have to be a little concerned about depth. Even if you only take out 1/64" more on two sides of something, that's a whole 1/32" which could be enough to screw up the cut on a shelf sizing.


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## m_ridzon (Sep 29, 2017)

SeniorSitizen said:


> I hope you aren't disappointed to - _possibly _- find a new blade of yesterday's quality isn't the same.


Truthfully, my dado set isn't that old and is still sold in stores. It hasn't had a ton of use either. No, I'm not disappointed. But he is the first one in the thread to mention a dado set that actually leaves a smooth cut. I'm excited to hear there's an answer to my quandary.


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## Trickkart (10 mo ago)

Iam new to this site but I was very interested in reading all the questions and answers about the not so flat dado bottoms. I have an old 10 inch Delta Rockwell that I use a lot because it is built like a tank and nothing moves around on it when its set. I just bought the Freud stacked dado set to replace a dado set I have had for 30 years and it never did produce a flat bottom dado.
So, I am making box joints 1/4" wide so I setup the Freud with 2 face blades and 2 (.004) spacer washers, setup my jig and I start cutting. I noticed the little ridge on the one side and thought I could get away with it but it held the tongue away from the bottom of the dado and left a gap. Being very unsatisfied with this result, I started to research it tonight to see if this was a common problem with this not so cheap Freud dado set. Luckily, I stumbled right onto this site and some interesting reading. The conversation about the long arbor threads caught my attention because that is exactly what the old Deltas have. So I went to the woodshop and loosened the arbor nut, setup a dial indicator on top of one of the teeth on the face blade back on the non threaded section of the arbor, zero the indicator and then reached down to the bottom of the blade and gently lifted as straight as I could and got .003/.004 movement on the indicator. Now I move to the face blade that rests on the threads set the indicator on the top tooth, reach down and gently lift the blade and I got .0018/.0020 movement on the indicator. I'm thinking this is major and what am I going to do about it? Looking around the shop, I spotted a roll of metallic tape used for duct work. I cut a strip 8" long by 1/4" wide and took the adhesive paper off the back. Very carefully I wrapped the tape onto the threads right after the first face plate and pressing it hard into the threads. When I thought I had built the diameter up enough, I turned the blade back onto the shaft and back over the tape. Checked it with the indicator and I had decreased the slop down to .006. Tightened the arbor nut and fired up the saw and cut some box joints. What a difference, totally flat bottom and now the joints are too tight to put together, so I will have adjust the jig. The other thing I noticed and it shouldn't be a surprize, the vibration in the saw is gone also, runs smooth and quiet. That Freud stacked dado really is a fine piece of workmanship and is a pleasure to use and add to my woodworking accessories!


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