# Home Made Dado Stacks - Genius or Lunacy



## Sigung (Nov 20, 2013)

I was divided about where to post this, but ultimately since I'm wondering if this is safe, this is where it wound up.

After looking at multi - hundred dollar dado sets, I had to ask myself, "Self, what really is the difference between a bunch of saw blades mounted on the same arbor and an "official" dado stack? It seems to me that if you had a bunch of high quality blades, all the same type and could mount them with the teeth not touching each other, that it would work just like a dado set.

So my question is, is this a viable idea, or is it a deadly accident waiting to happen?

All input is appreciated.


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## Rayne (Mar 9, 2014)

It should work, but only if your saw has the power to spin the blades of that size at those speeds safely. There's a reason DADO stacks tend to be smaller than that your saw is capable of for a single blade due to this. Maybe a stack of 7-1/4" blades from a circular saw and teeth not touching might be possible, although I still don't how flat of a dado you'll get since the teeth are not pointing in their respective directions.


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## Sigung (Nov 20, 2013)

> It should work, but only if your saw has the power to spin the blades of that size at those speeds safely. There s a reason DADO stacks tend to be smaller than that your saw is capable of for a single blade due to this. Maybe a stack of 7-1/4" blades from a circular saw and teeth not touching might be possible, although I still don t how flat of a dado you ll get since the teeth are not pointing in their respective directions.
> 
> - Rayne


Thanks Rayne, that is very good intelligence. I had not even considered the size - weight issue.


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## MikeThrockmorton (Nov 4, 2013)

I would think if you had say 4 fully toothed 10" blades shoulder to shoulder on your TS arbor and all those side by side teeth engaged a board at once you'd have a heck of an instantaneous load applied.

The typical dado set has those widely spaced tooth chipbreakers which reduces the load a lot.

Could stop your saw motor dead or hurl the board.


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## beamrider (Mar 19, 2010)

http://woodgears.ca/shop-tricks/dado.html


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## jumbojack (Mar 20, 2011)

I've stacked two together with no ill effects. I cut quite a few 1/4" dados and my stack needs to be shimmed to get 1/4" leaving some ridges. So when I need 1/4" for short jobs ill use my 10" stack. Can't say for more than two, give it a try, go slow, maybe a shallow cut the first pass just to see. Let us know how you make out.


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## Ghidrah (Jan 20, 2015)

There'd be a heck of a lot more torque on the arbor with the added weight, chippers are maybe 1/4 the weight


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## Robsshop (Apr 3, 2010)

Long time since we've talked Jer(lol)
I am no expert on this matter and I am sure there will be those on here that will give a more in depth response, but I feel that this approach will have many obstacles to over come. The Dado set I use is a typical stacked dado set consisting of two outer blades with standard teeth and several chipper blades that widen the kerfs width in 1/8" increments. The first issue I see as a potential problem is the shear mass of several full blades when cutting the larger widths. 1/4" dados are achieved with the two outer blades but I don't think I would want to be around the TS with 4 or 5 blades spinning that fast ! The next issue I see has to do with the teeth spacing in which the the dado set has built in voids on the outer blades. This is so that the chipper blades can be spaced evenly and with out any of the teeth contacting each other. It may be possible to do this with 2or3 blades but I cant see it working with more than that. There are probably some other issues that others will point out, but I would do a lot of research before jumping in! I know you have a level head on your shoulders Jerry and safety first is always the best practice. Be careful my Friend, I so enjoy our exchanges and let's keep it that way(LOL)


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## MrUnix (May 18, 2012)

I've used Matthias's method (linked above) with great success.. cheap 7.25" circular saw blades with shims. Not a problem.

Cheers,
Brad


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## knotscott (Feb 27, 2009)

It'll work. I've done it with three 10" 24T FTG blades for a really deep groove. Most 7-1/4" blades are ATB grind so it'll leave a rippled bottom. That might be ok, but don't expect it to perform like a good stacked dado set.

One of the more significant differences is that a stacked dado set has two outside cutters with top beveled teeth, each of which is dedicated to one side. Those beveled teeth protrude slightly above the inside cutters to reduce tear out on cross grain cuts.










A stack of ATB blades will leave multiple ridges from a series of v-shapes like this:


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## bandit571 (Jan 20, 2011)

Used to do this on my old Craftsman 113. Outer two blades have as many teeth as one can get on a circular saw blade, the inner one(s) were as few teeth as a rip blade could be. A paper shim between them helps, as well.


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## pintodeluxe (Sep 12, 2010)

Try a Freud Diablo stacked dado set. They can be had for around $80 on Amazon. I cut thousands of tenons and mile of dados before it finally needed to be resharpened this year. 
One big advantage of a traditional stacked dado set is the shims. You can make a perfect groove for even sizes, or undersized plywood.
Plus a 3/4" stack of 10" blades would require at least 6 blades, so the traditional dado stack may even be cheaper.
Good luck with it.


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## rick1955 (Jun 26, 2014)

I would call it inexperienced. You don't need a 10" dado for one. You haven't done the research or read enough in the magazines. 
http://www.amazon.com/Oshlun-SDS-0842-8-Inch-Tooth-Stack/dp/B0012YF25Q
The Oshlun SDS-0843 is highly rated. It compares to dado sets at $200.


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## ShipWreck (Feb 16, 2008)

> I was divided about where to post this, but ultimately since I m wondering if this is safe, this is where it wound up.
> 
> After looking at multi - hundred dollar dado sets, I had to ask myself, "Self, what really is the difference between a bunch of saw blades mounted on the same arbor and an "official" dado stack? It seems to me that if you had a bunch of high quality blades, all the same type and could mount them with the teeth not touching each other, that it would work just like a dado set.
> 
> ...


I love creative thinkers like yourself. But in this case, I think a 1 1/2 HP saw might be too weak. The diameter of the blades would bog the saw motor down…....IMHO. But there are smarter folks on here than me that could chime in.


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## rwe2156 (May 7, 2014)

Multi-hundreds for a dado set? You're either looking at 10" or Forrests.

As the poster said, a Freud 8" dado set is 90 bucks - about the cost of 2 blades. I've used one for years, in fact, I've had it sharpened twice and its still a decent cutter. A CMT is around 120. I'm a big fan of the orange blades (lots of carbide).

Just for the sake of argument, lets look at it:

You're making a 3/4" dado. For the sake of argument, lets say the blades cost $50.

1. How many blades would you need to stack up for 1 pass, 6 (2 xcut + 4 rip)? 5 blades = $250

2. 3 blades and 2 passes? 2 blades = $100.

3. 1 blade and 6 passes? This is what we're trying to avoid.

Solution: save your time and money and get a Freud 8" set. 
(Remember you will have to make a bunch of insert blanks for diff widths).

I've learned its best not to try to cut the depths perfect right off the saw
Just as a suggestion, here's how I do dadoes/rabbets:

1. Knife the two edges (deeply).
2. Cut dado set slightly above depth.
3. Make an initial scoring cut about 1/16" deep.
4. Finish to final depth with a hand router plane.
5. If its a through dado, always leave the board a little wide to plane off any edge tear out.

I think this technique will give you a superior dado or rabbet because:

1. The depth will be perfectly uniform.
2. If the dado goes to the edge there will be no saw marks.


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## JeffP (Aug 4, 2014)

FWIW, it is not the weight, but only the torque increase caused by the larger radius of the blades (compared to typical dado set) that is of any consequence here.

The increased weight of stacked blades will make the saw spin up slower, but once full speed is achieved the added mass of stacked blades would be a GOOD thing, not bad. (think flywheel) Once spinning at full speed, it does NOT take more power to spin a 100 pound blade stack than a normal blade. (well, ok, 100 pounds might very slightly increase the friction on the bearings, but you know what I mean)

I have heard that some people with a Saw Stop who are too cheap/lazy to purchase the additional brake cartridge required for a dado set have used the stacked 10" blade setup. You loose a significant amount of the Saw Stop safety advantage while doing this (since you are asking the brake to stop more mass and it can't do it as quickly). I suppose it could also damage the saw if it did detect a finger and attempt to brake…due again to the increased mass/inertia.

For the sake of clarity here…I have heard of such people. This euphemistically hypothetical individual…would not be me. (I use my router table instead)

For the un-initiated, the reason a Saw Stop user might stoop to this unsanctioned method is that the SS electronics "looks" for a blade within some tolerance distance of the brake, and will refuse to turn on if it doesn't find it. A normal sized dado set is too small for it to detect it…so you have to use a different size cartridge in the SS with a dado set.


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## Sigung (Nov 20, 2013)

> It should work, but only if your saw has the power to spin the blades of that size at those speeds safely. There s a reason DADO stacks tend to be smaller than that your saw is capable of for a single blade due to this. Maybe a stack of 7-1/4" blades from a circular saw and teeth not touching might be possible, although I still don t how flat of a dado you ll get since the teeth are not pointing in their respective directions.
> 
> - Rayne


This is an interesting idea, and yes the safety factor does concern me. Thank you for this.


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## Sigung (Nov 20, 2013)

> I would think if you had say 4 fully toothed 10" blades shoulder to shoulder on your TS arbor and all those side by side teeth engaged a board at once you d have a heck of an instantaneous load applied.
> 
> The typical dado set has those widely spaced tooth chipbreakers which reduces the load a lot.
> 
> ...


Another useful piece of the puzzle, yes, certainly the startup torque would need to be greater to compensate for the added weight, and we all know how dangerous kickback is. Thanks for your input.


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## Sigung (Nov 20, 2013)

> http://woodgears.ca/shop-tricks/dado.html
> 
> - beamrider


This is very interesting, I have great respect for Matthias Wandel. His take on the safety angle is also quite interesting to me. The fact that dado stacks are not allowed in Europe for safety reasons and the fact that he feels that 3 Skilsaw blades stacked are actually safer to his way of thinking than a dado set with chippers is enlightening to say the least. Thanks for this.


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## Sigung (Nov 20, 2013)

> I ve stacked two together with no ill effects. I cut quite a few 1/4" dados and my stack needs to be shimmed to get 1/4" leaving some ridges. So when I need 1/4" for short jobs ill use my 10" stack. Can t say for more than two, give it a try, go slow, maybe a shallow cut the first pass just to see. Let us know how you make out.
> 
> - jumbojack


Thanks Jumbojack, it's good to get intelligence from someone who's actually tried it.


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## Sigung (Nov 20, 2013)

> There d be a heck of a lot more torque on the arbor with the added weight, chippers are maybe 1/4 the weight
> 
> - Ghidrah


You've hit on the most consistently recurring theme on this thread, I think this is an important consideration. Thanks.


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## Sigung (Nov 20, 2013)

> Long time since we ve talked Jer(lol)
> - Robsshop


Ha haaa, you very funny guy


> I am no expert on this matter and I am sure there will be those on here that will give a more in depth response, but I feel that this approach will have many obstacles to over come. The Dado set I use is a typical stacked dado set consisting of two outer blades with standard teeth and several chipper blades that widen the kerfs width in 1/8" increments. The first issue I see as a potential problem is the shear mass of several full blades when cutting the larger widths. 1/4" dados are achieved with the two outer blades but I don t think I would want to be around the TS with 4 or 5 blades spinning that fast ! The next issue I see has to do with the teeth spacing in which the the dado set has built in voids on the outer blades. This is so that the chipper blades can be spaced evenly and with out any of the teeth contacting each other. It may be possible to do this with 2or3 blades but I cant see it working with more than that. There are probably some other issues that others will point out, but I would do a lot of research before jumping in! I know you have a level head on your shoulders Jerry and safety first is always the best practice. Be careful my Friend, I so enjoy our exchanges and let s keep it that way(LOL)


Your considered opinion and experience in this is greatly appreciated. I am rapidly becoming dissuaded from this idea. Thanks Rob.


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## Sigung (Nov 20, 2013)

> I ve used Matthias s method (linked above) with great success.. cheap 7.25" circular saw blades with shims. Not a problem.
> 
> Cheers,
> Brad
> ...


Thanks Brad, I do think it's worthy of consideration.


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## Sigung (Nov 20, 2013)

> It ll work. I ve done it with three 10" 24T FTG blades for a really deep groove. Most 7-1/4" blades are ATB grind so it ll leave a rippled bottom. That might be ok, but don t expect it to perform like a good stacked dado set.
> 
> One of the more significant differences is that a stacked dado set has two outside cutters with top beveled teeth, each of which is dedicated to one side. Those beveled teeth protrude slightly above the inside cutters to reduce tear out on cross grain cuts.
> 
> ...


This is a beautiful reply, thanks for the great explanation and the graphics. Great Information!!


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## Sigung (Nov 20, 2013)

> Used to do this on my old Craftsman 113. Outer two blades have as many teeth as one can get on a circular saw blade, the inner one(s) were as few teeth as a rip blade could be. A paper shim between them helps, as well.
> 
> - bandit571


Thanks Bandit, this is also great information.


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## Sigung (Nov 20, 2013)

> Try a Freud Diablo stacked dado set. They can be had for around $80 on Amazon. I cut thousands of tenons and mile of dados before it finally needed to be resharpened this year.
> One big advantage of a traditional stacked dado set is the shims. You can make a perfect groove for even sizes, or undersized plywood.
> Plus a 3/4" stack of 10" blades would require at least 6 blades, so the traditional dado stack may even be cheaper.
> Good luck with it.
> ...


Well, that's great to know. I've not seen anything that cheap from Freud. I was looking that this

http://www.amazon.com/Freud-SD508-Super-8-Inch-Stack/dp/B00004RK0P

and I just can't get beyond the price…


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## Sigung (Nov 20, 2013)

> I love creative thinkers like yourself. But in this case, I think a 1 1/2 HP saw might be too weak. The diameter of the blades would bog the saw motor down…....IMHO. But there are smarter folks on here than me that could chime in.
> 
> - ShipWreck


I only have 3/4 HP on my old Shopsmith Mark V, so this is rapidly becoming apparent that it may be too much for the motor. There is that speed control though, I could start off slow and ramp it up. Hmm…


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## Sigung (Nov 20, 2013)

> Multi-hundreds for a dado set? You re either looking at 10" or Forrests.
> 
> As the poster said, a Freud 8" dado set is 90 bucks - about the cost of 2 blades. I ve used one for years, in fact, I ve had it sharpened twice and its still a decent cutter. A CMT is around 120. I m a big fan of the orange blades (lots of carbide).
> 
> ...


This is an amazingly detailed, informative, and helpful post. You and Willie ( pintodeluxe ) have convince me. I was unaware that you could be a dado set this cheaply. The ones that I've been seeing were almost $200.00, so thanks very much for explaining all this to me and for your detailed information. Great Reply!!!


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## Sigung (Nov 20, 2013)

> FWIW, it is not the weight, but only the torque increase caused by the larger radius of the blades (compared to typical dado set) that is of any consequence here.
> 
> The increased weight of stacked blades will make the saw spin up slower, but once full speed is achieved the added mass of stacked blades would be a GOOD thing, not bad. (think flywheel) Once spinning at full speed, it does NOT take more power to spin a 100 pound blade stack than a normal blade. (well, ok, 100 pounds might very slightly increase the friction on the bearings, but you know what I mean)
> 
> ...


Thanks Jeff, what you say makes perfect sense to me. I have an old Shopsmith Mark V, so theoretically I could spin up the blades slowly because I have a speed control, but it begins to look, to me anyway, that the most significant safety danger here, especially with a Shopsmith, is that the strain of all that spinning mass could damage the quill bearings. ( For you non - Shopsmith owners, the quill is the part of the Shopsmith that you would normally call an arbor. Shopsmith calls it a quill because it can be extended away from the headstock by several inches. ) Add to that the fact that I would be limited to 3 blades at most, and those 3 blades could easily cost me $150.00, then the $80.00 Frued - Diablo stacked Dado set becomes the obvious choice here.


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## kirbi69 (Jan 24, 2014)

not all saw blades will be perfectly the same diameter. maybe when they sharpened the carbide tips, the took off more material, and thus now your saw blade is 1/10 of an inch smaller diameter.

that aside,... i watched my dad do stacks of skill saw blades on his radial arm saw when i was a kid, its how he achieved flat bottom dados as apposed to his wobble dado blades.


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## Sigung (Nov 20, 2013)

> not all saw blades will be perfectly the same diameter. maybe when they sharpened the carbide tips, the took off more material, and thus now your saw blade is 1/10 of an inch smaller diameter.
> 
> that aside,... i watched my dad do stacks of skill saw blades on his radial arm saw when i was a kid, its how he achieved flat bottom dados as apposed to his wobble dado blades.
> 
> - kirbi69


Good point, they would all need to be brand new.


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## UpstateNYdude (Dec 20, 2012)

Matthias at woodgears.ca has already helped you out.

Here:
https://woodgears.ca/shop-tricks/dado.html


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## JeffP (Aug 4, 2014)

Some other (potentially free) possibilities:

1) multiple side-by-side passes with a single good saw blade.
2) if you have a router, you can use that for making dado cuts. (I prefer this anyway, especially with a router table)


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## Kentuk55 (Sep 21, 2010)

My .02 is: I think too many full size blades together is asking for a boo boo. I'd think the extra weight of those full size blades wouldn't be too nice to your arbor. That's my own opinion. If you should try this I suggest you take really light cuts/depth on many passes.


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## gfadvm (Jan 13, 2011)

Jerry, I debated the same issue several years ago. I hate the shims that come with dado stacks so here's what I did (and I've been happy with the results): I bought a Freud Box Cutter set. It cuts perfect 1/4" and 3/8" dados with perfectly flat bottoms as well as box joints. The set of 2 blades wasn't cheap but they have cut a LOT of wood and are still SHARP. When I need wider dados, it is easier for me to make a couple of passes than fussing with shims.


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## ArlinEastman (May 22, 2011)

Jerry

I am so glad you asked this question. I have been going to ask it for quite sometime but kept forgetting.

I have a 3hp Grizzly cabinet saw and would like to know about this too.


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## Sigung (Nov 20, 2013)

> My .02 is: I think too many full size blades together is asking for a boo boo. I d think the extra weight of those full size blades wouldn t be too nice to your arbor. That s my own opinion. If you should try this I suggest you take really light cuts/depth on many passes.
> 
> - Roger


At this point I agree totally with you Roger.


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## Sigung (Nov 20, 2013)

> Jerry, I debated the same issue several years ago. I hate the shims that come with dado stacks so here s what I did (and I ve been happy with the results): I bought a Freud Box Cutter set. It cuts perfect 1/4" and 3/8" dados with perfectly flat bottoms as well as box joints. The set of 2 blades wasn t cheap but they have cut a LOT of wood and are still SHARP. When I need wider dados, it is easier for me to make a couple of passes than fussing with shims.
> 
> - gfadvm


You know, I actually have that same box cutter set, and I did consider that possibility. It does a great job on giving a perfectly flat bottom.


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## gfadvm (Jan 13, 2011)

I even use mine for milling all my half lap joints. One of my best buys.


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## Sigung (Nov 20, 2013)

> Jerry
> 
> I am so glad you asked this question. I have been going to ask it for quite sometime but kept forgetting.
> 
> ...


Me too Arlin, there is a lot of wisdom here on this website, and if you go through all the responses like I did, it becomes clear pretty quick that stacking saw blades is not the way to go. I suppose the smaller skil saw blades are safe enough, but as knotscott pointed out in his great graphic, they will not give you a flat bottom in your dado, and the higher the tooth count on the skil saw blades, the fewer of them you can stack before they start running into their own teeth, and as kirbi69 pointed out if the saw blades are used, even a little, inconsistencies will start showing up in their depth of cut because of wear. Even though skil saw blades can be as cheap as $10.00 apiece, by the time you buy 4 of them, you're half way to a Freud / Diablo dado set.


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## Sigung (Nov 20, 2013)

> I even use mine for milling all my half lap joints. One of my best buys.
> 
> - gfadvm


Great Idea! Question here for you, as you know, this set was not cheap. Do you do your own sharpening, and if you are using them for all that other stuff, have they gotten dull yet? I am really good at sharpening, and I also sharpen my router blades as well as planes, chisels, etc, but I've never taken on sharpening a saw blade yet. What is your take on how that should be handled,....you know, that might be another worthy forum question.


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## gfadvm (Jan 13, 2011)

Jerry, You sharpen router bits? I am impressed!!! My box cutter set is still super sharp but I do keep it CLEAN with Simple Green Purple formula. I will have our local sharpening guy sharpen them when they need it. He sharpens my 'disposable' planer blades, my cheap Diablo blades, my big planer blades, and everything else except my sawmill bands. I would never attempt to sharpen my box cutter set or any other carbide saw blade.


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## rwe2156 (May 7, 2014)

I, too, sharpen straight router bits, hand saws, etc. but I've never even thought about sharpening a saw blade. The technique would be very diff from a handsaw what with diff angles, offsets, etc.

If I was desperate on a long weekend I might touch up a FT rip, but never an ATB. (Actually I'd go to HD and just buy a new one).

Bottom line: My sharpening guy does a pro job for $12/blade and I've got better things to do ;-)

.....like throwing my .02 in here


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## MrRon (Jul 9, 2009)

Another issue could be chip clearance, especially in wood with high moisture content. The blades might get clogged and cause burning. There are dedicated line rip saws that can mount multiple blades, but they are used in industrial settings, not as a dado, but by ripping boards into defined width strips, but of course you already knew that.


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## Sigung (Nov 20, 2013)

> Another issue could be chip clearance, especially in wood with high moisture content. The blades might get clogged and cause burning. There are dedicated line rip saws that can mount multiple blades, but they are used in industrial settings, not as a dado, but by ripping boards into defined width strips, but of course you already knew that.
> 
> - MrRon


Interesting MrRon, Thank you for your contribution.


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## Ocelot (Mar 6, 2011)

If you read the woodgears page somebody linked to above… he says chip clearance was never a problem. He uses 3 7-1/4" blades.


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