Do Two Table Saw Blades Make a Dado Blade?

NO!

Not impossible, but unsafe and stupid. The teeth of a dado are specially designed to fit together and cut a certain way. Please don’t try using two regular saw blades. I’m sure you will have carbide bullets flying at you as well as the possibility of kickback.

• The teeth on dado blades are made to fit together so they can not slip and allow the carbide to come in contact.

• The hook angle of the teeth is zero or negative for a very non-aggressive cut so it can not “grab” your workpiece and throw it at you when taking big, wide bites.

An alternative would be making multiple saw kerfs with one blade or using a router and/or router table with a straight bit.

-- Check out my new website! http://www.blakeweberwoodworking.com

You have to be VERY careful. Dado blades have a left side and a right side for chip clearance. The teeth also are offset to not interfere with each other and nest side-by-side. If you use two regular saw blades, make sure they’ll “fit” together and they’re both sharp. I would not remove too much stock on each pass because you might get more kickback with your arrangement. Minimize kickback and chipout using standard shop practices/safety equipment since your blades won’t be designed specifically for your application. All-in-all, I’d recommend a cheap Sears dado set intead, mostly for safety reasons (I typed this post one-handed because I cut my middle finger off a month ago).

-- You can't control the wind, but you can trim your sails

I would recommend not trying this at all.

-- Check out my new website! http://www.blakeweberwoodworking.com

Blake said it. Do NOT Try This. The spacing between the larger blades in a dado set is such that each carbide tip rests between each tip on the adjacent blade. The carbide doesn’t touch the other blade at all making it so that the blades can come together flat and tight. The carbides on a regular saw blade are set to close to the disc portion of the blade so when you put two blades together the carbide hits the disc on the other blade. This creates a space between the blades that will close when you tighten the arbor, thus bending the blade on the outside to the other blade. At this point is when the carbide will chip off. My suggestion would be to set up a router and use a straightedge clamped to your pieces to make the dadoes.
For the record, I watched a guy install a freud super dado on the table saw. He put the nut on after loading the blades and didn’t tighten it enough. He turned on the saw and the blades spun at different speeds shattering several carbide tips off the blades. He is very lucky one didn’t catch him when it broke.
Work smart, be safe.

-- ~ Inspiring those who inspire me ~

I do not think that this is as dangerous as it is being made out to be. A simple shim (small stack of business cards with a 5/8 hole drilled in the middle) in between the blades will keep the carbide teeth from touching. You would then have a small sliver of wood not being cut inbetween the blades.

-- http://www.efcabineture.com/ You can be tired, or you can be broke, but you should never be tired and broke.

Or you could buy a used dado set from somewhere like ebay or craigslist and not have to jerry rig things. Safe or not, is it really worth the trip to the emergency room? Besides that 2 blades cost as much as a dado set. so after you ruin your 2 blades you’ll have to replace them and get a dado set basically doubling your loss.
This situation really is up to the risk of the user. I personally wouldn’t do this, but then again I have the knowledge to find other avenues of work. Good luck

-- ~ Inspiring those who inspire me ~

.

-- Ciao, gth.

Not Safe Do Not Try

It will Probably Wobble an it may bend your blades
I have wobble dado blade that dont use no more

-- Jim, Kentucky

NO

-- You can't get a hug from Facebook.

NO

-- You can't get a hug from Facebook.

AND NO! It’s not safe to try it, I don’t care how many shims you use. If you need to cut a dado and don’t have a dado blade then make repeat cuts – takes more time, but it’s safer. (You could, of course, argue that the more passes it takes to make a cut, the more opportunity for error and mishap.)

It’s one thing to come up with an alternate way to do something, but trying to modify two blades into something they are not, is not a good idea.

So my vote is NO, NO, NO, NO, NO. Don’t do it.

-- You can't get a hug from Facebook.

Use a router

-- Jim, Kentucky

NO – Before trying this, make sure your hospitalization insurance is up to date. I see half a dozen “No’s” above …any question?

-- Regards, Steve2

I have a Freud 8” SD508 super dado set that is in excellent condition. I’ll sell it for $90 + shipping.

It is a cheap and much safer investment.

This subject seems to be going along the one that shows the person cross cutting a dado freehand on a table saw using a fence as the only guide. It is extremely dangerous and foolish given the many ways to do it safely.

I try to think ” Safety First ” when having very sharp objects spinning fast and close.

-- Oldworld, Fair Oaks, Ca

I guess I knew it wasn’t safe or I wouldn’t have asked. I really appreciate all you folks speaking up to help keep me safe. I generally don’t do anything in the shop that makes me uncomfortable but sometimes there’s a little voice that says “ask the pros, they may have a solution that makes you comfortable.” In this case it turns out there’s only one safe way to get a dado set and that is buy one.

I hope anyone else reading this will conclude the answer is NO!

Thanks again,

-- Jim

I would like to point out that I am not an idiot, do not advocate jerry rigging in lue of safety and do not make up blades that do not exist. I do use business cards for shims. That being said, if shims are so dangerous to use in between blades, than why do all high end dado sets come with them, and why would companies sell after market sets. I am also aware of how a dado blade set works and that alternate teeth are in play, two 24 tooth blades layed ontop of one another will give adequate cleareance without carbide touching. Tighten the arbor and the blades will not spin seperate of one another. But I guess what I am suppossed to say is.
NO NO NO don’t do it.
p.s. I have one eye and only two fingers

-- http://www.efcabineture.com/ You can be tired, or you can be broke, but you should never be tired and broke.

I don’t think anyone was suggesting you are an idiot for your suggestion. I think everyone, including me, gets their dander up when questions like this comes up. Generally speaking, it’s not a good idea to do what was asked. It’s one of those times, if there are doubts – don’t do it.

I’m not much on mechanics, but dado sets that have shims, mine included, are intended to be used with the blades that have the offset teeth – so they are doing what they are designed for. I’m not familiar with the after market sets.

Another issue I have with this particular question is that generally someone who asks questions like this are not familiar with all the issues involved. Had he put two, non-dado blades together disaster would have been his companion.

I use playing cards and business cards for shims all the time, but would not consider doing so between two blades. Just me.

I hope that you were not offended by my response to the original question. But, I assumed from the question (which maybe I should not have assumed) that a novice was asking. I’d rather give a firm no rather than a “maybe if you did this” answer.

Just my two cents – for what it’s worth.

-- You can't get a hug from Facebook.

Please do not take a chance. Wait, get a router, but do not do it.

-- Tony "Everythings' gonna be gravy"

It is good to Ask Questions If you dont NO

-- Jim, Kentucky

WOW, I hope your insurance is up todate. I can see so many ways that this could go wrong. Please dont use any tool for something is was not intended to be. I am not sure what would be worse, the Kick back potential, or the carbide coming off the blade. And for the guy who suggested a shim, made out of buisness cards. get real. what do you think will happen to the cards as the blades sping, and what is going to happen when the shim fails. the blades come together, not a pretty picture.

At the risk of turning a very important educational topic into something less, let me repeat.

I am not going to try this. (Period)

Although I don’t consider myself a novice, I have never owned a dado set so I can’t tell what the safe way to put more than one blade on the table saw is according to those who sell dado sets and have assumed the liability for malfunctions. I consider advice from my fellow woodworkers a valuable resource. So, since most of you think NO is the safe answer, that’s what I’m going to do.

However, if someone else had the same question in their mind and wanted to ask but was hesitant, this can be a good resource for them. If we all remain cordial that is. I can speak from experience here. When people start attacking the person instead of the issue, I’m less likely to read the thread.

Anyway, thanks again for the help.

-- Jim

I’m with Rhett…

There are lots of published two blade tenon techniques, going back to Tage Frid. If the saw plates seat flat without tooth interference, the OP would be fine.

Dado sets are ground with a left and right edge to leave a cleaner wall, not to prevent death and disembowelment. <g> A dado set is also ground to leave a relatively flat floor, possibly with “batwings” to sheer veneer, normal blades are not.

It would actually be more dangerous to use one side of a dado set than to use two normal blades, due to the uneven grind on the dado half.

-- - Please help keep Lumberjocks an enjoyable escape by refusing to participate in political discussions. Simply spit out the bait and ignore the thread...

So OUtputter, what was your final answer? ;-)

I found a cheap set of dado blades at a harbor freight that have served me well; while the cut on the wider dadoes is a little rough, it’s small compared to the time-savings.

-- Making scrap with zen-like precision - Woodbutchery

NO NO NO!

I don’t NO about that.

If you had two identical blades with room to stagger the teeth without them touching, I would feel perfectly comfortable stacking them. The grind of the teeth might not make for the best dado, but I can’t see what the danger would be.

When I want to cut a very slightly oversize kerf I will use a single blade abd stick a paper shim between the blade and a portion of the arbor. This kind of makes a wobble dado blade.

I have seen a few TV shows (can’t remember which ones) that have used two blades with a real thick shim (like 3/8”) to cut tenons in one pass.

In my (apparently contrary position) opinion, if the blades are tight and the teeth don’t touch, it’s perfectly safe.

Flame away.

-- Gary, East TX -- The longest journey begins with a single step.

A few years back (I’ld have to look it up to give you the exact dates) American Woodworker magazine had a tennon set up the used two regular blades to cut it and recommended using playing cards as shims. Personally I use a router at home to cut dados, and a regular dado blade at the school. What I guess I’m saying is, if you are careful, you should be able to use 2 blades, but there are probably better alternatives.

-- remember always measure once and cut twice

As much as i hate to say it folks…... “rhett”....... is right…....about the blades…...the point is this….saftey is something that we all measure diferently. i have seen some master carpenters do things i would never think about doing. either that is the way they have always done it. or rather that is the only way to acomplish what they want. i know that over the years i have done a whole lot of experimenting with tools and blades, just to get the job done. “but i will not do it” if i fell it is beyond my comfort level or my knowledge for what the tool might do.
I myself was in the same position you were “outputter” a few years ago. i had no money for a dado set and i needed a small dado in the center of a wide plywood board. well the alternative could have been use a router and a straight bit. well i did not have a straight bit that size. so i needed to make a jig. well i also had no scrap wood to make a jig. so i asked around and found out that there were infact a few people who had used the method of throwing two blades together to make a dado set. ONLY IF SHIMS ARE USED to properly space the teeth. playing cards or thin cardboard works great. also a 7 1/4” blade from a circ saw works better. use a bade that has less teath and when you stack them alternate the teeth so that they are not parallel to one another.the two blades should be shimmed far enough apart that when you make your cut it leaves a small sliver of uncut material in the center of the two blades. you can later just pare that out with a chisel.
but after doing all that you will realize that you could have done the verry same thing by just moving the fence an 1/8th of an inch and making another cut side by side. hahaha the point is that there are no rules to woodworking there is not a certain way to use a tool. As long as you use good judgement and have common sense for what the tool will do in diferent cenario’s. now for most that only comes with experience. for some that never comes. wich is why the manufacturers still need to put a giant sticker on the outfeed table of a table saw, saying do not feed from this direction. ha. because some ediot probobaly really thought that it would work better from that direction. and because of that he now has a board permanantly sticking out of a tree in the back of his shop. i use no certain tool to get any certain job done. i use whatever is available to me to make that job easier. not faster, but esier. faster is a bad word in woodworking. so OUTPUTTER.. if you think that that is the only way to get what you need done then try it. as long as you feel comfortable. however i can garantee that there are a hundred other ways to substitute for that dado until you get a few extra bucks to buy a cheap one from the home centers. “BUT”i just wanted to clarify stacking two blades together to make a dado is possible….i know im gonna catch allot of shit for saying that but it is the truth

-- i can do all things through christ who strengthens me

Guess it all comes down to what you are comfortable with. But I sure would not do it.

Of course, I’ve seen Sam Maloof use his band saw and I wouldn’t do it that way either. But I sure would like to be able to build like he does.

Opinions are good, glad we can share them here.

-- You can't get a hug from Facebook.

I am glad to see I am not out on my own on this and that my name now gets ” marks. As for telling me to get real, maybe some should read books on woodworking techniques others have used. Last I checked a thin piece of wood, i.e. business card, will not spontaneously desintegrate when squeezed between two pieces of metal. I also think it is safe to run with scissors as long as you hold your arm out.

-- http://www.efcabineture.com/ You can be tired, or you can be broke, but you should never be tired and broke.

Actually dado blades are not allowed here in Europe at all for use on table saws.The authorities stop it by law so that all saws are made with too small an arbour for a dado set up, and if you decide to use an older saw on your own head be it not allowed under any ciscumstances for employees even if you alter the saw or buy American.The reasons I believe are that using a dado means removing the saw guard not allowed here.And the latest type of sliding table saws almost all new decent size saws here are sliding table they come right up to the blade with no throat to take a dado so Nanny state or not, we don’t have them on bench saws here at all.Now some radial arm saws still have them but again not for employees if you do your not insured and are acting against the law.I just thought I’d explain what the European Union thinks od dado’s.Alistair

-- excuse my typing as I have a form of parkinsons disease

Part of the issue with dado blades on Euro saws is spin-down time. Stack dados are heavy, and the EU has specifications on how long a blade takes to stop spinning.

-- - Please help keep Lumberjocks an enjoyable escape by refusing to participate in political discussions. Simply spit out the bait and ignore the thread...

Rhett, did you take my “jerry rigging” comment personally? Sorry man I wasn’t directing it to you personally. It was a statement. We all have to think about what is right from wrong. They make dado sets stackable for a reason. Because regular blades aren’t meant for stacking. Otherwise why even make the alternate? Thus, when you start putting blades together with shims and such that aren’t meant to be together it becomes “jerry rigging”. It’s not up to me to say what’s right or wrong. Everyone here has done things they shouldn’t and it’s worked fine. Doesn’t make it right does it. I’ve been very fortunate with how I do work. I don’t use guards, I push pieces through bare handed when I should use a push stick, etc. It’s my confidence. Will it get me in trouble. Yes, I know it will. But I don’t want to keep thinking about every little safety thing because then I am scared of the work and should just quit. Put the blades together and see if it works for you. If it works then great. You save 150 bucks or so. If it fails you may lose a lot more then that. Bungy jump at your own risk. When the band breaks that’s life, and part of the risk.

-- ~ Inspiring those who inspire me ~

Alistair, I own a Felder combo slider saw & shaper. I use Felder dado cutter heads for the saw arbor and the shaper. These are designed to be mounted either way. The saw motor and shaper motor have 10 second maximum stop electronic brakes. Their are a few euro machine owners who have purchased other standard USA made dado sets and have had them bored and punched for the alignment pins for their saws. You will see in the last photo that I made a zero clearance insert for the dado head. I make these up in batches and use them for different widths of dados. I use an overhead saw guard that has a spring loaded pressure head that puts pressure downward on the board. The sliding table has hold downs that secure the boards. I don’t know if this setup is allowed on your side of the pond, but they are quite popular here. I have two differnet sets of these dados that adjust, with shims, from 6mm to 20mm in width. I know that the more expensive Martin and other manufacturers have machines with the wider arbor and pins that allow one to use dados. It may be that they are a order special for the USA market. That, I will need to find out. I, for one, will continue to use this set up as it is very fast and safe.

John

-- Oldworld, Fair Oaks, Ca

i never knew that europe dosnt allow stacked dado sets. thats a crock of crap if you ask me… i dont know what i would do without my dado set. i certainly wouldnt be doing anymore casework thats for sure. so do they really enforce that thiere or is it something that they just prevent by altering the arbor size? well you europeans better start learning how to stack 7 1/4 circ saw blades if you wana make any dado cuts.

oh and for the record “RHET” or myself do not “jerry rigg” anything just because we have done something that might seem allitle dangerouse to others. based on the quality of work i have seen by “RHET” i would say that jerry rigging is the last thing he would ever do.

-- i can do all things through christ who strengthens me

Ladies and Gentleman. I am neither for or against stacking two identical blades together, but everyone is pointing out that this would be unsafe or jerry-rigging. I would think that the first stack dado blade was simply two blades stacked together to make a wider cut. Throw a shim in between and give it a try with a very shallow cut to see what it does.

-- Brian, Lebanon PA, If you aren’t having fun doing it, find something else to do.

the jerry rigging comment really got folks down!! Insecurity? Forget about it. I rebuttle. Nobody here is guilty for jerry rigging. Especially not me ;-)
BTW, I happened to post after RHET, that doesn’t mean that it was directed at him, or anyone else for that matter. It was a statement about the actual process, not the people involved. Take it how you will.
I’d also like to point out that jerry rigging the process doesn’t mean you are jerry rigging the project, just finding ways of getting it done that may or may not be adequate or safe. Time to get over the jerry rigging comment I think.

-- ~ Inspiring those who inspire me ~

—hmmm;
Just noticed this article//question and opinions, and so I went waundering through cyberspace to an-other site I some-times frequent….

....found this article from the Land of OZ and,
Woodwork Forums

Cheap Dado Sets in OZ!!!

....and then a picture using three blades; http://www.sentex.net/~mwandel/workshop/dado.jpg

Link to article: Cheap dado blade substitute

....so now some may be wondering, have I-do I-and would I recommend this and to that I can only say, some things are best left un-said as who knows what insurance company is lurking here and reading. So the out-come is that….”in the end I must decide my own woodworking fate.”

Thank you.
GODSPEED,
Frank

-- --frank, NH, http://frank.wordpress.com/

kolwdwrkr,
I did not mean to assault you or your post about this topic, I was just pointing out that most of what we do in woodworking today is because boundaries were stretched years ago.

-- Brian, Lebanon PA, If you aren’t having fun doing it, find something else to do.

Menards has a dado set for 27.00 it is a 6 inch set

-- There is no such thing as a mistake. Its called a design modification Rick Kruse, Grand Rapids, MI

Hello SCOTSMAN;
—very good point you make about how in the UK, saw//blade guards are not allowed to be removed.

I first heard of this some years ago at a woodworking show in upstate NY where the featured gentleman in this particular seminar was from England and doing a demonstration on table saw cuts. I’m sorry I do not remember his name at the moment….but he made the comment about how that the lose of fingers in England was down and almost unheard of, since all woodworking clubs and the government said no in the case of saw//blade guard removal.

And as I all-ways say:
”....work smart, work safe, and live, to work the wood....”

Thank you.
GODSPEED,
Frank

-- --frank, NH, http://frank.wordpress.com/

thank you “frank” for giving picture proof to the fact that it is something that people have done before.
“Do Two Table Saw Blades Make a Dado Blade?” there you go “OUTPUTTER” give it a shot untill you can get enough money to buy a stacked dado set.

i have one from freud. its a great set it comes with several chip breakers and metal shims that are within .001” tolerance that runs only about 99$ there are plenty other companies out there for allot cheaper but you might as well save for one that is of good quallity. the cheaper ones wont give you a much better quality cut then stacking your thin kerf blades. so good luck….. give it a shot with a shallow cut to begin with. such as “brianinpa” suggested.

DO KEEP IN MIND THO IT ISNT GOING TO BE A FLAT BOTTOM CUT. it will have litle V’s in each corner of the bottom side of the dado. im sure your already aware of that but just in case. GOOD LUCK

-- i can do all things through christ who strengthens me

Harbor freight has dado sets for $39 bucks. I don’t have one so I can’t state the quality.

-- What happens in the workshop stays in the workshop. No wait that doesn't sound right. Karson Southern Delaware karson_morrison@bigfoot.com †

Karson, it’s a stack that does a decent job for a decent price.

One thing we should all remember in using boards like this; great for information delivery, horrible for communication.

Good night.

-- Making scrap with zen-like precision - Woodbutchery

Betsy, I have watched Sam’s video many many times in awe and he even says not to do what he does and the I look at his missing finger tip in the video…

-- Never board, always knotty, lots of growth rings

I owned and used the Harbor Freight dado for a few years, and gave it away when I upgraded to a Freud. The HF cut quality wasn’t great, but respectible.

I’ve seen drawer sides made by using 8” dado blades to make the groove for the drawer bottom, then a wood disk for a spacer, then a 10” saw blade to cut off the drawer side at the right width … groove and rip in one pass.

-- http://www.north40custom.com -- http://north40studios.etsy.com --

You can do it

Ahhhh I see Frank beat me to it, but Mr Wandel is awesome and you should check out his whole site (he did the guesstimate thing I posted the other week on woodgears.ca)

-- I am always doing that which I can not do, in order that I may learn how to do it. - Pablo Picasso

OK – so I’m convinced. That’s what is great about this site. You start with one thought/opinion, listen to what others have to say, and decide if you are right or wrong. I think I was wrong on the main point of the question.

However, with that said, I still think——that you need to measure what you do with your tools with a large dooloop of safety in mind. If it does not feel right to you don’t do it. If it’s something out of the ordinary – think it through before you do it and be prepared for any consequences.

-- You can't get a hug from Facebook.

I’m still recovering from a broken leg a year ago, fusion of two neck vertabrae about six months ago, and shoulder surgery last month. I think I’ll play it safe and wait until I can afford a good dado set. Thanks for all the useful advice everyone.

-- Jim

Thanks for asking the question! The only stupid question is the one you failed to ask before proceding with the unknown. It’s good to see you got a lot of response, as they are all concerned about your well-being. You may be able to find the tools you want on sale or at discount websites.

-- "They who dream by day are cognizant of many things which escape those who dream only by night." ~ Edgar Allan Poe

I’m sure I’ll eventually be able to get the dado set. I saw one on Craig’s list today for fifty dollars. Unfortunately, with the economic climate like it is, Christmas approaching, and the first grandkid due in June, the dado set is a little far down the priority list.

I’m glad for all the opinions too.
Yes – 10
No – 15
It looks like the yesses are making a come back but I would still rather err on the side of safety (or at least on the side of being able to suit LOL).

-- Jim

I find it intriguing that everyone complains about TV personalities or “how to” shows and what not for not using guards on the saws, riving knifes, and what ever other various safety equipment is not used. Then offer up something doing the same thing as what is complained about. So, what’s it going to be? Safety or no safety? Sheesh.

-- ~ Inspiring those who inspire me ~