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Do Two Table Saw Blades Make a Dado Blade?

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Forum topic by OutPutter posted 2092 days ago 20963 views 0 times favorited 65 replies Add to Favorites Watch
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OutPutter

1194 posts in 2574 days


2092 days ago

Topic tags/keywords: dado blades question tablesaw

I can’t afford a Dado set right now and I’m wondering if I can take two regular blades and put them on my table saw at the same time and get a “thin” dado blade or is that unsafe, impossible, stupid, etc.

Thanks,

Edited 2/19/2011:
This subject keeps coming around every several months as other people look for dado or some such info on the site. I think it serves as a good reference to examine the pros and cons of the question but please keep in mind two things. I never did try it and I no longer need a dado set. Enjoy the debate and feel free to contribute your comments nonetheless.

Best,

-- Jim


65 replies so far

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Blake

3434 posts in 2458 days


#1 posted 2092 days ago

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.

-- Happy woodworking! http://www.openarmsphotography.com

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CaptainSkully

1190 posts in 2142 days


#2 posted 2092 days ago

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

View Blake's profile

Blake

3434 posts in 2458 days


#3 posted 2092 days ago

I would recommend not trying this at all.

-- Happy woodworking! http://www.openarmsphotography.com

View kolwdwrkr's profile

kolwdwrkr

2821 posts in 2174 days


#4 posted 2092 days ago

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 ~

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rhett

696 posts in 2251 days


#5 posted 2092 days ago

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://planeandsimpleblog.wordpress.com/

View kolwdwrkr's profile

kolwdwrkr

2821 posts in 2174 days


#6 posted 2092 days ago

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 ~

View gusthehonky's profile

gusthehonky

130 posts in 2326 days


#7 posted 2092 days ago

.

-- Ciao, gth.

View jim1953's profile

jim1953

2656 posts in 2425 days


#8 posted 2092 days ago

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

View Betsy's profile

Betsy

2913 posts in 2479 days


#9 posted 2092 days ago

NO

-- Like a bad penny, I keep coming back!

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Betsy

2913 posts in 2479 days


#10 posted 2092 days ago

NO

-- Like a bad penny, I keep coming back!

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Betsy

2913 posts in 2479 days


#11 posted 2092 days ago

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.

-- Like a bad penny, I keep coming back!

View jim1953's profile

jim1953

2656 posts in 2425 days


#12 posted 2092 days ago

Use a router

-- Jim, Kentucky

View Steve2's profile

Steve2

75 posts in 2154 days


#13 posted 2091 days ago

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

View John Ormsby's profile

John Ormsby

1276 posts in 2320 days


#14 posted 2091 days ago

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

View OutPutter's profile

OutPutter

1194 posts in 2574 days


#15 posted 2091 days ago

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

showing 1 through 15 of 65 replies

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