Crosscutting Dadoes

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Forum topic by wookie posted 11-22-2013 06:25 PM 1339 views 0 times favorited 15 replies Add to Favorites Watch
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154 posts in 3498 days

11-22-2013 06:25 PM

Topic tags/keywords: crosscuting dadoes table saw question

Hi Everyone,

I have to crosscut some dadoes in some plywood boards that are 15 7/8” wide by 8’ long on the table saw. I would like to use the fence and push them through with the mitre that also has s fence on it . I am going to square the mitre to the fence. Two guys will be guiding the pieces through. Will this work for accuracy and safety wise? Don’t want to get anything in a bind. Sound good or not?


-- Wookie=Wood Rookie

15 replies so far

View Loren's profile


10477 posts in 4062 days

#1 posted 11-22-2013 06:27 PM

You can do it that way but I prefer to use the fence as a stop
by attaching a board to it that stops shy of the front of the

View sdmref's profile


15 posts in 3621 days

#2 posted 11-22-2013 06:37 PM

Loren is on the money for the proper way to do it on the table saw, but DO NOT use the fence and miter guage together w/o a block to bump it out from the fence, you are asking for kickback if you don’t use one. You can also use a router and clamp a straight edge across the board which would be much safer.

View bigblockyeti's profile


5776 posts in 2135 days

#3 posted 11-22-2013 06:38 PM

8’ is pretty wide to be going across the tablesaw, would be safer to do that on a radial arm saw. If it must be done on the tablesaw, screw an auxiliary fence to the face of the miter gauge, the wider the better. If you have a miter gauge with screws to adjust how tight it fits in the miter slot, make sure it’s as tight as can be and still slide safely. Any minor slop in the fit will be greatly amplified at the end of the board. Might not be a bad idea to clamp the board the auxiliary fence on the miter gauge to further prevent movement.

-- "Lack of effort will result in failure with amazing predictability" - Me

View jmartel's profile


8481 posts in 2565 days

#4 posted 11-22-2013 06:40 PM

Straight edge and a router is going to be better.

-- The quality of one's woodworking is directly related to the amount of flannel worn.

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117651 posts in 3992 days

#5 posted 11-22-2013 06:44 PM

I second the router and straight edge ,much easier.

View pintodeluxe's profile


5949 posts in 3228 days

#6 posted 11-22-2013 06:54 PM

For bookshelf dados, and projects where the workpiece is long, I use an Emmerson clamping straightedge and a plunge router. I also use a shop made dado guide for custom width dados.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View TheDane's profile


5652 posts in 4078 days

#7 posted 11-22-2013 06:59 PM

I would not consider using my tablesaw for this cut … what happens if one of the two guys supporting the board gets a little ahead or behind? BANG … kickback.

If you don’t have a RAS, then a router and shop-made jig will get the job done quickly and safely.

-- Gerry -- "I don't plan to ever really grow up ... I'm just going to learn how to act in public!"

View RockyTopScott's profile


1186 posts in 3893 days

#8 posted 11-22-2013 07:07 PM

If there is a mating side (2 pieces) it might have been better to cut the dados then rip the plywood to 15 7/8.

-- “When you want to help people, you tell them the truth. When you want to help yourself, you tell them what they want to hear.” ― Thomas Sowell

View bondogaposis's profile


5451 posts in 2766 days

#9 posted 11-22-2013 07:22 PM

Don’t get me wrong I cut a lot of dadoes on the table saw, but in my shop I would never attempt that cut. Eight foot is too long to handle. I would much prefer to do this w/ router. RockyTopScott has the right idea too, route the dadoes then cut in half for two mating sides.

-- Bondo Gaposis

View MT_Stringer's profile


3183 posts in 3646 days

#10 posted 11-22-2013 08:37 PM

Make an exact width dado jig like this one and get on down the road…safely. :-)

Hope this helps.

-- Handcrafted by Mike Henderson - Channelview, Texas

View DangerDoug's profile


83 posts in 2061 days

#11 posted 11-22-2013 08:45 PM

Radial arm saw – about the only thing they are good for.
OR router, just need to correct order bit.

View ajosephg's profile


1880 posts in 3976 days

#12 posted 11-23-2013 12:15 AM

No way can an 8 foot board be cut accurately as described. Router with jig is the way to go.

-- Joe

View waho6o9's profile


8669 posts in 2991 days

#13 posted 11-23-2013 12:23 AM

Router with jig and make your cuts on the 4×8 sheet

and then rip to size, done.

View sixstring's profile


296 posts in 2658 days

#14 posted 11-23-2013 12:41 AM

if you have an extension wing that’s wide enough to support most of the piece, build a crosscut sled deep enough to accept it. i just did this recently for a 6’ long piece of 3/4 ply. in this way, i was able to safely crosscut the piece without any help. i suppose going back and forth to cut a dado makes this even more dangerous.

but yes, the router and straight edge has to be considerably safer so why take chances.

-- JC Garcia, Concord, CA : "It's easier to ask forgiveness than permission..."

View wookie's profile


154 posts in 3498 days

#15 posted 11-23-2013 06:34 AM

Thanks, guys. This why I put up this post. I was out voted on cutting the dados first then ripping to width.

-- Wookie=Wood Rookie

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