Crosscutting Dadoes

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Forum topic by wookie posted 11-22-2013 06:25 PM 964 views 0 times favorited 15 replies Add to Favorites Watch
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154 posts in 2502 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


8158 posts in 3066 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 2625 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


3569 posts in 1139 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.

View jmartel's profile


6464 posts in 1568 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.

View a1Jim's profile


115171 posts in 2995 days

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

I second the router and straight edge ,much easier.

-- Custom furniture

View pintodeluxe's profile


4824 posts in 2231 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 (online now)


4930 posts in 3081 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


1184 posts in 2896 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


3969 posts in 1769 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


2818 posts in 2649 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


62 posts in 1065 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


1878 posts in 2979 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


7115 posts in 1995 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 1661 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 2502 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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