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Crosscutting Dadoes

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Forum topic by wookie posted 11-22-2013 06:25 PM 983 views 0 times favorited 15 replies Add to Favorites Watch
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wookie

154 posts in 2548 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?

Thanks,
Jack

-- Wookie=Wood Rookie


15 replies so far

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Loren

8304 posts in 3112 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
blade.

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sdmref

15 posts in 2671 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.

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bigblockyeti

3668 posts in 1185 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.

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jmartel

6572 posts in 1614 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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a1Jim

115202 posts in 3041 days


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

I second the router and straight edge ,much easier.

-- http://artisticwoodstudio.com Custom furniture

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pintodeluxe

4856 posts in 2277 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

TheDane

4997 posts in 3127 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!"

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RockyTopScott

1184 posts in 2943 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

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bondogaposis

4030 posts in 1815 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

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MT_Stringer

2853 posts in 2695 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.
Mike

-- Handcrafted by Mike Henderson - Channelview, Texas

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DangerDoug

62 posts in 1111 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.

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ajosephg

1878 posts in 3025 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

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waho6o9

7174 posts in 2041 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

sixstring

296 posts in 1707 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

wookie

154 posts in 2548 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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