Shelf Dados on Table Saw Method?

[Noah Starksen]

Working on cabinets for the first time and going to have permanent shelves attached with dados. Cabinets are 30” tall and 13” deep. Trying to figure out how to cut the dados into the sides.

While I do have a router, I prefer the table saw. Mostly because it’s the tool I’m familiar with (have basically only used the router a few times) and because I already have a dado blade, but don’t have the bit for the router. Would prefer not to have to but it for this.

If I were to do this on the table saw, what would be the method? I’m assuming running it along the rip fence won’t work well because the workpiece is twice as long as it is wide. Miter gauge seems like an option, but doesn’t create much of a reference surface for the large piece. I have a crosscut sled, but the width of the dado would each into my fence, so don’t really want to do that.

Are there other table saw options? Or is table saw just not the best idea for this?

[Thomas McCurnin]

Not the ideal tool for shelf dados. The piece would move too much and would either be sloppy or present a danger, or both. Also stopped dados would present a special problem.

I'd use a router with a guide clamped to the sides. Remember to size the router bit to the plywood or take two passes.

[Fred Falgiano]

I’m not seeing the issue with using the rip fence.

I’ve cut dados this way many many times in both hardwood and sheet goods (for cabinet shelves like what you propose) with no issues. I do have a pretty wide saw, so maybe that’s the issue you’re up against.

[Noah Starksen]

I’m not seeing the issue with using the rip fence.

I’ve cut dados this way many many times in both hardwood and sheet goods (for cabinet shelves like what you propose) with no issues. I do have a pretty wide saw, so maybe that’s the issue you’re up against.

I have a shopsmith, which means I can basically make it as wide as I want. So that’s not the issue. Im more meaning the general rule of thumb to not use the rip fence for a piece that is wider that it is long. Seems challenging to keep the piece against the fence when it’s this wide. But I’m also not standing at the saw trying it to see. Maybe I’m wrong?

[Edwin Santos]

I think the dimensions of your project are very manageable on a table saw. I suggest making a crosscut sled exclusively for dadoes. You may be surprised how often you end up using it. On mine, I used some jig hardware to attach a secondary replaceable fence that can slide and microadjust. If your dadoes are equally spaced, you can cut and insert an indexing key in the secondary fence just like the principle behind the typical box joint jig. Even if not equally spaced, the key will function as a stop block registering to the adjacent dado and help you with consistent accuracy so long as you work methodically and take care with the orientation of your parts.

I realize many prefer cutting dadoes and grooves with a router, but it is my habit to use the table saw and sled, unless the workpiece is very big.
Either method will work. One is not "better" than the other.
Good luck with your project,

Edwin

BTW,
Your instincts are correct, DO NOT cut a 30"x13" workpiece at the table saw with the 13" side against the rip fence.

[Bill Kugler]

If you haven't already cut your plywood pieces, you could always leave 2 sides together (26"x30"), which would be a much easier piece to push against the rip fence. I've done something similar before in a pinch, instead of making a new crosscut jig. Heck, if you've got enough, leave it 30x30 and rip the 4" off after. Or if the math of that still leaves you uncomfortable because of 'the rules', leave the pieces 31x30. Now it's technically a rip cut! ;-)

[Carroll Courtney]

Maybe make yourself a sled for your dado's,which would help with keeping it square with the blade if your sides are little hard to manager by yourself. But like Bill is saying instead of ripping the plywood first into the sides of your shelves cut your dado's with a straight edge that you make for that router with that plywood bit that is for the correct size. Which will depend on the plywood that you are using which can be pain to fit if your bit is not the same size.

[Art Mann]

I think it is time you took this opportunity to learn more about how to use your router. It is the tool for the job. There are all sorts of router dado jig plans out there to help you get it right the first time.

[Jim Becker]

I’m not seeing the issue with using the rip fence.

I’ve cut dados this way many many times in both hardwood and sheet goods (for cabinet shelves like what you propose) with no issues. I do have a pretty wide saw, so maybe that’s the issue you’re up against.

The issue using the fence is safety...these dados are across the narrow dimension so only the narrow dimension would be against the fence, in this case (pardon the pun), 13". One of the only ways to do this work safely on the table saw is with a sled that engages both miter slots and is big enough to fully support the workpiece. I personally do this kind of work with a router and a guide, using tooling that's narrower than the final width of the groove so that it can be "exactly" the thickness of the material that will be seated in the dado. Sheet goods are never the same thickness as their nominal size.

[Jim Dwight]

You are right to question guiding a 13 inch wide by 30 inch long piece by the rip fence. If you do it, cut from both ends so you are less than 15 inches from the blade. But you will risk kickback if the piece gets a little cocked. I would use a router or do two sides at once. Straight router bits are cheap, I like MLCS Woodworkimg for this sort of bit.

[Robert Engel]

Yes, safest done with a router.

A panel cutting sled can be used. (This is a sled that rides in one miter slot to the left of the blade, and has one fence on the far side). Hold down clamps a must. Support under offcut side of blade may be necessary.

I do shelf dados prior to ripping the sides to width, depending on dimensions, it often gives enough width to safely run with a fence. Plus it keeps dados perfectly aligned.

You can also switch a miter gauge from left to right slot as needed. Again, clamp to fence.

[Von Bickley]

I have started making my dado's with a router. I recently made an "Exact Width Dado Jig" that works very good. There is a lot of You-Tube videos on an exact width dado jig.

dado1.jpg

[Thomas McCurnin]

Building a deadly accurate crosscut sled would also be a good first project. You'll actually need two--one for crosscuts and one for dados or build one with a replaceable zero clearance slot. There are many YouTube videos on the subject. William Ng seems to have mastered the job with his accurate crosscut sled using a simple algebraic formula and some automotive feeler gauges.

[Dan Cameron]

This can be a safe and easy job if you have a miter gauge and like most gauges it has a pair of thru holes to mount a long extension. (eg a 3' 2x4). For each shelf position screw a stop block on this extension to establish the left/right position.

[Jamie Buxton]

OP, you don't say what material the cabinet wall is made from. If it is plywood, and the face grain runs across the dado, you're likely to get chip-out on the edges of a dado cut with a dado head. A router will not give you that issue.