Best way to make a big dado? (With limited tools available)

[Matthew Wright]

Part of my workbench project requires 8 cuts like the one pictured in the attachment. Sorry if "dado" isn't the right word.

What's the best way to do this with no dado blade? I have to make at least seven more. This one came out a little too wide (meaning there will be a little gap because it's slightly wider than 3.5"). My choices are table saw, Hand saw, coping saw, chisels, or, a tiny old 1HP router I've never really used. I suppose I could also try my cordless drill with a big bit.

On the table saw, I can control the depth but I have trouble being precise with the width. It's hard to line up a non-through cut and the rails are unwieldy on the table top.

With hand saws, I can be precise with the width (assuming it was measured/drawn correctly) and I can do a decent job of hitting the depth mark twice (one for each side), but not necessarily with all the relief cuts. More importantly, it is tough to hog out that much waste. I tried with the coping saw but had to do it in a couple of slow passes because I couldn't initially get the blade down to the bottom of the cut. And surely it's not supposed to take that long. In the picture, I tried it several ways until I finally reached the right depth making multiple relief cuts with the table saw. But it was a little too wide.

Basically, the side rails of the bench are made by laminating three (nominal) 1x4's about 80" long. On the two "inside" boards I'm trying to cut a dado so that the top rails (2x4) will sit flush with the top of the top rails. The benchtop will be a solid core door (currently visible under the operation).

Sorry if my description is bad.

[Ken Fitzgerald]

Mathew,

1. You could use your handsaw to cut the ends of the mortises and then use your table saw to hog out the middle between the two cuts.

2. I have a backer board on my miter gauge for my table saw. I would make a couple marks on the backer board....one for the left edge of the blade cut...one for the right edge of the blade cut.....use those lines for lining up the side cuts on the mortises.

3. Use a hand saw to make the end cuts on the mortise and sharp chisels to chisel out the middle.

4. Use a handsaw for the end cuts....a circular saw to make period cuts and then chisel out the remainder.

[Stephen Edwards]

If I'm understanding you correctly and if all the cuts are going to look like the one in your photo, here's how I've done that many times without a dado blade on the saw:

1. Mark all of your boards where the cuts will be. Mark them as you did on the board in the photo with the marks transferred to the face of the boards.

2. Set the the TS blade to the correct height, which would be the bottom of your cuts.

3. Using your miter gauge make a cut on each outside edge of the cutout portion. Then, multiple passes until you've cut out all of the waste in between.

4. Clean up the bottoms with a chisel.

Really, it doesn't take as long as you might think. As long as your boards' edges are straight, you'll have the same depth of cut all the way across the cut.

[Don Jarvie]

Your best bet is the router. Clamp the boards together and mark out the area to be cut. Clamp a guide board on one side and make a few passes to clean out the area.

[Matthew Wright]

Thanks, Stephen, Ken, and Don.

Stephen:

That was my thought initially. But, standing at the table saw, it is hard to eyeball the proper alignment with the blade. In other words, it is hard for me to hit my line. It's easier (to me) on a through cut because I can see the mark on the top and line it up with the top of the blade before I start it.

Here, I marked the part where I would actually cut, but I did not mark the bottom of the boards (which appears to be the top as I'm cutting).

I suppose those little measuring tapes on the table saw's rails are supposed to signify the location of the blade... perhaps some adjustment is in order...

[Jim O'Dell]

Perfect opportunity, (read as need) to get a new tool. In this case, a dado blade!!!:D
I usually do mine on the table saw if I just have one to do, and I'm too lazy to install the dado blade. I set the depth, then use the blade to mark the outside of the first cut, then go across the cut area, and sneak up on the other end's cut. I mess up every once in a while on the width, but usually pretty close. if you feel more comfortable using a hand saw to mark the outside edges, then I'd use Ken's first method. Jim.

[Jason Hanko]

Before I had a dado set I used my router for things like this. 1HP should be fine, just use any old straight bit and take small cuts (<1/4'') at a time (this is a good practice even with higher HP routers).
If you do decide to use the router, make yourself one of THESE (http://www.woodsmithshop.com/download/204/adjustabledadojig.pdf).
To be honest though, I built that fancy adjustable jig and 95% of the time I only use one half of it - basically a circular saw guide (http://www.kudzupatch.com/woodshop/saw_guide/) for your router.
Another nice thing about using the router: you could line up all your boards, clamp them together, and cut them all at the same time! (Im assuming all your dados need to be the same size).

[Stephen Edwards]

Thanks, Stephen, Ken, and Don.

Stephen:

That was my thought initially. But, standing at the table saw, it is hard to eyeball the proper alignment with the blade. In other words, it is hard for me to hit my line. It's easier (to me) on a through cut because I can see the mark on the top and line it up with the top of the blade before I start it.

Here, I marked the part where I would actually cut, but I did not mark the bottom of the boards (which appears to be the top as I'm cutting).

I suppose those little measuring tapes on the table saw's rails are supposed to signify the location of the blade... perhaps some adjustment is in order...

I lean over the work piece so that I can see the marks in relation to the blade. I cut the two outside cuts first, less chance of making the cut too big. Cut to the inside of the line, then make a second pass to sneak up on the line, as Jim put it.

I never trust the tapes on the saw's rails. I always work to my marked lines. Different strokes for different folks. That's how I do it.

Good luck with your project!

[Dino Makropoulos]

Part of my workbench project requires 8 cuts like the one pictured in the attachment. Sorry if "dado" isn't the right word.

What's the best way to do this with no dado blade? I have to make at least seven more. This one came out a little too wide (meaning there will be a little gap because it's slightly wider than 3.5"). My choices are table saw, Hand saw, coping saw, chisels, or, a tiny old 1HP router I've never really used. I suppose I could also try my cordless drill with a big bit.

On the table saw, I can control the depth but I have trouble being precise with the width. It's hard to line up a non-through cut and the rails are unwieldy on the table top.

With hand saws, I can be precise with the width (assuming it was measured/drawn correctly) and I can do a decent job of hitting the depth mark twice (one for each side), but not necessarily with all the relief cuts. More importantly, it is tough to hog out that much waste. I tried with the coping saw but had to do it in a couple of slow passes because I couldn't initially get the blade down to the bottom of the cut. And surely it's not supposed to take that long. In the picture, I tried it several ways until I finally reached the right depth making multiple relief cuts with the table saw. But it was a little too wide.

Basically, the side rails of the bench are made by laminating three (nominal) 1x4's about 80" long. On the two "inside" boards I'm trying to cut a dado so that the top rails (2x4) will sit flush with the top of the top rails. The benchtop will be a solid core door (currently visible under the operation).

Sorry if my description is bad.

One of many ways.
Use your circular saw and a straight edge.
Follow with a rooter and a straight edge.
My simple way that can be done with any straight edge:

Gang-scoring-cutting and routing is very easy-safe and accurate.
Instead of dealing with one piece at a time, you're dealing
with one secured panel.

good luck.
dino
eurekazone

[Myk Rian]

In other words, it is hard for me to hit my line. It's easier (to me) on a through cut because I can see the mark on the top and line it up with the top of the blade before I start it.
Put a mark on the saw top in line with the blade. Or a piece of tape.

[Chris Parks]

Put the end cuts in and gang cut with a circular saw as many times as you want, then clean up with a chisel as Dino said.

[glenn bradley]

As stated, I do the outer cuts a bit shy and then several cuts in between with a circ-saw, then chisel the waste out and pare the outer "shoulders to fit. However, you didn't mention a circ-saw as a tool you had. For this, I would try to beg or borrow one for 30 minutes.

[Matt Day]

If you have 7 more of these cut outs to make in the same 80" board, the table saw is probably best. Though, an 80" board will be hard to handle on the table saw on the ends so make sure to support it properly.

Also, remember that if you use the table saw, your blade probably doesn't have a flat bottom to the curf so you'll need to clean it up with a chisel as others have said if you want the bottom to be flat.

Be careful of tear out with whichever method you go with - especially the router. Try using a backer board to reduce/eliminate it.

I do the same as other have said, about creeping up on the line with the table saw. Don't go for it on the first cut but rather cut inboard of it, then move the board ever so slightly until you hit your line. You should be able to get it perfect with the table saw. I also agree with putting marks on your miter gauge that reflect each side of the cut.

Good luck!

[Greg Hines, MD]

I would use a router and make a template to make them all the same dimensions. Then you can guarantee that each one is the same. You can also use it on the edge of the board to make the corners square, otherwise you have to square up the corners afterwards.

Doc

[Chris Parks]

Without trying to offend anyone, you could handsaw and chop the trench with a chisel in the time it would take to use a table saw or router. The craft does become more rewarding if machines are not relied on totally. You will be surprised at the amount of satisfaction you get from some handwork and that is coming from someone who reckons digital readouts are the greatest thing since sliced bread.

[Caspar Hauser]

Without trying to offend anyone, you could handsaw and chop the trench with a chisel in the time it would take to use a table saw or router

I second that.

[John A Walker]

I think so too.

But if you have to use a machine, do it with a router. That's what a router is good at; hogging out. Plus, it's safer and quicker than a hand-held, power saw.

JW :p

[John A Walker]

I just had another look at the job you want to do.
If you could clamp all the pieces together, you could do all seven housings/dadoes in one go, with the router.

Just make the side limiting cuts first, then hog out the waste, in about three plunges.

1HP is ample!

JW ;)

[Matthew Wright]

Thanks for all the replies, everyone.

The winning tip, at least for the four dadoes/mortises on the interior of the boards was to tape a business card on the table to show where the blade line. I made several relief cuts and so it was easy to use coping saw and chisel to cut out the tiny pieces that were left. Hopefully one of those will be the right width to fill up the gap in my first, two-wide cut. :D

Now, the ones on the ends make the rail too unwieldy to use with a miter gauge. It hangs off too far and I don't have anything appropriate to support it.

I'm probably going to try them with the router.

Something I didn't make very clear, I think, is that there are only two rails which need to have 4 holes in each. So I can cut them two at a time with the router (going to try) but that's all.

Also - - on the hand-tool route - - that's how I wanted to do them. And I tried. But I don't have the skills to be precise enough. At least not yet.