A quick question about dado bottoms

[Tyler Bancroft]

I'm far from perfect at cutting dadoes by hand, and I find that I often have uneven dado bottoms (e.g., the occasional divot/deep spot). My understanding is that the most important surfaces for joinery are the edges of the dado, not the bottom - as long as I am getting a good fit on the edges, how important is a perfectly flat/smooth dado bottom?

[Derek Cohen]

Hi Tyler

Perfectly smooth is unnecessary Even perfectly flat is not important. But perfectly coplanar is vital and at the appropriate height to fit the piece.

Having stated this, it is really a straight forward process with a saw, chisel, and router plane, or a dado plane.

http://www.inthewoodshop.com/Furniture/HarlequinsidetableFine%20dados_html_m2dcf87fa.jpg

http://www.inthewoodshop.com/Furniture/HarlequinsidetableFine%20dados_html_59bf1430.jpg

Regards from Perth

Derek

[Andrew Pitonyak]

Perfectly smooth is unnecessary Even perfectly flat is not important. But perfectly coplanar is vital and at the appropriate height to fit the piece.


That is the biggest problem for me since I do not yet own the correct plane. It is on my list of things that I want to own. :-)

[Tyler Bancroft]

Hi Tyler

Perfectly smooth is unnecessary Even perfectly flat is not important. But perfectly coplanar is vital and at the appropriate height to fit the piece.

Having stated this, it is really a straight forward process with a saw, chisel, and router plane, or a dado plane.

Coplanar with the faces of the boards in which the dadoes are cut, I assume?

My difficulties are primarily in stopped dadoes, as I have been chiseling the walls rather than sawing - I have difficulty sawing those adequately. On my next project, I plan to chisel out a small area at the end of the dado to let the saw travel freely to cut the rest. (Making a dado plane is also on my lengthy to-do list.)
Thanks,
Tyler

[Jim Koepke]

Coplanar with the faces of the boards in which the dadoes are cut, I assume?

My difficulties are primarily in stopped dadoes, as I have been chiseling the walls rather than sawing - I have difficulty sawing those adequately. On my next project, I plan to chisel out a small area at the end of the dado to let the saw travel freely to cut the rest. (Making a dado plane is also on my lengthy to-do list.)
Thanks,
Tyler

All the high spots on the floor of the dado need to be on the same plane. Some tear out below that surface will not matter.

Depending on where you live it might be easy to find a used dado plane at a reasonable price.

One of my recent finds was a Stanley #39 - 3/4":

https://sawmillcreek.org/showthread.php?278928

This was a experiment to make a stopped dado.

It is fairly easy to make a dado with a saw and chisel:

https://sawmillcreek.org/showthread.php?208154

Before sawing a space is cut with a chisel at the stopped end of the dado for the sawdust to collect.

jtk

[Warren Mickley]

Coplanar is not used correctly. Something needs to be coplanar with something else. Like you can't be a co-conspirator without a partner. And the bottom of a dado is not coplanar with the surface of the face of the board; they are in different planes. Perhaps he meant flat.

Whether one is making a dado with a chisel, saw, or dado plane, the bottom is not particularly smooth, nor does it need to be. We usually use dadoes in conjunction with other joinery (like dovetails), so that they are not the only thing holding the piece together.

[steven c newman]

426824
Might have a loaner...

[Frank Pratt]

A router plane is a wonderful tool & one that is below the radar of many woodworkers. I inherited one from my Dad & putting it to use has been a real eye opener. With dados cut on a table saw, I always run the router plane down them to make sure the depth is consistent because you never know when the board has lifted off the table a tiny bit. They are also great for fine tuning a tenon cheek because it will ensure that it stays parallel with the face of the board.

[Rick Herrick]

Hi Tyler

Perfectly smooth is unnecessary Even perfectly flat is not important. But perfectly coplanar is vital and at the appropriate height to fit the piece.

Having stated this, it is really a straight forward process with a saw, chisel, and router plane, or a dado plane.



Regards from Perth

Derek

I never knew a plane like that existed. Thats absolutely gorgeous. I will keep that on my list of things I would like to have but it looks like yours is very high quality and finding one like that may be hard and/or very expensive.

[Charles Guest]

If you're not using a stopped dado, make sure you don't blow out the bottom at the front of the cabinet. It'll show unless a moulding will cover the edge. Sometimes the grain cuts better with the tool exiting at the front, but it's pretty much standard procedure to cut from the edge inward toward the middle of the dado if the grain will allow it. At any rate, as you're sinking the dado you'll get plenty of feedback on how the grain is running before you make your last few passes on the floor of the joint.

[david charlesworth]

You can make a wooden Old Womans Tooth plane with a block of wood , wedge and chisel.

Even simpler is a bit of hardwood with a nail knocked through, this will check depth.

Best wishes,
David

[Derek Cohen]

As David mentions, you can make your own.

There are plans and a pictorial on my website: http://www.inthewoodshop.com/ShopMadeTools/BuildingaWoodenRouterPlane.html

https://i.postimg.cc/prNBGV0z/4ffd41ef-7a8d-4d58-a009-4a323afa35fa-zpsr5uu7jjk.jpg

I made a lot if these at one time.

https://i.postimg.cc/65zpgHch/8-ACDCA0-A-E16-A-4706-99-EF-4340-C6-D40943.png

Regards from Perth

Derek

[Frank Pratt]

I seem to recall a Paul Sellars video where he shows how to make some very simple but effective router planes.

[steven c newman]

Like these?
427024
Had to slim things down a bit...
427025
So the bread boards could fit..
427026
Panel is for a lid, and is only 5/16" thick....if that much.

[Rush Paul]

As David mentions, you can make your own.

There are plans and a pictorial on my website: http://www.inthewoodshop.com/ShopMadeTools/BuildingaWoodenRouterPlane.html


I recently made one of these router planes from Derek's instructions and it works very nicely. Thank you, Derek!

[Tyler Bancroft]

I do have a router plane, but was still having the square blade catch "bundles" of fibers and tear them out of the bottom, even with a shallow cut. I switched to a spear-point blade with much better results. Out of curiosity, when is a square blade superior to a spear-point blade?

[Derek Cohen]

Tyler, I rarely use the spear point blade. They are tricky to sharpen, and when too sharp will catch fibres.

On the other hand, the straight blades do it all. You need to get them Sharp. To do this use the method I developed. It really works so well, and is so easy.

http://www.inthewoodshop.com/WoodworkTechniques/SharpeningRouterPlaneBlades.html

Vic Tesolin made a video of it for FWW magazine ...


https://www.youtube.com/watch?v=cuNu-GlgH88

Regards from Perth

Derek

[Warren Mickley]

I use a router plane to rout recesses and to smooth the bottoms of recesses. For this work we plane with the grain and not cross grain like you are doing, Tyler. I think the square blade is better for this work.

I used a dado plane for more than a decade before I ever got a router plane. I think a moving fillister, a plough and a dado plane are much more valuable for cabinetmaking than a router.

[Derek Cohen]

I’m a little confused by your reference to planing with the grain, Warren. A dado is across the grain. Am I missing something here?

Dado planes are good, but to use for stopped dados, as Tyler noted, they become extra work since this requires the toe first be excavated before planing. They are best for through dados. Stopped dados are easier to do with a chisel, saw and router plane.

Regards from Perth

Derek

[Warren Mickley]

In routing we make a flat surface below the surface of the board. We use this for carving or some inlay etc. Or the bottom of a small box that is cut out of the solid. For this kind of work we usually go with the grain and use the straight cutter.

We rarely use stopped dadoes or stopped grooves, but in this case I would probably chisel the bottom of the dado. It probably works better with a flat bevel.

[Derek Cohen]

Okay, this has been a crossed discussion: Tyler was asking about the use of a router plane for a dado, not inlay, grooves or excavations. In regard to the latter, I find it easier to first work across the grain before smoothing with the grain. The V-cutter is intended (as I understand) for smoothing, but I rarely use one, preferring to use a straight all the time. Excavating dados (across the grain) with a chisel works for me as well, but I always finish with a router plane.

Regards from Perth

Derek

[steven c newman]

Have worked across the grain with:
a chisel that fits in the dado
a dado plane like a Stanley No. 39...
Have done dados with the Stanley No. 45....leaves a smooth bottom at the correct depth

And lately? Mitre box to saw the walls of the dado, chisel to pop out 95% of the waste, then the new to me Stanley No. 71-1/2 Router plane to level the dado's floor...could not care less IF said floor was smooth as glass....just has to be level across. Since the mitre saw cut to the exact depth needed ( depth stops are a nice touch..) the straight edge of the cutter just peels away to the kerfs...shavings? More like miniature pine needles....but the glue and the part couldn't care less how slick the surface is.....

Dead Horse.......bury the bones...

[Mike Allen1010]

I’m hard-core hard-core hand tool guy. No Table saw in my shop - xall stock dimensioning gets done with hand saws and planes. Not saying that’s best or criticized other methods.

However when it comes to cross grain, stoped dados I use an electric router.

[Joe A Faulkner]

You can find used Stanley 71 Router Planes for < $100. Lee Valley sells blades that fit them.