Tear out free dado in cherry?

[David Ragan]

Hi,

Have recently had some tear out using a cheesy bradpoint bit on some cherry for the hope chest. (Greene and Greene-combo of Darrell Peart and Mark Spagnuolo's designs.)

So, I thought before cutting the stopped dado/groove around the inside (for the cherry ply bottom), I would ask you all what is the safest way to do it? For no tear out.

3/4" wide, maybe 3/8" deep.

chest is about 18 by 28"

Have DeWalt Dado stack, and lots of cool Neander tools, but aint excited about Neander way of doing it.

Nor, do I want to buy a compression bit.

I have some Whiteside straight double fluted bits.

Thoughts?

[scott vroom]

Not familiar with the DeWalt dado stack. If the 2 outside cutters are SHARP carbide teeth then you should be OK with multiple passes, taking out just a little bit at a time. Test it out on a piece of scrap and you'll have your answer.

In the past when I've been concerned with dado tear out I've pre-cut the inside and outside edges of the dado with a sharp TS blade, and then cleaned up the middle with the dado stack. A PITA setup, but effective.

[Warren Lake]

solid or veneer? veneer more likely to chip they have negative rake dadoe blades think the set i have are Dimar they work well no blow out cross grain.

[Brian Holcombe]

Mark with a knife first.

[Martin Wasner]

Do a climb cut to more or less score it with the dado head in the table saw. If you're not familiar with the maneuver, then you probably shouldn't do it though.

[David Ragan]

I was relieved to figure out that it will be a groove, not a dado.

[glenn bradley]

I was relieved to figure out that it will be a groove, not a dado.

But it is still "stopped", right? The router is the tool of choice for me for stopped dados. Any sharp straight bit gives me good results in cherry; not so in all materials but cherry is pretty machinable. Certainly scoring the outside lines with a knife will help if your cutters are giving you poor results. Downcut spirals will also give a cleaner result than an upcut but, 2 flute straight bits work fine for me. Take multiple passes for a cut that large. given the rule of thumb of a maximum material removal per pass of 3/8" square, a 3/16" deep by 3/4" pass would be your max. In tearout prone woods I take a first pass of 1/32" to 1/16", then 1/8" bits to completion.

[David Ragan]

But it is still "stopped", right? The router is the tool of choice for me for stopped dados. Any sharp straight bit gives me good results in cherry; not so in all materials but cherry is pretty machinable. Certainly scoring the outside lines with a knife will help if your cutters are giving you poor results. Downcut spirals will also give a cleaner result than an upcut but, 2 flute straight bits work fine for me.


Yes, stopped.

For this downcut spiral router bit, the wider bit will give me longer life, and be a cleaner cut, and less chance of breakage? Is there a downside to using as wide a bit as the router will hold for any given job?

What brands do you all like?

[Kent A Bathurst]

Dude -

Make the stopped groove/dado 1/2" W x 3/8" D. Use the simplest/fastest method you have. Worry not about tear-out - - it will never be seen [we, of course, will always know it is there - deal with it].

Use your very best ply saw blade on your TS to "outline" the corresponding rabbet in the top side of the py bottom.

THen -
[a] put on dado stack to take the rest of the rabbet; OR
[b] bump the TS fence a couple times to keep taking single-blade kerfs off; clean up with chisel/rabbet block/summit; OR
[c] neander router plane, OR
[d] whatever - get rid of the rest of the waste to create the rabbet - it can be ugly as sin also, because it will never be seen.

You need to have that one cut on the top surface [all 4 sides, of course] of the ply bottom be perfect - it will hide whatever mess you created with the groove/dado.