Router bit for mortise and tenon joints

[Isaac]

I've got to make some mortise and tenon joints for my latest project. I'm planning to do 1/4" mortises in 3/4" material. I've got a router table, so I'm thinking I'll plunge the material and do them that way, unless someone convinces me that doing them from above, hand held is better?

I don't really have a good 1/4" bit, so I'm going to buy one, Looking for suggestions on what type, is a spiral up cut bit the best/most appropriate option?

I'm sure this is a really basic question, thanks in advance for humoring me guys.

 

 

[estesbubba]

This is a time where I prefer to keep to stock stable and use a plunge router and guide to make the mortises. Spiral upcut bit like you posted is perfect - hartvilletool.com has them and 'wn15' will give you 15% off plus they have free shipping. 

Of course the easy, but expensive, way is to get a Domino. 

[MisterDrow]

Yes, a spiral up cut is exactly what you need. Just do it incrementally so that you don't strain the bit too much and you're golden. I did some the other day using that exact bit in my new router.

You can do it with normal straight bits but they don't have a cutting surface in the middle of the flutes on the end of the bit so you can't go very deep with each pass but it's just as effective.

[Chestnut]

I'd say that doing them by hand is better. I think it's easier to do the multiple passes necessary to get full depth.

A good trick is plunge full depth or drill with a mortise bit at the beginning and end so you don't over cur your mortise.

[Coop]

Just the thought of it sounds dangerous to me. I've done stopped grooves and dados on the router table before, where you "tilt" it down onto the bit, but never plunged it down. By tilting it down for a mortise, your shoulder is no longer square. And by plunging the end of a board down onto the bit, you have little, if any control of keeping it flush to the fence during the plunge or during the cut. I definately would gang the boards together and make these cuts from above with a plunge router.

[MisterDrow]

I should clarify... I did not do said mortises on a router table... I did them by hand with a plunge router and edge guide.

[wtnhighlander]

I've done them on a router table. Incrementally raising the bit isn't hard, especislly if you have a lift. I recomend using stop blocks at either end to limit travel, and a removable spacer so you can tilt/plunge in the middle of the mortise, then go side to side to square up the ends. You can also clamp a board across the table to keep the workpiece against the fence, like a featherboard.

Alternatively, I have used a slotted scrap of plywood and a collar on the hand held plunge router. I clamp the jig so it overhangs the vise at the end of my bench, and aligns properly when I clamp the workpiece in the vise. Make repeated plunges to hog out material, then side to side for clean up.

[RichardA]

Maybe I'm old fashoned. Drill them out on a drill press with a good fence, and clean them up by hand!  No brainer, and no problem!

[Chestnut]

6 minutes ago, RichardA said:

Maybe I'm old fashoned. Drill them out on a drill press with a good fence, and clean them up by hand!  No brainer, and no problem!

I think old fashioned would be grabbing a mortise chisel and a hammer. Your way is a different type of new.

[treeslayer]

i do them on the router table most of the time with a spiral bit of the appropriate size, shallow cuts and a tall fence help as do good lay out lines if you are unable to use stops. use tape and pencil lines on the router table to mark your start and stop points. if you are doing table legs pay particular attention to your layout marks. i square the mortice with a chisel when I'm done or you can round the tenons. 

[Coop]

Well EXCUSE me for being such a whiney girl! I need to take these culottes off and put some big boy pants on!  Seriously though, I learned something here!

[Mick S]

There are times when I need to do a stopped plunge on a router table, but I really dislike doing it. I'll look for any other way to cut them first.

I'd take a look at making a mortising jig that you could use on lots of other projects that would use a plunge router from above. It's much safer and I think you'd be happier with the more consistent results.

Here's one that doesn't require using guide bushings - 

I also like Philip Morley's jig that uses guide bushings - 

 

[treeslayer]

do those culottes have daisies on them coop? seriously i do them on the router table because i don't have a morticing machine and I'm too lazy to set up a fence on my plunge router, maybe if i make an adjustable fence for the plunge router i would use it more.

[Brendon_t]

41 minutes ago, K Cooper said:

Well EXCUSE me for being such a whiney girl!

You get a pass, your Texans ate currently beating the piss out of themselves in spectacular fashion

[Isaac]

Holy cow, thanks for all the responses guys, I was just expecting someone to say, "yup thats the right bit".

i guess I will reconsider my method.

This is the sort of approach I had in mind, but it seems like the consensus is to plunge from above instead.

http://www.woodworkersjournal.com/mortising-router-table/

[MisterDrow]

Like many have said, you can do it on a router table... and many do... but you have to take extra precautions when doing so.

[xxdabroxx]

How would you keep the plunge router flat on the top of a 3/4" board?  That sounds sketchy to me.  (I only have a trim router so far so this is all out of my wheelhouse)

[Isaac]

8 minutes ago, xxdabroxx said:

How would you keep the plunge router flat on the top of a 3/4" board?  That sounds sketchy to me.  (I only have a trim router so far so this is all out of my wheelhouse)

You'd definitely sandwich with additional material to give a good base to rest on.

[gee-dub]

I have a few of the RU4700's. They are my go-to for 1/4" thick tenon stock.  For mortising I use a Mortise Pal. Alas, I cannot recommend this wonderful product as it is no longer made.

 

[MisterDrow]

This is a fairly handy little jig... planning on making myself one of these this weekend.

http://jayscustomcreations.com/2015/11/router-edge-guide-and-mortise-jig/

[Ronn W]

I use my bench vise which is flush with the surface of the bench.  Set the work piece flush with the table and use the router edge guide along the face of the vise.  Sometimes I will clamp a couple of stops to the bench if I am doing several.  I put pencil marks on the bench and the work piece when batching out several.  Works well.

I usually make 3/8" mortises in 3/4" stock.  Does anyone think that 3/8" is too large?

[Isaac]

I've typically seen recommendations for either 1/3 or 1/2 the base thickness, so you are in that range. I think the fear with going too wide on thinner stock is just side wall blowout. I'd personally be concerned about that if the wall thickness gets down to about 1/8" or less. 

[RichardA]

On 10/25/2016 at 1:36 PM, xxdabroxx said:

How would you keep the plunge router flat on the top of a 3/4" board?  That sounds sketchy to me.  (I only have a trim router so far so this is all out of my wheelhouse)

You make a jig for the router base to rest on.