Making a Large Mortise

[Joe Von Kaenel]

Hello,

Not sure if this would be a Mortise or Dado. I have a Oak 4"X 4" three feet long. I need to make a recessed area at the middle of the board outside surface. From the top edge 1 1/2 " in width, 1 1/2" in depth and 10" in length. I will include a drawing to perhaps help. I am certaining not artistic. 198650 How should I make this? I am not good at freehand routering. I do have a router table, Mortise Pal, Table saw, Drill press etc.
Thanks

Joe

[Frank Drew]

I guess I'd call that a housing, and if I didn't have a mortiser I think I'd use a straight bit on a router table with stops to prevent the work from getting away from me, gradually moving the fence back to remove material.

Wouldn't take all that long to chop out with chisels, though, maybe predrilling to excavate the bulk of the waste.

[Bob Riefer]

I'd either pre-drill and chisel, or build a guide box to clamp to the post so that I could run a router inside the box (and then chisel out the excess). With the router method, just take a little at a time (don't try to plunge the entire bit in at once). If your chisels aren't sharp, it'll be well worth the effort to sharpen them before going for either of these methods.

[Bill Huber]

I think this is what you are wanting to do, is that correct?

198677

If so I would just do it on the table saw with a dado blade if you have one. I would just take some old 2x4s and cut 45° notch in them to hold the board. Then with an extension on the miter gauge to support everything and cut away.

198678

[Prashun Patel]

I interpret your picture to mean you want to make a "stopped rabbet".

If it were me, I'd rip the board into 2 pieces (1 1/2 x4 and 2 1/2 x 4). In the 1 1/2" piece, use a miter fence @ the table saw to cut a 10" dado the appropriate depth. Then glue up the 2 pieces. A good glue joint will be virtually invisible and very strong. This will leave you with perfect cheeks and corners.

(edit: I'm with Rod S., I think that's a deep cut to do on the router table; I didn't consider that).

[Rod Sheridan]

I'm with Prashun on his item #1, it looks like an insertion molding job (or stopped molding).

I have to admit that 1.5" X 1.5" is a deep cut on a router table, I wouldn't think twice about it on a shaper, however I'm not familiar with the capabilities of a router...Rod.

[Peter Quinn]

I'd hog the majority of it out close to the line with the drill press and a forstner bit, then build a quick template from MDF to guide a top bearing pattern bit in the router to clean up the whole thing. You will only be routing maybe 1/16" +_, you can do it in steps if it proves difficult, and you will be guided by the template. You may need to make a quick "bridge" or offset router base to span the opening for cleaning up the bottom of the cut. A router 1 1/2" from the edge of the board would be a bit tipsy otherwise. I would stop the drill bit maybe 1/8" shy of the bottom unless the bottom will be blind in use, then you could go a bit deeper.

I like the idea of ripping and reglueing the best, but if that is not possible, the DP is IMO the best tool for removing lots of wood safely and quickly with minimal dust and noise. Removing lots of material with a router is IME the least best option in pretty much all cases.

[Joe Von Kaenel]

Gents,

Thanks for all the help. I ended up making a frame, clamping it to the 4X4 routered 1/2" then lowered the straight cut bit did the next 1/2", the lowered the bit and did the last 1/2" turned out pretty nice. Again Thanks

Joe