How to make this cut?

[Sean McCurdy]

Hey folks, looking for some advise on how to make this cut:

353110

Some background, helping a friend turn an piece of a fallen family barn timber into a mantle. This cut is to help sleeve it over the brickwork.

353117

It won't be easy cutting, this is old growth red oak.

353116

Before everyone freaks out about a waste of lumber, know that there was A) lots of nails that had to be removed. B) Lots of rot and worm infestation, which this cut will finish taking out and C) This was otherwise heading to the burn pile.

I have a relatively well equipped shop (14" bandsaw, 10" Unisaw, 8" Jointer, 12" Miter Saw, etc). I thought about using a circ saw, but the 7.25" blade simply doesn't have the reach.

Right now, my best thought was a plunging cut with my chainsaw, but really not looking forward to trying that.

I'd prefer a technique that saves as much of the wood as possible, but it is what it is.

[roger wiegand]

I'd cut as deep as possible with a circular saw then clear out the remainder with a mortising chisel. Might take you 20 minutes and be a bit of a workout, but easier and safer than a chain saw!

[Prashun Patel]

There are two ways I would consider:

1) Cut the beam in half, notch the one half at the bandsaw, then rejoint/reglue the halves.
2) The second, massochistic way is to chop out the waste. Use the chainsaw to carve and hollow out as much as possible. Then use a slick to square the sides.

[Steve Demuth]

How finished and what dimensional tolerance do you need in the cut?

[Charles Taylor]

If your drill press has enough depth of travel, you could hog out material near the 4" and 6" lines respectively with a Forstner bit, as though you were doing the initial cleaning out for two long mortises, then hog out along the two short sides with the drill press, and finally clean up with some chisel work.

It doesn't sound quick and easy regardless.

[glenn bradley]

Hog with Forster, router or circ-saw and chisel to finish.

[Sean McCurdy]

Drill press is a Powermatic 1150, so I do have 6" of travel, so this is probably what I'll be doing. This is going to be some work...

[Sean McCurdy]

Finshed surface is unimportant, as it's all hidden. Tolerance of about 1/4" or so. I.E. very rough is totally fine.

[Mark Gibney]

I would cut a piece 4" x 6" and then cut out the huge rabbet. Then add back in the two blocks at each end.

Or as I think Prashun said mill two boards and glue them up as an long L shape, then glue in the two blocks.

However - maybe you need to show the endgrain on each piece as it exists? So the above wouldn't work.

[NICK BARBOZA]

There are two ways I would consider:

1) Cut the beam in half, notch the one half at the bandsaw, then rejoint/reglue the halves.


Prashun is onto something here, in my opinion. the only real evidence would be a minor glue line on the top and ends of the mantel.

[Bradley Gray]

If you have a band saw, I would resaw the beam in line with the 6" face of the notch, cut out the 4" faces also on the band saw and glue the first cut back bandsawn box style.

The glue line will virtually disappear especially in the roough surface

[David Spurr]

Circular saw and chisel. Won't be as bad as you think.

[Lee Schierer]

Do you know anyone with a bridgeport type milling machine? This would be an easy cut on a milling machine using a 4" long end mill. Probably less than 1/2 hour of work, not counting cleaning up the chips from your friends mill.

If you don't know any one with an end mill, then I wold cut all the straight lines as deep as I can wit my skill saw. Then Using a 2" forstner bit I would bore a bunch of slightly overlapping holes to the 4" depth removing as much material as possible. Then take a hammer and knock of the stub pieces that stick up after boring. Finally use a sharp chisel to clean up the remaining bits and pieces.

[Matt Day]

I agree with cutting the long straight lines with the circ saw (though that's going to going to be a pucker of a plunge cut!) then using a forstner bit plunge at the cut line and ends to remove the large chunk left by the circ saw.

A track saw would be nice on those cuts.

[Andrew Pitonyak]

I agree with cutting the long straight lines with the circ saw (though that's going to going to be a pucker of a plunge cut!) then using a forstner bit plunge at the cut line and ends to remove the large chunk left by the circ saw.

A track saw would be nice on those cuts.

Had not considered the "pucker factor", but I own a track saw that I can plunge..... Pretty much anything that can follow a straight edge and plunge would be a huge help here. For example, a router with multiple passes as deep as you can go. This still leaves a bunch to clean out, but, with the "initial" reference surface in place, I expect that would help a bunch... After the reference portion was done, you can likely hog out a bunch of it with forstner bits, even hand held, just don't get too close to the edge.

[Sean McCurdy]

Some feedback:

When cleaning up the worm-rotted surface that you can now see in the pic what I did was a full depth circ saw pass about an inch in from the face, then took it over to the bandsaw. My experience there was not particularly great. Wresting a 80 lb beam around on the bandsaw wasn't great, and my 1/2" 3 tpi blade struggled with the cut. It's a 1hp 3 phase motor, the problem was the belt drive would just slip. The old growth stuff is just that tough. It also had tracking issues, so I'm not thrilled about the ideas of slicing off a face then re-glueing it.

Lee, I wish I knew someone with a sizeable end mill, but no luck there. Otherwise, a great idea. I'm wondering if this is something I'd want to try on my mortising machine now...

At the moment my most likely plan is to cut the lines with a plunged circ saw (yikes indeed) then follow up with a forstner for additional depth.

[Matt Day]

Just thinking out loud, but how handy are you with chainsaw? Seriously, with a small saw you could hog most of it out and clean up with your mode of choice.

[Jesse Busenitz]

Just thinking out loud, but how handy are you with chainsaw? Seriously, with a small saw you could hog most of it out and clean up with your mode of choice.

This would be my choice as well, but I've logged a few hours on a saw before (no pun intended).

[lowell holmes]

I would route it and square the ends with a chisel.

[Tim Bueler]

Depending on what tools you have available... I would cut just inside the line w/ a circ saw. You can come at it from all directions. Then I'd alternate between a OMT and a heavy blade chisel to hog out the majority of the waste. Set up a router guide to follow your cut line. If you have a pattern cutting bit you can do your first cut with a guide, then use that cut as the guide for the next cut. It shouldn't take too much to chisel or OMT whatever waste is left. I've used a similar approach several times notching newel posts around various obstacles and always tried to make a cabinet grade cut even when it didn't count so I was practiced when it did count. It'll be fun!:)

On your circ saw plunge cut keep the blade moving forward, it doesn't take much, as you plunge will help avoid the back end of the blade from grabbing. On a piece that large you could even set up a guide for the saw foot if it makes you feel more comfortable. One less thing to watch.

[Sean McCurdy]

All,

Just a quick update. I did complete this this weekend successfully. Well, mostly.

Results:
353321

Method:
Ran the circ saw down the lines, and again with overlapping cuts; for a total of 5 plunged rips. Unfortunately, this only freed the one corner. The rest stayed put, even with some considerable prybar application.
So, we turned to the drill press. Chucked up a 1 1/2" Forstner bit and an extension so the chuck wouldn't hit the work. I was hoping to use my cheap-o Ryobi set, but it doesn't have the depth needed without the extension. So instead I used my nice Colt Maxi-cuts.

Running two 6 foot rows of overlapping holes resulted in approx. 150 bores of 4-6" depth each. This took a lot of time, as I'd have to pause every 4 holes to let the bit cool down. Despite that precaution, I still managed to overheat the bit. And sieze it in the extension. Looks like I have another project.

About 2/3 of the way through I did resort to resharpening the bit with a fine file, but since the edge had been overheated this didn't last very long. Roughly a $40 mistake.

[Tim Bueler]

Way to go Sean! Where there's a will there's a way.:cool: Knowing what you now know, just think how much easier it'll be next time.:rolleyes: