Help with Mortises

[CubsFan]

So I've cut mortises before before, and always find it kind of fun. But now I'm faced with a new challenge: arts and crafts furniture. Specifically a morris chair. This one has through tenons, which I've never done before. All of the rest of my mortises I could kind of count on the shoulder of the tenon hiding any sloppiness, but now I have to be a little more careful.

I have the following at my disposal which may be helpful:

chisels

Router/Router Table

Drill Press

Mortise Mill ( By JessEm)

Also, the leg that I'm working on is 2 1/4" thick, so a decent amount of material to go through.

Which way would you cut them? Router and then chisels? Drill press and then chisels? Something I haven't thought of? Buy a mortiser?

Thanks!

[Beechwood Chip]

Mortise attachment for the drill press?

[JMadson Custom Wood]

How many these will you have in the chair? Do you plan on doing more A&C furniture?

If you only have a couple to do, I would do them by hand. You can do a practice board to see if you can get a good fit.

If you're not happy with the fit or if you have a ton of them to do, then look into a mortising attachment for your drill press or buy a dedicated mortiser.

(Go Sox!)

[Boatworks Today]

You're going to get the cleanest mortises with a drill and chisel IMO. On my mortiser (PM 719) it has a tendency to leave a VERY slight wobble from the auger bit outside of the chisel head. Not an issue if you're leaving a shoulder around the tennon, but if you're looking for a clean full (un-shouldered) tennon it may be a bit of a crap shoot with a mortiser. They are great, don't get me wrong, but this has just been my experience. If I were doing this and needed it 100% dead on, I'd hog out the material with a forsner bit and clean it up with a very sharp chisel.

My mortiser issue may be with the chisels (I have the PM set rather than some of the others). I can't say for sure.. I love the machine and have used it a lot. For what it's worth, I haven't noticed any play in the mechanisms (which leads me to believe it may indeed be the chisels)... By very slight wobble I mean probably 1/32 or so outside the chisel (just enough to be a little annoying)..

Edited December 16, 2011 by Boatworks Today

[CubsFan]

You just hit on what my impression of mortisers has always been: absolutely great tool for the stopped mortises, but not quite as great for ones that show. I actually am planning to do quite a bit of stuff that requires M&T, so a mortiser is probably in my future. But it sounds like the good old fashioned way might be the way to go right now.

The legs on this chair have 2 through mortises each, and 1 stopped. So right now I'm looking at a total of 8 through and 4 stopped. I haven't looked too much further ahead

[rmac]

I used the drill-and-chisel method for the very few through mortises that I have attempted. If you're hyper careful with the layout and super careful with the chisel, they'll come out good.

-- Russ

[CubsFan]

That looks great. I figure I'll spend a day cutting mortises in scrap wood to get in a lot of practice.

On a separate topic, I see you build the Aurora nightstand, which is another one on my list. Would you say that was a difficult thing to build?

[Boatworks Today]

One thing I would recommend getting if you don't have it already is a thin exacto-knife for cutting the layout for the mortises; I wouldn't use a pen or pencil as the line isn't tight enough. Score the wood all around with the knife, hog out the middle and creep back to the layout lines with the chisel.. Takes some patience but works very well.

Now I am a little curious about my mortise chisels.. May have to buy one of the more "high end" sets and see if the wobble still persists. When you do decide to take that plunge and get a machine, I would strongly recommend the 719. It is a bit of an investment but depending on your use / need you will never need to upgrade again IMO it's probably the best unit avail for the money in both quality, features and design..

Good luck!

[CubsFan]

I was looking at the PM701 for $479. What's the 719 go for? I can't seem to find a price online (which is probably a bad sign )

[dwacker]

One thing I would recommend getting if you don't have it already is a thin exacto-knife for cutting the layout for the mortises; I wouldn't use a pen or pencil as the line isn't tight enough. Score the wood all around with the knife, hog out the middle and creep back to the layout lines with the chisel.. Takes some patience but works very well.

Now I am a little curious about my mortise chisels.. May have to buy one of the more "high end" sets and see if the wobble still persists. When you do decide to take that plunge and get a machine, I would strongly recommend the 719. It is a bit of an investment but depending on your use / need you will never need to upgrade again IMO it's probably the best unit avail for the money in both quality, features and design..

Good luck!

Not to take the conversation off the topic but are your chisels actually wobbling, not tightening down? Or are you talking about deflection on a partial cut?

Don

[Boatworks Today]

Cubs: check out www.cpopowermatic.com http://www.cpopowermatic.com/powermatic-mortisers/powermatic-mortisers,default,sc.html

A few times a year they run a 15% discount which brings it down to roughly $1K. Like I mentioned it's an investment but it's a lot of machine and you won't be disappointed They also do free shipping. I've bought my pm tablesaw and mortiser from them and have been very happy (also best prices I've found for their stuff)...

dwacker: I think it's deflection of the auger bit, OR that the auger itself is a little off. All the mechanisms are dead on (no play, tight, etc) but it seems like one of the cutting blades somehow sneaks out beyond the pattern of the chisel. I'm going to be using it later today and will try and take a pic to show what I'm talking about. It's very minor, but can be a little frustrating. Notice it more on the 1/4". The larger sizes tend to be a little more accurate.. Any thoughts?

[dwacker]

Cubs: check out www.cpopowermatic.com http://www.cpopowerm...default,sc.html

A few times a year they run a 15% discount which brings it down to roughly $1K. Like I mentioned it's an investment but it's a lot of machine and you won't be disappointed They also do free shipping. I've bought my pm tablesaw and mortiser from them and have been very happy (also best prices I've found for their stuff)...

dwacker: I think it's deflection of the auger bit, OR that the auger itself is a little off. All the mechanisms are dead on (no play, tight, etc) but it seems like one of the cutting blades somehow sneaks out beyond the pattern of the chisel. I'm going to be using it later today and will try and take a pic to show what I'm talking about. It's very minor, but can be a little frustrating. Notice it more on the 1/4". The larger sizes tend to be a little more accurate.. Any thoughts?

I see, thats what I thought. Try to keep 4 sides supported. Cut both your ends first, two four sided cuts, skip 1/3 the chisel width and make another four sided cut when done go back and clean out the spots skipped this should cure your issue.

Don

[Boatworks Today]

huh, that would awesome if it takes care of it. I like simple fixes I'll let you know.. Thanks!

[rmac]

On a separate topic, I see you build the Aurora nightstand, which is another one on my list. Would you say that was a difficult thing to build?

If you don't have them already, you can get the plans here. They are detailed and complete, and I think you should be able to gauge the difficulty from them pretty well. Overall, I'd peg the nightstand as an intermediate project with about the same level of dificulty as your Morris chair.

After you've built the chair, I'd say that there are only two aspects of the nightstand that might prove challenging. One is making the templates for the curved parts just right so that the gap around the drawer is nice and uniform. The other is making the decorative ebony splines that go between the main part of the top and the breadboard ends. The plans give instructions for both of these operations, and there is even more detailed information about making the splines in Darrell Peart's book, Greene & Greene Design Elements for the Workshop.

As it turns out, I wound up using different methods than Darrell's for both the templates and the splines. A few of the articles in my blog explain why I deviated from Darrell's suggestions, and what I did instead.

-- Russ

[Boatworks Today]

Here's the problem I was talking about with my mortising chisel.. It's a single cut with a 1/2" chisel. Like one of the auger blades extends beyond the cutting edge of the chisel. I don't think this has anything to do with the machine, but rather the chisels (they're a powermatic set)...

[CubsFan]

Ok, here's my first attempt. It came out ok. Not great, but I'd say fair. I didn't worry too much about the back side, since that'll be covered by the shoulder of the tenon. So, this may be a dumb question, but what's the inside supposed to look like? I have this image of a perfectly smooth mortise, but I'm not sure if that's realistic or not. I don't suppose it matters too terribly much, since after the glue is in it'll never be seen again.

My impressions:

- I think I set a world record for slowest mortise attempt

- This seems like a pretty good skill builder

- I will be buying a mortiser some day

[Boatworks Today]

Not too bad you're right in that it is a GREAT skill builder (and tester of patience).. Looks like you should be able to clean up the inside a bit providing your chisel is very sharp and it won't open up the mortise too much that it creates a loose fit. I'd do this by hand (no mallet).. Give yourself a pat on the back and grab a cold one with the other hand You done good!

[Darnell Hagen]

^{Boatworks, I had the same problem. Turn on your mortiser and run a file lightly against the side of the chisel until the bit is of the proper diameter.}

[Boatworks Today]

That took care of it! Once again, common sense prevails! Thank you! Now I'll have to run through the rest of the set and clean up the edges Out curiosity are you using a PM set or another brand?

Thanks again!

[dwacker]

Your augers may be bent. Did you set your depth with a nickle.

Don

[Boatworks Today]

They're relatively new (at leas the 1/2" chisel; I've used the others quite a bit)).. I set the auger bit all the way up in the chuck and the chisel probably 1/8" (may a LITTLE less) above that.. When I ran the file over the edge of the bit (and chisel head) it was very little of the auger edge that was removed... I didn't hear anything telling me that the auger was rubbing up against the inside of the chisel (as if it were bent), but to be honest I don't have a ton of experience on this machine (maybe a couple hundred mortises or so)... Is there something I should be checking?

Also, I don't want to hi-jack this thread.. Should I start a new one on this topic?

Thanks!

[Darnell Hagen]

Boatworks, my chisels are Dimar, but I've seen that big auger problem in almost every make I've come across. I would bet that your drill isn't straight, they're so long and thin it's almost impossible for them to be straight, but as long as they aren't binding in the chisel I wouldn't worry about it. 1/8" is a little big, I stick a dime between the chisel shoulder and the chisel seat on the machine, set my bit as high as it will go, then remove the dime and move the chisel up.

Cubsfan, your chisel could use a sharpening. You can see how the long grain sides have fibres that were rolled out of place instead of being cleanly severed. That will make the endgrain work easier, too. Otherwise, not bad. Yours certianly look better than my first chopped mortises, which looked like I used a beaver to chew them out.

[Boatworks Today]

I guessed a little bit on the 1/8"; truth be told I use the amount of vertical play in the bushing for the chisel which is probably closer to 1/16" or so.. I set the auger all the way up, tighten that down, square up the chisel on the back fence and lift it whatever the play is (1/16" or so). Haven't had a problem with chips getting caught or the auger burning... Does this seem about right? Never had any formal "how-to's" on this machine; just what I've read online and the doc's that came with the tool

[Onboard]

Boatworks, have you seen this webpage? Nice review video at the bottom.

[Boatworks Today]

Just watched it (I like this guy; he's a Packer fan! ) I think I'm getting about the same amount of clearance with the way I've been doing it, but will try the coin shim and compare results.. Thank you!