Newbie question

[StorminN]

Hi guys,

I'm a newbie to the timberframe thing... I helped build and raise my uncle's house years ago and I lived in them for many years in New England, but now I'm on the west coast where they are few and far between. I love the feel of a timber frame, so I'm hoping to build a timber frame house one way or another in the next few years. I do have a sawmill and nine acres of forest to choose from, so that may help.

I've decided to make a pair of timber trestle sawhorses as my first project... to see if I enjoy the work and to see if I'm any good at it, too. It's been a long time since I've done any real woodworking. My dad was a woodworker and most of my experience in the shop was just helping him build furniture, etc.

So... my newbie question is... when cutting mortises (without a mortiser) is there a general rule of thumb for the size of auger to use? For example, do most people use an auger 1/2 the size of the mortise? (1" auger for a 2" mortise)... or do people go smaller or bigger than this? I'm just trying to figure out what would work best.

Also, for rip cuts for tenons... what are most of you guys using? Handsaws? Beam saws? Just curious.

Thanks in advance for any input.

-Norm.

[Jim_Rogers]

Norm:
Welcome to the forum.
You've asked some good questions.

is there a general rule of thumb for the size of auger to use?

Usually we use the width of the mortise for the diameter of the bit. The point about using a bit to remove wood from the mortise is to remove (hog out) as much wood as easily as possible.
So that's the why we do it. The more wood your remove by bit the less you have to remove by chisel (which is harder).

Here is a mortise layout drawing:



You'll notice by the drawing that the mortise is 2" wide and we are using a 2" bit. Also that we keep the end hole back a little from the end of the mortise so that the end grain can be cut with a chisel to insure that it will be done in the correct location and done at the correct angle to the surface.

You asked:

for rip cuts for tenons... what are most of you guys using? Handsaws? Beam saws?

Well, I was taught to chisel the side or cheeks of a tenon but recently I saw Jack Sobon cut a tenon using a rip hand saw.
Whenever a student has tried to use a power saw here at my workshop sessions they always cut away too much wood and didn't "leave the line" and we had to cut the timber back and do the tenon again. So, I usually try and teach them how to do it with a chisel and not use a saw.
But, others have used a power saw and as long as you make the cut correctly and "leave the line" so that you can "pare to the line" with a chisel it's ok with me to use a power saw.

Jim Rogers

[Dave Shepard]

Jim, when you say you are using a chisel instead of a saw for the tenons, do you mean you are splitting away the wood, and then paring to the line? That is how I do it, faster than sawing, provided the grain cooperates. I have also used an axe to split the waste away.


Dave

[Jim_Rogers]

Yes, Dave splitting or chiseling away the wood, once the shoulder line is cross cut with a hand saw, as Dave Carlon and Jack Sobon taught me....
I find it very accurate and as fast as cutting with a saw.
When you have all your hand tools within reach, and you're ready to go, it doesn't take long.
If you add the time to setup the extension cord, get the saw, plug it in, and make the cut, chiseling is equal if not faster. Less worry and no noise.
I posted the procedure in one of the many posts in the tools for timber framing thread....

Jim Rogers

[StorminN]

Thanks Jim and Dave...

Jim, when you're chiseling away the cheek of the tenon, are you just taking 3/8" (or more, or less) off at a time? I tried this for the first time a couple of nights ago. I was chiseling doug fir with a 2" chisel... what happened was, the wood split off along the grain, over the lines for my tenon... I ended up with a ragged tenon. I was thinking I needed to take smaller bites next time. Do most people make multiple saw cuts on the cheek and then clean it up with the chisel, or make just the shoulder cut and then hog it away with the chisel? Just wondering...

Thanks again,
-Norm.

[Dave Shepard]

It all depends on the grain. When chopping out the wider side, you can take a lot of at once. I always take the corners off, and then the high spot in the middle. After a chip or two, you can get a feel for the grain and decide from there. I have had the grain run over the line, it does make the tenon look ragged, but it is usually just cosmetic. I cut the shoulders with a hand saw, and then chop out the tenon, and pare to the line with the slick. As Jim mentioned, with the right tools handy, it is very fast, plus no harsh noise or airborne dust. Watching someone who has done a lot of this kind of work is amazing.


Dave

[StorminN]

Hi Jim,

I just tried this mortise method tonight, and I like it! Worked well for me... only trick was to make sure I don't bore beyond the lines...

Tomorrow night, maybe I'll try cutting the tenons...

Thanks,
-Norm.

[Jim_Rogers]

Norm:
There is a drawing in the thread "Tools for timber framing" that shows the end grain of a timber with colored lines on it.
These colored lines represent the position of the chisel as you work your way down to the tenon cheek surface.
When splitting off these chunks of wood, I do it with the bevel of the chisel down towards the ground. This forces the chisel to lift the chunk off the timber and loosens it up real fast.

You have to "read" the grain and do not take very much off at a time until you see how the grain is running and if it's diving into the tenon then change your angle of attack so that you don't chop in to deep....

Jim Rogers

[StorminN]

Ah ha! Thanks Jim...

The part I missed the first time through the "Tools for timber framing" pinned thread was the VERY important part at the end that says "See thread called "Cutting a tenon on a timber" for the next steps in this series of stories."... whoops.  : :D

Thanks a ton!

-Norm.