Thursday, February 25, 2021

Desk-side Table, Part 2: Reference Surfaces and Joinery

As I've progressed in my woodworking, choosing faces and edges to be used as references has become much more clear.  I find it a good intellectual exercise.  For instance, the legs have the two inside faces as the reference surfaces.  That will make them perfectly square where the joinery goes, practically ensuring a square structure.  [I know there are people (looking at you, Richard McGuire) who teach an alternative way where the two inside faces are planed purposely a little bit out-of-square to each other.  This can help create gap-free joints at the show faces, and allows gappy joints on the inside.  It might speed up some aspects of furniture making, but I don't subscribe to this method.]

Having my legs' reference surfaces on the inside faces makes it important to figure out ahead of time which surfaces will be the show surfaces.  Before the legs were planed square for joinery, I put them in the most visually pleasing orientation and this showed me which surfaces to plane perfectly straight and square.

Legs in position, short side facing camera is front of table

After planing straight and square, the two inside faces are marked for joinery

I'm no longer planing the non-reference surfaces perfectly square (they're close, though) to the adjacent faces.  This saves time, but there's another thing to be aware of.  For this table, the aprons will be closer to the outer surfaces of the legs, with a 1/8" reveal.  The mortises for the apron tenons will be closer to the legs' outside faces.  One might be tempted to mark a mortise registering off the closest face, but with the reference surface being the inside face, you need to extend the mortise gauge and mark from that inside face.

Notice the 1/8" spacer bar to the right of the apron.
An apron (with tenon marked out) is set in place on the leg and the layout lines
are transferred to the leg.  I get the mortise gauge setting from these marks.

Marking the mortise, referencing off an inside face

For the aprons, I used the inside face and top edge as references.  I want the top to sit flat on the frame, so it made sense to me to use the top edge.  I don't think it mattered which face I used, but I chose the inside.

For this table, two lower shelf rails are connected by three shelf boards and I want the tops of the shelf boards to be level with the top edges of the rails.

The overall design - note the shelf boards and rails

To keep those parts in line, The short tenons of the shelf boards will be laid out using the top surfaces as reference.  The reference edge won't matter.  For the rails, the inside faces and top edges are the reference surfaces.  Marking the rails' shallow mortises off the top edge and marking the shelf boards' tenons off the top surface will help keep the rails' top edges in line with the top of the shelf boards.

OK, back to construction and the choices one must make.  I used two different methods to create the leg mortises.  Some were bored out with brace and bit to remove most of the waste and others were chopped.  I'm not sure if one method was quicker than the other.  I chose 5/16" mortise width ( 5/16" thick tenons) just because I thought 1/4" might be a little too flimsy and 3/8" might leave too small a shoulder.  In retrospect, 3/8" would have been fine and would have simplified the chopping.  I don't own a 5/16" chisel.

Most of the waste bored out

Mortises complete.  I added a haunch help prevent racking.

The aprons' tenon cheeks were split off and refined with chisel and router plane.  I got a nice fit all around.

An apron/tenon fitted to a leg/mortise

View of the top of the joint - note the haunch

Another choice I had to make had to do with the lower shelf rails.  They will have tenons that fit into mortises in the legs, but the legs will be tapered, so which to do first: taper the legs or cut the mortises?  As it turned out, it doesn't really matter.

Two legs before tapering - one mortised, the other not

I tried both ways.  If you mortise before tapering, you just have to cut a deeper mortise.  And as this mortise was only 1" long, it can be a little tough to cut deep enough.  If you taper first, you have to make sure you wrap your mortise layout lines around the adjacent sides so that you can re-establish them on the tapered surface later.  BTW, both inside faces will be tapered, but I only needed to taper one now since the other doesn't get any further joinery.

Layout lines wrapped around before tapering

More choices: to saw or plane the tapers.  I recently saw a Bob Rozaieski blog about the plusses and minuses of the various methods of tapering legs.  One thing he didn't mention was that if you saw them, you can use the offcut to help with clamping when you needs to work on the tapered leg.  I used both methods.

Upper leg taper was sawn, lower leg taper was planed.
Both were cleaned up with planes.  The two methods took about the same time.

All four legs tapered and mortised for the shelf rails

Next time I'll show how I laid out for the shelf rail tenon shoulders that had to fit between tapered legs.  Hopefully by then I'll have completed all joinery and shaping and have it glued up ready for finish.

Thursday, February 18, 2021

Desk-side Table, Part 1: Planning and Stock Prep

Last week I wrote about getting out of a rut.  I finally got to some hard work this week and I can't believe how out of shape I've gotten.  Woodworking shape, that is.  I've been dog-tired at the end of the day from planing oak boards and my right elbow is a little tender.

My first project on the honey-do list is a small table that will fit to the right of my wife's desk in a space formerly occupied by her old-fashioned computer CPU.  The space is about 13" wide and 31" deep, so I'll make the top 12" x 31".  Since she wants to be able to expand her desk-top area, the height will be the same as the desk, about 29 5/8".  I'm using oak to match her desk.

Here's a Sketchup model of what I'm planning.

Overall design - a short side will be the front

With top removed to show apron locations

I had to modify the design to suit the materials I had on hand.  A while back, I bought a couple pieces of 13" wide oak for a project that never came to pass, so I wanted to use that.  I was able to get the top from a single board.

Here's the material that will become the table

After I had cut pieces for the top, aprons and legs, the longest piece left was about an inch too short for the shelf boards.  I had some other "pre-used" oak that I could have used, but I wanted the shelf boards to look like the rest of the table and I really wanted to use up the oak I had bought.  So I modified the design a little bit.  Instead of having the top extend 1" past the aprons all around, I'm making it extend 2" at front and back (the short sides).  That shortens the length I need for the long aprons and the shelf boards.

Here's the product of this week's labor

From left to right: the top, three shelf boards, two short aprons, two long aprons, four (glued up) legs and two shelf rails.  All these parts came from the wood shown earlier, except for one of the legs.  That leg might look a little different, so I'll position it at the back.

I've started to do some layout on the legs.  I tend to go really slow on that to avoid mistakes.  I really should get into the habit of drawing the parts out on paper, showing all the important locations and details, so that I have a reference right there with me.

Next time I'll get into a discussion of reference surfaces and the details of layout and joinery.

Thursday, February 11, 2021

Getting Out of a Rut

I don't know why, but I've been in a rut for a while.  I've been lazy and feel guilty about it (no doubt, a product of my upbringing).  I've got some projects that I want to build, but haven't been able to get started.

A couple weeks ago I'd had enough and got out to the shop just to dovetail together a couple pieces of pine.  Well, as long as I was practicing some dovetails, I might as well make them into a box.  And as long as I was making them into a box, I might as well put a raised panel into grooves for a bottom.  And as long as I was doing all that, I might as well put some compartments in the box.  And I might as well experiment with shaping the exterior of the box.  And ...

As you can guess, one thing led to another.  I ended up with an interesting box with two levels of compartments inside.  It's 8 1/2" x 7 1/4" x 4" tall (plus handle).

The finished box

Box with upper tray removed, lower compartments can be seen

One corner of dovetails - the shaping makes them look funny

The Douglas fir bottom is a raised panel fit into grooves in the box sides

The removeable lower compartments were made from four sticks of 1/4" oak

The removable upper tray was dovetailed together, with permanent dividers fit into dadoes.
All 1/4" oak.  Its bottom is 1/8" oak plywood, glued on.

The upper tray slips into the box with a nice fit

The lid was made from poplar and it is rabbeted on its underside to fit tightly into the box.  The above picture shows a little space above the tray to allow the lid to fit down into the box.  The lid's handle was simply glued on.

I experimented with the exterior shape, just based on images in my head.  Sort of an "S" shape.  You can see in the first picture above that the lid continues the shape of the upper part of the box.

This picture makes it look like the upper part is wider than the base,
but they're the same width

I guess the point of this post is this: whether you have a project to do or not, sometimes you just have to get out to the shop.  I don't need a box and don't have anyone in mind to give it to.  But it was fun and allowed me to practice some techniques and to be a little creative.  And it also used up some scrap wood.  All good things!