Some Practice With Dovetailing

Shop time has been tough to come by lately.  But I did get a little time in last week.

In the not-too-distant future I'm slated to build some cabinets that will be our entertainment center. The thought is three side-by-side cabinets, each about 36" tall, made of cherry.  I'd like to dovetail the corners of the cabinets and while I've done some small scale dovetailing, I've not done a row of DT's more than a few inches long.  These cabinets will probably be 15 - 17" deep.

So I bought myself a couple lengths of 1x12 pine to practice on.  I straightened one edge and squared the end as best as I could, but I didn't remove any cup or get the boards consistent in thickness.

One of two practice boards

My pictures here will be a little out of order because I didn't take the pics at the right moment.  I went back and took pictures later - you'll notice where it looks like I'm doing something weird!  I knew there was a bit of cup in these boards, but I didn't want to plane them flat since this is just practice.

Pic showing amount of cup I'm working with

A closer view:

This is probably about 3/32" gap at the center of the board

I figured I could clamp a straight piece of wood to my board to remove any cup and that's what I did.

Clamping a straight piece of wood to remove cup

My first step was to lay out the tails with a caliper.  I left 3/8" on each end and set the calipers by trial and error to step out 8 tails.  Those with a lot of DT experience do this without thinking, but for me, I really have to think about what I'm doing.  The caliper setting includes a tail plus a pin.  You start from the far left edge of the board and step off eight sections until you reach the mark that is 3/8" from the right edge.  These eight steps give you the right side of each tail.  Then you start at the right side and step left to mark out the left side of each tail.

Stepping out the tail layout

After marking the end grain, I used a Sellers-style DT marker to mark the angles on the face grain.  Then the sawing began.  I have a lot of work to do on sawing straight.  I'm using a 14 TPI gents saw (a $5 garage sale find) that I recently sharpened and in this pine it leaves dust and debris on my side of the board that hides the layout line.  I have to wipe/blow away the dust every few strokes.  I got close to my lines, but you can see from these pics that it's not perfect.

A little slanted from the layout line

Great on the left, not so great on the right

To anybody new at dovetailing - ALWAYS mark the waste (in my case with an "X").  I can't tell you how many times I've either cut on the wrong side of a line or much worse, removed a dovetail when I was supposed to remove a pin recess!!!

In the past, I have chiseled out the waste, but I wanted to try sawing out most of it and chiseling the rest, as Schwarz writes about in "The Joiner and Cabinet Maker".  After sawing to my lines, I used a "Knew Concepts" coping saw to remove most of the waste and then pared with a chisel to the base lines.  Chiseling was much harder than I thought it would be.  Maybe because this is pine and I had more than a few thousandths to chisel out - more like 3/32 to 1/8".  My chisels are freshly sharpened.

Pin recess #1 removed

Once the pin recesses were removed and the bottoms cleaned up, it was time to mark the pin board.  I clamped it to the front of my bench to remove the cup and laid the tail board on top of it.

Pin board clamped to front of bench

I did the marking of the pin board with a knife and later filled those lines with pencil.  Sellers has taught to mark pine with pencil and hard wood with a knife but I wanted to try a knife here.  Again, I took the pic after I had already marked and penciled in all lines.

Tail board in place to mark pins

I squared the lines on the face of the board using my small machinist square.

Squaring the lines

I sawed on the waste side of the lines, getting as close as I could to the knife line without go over it.

Sawing to the lines

And later sawed out the waste with the coping saw.

Sawing out the DT recesses

After paring out the bottoms of the recesses to the layout lines, it was the moment of truth.  Fitting the tail board to the pin board.  The first fitting went in a few millimeters.

First fitting - too tight

I decided to make some pencil marks on the leading edges of the tails.

Pencil marks on tails

This would allow me to see where the tight spots were on the pins - judging where the tails were rubbing on the pins.

Tell-tale marks showing where to remove tight spots

After several go-rounds with fitting, marking and paring sidewalls of pin recesses, I finally got the tails to seat in the pin board.

Final fitting

This doesn't look too bad, especially for not cleaning them up and removing all pencil lines.  But when you look closer, the left side of each DT had a gap.  EVERY one of them!

Gap on left side - all tails had this same gap

Thinking about the cause - this was probably due to one of two things (or both).  First it could be me not sawing straight on the pin board.  But just as likely is that when paring away thin shavings on the sidewalls of the pins I was too aggressive at the tops.  The gaps get smaller as the tails get deeper into their recesses.

I'd love to hear any comments about this.  Any suggestions for smaller gaps?  Meanwhile I'll keep practicing.