Tag Archives: marking gauge

Wraparound Dovetails – How I Fit Them

Most of us are familiar with the techniques for fitting dovetails during construction.  You cut the pieces to size, mark your dovetails, and cut away.  Even if you machine-cut, the process is basically the same.  Everything is measured from the end of the board.  However, there are times when this approach doesn’t work.

This blanket chest is a perfect example of this.  Christopher Schwarz’s Anarchist’s Tool Chest is another.  In both cases, a base or dust seal wraps around the basic structure of the chest, and is dovetailed into place.  The problems start to arise when you realize that the pieces cannot be precut to length, but must be fitted to the existing structure to ensure a good fit.  No, measuring with rule is not a substitute for a good direct measurement.  Of course, your measurement doesn’t tell you how far past the end of the casework the board should extend for the overlap that will give a good, snug dovetail.  This is how I do it:

Dovetail Tuning 1

Start by dovetailing one corner to act as a reference, leaving the board overlong.  Then, with the assembled dovetail snugged into place, mark the corner of the casework on the other end.  A marking knife will work, but I find that a pencil will angle into the corner more easily without wandering.

Dovetail Tuning 2

Next, stand the opposing board (or an offcut of the same) on edge on this board, with the inside edge flush with your pencil line, and mark the location of the outside face.  This measurement isn’t really critical – you just don’t want to be too short.  Next, crosscut the board to just outside this last line to establish the rough length.

Dovetail Tuning 3

Now comes the trick.  Take your marking gauge, which you already set while cutting the first dovetail, and place it against the sawn end of the board.  There will probably be, as shown above, a gap between the knife/pin and the pencil line.  Simply plane away the excess with your shooting board (you do have a shooting board, don’t you?) until the marker touches the far edge of the pencil line.  If your marking gauge was set correctly in the first place, you should now have the correct amount of overlap to yield a dovetail that wraps snugly around the casework.

With a little thought and modification, this technique will also work with dovetailing jigs.  Simply set your marking gauge to the base of the first dovetails, and proceed as above.  Since all you’re doing is effectively cutting a board to length, the dovetailing method is really irrelevant.  Give it a try!

Advertisements

Blanket Chest – Shouldering On.

Now that the stock was dimensioned, the easy part was over – it was time for the joinery.

Blanket Chest 4

As I mentioned previously, I had thicknessed my stock to 7/8″.  The reason for this was to have a 1/4″ groove 1/4″ in from the back (inside) face of the frame, leaving 3/8″ on the front (outside) face.  Since I was planning on using applied 1/4″ x 1/4″ moldings to dress up the frame/panel joint, this would yield an extra 1/8″ “step” at the top of the molding for more visual interest.  After plowing a groove in a piece of test stock with the plow plane, I carefully transferred this spacing to my marking gauge in preparation for cutting the tenons.

Blanket Chest 5

I have a confession to make:  I’m terrible at sawing tenon shoulders by hand.  Cheeks are no problem, but my shoulders are hit or miss.  Yes, I know I need more practice – I’m a bad galoot.  But, for now, with 24 tenons to cut, I didn’t need to be making mistakes.  So, with my tenons marked, I dropped my crosscut sled into place and set up to cut the shoulders on the tablesaw.  This is still a tricky business.  Remember, the tenons are offset towards the inside surface of the frame members.  That means two separate setups, two series of cuts, and 12 chances to cut the shoulder on the wrong side, since each component has a tenon on each end.  Never has good parts-marking and workflow organization been more crucial.

Blanket Chest 6

Ah!  Success!  Some of the shoulders are cut on all four sides, and some are cut on only three.  The four-sided ones are for the internal stiles that separate the panels on the long sides, while the three-sided ones are the rails.  Since these will go into through-grooves in the stiles, they will have a haunched tenon to fill the gap.  The rough-cut version of one of these is shown below:

Sawing Tenons 6

The haunch will be cut later during the fitting process.

Blanket Chest 7

As I said, I planned to cut the tenons by hand.  So, it was time to get to sawing.  24 tenons later, I had a pile of rough-cut joinery all ready for final fitting.  Surprisingly, though, I wasn’t that tired, as my Bad Axe large tenon saw makes short and easy work of such things.

Stay tuned!

Krenov Sawhorses – Roughing the Stock

Once the boards had acclimated, it was time to rough-dimension them.  I have learned from hard experience that it’s better to make the initial rip cuts somewhat oversize, especially in flat-sawn stock.  Boards with this grain orientation have a greater tendency to twist or bow when cut, and an oversize piece gives more room to correct this.  Also, I prefer to rough-dimension stock prior to planing to final thickness.  Wide boards often have some cup to them, and ripping them to near-final width means that less wood thickness has to be removed to flatten them.

I begin the process by doing a rough layout of the pieces required for the project, picking the best combination to give good grain, while avoiding any obvious trouble spots.  I’d rather throw some stock away than include bad wood.  Then, I crosscut to workable sizes.  In this case, all the parts are going to be 3″ wide, and I picked stock in excess of 6″.  Since all pieces were paired (I’m making two bents), I could crosscut and get two matching parts from each piece.  Don’t forget to allow some extra length on each piece for later finish planing (snipe) and unexpected problems (end checking).  Life isn’t always this simple but I’ll certainly take it when it is!

Krenov Sawhorse 2

The next step is to get one reference edge on the board.  Since these edges are rough, I start with a scrub plane set light, and then finish with the jointer plane.  I’m not worried about a reference face yet – that will come after everything’s cut to rough width.

Krenov Sawhorse 3

Now that I have a reference edge, I can lay out my rip cuts with a marking gauge, being extra-generous on this first pass.  This was a good precaution, as you’ll see later.

Krenov Sawhorse 4

Now for the hard part, ripping to rough width.  A good, sharp rip saw is worth its weight in gold here.  Mine is a 6.5 ppi Henry Wilson & Sons that I sharpened not too long ago.  A coarser saw, 5 ppi or so, would make things go faster, but this one did well enough.  I used my paired saw benches to support the opposite ends of the board, giving a sawing space between them.  Fortunately, this was short stock.  Any longer, and support of the ends would have been a problem.  Oh yeah, that’s why I’m making these saw bents!

Krenov Sawhorse 5

With the cuts completed, the boards go back on the bench for a look.  Yep, as I feared, there was some bowing in some of the pieces.  That will have to come out, but we’ll save that operation for next time.  Stay tuned!

Shop Tip: Marking Dark Wood

Marking Dark Wood

The shaving rack project brought home to me the difficulty of working with dark woods such as the ebony featured in this project.  Regular pencil lines are practically invisible, and even scribed lines fade into the background without proper lighting.  One thing that can often help is colored pencils.  They are available at any office or art supply store, and come in a range of colors.  White is the most useful choice on nearly back woods such as ebony, but other colors such as bright orange or blue can be helpful on other species.  While they often mark poorly on very smooth woods due to their high wax content, the leave a very visible line on surfaces that are still a bit rough.  In addition, they are wonderful for highlighting the kerf left by a marking knife or gauge.  Grab a couple and give them a try!

Poll – Marking Gauges

Marking Gauges PollThose of us that do hand-tool woodworking to any extent are intimately familiar with the marking gauge.  This little gadget allows measurements to be transferred accurately and repeatably time after time without the need to use a rule.  Once set, it doesn’t change.

This post was prompted by a comment that Todd Clippinger made on Twitter concerning his current stable of 15 (yes, FIFTEEN) routers.  He said that, once a bit was installed and adjusted, he often would not move it until the end of the project, thus necessitating several routers.  It occurred to me that marking gauges are used the same way.  A gauge is generally set once, and not changed until all joints requiring that setting have been marked.

So, how many marking gauges do you have?