FLW Cabinet - #10 Starting the Leg/Rail Tenons

My first step in cutting the tenons is to precisely lay them out on the top and bottom rails carefully marking which parts get cut off and which needed to remain.  That sounds simple but it is not all that hard to set up a jig to cut on the wrong side of the line which is not a good thing. 

The order and criticality of the cuts is next.  In this case the back of the rail needs to be flush with the back of the leg.  That means the critical measurement is the distance the mortise is from the back of the leg and it needs to match the distance the cheek of the tenon is from the back face of the rail.  In a perfect world that would be the ½” shown on the drawing.  However, when measured it’s 1/32” larger or 17/32”.   The mortise is 3/8” so the tenon needs to match that.  Last, is the distance from the outside face of the tenon to the outside face of the rail and that’s whatever is left over.  The drawing below shows how everything is supposed to fit together at the bottom rail/leg joint.  The top rail is similar except the top of the rail and the top of the leg have to align.

Since the back cut on the rails is the most important one, I start there.  Using the tenoning jig test cuts are made until the cut is the right size.  Blade height is 1 7/16” which is 1/16” shy of the final tenon length.  That will be cut to exact size later.  Here is what the setup looks like after my first test cut.  As you can see, I need to take a bit more off to get to the line.  When set it’s a matter of cutting both ends on all eight pieces.

Next is cutting the tenon to width.  Here the top rails are being cut.  Their easy as both the top and bottom are the same dimension.  In this case rather than cut the tenon to the exact width of the mortise I am making it 1/16” smaller.  That way I have a little wiggle room to align the top of the leg and the top of the rail. 

The bottom rail uses the same method except the top and bottom are different measurements requiring two setups.  Here is what I mean.

At this point three sides of the tenon are done leaving just one to go.  Here is what the rails look like at this point.

On the last side I am not concerned what the distance the cut is from the face of the rail.  What is critical is when done the tenon needs to fit snugly in the 3/8” mortise.  Ideally it would be 3/8” but I am going for a hundredth of an inch oversize.  I can remove material but if the joint is sloppy it won’t give me a strong glue joint and fixing that can be done but it’s a lot more time consuming.  Being a few thousands of an inch too wide is much less of a problem as I can shave the tenon to fit with a hand plane or work on the mortise with a rasp.  The actual cut on the table saw is the same as above.

Once the tenon is sized I cut the waste off on the bandsaw.  Mind you this is not the final length of the tenon, it’s about 1/16” short.  The final cut will be made later.  Now I want to do is free the tenons up and fit them to the mortises. 

For as much care as I take in doing setups and making test cuts to assure the pieces are identical when the top rails were lined up ready for the bandsaw, I noticed that one of them was shorter than the other three.  Not the most pleasant revelation.  A chip must have gotten between the stop on the chopsaw and the board when it was being cut to length causing it to be cut short.  Fortunately, finding it now makes the fix pretty easy.  The important measurement is not the overall length of the rail but the distance between the shoulders of the tenon.  That’s what establishes the distance between the legs so all I have to do to correct the problem is to make one tenon shorter by the same amount the rail is short.

Making a snug fitting tenon and mortise joint is next.  After looking at the two parts I decided that since the inside of the mortise was the roughest, I would adjust its width in lieu of adjusting the thickness of the tenon.  The thin light-colored piece of wood is a pine blank exactly 3/8” thick that will be used to gauge the mortise width.  When it is slightly loose the fit between the mortise and the actual tenon will be just about perfect.  A couple of rasps of differing coarseness are used for the fitting.  The rasp with the blue tape is the coarse one and what I start with.  The tape is set ¼” longer than the tenon for a couple of reasons.  First, no need to size the mortise where there will not be a tenon.  Second, and more important is I do not want to damage the other side of the mortise.  There will be a faux through tenon set in it later and I want a tight joint between it and the mortise.  Any minor cleanup of the opening will be done from that side and the sizing will be done on the faux tenon piece.  More on that later.  Once I got into the rhythm of fitting things went pretty quick only two or three minutes for each of the 16 joints.

Next up – Finishing the Leg/Rail Tenons

FLW Cabinet - #9 More Leg Problems, Cutting Mortises & Peg Holes

Doing some layout work on the legs is next or at least I thought it was going to be.   Checking one last time to see if any of the legs had moved uncovered a bit of a problem with two of them.  Below you can see the gap at their center.  What was once a set of nice straight edges had developed a bow.  Naturally these two legs are the front ones where the door goes.  Trying to put a straight square door into a curved opening is not a good plan.

Straightening them required a bit of setup.  Since the legs are tapered, I could not work off the opposite edge.  Using the router with a ½” carbide spiral bit run along a known straight edge is the solution. Below is the setup.  Three legs are clamped together to make a level surface and my straight edge in this case the 8’ level is clamped down so the router will take off nothing at the low point of the curve.  That ended up shaving of just under 1/16” at the high points.

After a couple passes with the router the two legs have straight edges and fit together with no gaps.

NOW, I can start working on the leg layout.  Up until now all the legs are the same.  From here on they will be split into left/right legs and also front/back legs.  I need to carefully mark which is which as ending up with too many of one type of leg is not that hard – that’s the voice of experience speaking.  As you can see, I do put a lot of information on pieces to make it easy to keep track of what’s what.

The top photo below is the layout for the mortises and the square holes for the pegs.  To speed things up and make sure the layout is the same from piece to piece I made a jig with master layout lines.  The bottom photo shows the bottom end with the jig in place with the mortise and square holes laid out.

Since the 3/8” mortise chisel is already set up the through mortises will be cut first.  Here is the setup for cutting the mortise into the tapered face.  The machine is set so it cuts the mortise dead center and slightly more than half way through the piece.  A stop makes sure that all of the mortises start at the same point.

The order of cuts is to make one at each end then cuts between them followed by cuts to remove the remaining material.  I use full cuts because it equally loads the chisel.  A three-sided cut could cause the chisel to drift stressing the chisel/drill assembly.

After all the pieces have this cut made the piece is flipped end-to-end so the same face is against the back of the clamping assembly.  That’s so the cuts are all registered against the same face and line up perfectly.  If I were to just flip the piece over and make the cut any difference from the mortise being absolutely centered would keep the cuts from lining up and that’s a problem.  There is one other little quirk in cutting this face and that’s the taper.  Since the tapered face is now down the mortise would not be square to the first setup.  It’s not hard to fix, a short piece from the original tapered offcut is put under the leg which squares things up.  With that done the second half of the mortise can be cut so it ends up aligned with the previous mortise.  Because the leg top and bottom mortises are not the same distance from the end of the leg the whole procedure needs to be done with different start and stop points.

Once all the mortises have been cut a little interior cleanup using a rasp and occasionally a chisel was needed to smooth the surface left by the mortising chisel and clean up any small irregularities.

Cutting the square holes for the pegs in the legs is next.  Here is the top half of the cabinet to give you and idea of the leg pegs.  

 

Changing the mortising bit from 3/8” to ½” is first.  That is followed by setting the distance the pegs are from the inside face on the mortise machine because it is the same for all of the holes.  Last is to set up a roller stand on each side to support the leg when it is cantilevered way out beyond the edge of the table.  The center photo shows that except the left stand is out of the photo.  The right photo shows one hole cut and my small square being used to align the edge of the bit with the layout line.  What does not show up in any of the photos is a 3/8” spacer that fills the through mortises so when the peg holes are drilled the interior side does not blow out when the chisel exits.

After drilling 64 holes for pegs the legs can be set aside until later.  They well underway now but still need; a stopped rabbit for housing the back, final sanding and putting a small radius on some of the edges to soften them.  Below are the legs and a closeup of the bottom of the leg.

Next up are the cross pieces or rails that go between the legs at the top and bottom.  First is to sort through the blanks to decide which ones will be used in the front, the back, which will be the show face, its up/down orientation and marking them accordingly.

Since the rails are 1 1/8” thick and the legs are 1 3/8” thick and I want the inside faces flush means that the tenons are not centered but offset.  Add to that the bottom tenons are not centered vertically means there will be lots of places where things can go very wrong very fast.  Looks like I will be doing a lot of measuring and double checking before cutting.

Next up – Starting the Leg/Rail Tenons

FLW Cabinet - #8 Cutting Peg Holes, Gluing up Doors & Fixing Cracks

With the honed mortising chisel installed in the mortiser the cutting can begin.  Here is how the piece looks after the first cut of four cuts with this setup has been made. 

All told four different setups will be required.  Resetting the machine to make each set of cuts is fairly quick.  Here the second setup is being made with the heel of the square being used to assure the chisel is lined up.  The black rod on the left is the left side stop and has already been set.  Note the spacer filling the mortise.  That’s for backing during the cut to eliminate any blowout on the back side of the cut.  The third and fourth setups are done in quick succession to finish this work.

One bit of work on the table saw remains and that is to rip the stiles to their final width which will get rid of the little bit of chip out on the tenons.  After that all that remains before gluing up the doors is to drill and countersink where the screws will go through the tenon into the sides of the mortise.  Here is that setup on the drill press.  The penciled in squares are where I traced the mortised holes onto the tenons while the door was clamped up checking for squareness.  The countersink bit’s depth is controlled by a stop set on the drill press while the spacer backs up the tenon being drilled.

Glue-up of the first door is next.  Generally gluing an assembly almost always seems to me like a mad rush.  Here I am using Titebond III waterproof glue.  Not because I need a waterproof joint but because it gives me a working time of 8-10 minutes versus 4-6 for Titebond Original and every little bit helps.  It’s spread the glue, assemble the pieces, put on eight clamps, check diagonals to make sure the door is square, adjust as necessary and last wipe off any glue squeeze out.

After an overnight curing of the glue the clamps are removed and some sanding is done to get rid of the raised grain caused when I was wiping off the glue squeeze out with a wet cloth.  Below is a typical photo of the completed bridal joint.  The doors as set aside for now but will be referenced soon as they will now drive the measurements of the rest of the piece.

Next up is to do some more work on the legs.  They have been setting for a while and in checking all but three are straight and square.  The one blank that twisted when cutting the taper has relaxed and while it still has a bit of twist it’s not insurmountable.   The other two have only minor problems that should not be hard to work around.  However, two of them while straight and square have some substantial problems that need to be addressed.  This photo is from the third post Making & Using the Taper Jig that shows my two problem children.  The bottom piece’s flaw showed up while I was surfacing the planks.  For now, I plan on filling it in with black epoxy.  The third piece from the bottom has three cracks that showed up when I ripped the taper. 

Here is a closer look at the piece with the three cracks, it is the one I am going to work on first.  The center crack is the biggest most difficult to take care of as it wraps around the piece and is visible from three sides. 

Doing some poking and prodding I found that the faces of the center crack have some flexibility which will allow me to glue and clamp them closed.  The large crack on the edge would not close cleanly and the end ones would not budge at all so they will need a different repair.  The problem is how to get glue deep into the crack so it can be securely glued together.  My solution is to run a bead of glue on the top then use the shop vac pull the glue all the way through to the other face.  When clamped the glue squeezed out at the joint on all three sides confirming that it had gotten all the way through.

Once the glue cured, I took off the clamps and sanded the faces smooth.  Below you can see how the face cracks disappeared but the split on the top is still pretty ugly.

For the remaining cracks I plan on routing the flaw out and patching using a method similar to what was done on the door.   To start a line is drawn down through the center of the crack.  This represents the center of the channel to be routed.  Since the cracks are not very wide a ¼” bit in a hand held router will be used.  Next is to cut a spacer that equals the distance from the router edge to the centerline of the bit.   One edge is set on the pencil center line and a fence is clamped in place on the other side.  This will assure the center of the bit follows the pencil line and makes a straight cut.  One pass and the slot for the patch is cut.

In order for the patch to truly blend the optimal solution is to cut if from a piece adjacent to where it’s needed.  In this case the taper cutoff from this piece is going to be the perfect donor.  Because the slots are at an angle the patches need to be cut at an equal angle so the grain matches up.  After some careful layout with an adjustable angle gauge and a scale I have the three patches marked.  Shown below is the cut slots and the patches marked with chalk.

With the layout done I use the table saw to cut a blank off about 1/16” thicker than the dept of the slot then rough cut the patches about 3/32” wider than the final width using the bandsaw.

The final fitting of the patches is done using a 12” disk sander and a dial caliper shown in the top photo to sneak up on the finish width.  When the patch fits the top face is sanded down so it is just a little thicker than the slot is deep.  The bottom photo shows the patches set in place ready to glue.

After that the patches are glued and clamped in place.  Once the glue cures the patch is brought down flush using a hand plane, scraper and sandpaper.   This shows the nearly invisible finished patches; the chalk marks show where the patches start and finish.

With the patches done the last bit of preparation work is to remove the saw marks from when I cut the taper on the legs.  In the photo below I have chalked the edge to show the saw marks and rather than sanding the surface smooth I used a card scraper.  It is just a piece of steel with a burr on the edge.  The sharp burr cuts paper thin shavings off and will flatten the face in nothing flat as shown in the bottom photo.

Next up – More Leg Problems, Cutting Mortises & Peg Holes

FLW Cabinet - #7 Door Joints Part 2 & a Patch

Once the saw was ready, I wanted to guarantee that I made the cut on the correct side as I sure didn’t want to get this far into making the door and trash out a piece.  The method for preventing that is simple.  Set all the stiles together and using chalk mark which face is up when making the cut.

With that done it’s a simple matter of running the pieces through the saw then clamping the stiles and rails together to see if the joints were tight and door frame square.  It was all good, the joints are tight on the front and back plus it was almost perfectly square just clamping it together.  The top photo shows the clamping arrangement.   The bottom left is the backside of the frame while the bottom right is the front.  Also, in the bottom photos note that the tenon sticks out just a little in the front and some of the edges are chipped.  The chipping is a result of the dado blade cutting across the grain even with a sacrificial backup piece.  In this case that won’t be a problem as when I trim the piece to its final width the chips will be cut away.

There is only one problem that needs to be addressed and that is a small defect on the inside near the bottom of the door.  Here is a close view of the problem area.   The fix is to cut in a small patch using a router.

Here everything is setup and ready to go.  The router has a small straight bit in it and a guide to assure the cut is parallel to the edge plus a stop block to make the end of the cut square with the edge.

A couple of passes and here is the result.  A flat bottom recess with straight and square edges except for the back corner.  That little radius is what the round router bit leaves when changing direction.

Using a sharp chisel to square up the corner makes it ready to fit a patch in place.

When cutting the door pieces to their final length I kept the cutoffs with a chalk mark as to which piece they came off of – just in case.  This let me pull out a piece to make the patch that almost perfectly matches the color and grain where it was needed.  The cut-off the patch will come from is about 3” long and the patch itself is just under 1/8” thick.   To cut that thin a piece off that short a blank could be done with a hand saw or the bandsaw.  Since I am a lot better with a bandsaw it’s my choice.  That said I for sure don’t want to get my fingers that close to the blade.  Using a hand screw clamp let me securely hold the piece in place at 90 degrees to the blade with my fingers well away from it.

Once the patch blank was sliced off, I carefully fitted it to the recess working to get tight joints and matching the grain.  Here is the finished patch ready to be glued in.  If you look closely the rough sanding scratches from the disk sander are visible.

A little glue plus clamps hold it down, tight to the right side and tight to the top.

After letting it cure overnight, I removed the clamps and did the final fitting.  Here the patch has been brought down flush with the face of the stile.  The right side has also been trimmed flush with the tenon shoulder.  Last is to trim the edge flush.  So, you can see what’s going on the stile has been rotated 180 degrees with the patch not at the top.  The hand plane shown is a shoulder plane whose blade is a little different in that it runs the full width of the body.  As shown here the plane is on its side resting on the rabbit and trimming the patch.   A few passes and the patch is flush.  The end of the patch is even with the left end of the plane.

Here the patch is all done and I am happy with the way it turned out.  I believe after the finish is applied it will be barely visible besides it’s at the bottom of the door frame on the inside.  For scale reference a 1/16” drill bit is set at the inside corner of the patch.

Next up is the 3/8” square holes for the door pegs.  There are two faux pegs in each corner.  They are not functional pegs but plugs to cover the screws that will be used to reinforce the corner joint.

How does one go about making square holes?  There are a couple of ways, one is to drill a round hole and square it up with a wood chisel and the other is to use a mortiser.  Since I have a mortising machine guess which will be used?  A mortiser combines the cutting of a four-sided chisel and a drill bit in the center to remove most of the material while the chisel assures the edges are straight and clean.  This is what my mortiser looks like all set up ready to go.  The wheels move the bed left/right and in/out while the clamp holds the piece securely in position.  There are stops to locate the piece and control depth so once all are set you can quickly make matching repeat cuts.

To regress a moment before the cutting actually starts, I’m going to take a short side trip.  Not all equipment is fully functional when you get it and the mortiser chisels fall in this category.  Below are a couple of chisels, the one on the top is the way it comes from the factory while the one on the bottom has had some tender loving care and plenty of elbow grease applied.  There are two places where work was done and they make a huge difference.  First, is the finish on the chisel while they were all nicely ground flat and square all the little ridges left over from the factory grind act like little teeth and really hold the chisel in the wood.  The bottom one has been hand-polished to a mirror finish starting with 220 grit silicone-carbide paper working all the way up to 2,000 grit.  An 8,000 grit water stones takes over from there with the final touch being on a buffing wheel charged with polishing rouge.  The second bit of work is the inside of the chisel where the cutting edge is honed with a conical circular 600 diamond grit hone.  NOW, they are ready to use.

Next up – Cutting Peg Holes, Gluing up Doors & Fixing Cracks