Green & Green Settee Part XIV

Center Splat:

The center splat is nothing spectacular to look at.  It will be hidden by upholstery.  However, it will be visible from the back so I want the joinery looking nice.  The splat will have integral tenons and they will be flush with the front (which means there will be no front shoulder, only a back shoulder - this makes things a bit easier).

I had cut the mortise in the back rail long ago before glue up.  I need to cut the mortise in the freshly fitted crest rail.  First, I'll go ahead and remove part of the rabbet with a handsaw and shoulder plane.  While the mortises will be "centered" on both the crest rail and the back rail, it is pretty difficult to get perfect alignment.  Consequently, I'll put side shoulders on the bottom tenon and cut the tenon a bit narrow so I can adjust it side to side.  I will not be able to do that up top with the rabbet.

 

Ok, its time for the tenons.  One can take one of two approaches.  1)  treat one of the tenons as a straight tenon and the other as an angled tenon 2)  treat both as angled tenons.  Now, the former sounds like it would be easier, and perhaps it is a tad easier.  For example, one could treat the bottom tenon as a straight tenon and only angle the top.  But there is a big disadvantage.  Since the entire splat curves back quite a bit one would need a very thick board to make this work.  Also, the top tenon would end up compensating for all of the angle and we will probably end up with a weak tenon.

Option 2 is much more forgiving on the amount of wood required since we can angle the board.  Also, both tenons are angled but the amount of angle on each is not too bad.

First, I establish the relationship between the two tenons.  I put temporary floating tenons in each mortise and glue a piece of plywood to both:

 

The splat front will pretty much have the same shape as the rear posts.  So I use my rear post template to layout the shape.  Then I place the splat jig onto that layout to determine where the tenons will go.

In the photo above note that I have marked where the shoulder will be.

Ok, now I need to cut the tenons.  First, I need to know my angles.  I've learned long ago that if one wants to build chairs then one needs at least 2 bevel gauges - top/bottom, left/right, etc .  Starrett bevel gauges are excellent and well worth the few extra bucks.

I'll use my tablesaw to cut the tenons.  I have a high tech tenon jig (the Mach 7 Tenon Jig) with a perfect 90 degree face to which I will clamp the splat.  Given this fact,  I clamp my splat to a 90 degree surface.  I could use the Mach 7 Tenon Jig but I find it easier to clamp to my jointer fence, which is also 90 degrees (note that the splat has been milled flat and square).  Note that the splat jig is clamped to the workpiece.  After getting the angle for the first tenon, I carefully flip the workpiece and use the other bevel gauge to measure the opposite tenon, making sure that the splat jig stays firmly clamped and does not move.

 

 

Then I clamp it to the Mach 7 Tenon Jig:

Now, given a right tilt blade, there is a risk that the blade could ruin my Mach 7 Tenon Jig.  Fortunately, I have enough wood in front so that this does not happen.  In the photo above, I have cut the front face of the tenon.  I move my fence to the right and cut the back part of the tenon.  My table saw fence has a micro-adjust on it - which makes it easy to dial in for a nice fit.  Still, I leave it a hair thick and finalize the fit with a shoulder plane.  Note that the rear shoulder was rough cut with a bandsaw to allow me to test fit the tenon.

Once the tenon is fitted, with the same blade angle I cut the rear shoulder.

I go through the same process for the opposite tenon, using my other bevel gauge to set the saw blade.  I then cut and fit the other tenon.  Note that I am a bit conservative when cutting the shoulder.  I do not want to remove too much so that there is a gap between the shoulder and the crest rail.  So cutting the top shoulder may require creeping up to the final fit and a pass or two with a shoulder plane.

I bandsaw the front profile and here is the splat in its rough state:

To shape the splat I use a shoulder plane, rasp, spokeshave, sandpaper.  If one had a long belt sander this would work as well and faster - but the hand tool approach goes quite fast.  If the splat was wide or had a more complicated shape (i.e. a Chippendale style splat) then the hand tool approach would be the only option.

Here is the back where it meets the crest rail:

Before glue up I clean the ends of the crest rail with a sanding drum on my drill press.  I get very close but leave a smidgen which I can easily sand down flush with the rear posts after glue up.  The end flares out a bit - a thick 1/8" or so.  This gives it a nice look.

 

While I'm at it, I shape and glue on side cleats for the rabbet.  Later I'll glue on some strips at the bottom to complete the rabbet all around for the upholstery. 

If I build this again I will probably integrate the bottom rabbet into the rear rail rather than glue on cleats. However, for the sides I need to glue on cleats unless I go with lumber thicker than 8/4.

Green & Green Settee Part XIII

As much as I try to control the ebony dust via dust collection, it still gets everywhere.  I wash my clothes immediately and the next day enter the shop with clean clothes.  However, once I start working the cleanliness lasts about 2-3 minutes - tops.  I vacuum around as much as I can to get the dust removed.

Time for the crest rail!  It starts off as a slab of lumber - just over an inch thick.

 

I begin the shaping first.  My first template based on my drawing represents only half of the crest rail.  I create a full size template off of the half size template.  The template is extra long to allow for screws at the ends.  I will also create a rabbet in the crest rail.  At the location of the rabbet I throw in some extra short screws.  A 1/2" template can still flex and once I cut the rabbet those screw holes will disappear.

I use a rabbeting bit and go thru a series of bearings to get to a final rabbet 1/2" wide and 3/8" deep.  Fortunately, I had no major wood movement after doing so (unlike what happened to my front rail!).

Where the rear post meets the crest rail I need to remove the rabbet before cutting the mortise. (I am using a floating tenon - the rear post already has a mortise on top).   I mark the location and cut the shoulders with a handsaw.  Now, I am by no means a beginner with the use of the handsaw.  Nonetheless, I use it infrequently enough so that I do not trust cutting exactly to a line.  I leave a little meat and then use a chisel and pair to the line.  I place the chisel in the knifed scribe line and then gently tap with a hammer so that the chisel exactly follows the scribe line down the side of the shoulder.  Light tapping gives me a lot of control and excellent results.

After bandsawing the waste I then use a shoulder plane and a wide chisel to clean the area. I just check for a 90 deg surface vis-a-vis the front of the crest rail.  I'll fine tune the fit after cutting the mortise which will allow me to see how the crest rail actually fits on the rear post.

 

I take it to the multi-router and then cut the mortise.  I used a scrap piece of wood first to adjust the mortise location height before cutting the real mortise.

 

With my first fitting I was actually pretty darn close!

I had to use a shoulder plane to tweak the crest rail shoulder area to close a few very small gaps here and there.   

I've decided to quit here.  I'll write another post where I build the center splat which is worth its own post.  If you want to build chairs then the next post will be very worthwhile, as most traditional style chairs have curved splats.

Green & Green Settee Part XII

The last thing to do before the major glue-up is to install the ebony plugs on the arms.

I only mark the center of each plug.  Then I use a template with different square sizes to draw out the plug locations.  Helps to keep the plugs somewhat level.

  

 

I am using Veritas plug cutters.  These work great.  Although the next photo does not show it, I also use a square to position the plug cutter for the first hammer strike.  After that the square is no longer needed.

With the plug cutter positioned, I install the drill bit and twist the drill bit by hand  to mark the center location.  I remove the plug cutter then drill down about 5/16".   The photo above shows the plug locations immediately after drilling.  Then I use a small chisel to clean out some of the wood.  I find the plug cutter will not penetrate deep enough unless I clean out some of that wood.  Then I re-install the plug cutter and hammer down to get clean shoulders and back with the chisel to remove all those goobers at the bottom.

I recommend reading Darrell Peart's book on G&G techniques, in particular the part about preparing the plugs.  He uses a jig on a disc sander to define the initial pillow - then swipes by hand using the higher grits.  I do not have a disc sander so it is all by hand.  This is a rather tedious endeavor.

I start with 120 on a hard surface.  I find it does not take too many swipes - but no matter how careful I am I have to fiddle around to get all the shoulders even.  This is where Darrell's jig would save a lot of time. Then I put 150 sandpaper on a sanding pad and make a couple swipes.  The sanding pad helps to define the pillow on the top.  Then I remove the 150 paper then use the 220 pad directly.  Then I use 320 and 600 on the sanding pad.  Only a couple swipes are necessary.

I use a buffer on a dremel tool to buff the top (with some buffing compound), cut the plug by hand with a fine saw and a make shift MDF miter jig and then bevel the sides.  I cut the plug about 1/4".

Note that I also install plugs at the various other locations on the legs and rear posts.  When finished with the plugs, I'll go ahead and buff the ebony spline.

TIME FOR GLUE-UP!  At least for the base. 

The sides are already glued up.  I did not photo the glue-up.  Glue-up is somewhat stressful and having someone follow you with a camera can be annoying (even though that person may be myself).  I ran one or two practice runs just to make sure the clamping strategy is in place.  If a joint binds I want to make sure I can deal with it appropriately.

I did the base glue-up in 4 steps.  1)  Glue the sides together (already done) 2) glue the center rail to the front and back rails  3) then glue the center assembly (i.e. center rail, back rail, and front rail) to one side assembly  4) then glue the whole contraption to the other side assembly.  All the joints were 90 degrees except for the center stretcher.  I had angle blocks taped to the side stretcher to create a 90 degree clamping surface for the center stretcher.

After glue-up I installed a round dowel from below into the center stretcher tenon and then capped it with an ebony plug from above (I cut the holes before assembly).  The round dowel actually penetrates the tenon.  The ebony plug is decorative.

Green & Green Settee Part XI

Time to glue up the sides.  Here I'm preparing the tenons for wedges.

Now, I like to drill a small hole at the base of the saw kerf.  Not sure if it works, but it does seem to reduce the risk of splitting.

Glue-up...

Next glue the arms on and then drill a hole into the back of the post to secure the arm with a #12 wood screw.

The screw hole will later be covered by a cleat upon which the upholstery back will rest.  While I have the glue out, I'll glue the cleats onto the side rails (upon which the seat will rest).

 

Now I need to smooth the front and back transitions where the arms meet the front legs.  I left the arm slightly thick in both the front and back for this purpose.  For the back transition, I tried a couple techniques with the Blacker House arm chair - shoulder plane, carving gouge, small scraper, etc.  I found that a straight chisel works best followed by a file and sand paper.  Works very well.

Now its time for the ebony splines.  I use a bandsaw to cut the profile and rough cut the thickness.  Then I use a small Jet 10-20 drum sander for final thickness (a wonderful machine, I must say).

 
IF I WERE SMART, I WOULD CALL IT A GO AND GLUE UP NOW!  Well, in an attempt to be clever I rough cut the splines thinking that this would save work later.  Wow, was this a mistake!!!

After gluing up the first spline (which went just fine), the second spline decided to split - which went all the way into the groove.  Here I'm frantically trying to glue the split back together, swearing in the meantime.  I believe those swear words are still dangling in space somewhere above my fluorescent lights.

Of course this did not work.  I tried to perform a local repair, but to no avail.  I had to quit and then take another full day off from the shop after this incident.  I then decided to take a few more days off to visit my grandparents.  Time is the best healer.

A few days later, I went into the shop calm but resigned to the fact that I would have to 1)  chop the entire groove to remove the old ebony, 2) expand the groove to renew the edge, 3) and then do the same on the other spline on the other arm so they would be consistent.  This would have to be done by hand as now, with the sides glued up, I could not use the router table.  On the Blacker House arm chair I cut the groove by hand to begin with, so I knew that this is a very feasible task.  Furthermore, at this point I definitely trust my hand tools over using the router hand held to re-cut the groove.


However, on a whim, I decided to see if I could chop out that top spline without mucking up the side walls.  I didn't think this would be possible.  The glue bond would prevent this.  However, with patience this worked!   I use a 3/16" chisel to chop away the ebony center.  With some testing, I was able to find a spot or two on both sides where the ebony chipped away from the side wall just enough to act as a reference edge upon which I could rest my chisel.  With a reference edge, I was able to carefully (and slowly) pare away the remaining ebony from the side walls.  I think the ebony, being very brittle (which caused the split in the first place), allowed me to do this.  For most other woods this probably would not work.

Now, there is still some yellow glue residue in the groove.  I'm a member of the Siskiyou Woodcraft Guild.  We have some very fine furniture makers in the guild with a lot more experience than myself.  I talked to one and he said that as long as I rough up the surface of the side walls the yellow glue will stick to itself.  Since this is a non-stressed joint I'm totally find with this answer.  So, I use a small file and carefully file the side walls, beginning just below the top and only pushing down.  I do not want to damage the top!

Below is another ebony spline fitted and glued into the groove.  Notice that I left copious amount of wood this time!

 

All in all, this mistake set me back almost a week.  However, the project is once more moving forward and not backwards.   I use a coping saw to cut away most of the extra wood.  Then I use a dremel with a course sanding drum to level the spline.  This works very well and fast. 

How proud should the ebony be above the surface?  Obviously, it should be the thickness of a "CharlieCard"...

When I went to North Bennet Street School a couple years ago we used the CharlieCard frequently as a thickness gauge.  I still have a couple.  The CharlieCard is the MBTA train ticket.  Who needs stinkin' rulers anyway!

I'll spare you the dreadful details of sanding, only so say that I take it up to 320 and round it over so it feels good to the hand.  Later I'll swipe it with 600 and then buff it out for a nice shine.