Green & Green Blacker House armchair - part VII

Splines and attaching the arms and glueing up the splats!

Here is the original.  Check out the beautiful ebony splines on the arms.

Before attaching the arms it makes sense to cut the splines in the arms.  Now, if I build this chair again I will definitely attempt to cut the splines on the router table before glueing up the chair. Unfortunately, I have already glued up part of the chair to make cutting the splines with a router table impossible.

I could try routing free hand.  On Darrell Peart's website I see that he cuts the top arm splines free hand for his rocker (not sure about the splines under the arm). I toyed with the idea of using a router free hand.  But I seem to have had trouble getting the router positioned correctly to handle the parallelogram shape of the arm - especially with part of the chair glued up already.  I did not have a warm and fuzzy feeling using the router free hand.  One thing about the parallelogram arms - a bearing will not ride flush to the bearing face but on edge with the consequence that the bearing will dig a nice bearing groove into the wood.  I wonder how folks handle this.  I tried on some scrap and got bearing marks on the wood - even through a couple layers of tape to protect the wood.

I finally decided to grab the marking gauge and chisel.  I will use the marking gauge to define an undersized groove and then chop a 1/4" deep mortise with a chisel.  Since it is undersized I will not worry about thrashing the side walls a bit.  This went surprisingly fast.  I aligned the chisel not 90 deg to the surface to be chopped but inline with the parallelogram side walls - so that the spline will slide in properly along the entire length.  Note that the front inside edge of the arm is a flat reference surface.

Oh yes, I also cut the spline groove along the underside of the rear post - much easier now before glueing up the splats.

Note that the final groove size for the front of the arm (top and below) is 5/16 and the groove size on the rear post under the splat is 1/4".  Consequently, for rough cutting the undersized grooves I cut 1/4" grooves up front and a 3/16" groove on the rear post.


Now that the grooves are roughly chopped, it is time to glue up the arms, drill and insert the screw to reinforce the rear arm to the rear post, and then plug up the screw hole with a 1/2" square ebony plug.

I had some small scraps of ebony so I defined the ebony plug by hand planing 2 reference surfaces (90 deg to each other) and then using the bandsaw and hand plane till it fit the mortise.  I shaped the top of the plug to give it a pillow effect - using sandpaper then eventually the buffing wheel (see Darrell Peart's book on how he does this)


Now that the arms are attached to the chair I can then define the final width of the grooves with the marking gauge.   No chopping here - just slicing.  Since I will be slicing very little wood I can also go pretty deep to help define the side walls about a 1/16" deep.  I then used a chisel to define the side walls all the way down, being very careful not to gouge the cleanly sliced top edge.


OH NO!!!!! Everything was going fine until the very last groove on the top of the right arm.  I got distracted than came back and did not tighten the marking gauge - the gauge wondered off course and, oh crap!  Well, after much cussing, regrouping, cussing some more, I had to re-define the groove with the marking gauge for the top of both arms - to fix the mistake, re-center the groove, and then to make both arms consistent.  Well, rather than a 5/16" groove on top I now have a 7/16" groove.  Did I say I am sorely pissed?  Needless to say, a 7/16" ebony spline may look heavy and lack balance with the other ebony splines and later the plugs.  Did I say I am sorely pissed?

Well, time to move on (did I say I am sorely pissed?). 

Nothing like a new machine to lift up the spirits.  During this time I bought a Jet 10-20 drum sander.  I bought this sander specifically for handling small pieces that can be awkward or dangerous in a planer or tablesaw.  I can sand a piece as short as 2 1/4" inch long - and sand off only a thousandth of an inch - a nice feature when dealing with ebony that costs an arm and a leg.  I'm using only 120 grit - rough enough to take off material without burning but not too rough to leave a nasty surface.  (I would not use this drum sander to sand lots of board feet.  I think one would have to go to a much more powerful machine for those tasks).  

Below I bandsawed the ebony spline for under the splat then used the drum sander to get a perfect fit.  (I will make a rolling cart for the new machine later).

For the arms, I cut out some paper templates to represent the inside curve of the spline mortise.  I cut a piece of ebony to rough thickness on the bandsaw and then used the drum sander to achieve final thickness.  Then I layed out the inside curve on the ebony and bandsawed that curve out.  I had to clean the side walls of the spline mortises here and there - being careful to not touch the cleanly sliced top.

I had to fix one side wall that got dinged up a bit - I'll glue the fix during final glue up.

Then I used a pencil to mark out where the spline meets the surface - and then bandsawed the waste about 1/8" over.  Here is what they look like.

I then glued up the arm splines underneath then prepared the top splines the same way as the bottom splines.  I had to cut new ebony since the top spline is now 7/16" wide (did I say I am sorely pissed?).

There was a little bit of fussing to make sure the 2 spline sections were nice and tight where they meet.  I used a shooting board and handplane to slice the lower spline length shorter till I got a nice tight fit.

Glue-up.  I took some sandpaper and sanded a bit of mahogany-glue slury to fill any minor gaps around the spline.

Now for final shaping.  I tried using a rasp but a couple times I came dangerously close to blowing out the ebony side wall.  I grabbed my dremel and slapped on a coarse sanding wheel - this worked very well and got me down to about 1/32 over.  I then used a combination of file, sandpaper, and spokeshave to get the final shape.

Are the top splines too heavy???  Because the spline is now so wide it appears rather flat.   Oh well - move on.

While I'm add it - now is a good time to glue up the splats.  Given that there are so many splats and those little doohickeys between the splats I glued the splats in 2 phases.  First, I glued the splats to the bottom rail - dry fitting the top crest rail only.  The next day I glued the top crest rail.

It's finally looking like a chair!

Green & Green Blacker House armchair - part VI

Decorating the center splat!

With limited experience with inlay, I looked forward to this next phase with excitement and some trepidation.  The center splat has a lot of splash.  I knew it would take some time and I was right.  Now, someone said that the craft of woodworking consists of being able to cut to the line (and you are an artist if you cut beyond the line as you are then in unchartered territory).  Cutting to the line is tough if you cannot see the line!  Consequently, much of my struggle with the inlay was dealing with lighting and attempting to see the scribe line.  Well, half way through the inlay process I broke down and ordered an Optivisor DA-4 from Stewart-Macdonald.  They arrived just just when I finished the center splat.  No problem, as I have already used the Optivisor going forward.


First I chopped and routed out the various negative spaces.  Negative space is just as critical in the design of a piece as the positive space, and the Green & Green designs are wonderful in their mastery of negative space.

I really like those 2 squigglys!  It takes some confidence to take a beautiful piece and throw in some squigglys here and there.  I may have been able to come up with something like those in 4th grade - but now after years of software engineering my artistic expression has become ossified by too much precision - so exploring the artist free-expression of these old masters is liberating.  Now, one could argue, by attempting to reproduce and copy this original, that I'm striving towards too much accuracy (in contrast to precision).  However, I'm learning a lot about design here so I think it is worth the investment.

Next are the tulip vines.  I'm using white oak here.  I think the originals were white oak as well.  I used double stick tape to hold the vines while scribing.  Since they are so thin I would have obtained a better result by using an acetone based model airplane glue (i.e. duco cement). Those that do guitar inlay will use duco cement then release the piece with a bit of acetone. 

After the glue dried I hand planed the vines level with the surface.  I had to go and fill in a few gaps with glue and dust.  Next time I will sand the surface during the initial glue up to fill in the gaps.

Next are the various small pieces at the base of the vines.  I think the original chair may have used purple heart (not sure).  I used silver - for some extra splash.  I have some 14 gauge silver wire that I bought from Rio Grande.  I took the wire and hammered a flat surface above and below.  After cutting to various lengths using an electricians wire cutter I clamped the small rectangular silver with a piece of wood and filed the ends square.

Here are the pieces cut and layed out to plan:

Now, scribing would be difficult with double stick tape.  I could use duco cement then release with acetone.  But I was afraid that the acetone would seep into the vine section and do who knows what to the yellow PVA glue holding the vines in place (acetone is some pretty nasty stuff).  Instead, I grabbed a hammer and tapped the silver, leaving a nice impression.  David Price, who does absolutely beautiful carving and metal inlay on gunstocks, uses this technique to inlay silver into gunstocks (see http://www.davidpriceflintlocks.com/ ).  The trick is not to hit too hard and crush the fibers excessively - which I may have done with one or two.

I then took the dremel and routed to the necessary depth (only about 1/16").  I used a knife to shave the edges for final fitting.

Once they were fitted, I did not glue in place.  I need to route out the tulips first since the silver will be slightly proud of the surface and may interfere with the tulip routing.  Consequently, I cut the tulips, used double stick tape to scribe the cut lines, then routed.  The double stick tape worked ok, though one shifted a bit and created a gap which I later had to fill in with glue and dust.

By the way, getting the tulips to look something akin to tulips took more than one attempt!

I did not route to the line (could not see the line well enough).  I routed close and then sliced the edges with a knife.  This worked reasonably well.  Upon receiving my Optivisor I did a test inlay and routed directly to the line no problem - and with better results.  Its nice being able to see things clearly.

For glue up, I started with the silver using thick super-glue.  After drying overnight I leveled the silver with a file (protecting the surrounding wood with tape).  After that, I then glued the tulips in place.  The tulips are proud of the surface by a about a 1/32, then rounded close to the surface at the edges for a nice pillow effect (I used a shallow carving gouge and sandpaper for this).

 

Now, the tulips in the original chair has some texture with a carving gouge.  I took a gouge and highlighted the tips a bit:

Except for some light sanding here and there, the splats are done!

Green & Green Blacker House armchair - part V

Splat doohikeys!

Those spacer blocks that tie the chair splats together, what are the called?  Doohikey will work for now.  There are 8 doohikeys.  Here is the original so you can see the objective - a great design.  One thing to note is that the 4 outer spacer lengths (from top to bottom) are slightly longer by about an 1/8" than the inner spacers - one of those small touches that makes a difference I think:

I suppose there are more than one way to install them.  I believe some folks may edge glue the spacers to the splats and I think others edge join with screws.

As I quickly discovered, those 2 techniques are problematic with my chair since I hand shaped the splats as well as beveled the outer edges to lighten them up.  The four narrow splats curve back, curve out, and have beveled edges and are each slightly unique. In the photo below you can see how the splat appears thinner in the center where it is beveled.  The top and bottom are not beveled and are noticably thicker.

The splats are 1/2 inch thick.  During the design phase I had a difficult time  determining from the photos of the original chair the correct thickness of the splats and whether or not they are beveled.  The more I look at the photos the more I think 1/2 inch may be too thick.  Beveling the edges is a great way to lighten up the splats and reduce the perceived thickness.  Now, I only beveled the "outer" edges.  For the center splat, both edges are beveled since both edges face out.  I did not bevel the inner edges because I felt that an inner bevel would have conflicted with the over-all curvature of the base as well as the angles of the side seat rails.  I did not test this out with a sample, so I may be wrong.  I look forward to seeing the original to answer these questions!

Here is a photo of the spats ready for the next phase.

The original builders mortised the doohickeys - which is what I will do.  Still, mortising requires laying out a mortise - which is difficult without reference edges.  I could not use a marking gauge.  Consequently, I came up with this cute little flexible jig to lay out the mortise on the beveled or outer edges using a marking knife.  The space is the thickness of my doohickeys - 3/16".  Now, I only used this on the outer or beveled edges.  I will lay out the inner edges later.

Here is the center splat with the mortises chopped out.  I chopped them by hand.  I could not use my small dremel since the edge was beveled.  (Next time, perhaps I will bevel the edges AFTER I cut these mortises!!!)

Next I fabricated the doohickees.  They are about 3/16" thick and the length is 1" for the 4 inner spacers (next to the center splat) and are 1 1/8" thick for the 4 outer spacers.  I pretty much just bandsawed and handplaned the spacer to final thickness.  So, here is the first spacer:

Nice fit!  But, ooops!  As you can see, because the splats are layed out along an arc the spacer is way off center against the next splat.  That first mortise would have to be chopped at an angle so the spacer lines up correctly with the next splat.  It could probably be done but it is too late for this chair.  I could taper one side of the mortise.  Instead, I tapered the spacer itself:

One edge of the spacer in the mortise will not have a good glue surface with the mortise wall.  I could use epoxy.  However, I do not expect a lot to happen with these little fellows so I think there will be enough glue surface all around to make things hold.  I think next time I will cut the mortise at an angle.

With the spacer lined up correctly against the next splat I used my marking knife to lay out the next mortise.  Because this next mortise is on the inner face of the next spat, which I did not bevel, I could use my dremel to cut the mortise:

Here are the doohickeys installed (dry fit).