Saturday, October 29, 2016

A Ming-Inspired Cabinet (76)

Lotsa pics today.

As I fit the demountable panel frames together, I fitted the assembled outer frames, rails and stiles, to the carcase:

In most cases, I found the frames just a hair tight for their openings, which was more or less by design and closely adhering to target dimensions. Final approach, size-wise, was made by hand plane:

I found that a saw horse is a handy planing beam as the frame can be assembled, or slipped, around it quite easily:

Everyone should have a joined Japanese irregular slope splayed sawhorse for this very reason. :^)

When the frame is in place, I swung around the other side to see how the miter lines were meeting the junction of rebate and infill strip:

That was the entire reason for the unequal miters.

Here the upper two panel frames have been fitted to cabinet 1:

The front faces of the frame corners have miters, as mentioned, and I omitted pics last time, so how about one today?:

Otherwise this is a standard sorta haunched mortise and tenon connection:

I will glue these connections, and wedge the tenons.

Cabinet #2 with the three rear frames fitted:

And same then for cabinet #1:

A closer look at a confluence of parts at the back, with the back surfaces of the demountable frame members still, obviously, needing a finish planing:

 Another look from inside the cabinet:

Next task was to adjust the panels so as to fit the frames, having left the panel rebating depth a little on the fat side previously:

The panel is just hanging there of its own accord, not a terribly tight fit but not so loose that it would fall out at this juncture.

Next the middle panel is adjusted to fit:

And then the bottom one:

Same process was repeated for cabinet #2.

Once the panels were good to go, I assembled the battens part way onto the panels and then drew up a rail:

Then, by sliding the dovetailed battens forward, I was then able to scribe the mortise location directly on the inside face of the rails:

Said mortise then met its fate at the land 'o the hollow chisel:

Rebates were also processed on the rails and stiles, the location of the panel dado carefully worked out in advance so as to just fit between tenon and the mitered flap housing:

 Time then to put a frame and panel together:

Clamps helped for that last few millimeters:

Next, the stiles slide on, and since the arrangement of tenons and mortise here is reversed to that between battens and rails, a self-locking assembly is realized:

Another view:

One stile in place:

Everything is just dry-fitted for the time-being:

The batten tenons are left long along one side, as they will form part of the mechanism by which the panel assembly is attached to the cabinet carcase:

A view from the front of the first assembled rear upper demountable panel assembly:

The panel is standing in the same orientation as it will reside in the cabinet, and I took care to place the panel such that it's quartersawn grain figure, which had a slight curvature, bowed upward.

A closer look at one side:

I'll adjust the gaps between panel and frame later on to some suitable size and evenness.

I'm thinking another shop session should seem me through the completion of the other panel assemblies, and hopefully their fitting to the cabinet carcases. Another day after that to do the panel clips. Once the rear panels are in, I can move on to the final fabrication task on these two cabinets, namely the front doors.

Thanks for visiting the Carpentry Way. Say 'hello' to post 77 next.

Wednesday, October 26, 2016

A Ming-Inspired Cabinet (75)

The past week or so has involved a little side work at the Museum of Fine Arts in Boston, repairing some shōji, and putting together an estimate for a Japanese ceiling in a tea room just outside of Boston - wish me luck with that - so progress on the cabinets has been slowed somewhat. Every time I put together an estimate for a job I am reacquainted with the fact that good wood is steadily getting harder to find, and more expensive all the time.

I have made progress on the frames of the demountable back panels on the two cabinets. As these rear panels are viewable on the front face only, the back of the cabinet being against a wall, the joints I chose to joint the frame corners are haunched mortise and tenons, with a mitered tongue for the front face. I will wedge and glue these connections.

As the frames abut against carcase board rebates as well as infill strips, which happen to be dimensionally different, the miters are made unequal so as to have the line of the miters meet the junctions at the corners of the cabinet properly. This is the sort of detail nobody will likely notice, but it's the sort of thing that, when I see it overlooked in casework or finish carpentry I happen upon, disappoints slightly.

Here are the parts after the rails have been tenoned and rough-mitered, and the stiles have been mortised:

A closer look at the stiles:

I then moved to cutting the miter housings on one end of each of the stiles, after which I could start fitting the joints up:

These 4 stiles were cut at exact length to fit the opening, because I simply had no extra stock to draw from. The rail's surface sits a hair proud, however when finish-planed that will be cleaned up - same goes for the outer faces of the stiles.

A closer view:

On the other sets, I was able to leave the stiles long, with little 'horns', though these might be a bit on the meager side length-wise:

Normally you leave the horns on so as to allow for tight mortise and tenon fits without risking the end of the stile splitting open, and I think in some woods longer horns are all the better. These shorter horns sufficed for the bubinga - they had to.

A view of the tenon exit faces-  I'll be flaring the mortises to wedge them, so the vertical tolerance could be a little loose:

This is about half of the joints fitted, and horns trimmed down:

I'm not sure why, but I neglected to take any pictures of the miters, however those pics will be coming along in the next post.

Another view:

The next session in the shop, tomorrow, should see me through the rest of the miter joints, and then onto the dadoes for the panels and mortises for the panel battens.

All for this round - thanks for visiting! More thrills and spills ahead with post 76.

Saturday, October 15, 2016

A Ming-Inspired Cabinet (74)

Both bonnet tops are now ready for finish:

I'll save final assembly until I have applied finish to the parts individually. I'm also working on a decorative element for the front of the bonnet riser panel. More on that at a later date.

Next up is the second-to-last construction task on these cabinets, namely the rear demountable panels. Perhaps it is worth explaining some reasons as to why I am making the panels demountable, as it is hardly the easiest way to fit back panels to a cabinet. After all, once the cabinets are full, you can hardly see the back panels. Perhaps I should just nail some rough sawn boards on, planed only on the face that shows? Perhaps a secondary wood should be used, as the client is unlikely to have any reason to directly specify bubinga back panels. Plywood is certainly a common choice for back panels.

Well, while there are certainly virtues to economy and frugality, virtues that might guide my endeavors in other spheres of activity, that's not what this project is about. The argument that because something isn't directly obvious it should not be given the same elaboration as other elements has never carried any weight with me.

I'm making the back panels out of quartersawn bubinga, and placing them in separate frames, also of  bubinga. These frames will be attached to the cabinet such that their removal will be a simple affair at any point in the future. Why does this approach offer an advantage? Well, consider for a moment if your task was to refinish the cabinets. Would it be easier to refinish the back panels in situ, or with them removed and laid flat? If the panels or their frames were to get damaged, the fact that the units can be easily removed means they repairs can be enacted, without any recourse to surgery on the main cabinet parts. Sure it is extra work to prepare cabinet back in this manner, but I feel it is well worth it - and I'd like to think that it let's the craftsperson who fixes this cabinet at some later point when I am long gone that I was thinking of him/her when I built it.

The panels were prepared from rough stock months ago, first down to 0.5" thickness, then allowed to sit for 3 months, and then taken further down to 0.375" thickness, and then allowed to sit a further three months. They have remained very flat though that process, so I'm confident they will continue to behave that was on into the future - even more so, as I have reinforced their backs with three dovetailed battens each:

At this juncture, the battens are little more than roughed out and only started in the fitting process.

A closer look:

The strategy of stiffening thin panels with dovetailed battens has a long history and is very commonly seen in the best Chinese classical furniture. It's a sign of quality work, even to the point that it became a copied design element, sans sliding dovetail (unfortunately) in later works, both in China and Japan.

Solid hardwoods are heavy, and therefore it is a good plan to keep panels thin wherever possible. Thick slabs of wood, like tabletops, say, can also be reinforced with dovetail battens, however there is a sort of cascade effect there which makes them a less desirable solution in many instances. Why? Well, for a batten to have a significant role in keeping a panel flat, it needs to be stiffer then the panel, which means significantly deeper in section, or, if the panel is a softer and weaker wood, it could be made simply out of a harder and stiffer material. I'm not sure where the precise line might be, but I would imagine that a batten which is two times as deep as the panel is a reasonable starting point. The deeper the better. With a thick table top however, say 1.5 or 2", then you would quickly end up with battens that were anywhere from 3~4" tall, or more, and this might be detrimental to design in other respects, practical or aesthetic.

Making the panels thin keeps them light, and appropriately sized battens keep them flat. Trenching crosswise breaks up the run of the grain, giving the panel decreased ability to warp or bow over time.

There is another major advantage to frame and panel construction with dovetailed battens, besides the obvious fact that it allows a wide panel movement within a framework and keeps panel flat. The connection of battens to the panel with sliding dovetails, and then battens to frame with mortise and tenoned joinery, allows the frame to borrow shear resistance from the panel itself. This is a major boon to door construction, and I will be employing it on the bifold doors for this cabinet.

With the panel backs, the shear strength aspect is relatively unimportant since there are no shear loads on the panels, however I thought I would make mention of it as a side benefit all the same.

I cut the sliding dovetails without taper, employing a jig along with router and guide bush to make the dovetail grooves, and then router table to make the dovetail males.

Even with careful work, sometimes a bit of debris gets between the guide bush and template, or if I decreased side pressure for a moment while cutting, certain parts of the groove can end up with niggling areas of interference. For that, there is a handy Japanese plane called a hifu-kura-ganna to make slight corrections:

Another view:

This plane can be a little tedious to adjust, but it does the job for sure:

The first of the wide (middle) panels with battens all fitted:

Another view -the batten has been planed and chamfers and tenoned, it might be noted:

 A batten is properly fitted when it is a snug fit and yet no so tight as to cause the thin panel to bow:

 At this juncture I have completed the work on the battens and panels for both cabinets:

As for the cabinet frame members, they are cut to width, thickness and length, and I have commenced layout for the joinery. I'll detail the work on those pieces in the next post.

Thanks for visiting the Carpentry Way. Oh, and by the way, I was invited recently by the Woodworker's Guild of America to submit this blog for an awards contest. I'm certainly not going to do that myself, however if you do like what you read here and would be willing to vote your support, then please take a moment and click on this link to register your vote for favorite woodworking blog - even if it isn't this one. And if I win, I get a million dollars or something like that. Well, maybe something less grand - possibly, at a minimum, wider exposure for this blog on the world wide web. Seems like that would be a good thing. Next up in this thread is post 75.

Tuesday, October 4, 2016

A Ming-Inspired Cabinet (73)

While working on the BCM tansu for the past few weeks, I have also been chipping away at the cabinet project I have been engaged upon for some months now. Been doing some finishing, some hardware patination, and a little construction here and there.

At this juncture, I've just fitted the middle panel to the top of the bonnet:

As the bonnet's upper frame rails are curved, the panel initially is proud at both ends from the frame:

I sized the panel so as to be just at matching height with the frame in the mid-point area:

A while later, I had the second middle panel (as there are two cabinets under construction) similarly fitted to its frame:

Taking the panel down so as to match the frame rail curves was accomplished by hand plane, commencing with some cross-grain passes to remove most of the excess material:

Another shot of the same:

Eventually I had shaped the panel surface flush to the frame rail:

Then, after repeating the just shown cross-grain planing work on the other end of the panel, I commenced planing along the grain, down the hill each way from the apex:

That was a good workout, and it went smoothly and produced a clean surface without plane blade tracks. I think that's the general idea with the tool. The plane completed the work with just the one sharpening to start, which was jolly decent of it. Genmyō is my friend.

Once the planing was done, I scuffed the middle panel with #320 paper in preparation for the finish application.

The smaller side panels had been previously fitted and shaped to the curved frame rail sections at each end:

Knocking things together, just to corral the parts so I could set the assembly aside for the time-being:

With the panels installed in the upper section, this first bonnet is largely complete now:

The three panels are not all cut from one board, as might be ideal, however the top surface of the bonnet is not a visible area of the cabinet, unless the viewer is 6'8" or taller. A minor aesthetic shortcoming I suppose, but of no consequence.

Another view:

I should have bonnet #2 to the same point after another day in the shop. Once the bonnets are done, my attention will turn to the last two construction tasks, namely the demountable frame and panel backs, and then the bifold doors.

Thanks for visiting the Carpentry Way. Comments always appreciated. Post 74 is up next.