The very latest project LaPlaca Woodworks will be undertaking is Boston style Blockfront chest, the chest has been modeled in Sketchup I know it seems kind of strange to combine 21st century design software with 18th century designs, but I have found that 'virtually building' the project in Sketchup really helps when we start with the real wooden components, this is the second piece of furniture that LaPlaca Woodworks has been completely modeled in Sketchup, the first piece was the Boston Oxbow chest that is currently featured in Chests
As our first entry in this blog we will show what the modeled chest will look like, this particular chest was modeled after a chest featured in the book Boston Furniture of the 18th Century on page 81. This chest is going to be built from South American Mahogany that LaPlaca Woodworks has sourced from Irion Lumber, the secondary lumber is Yellow Poplar that has been sourced from Groff and Groff Lumber. The chest features four graduated drawers that will be carved from 12/4 mahogany stock the chest is 35 1/2"h x 21 9/16"d x 40 w. At this point we still haven't made a decision about the style of brasses (either a escutcheon or rosette style pulls).
I promised myself that going forward we need to do a better job documenting the progress on projects, that is the purpose of this blog that I have created. Anyway.. Although it's not the most exciting post in the world, I have documented the lumber selected for the main part of the case,the lumber we buy at LaPlaca Woodworks is all rough sawn lumber, at this point the lumber has been rough milled +1/8" over in thickness, then stickered and stacked to let the lumber re-acclimate, before final milling..
It important to point out that none of the lumber required for the drawers or the back of the case is included in this stack of lumber, after we start assembling the case we will then rough mill the lumber for the drawers.. Then after after we start the assembly of the drawers we then mill the stock for the case backboards..
Templates are yet another reason we at LaPlaca Woodworks have been prototyping our 18th century reproductions with Sketchup, it's not the easiest thing in the world to print a full size template from the non-professional version of Sketchup, but it is possible. When completing complicated pieces like the Boston Oxbow or the Boston Blockfront the templates are very valuable
The lumber for Boston Blockfront chest has been finial milled to thickness, the photograph is of the chest top which consists of two boards of Mahogany, one of which is 16 inches wide, the finial dimenstion of the top is 42" long x 20" wide x 13/16" thick. We use hot hide glue for all glue up's, the glue is period authentic and also has the added benefit of being very reparable in the future, unlike many modern adhesives.
Here is where the Sketchup templates that have been printed and mounted to Baltic Birch plywood start to pay dividends, the next three pictures we are template routing the front moulding, then profiling the front and side base mouldings...
Here we are attaching the prepared template to the 1 9/16" thick Mahogany stock.
Next after bandsawing the profile oversize then using a Whiteside spiral flush trimming bit to match the template exactly..
Next after profiling the front and side mouldings with a Whiteside Cove and Bead bit..
Nice and crisp profile..All that needs to be done is to cleaning up the sharp corners with some carving tools..
Next we need to cut the half blind dovetails on the bottom of the case sides. The first photo is of the dovetails marked out, then sawn, the pencil marks remind us which is the waste that needs to be removed..
Next up is the all the jointery, first the bottom of the case sides and the case bottom are assembled using half bind dovetails cut into the case sides. The dovetail pins are cut by hand, then as a tip we borrowed from Glen Huey we remove much of the waste with a forsner bit in a drill press, then chop out the remaining waste...
The front moulding on the bottom of the case it then jointed to the front of the case bottom with the signature Boston giant dovetail joint..
The case sides then receive a shallow dado and finally the dovetail sockets for sliding dovetail for the drawer blades (aka. dividers)..
Finally the top of the case sides receive the signature sliding dovetail pin that will secure the top of the case to the case sides..
First we are pattern routing the drawer blades using a 1/4 " spiral double ball bearing flush trimming bit..
Next we need to need to start creating the beading on the drawer blades, this is done with a 3/8 slotting bit in two passes...
Finally the actual bead is cut using a 3/32 radius beading bit with an oversize bearing..
The beading on the drawer blades is not complete, as the router cannot cut the bead in the sharp corners, this needs to be completed by hand using carving gouges and some riffers (note how the bead is now properly shaped in the 90 degree corner)...
Next step to remove the excess material from the sliding dovetail pins on the drawer blades, as the drawer blades actually stand proud of the case sides (as seen in the picture above) by a scant 1/2 (15/32 actual), this leaves room for a moulding that is applied to the case sides, that contains the cockbeading for the front inside edges of the case.
Now on to the dust panel construction, the whole sub panel assembly is made of Yellow Poplar. Behind the Mahogany 'drawer blade' (or drawer divider) is the drawer blade sub-back, it gets glued to the front drawer blade and rides in a shallow 1/8" deep x 7/8" wide dado in case side. The drawer blade sub-back receives a 1/4" w x 1" deep rabbit, as does the rear drawer blade, the rear drawer blade also is dovetailed into the case sides using a blind sliding dovetail..
Each of the drawer divider rails received a 1/4" x 1" tendon on both ends, we cut the tendons on the tablesaw using a dado stacked cutter. The one inch thick piece of MDF makes sure the tendon shoulder is properly spaced, but gives us proper clearance when using the miter gauge. Using the miter gauge and the rip fence (without a spacer) is not a safe practice, it is a kickback waiting to happen..
And finally this is what the semi-finished drawer blade sub-back (we are still missing the actual dust panels themselves) looks like. The gap at the back is intentional, it allows for the case sides to expand and contract.
Now onto the Boston Blockfront case top, the case top starts as a two board glue up of Mahogany 40 1/4 " x 20 3/4" x 13/16". First we need to create the sliding dovetail socket that will attached the case top to the case sides. First we need to create a dado in the underside of the case top, it's a pretty good size excavation, 20 3/4" x 5/8" x 1/2", this needs to be staged with a plunge router..
After we create the dado, next we use a 14 degree x 3/4" dovetail bit plus a 3/4" bushing in a fixed base router to create the sliding dovetail, no staging the cut here...
The case top has a pattern that is a 7/8" offset of the pattern of the drawer blades, we make a plywood template of the offset, then use the plywood template to pattern route the front of a piece of 40 1/4 x 20 3/4" x 3/4 MDF..
The full size MDF pattern will be used to pattern route the front of the case top, it will also be used when the edges of the top are profiled, a full size pattern is necessary as the the whole edge of the top will be profiled. Since the top is so large, rather than wresting with the top on the bandsaw, we use a saber saw to remove the waste on the top..
Now off to the router table with the mdf pattern attached to case top to pattern route the front edge with the 1/2" spiral double ball bearing bit (this bit is awesome)..
Then finally using a special 18th century table edge bit by Amana Tool designed by Lonnie Bird, we profile the front and sides of the case top. This bit removes a tremendous amount of material, so we stage the cut by replacing the stock 5/8" bearing with larger bearing, taking 5 passes with a smaller bearing in each pass, finally ending up with the stock 5/8" bearing installed (as pictured)..
It's been a while since we have posted updates to the progress of the Boston Blockfront project since we have been busy finishing the Boston Oxbow chest project.. I have to say that finishing is my least favorite furniture building activity, lots of sanding, more sanding and then some more sanding...
Anyway, in a prior blog entry we moulded the bottom of the case mouldings, now the front moulding needs to be 'detailed'. Here is the bottom moulding as it comes off the router table..
Now notice that the profile is 'rounded' in the inside 90 degree corner, this is as far as the bearing guided router bit can reach, the remaining material must be 'detailed' using carving gouges and rifflers. Now the after photo..
Actually the beaded area below the cove and fillet area also needs to be detailed, but it's not shown in this photo..
The front base moulding on the Boston Blockfront chest needs to be mitered before the moulding is glued to the case bottom, mitering this moulding is not as simple as tossing it on the miter saw and cutting a 45 degree on each end (unfortunately).. The miter joints are actually miter lap joints, this reinforces the weak miter joint and also allows the bottom moulding side pieces to float on the case bottom for expansion and contraction.
The photo below shows the bottom of the front moulding, the two miters are actually a 90 degree flush cut that lines up with the outside edge of the case sides and then the required 45 degree miter, unfortunately I got caught up in the action and forgot to take a photo of the miters being cut. We needed to use a 45 degree miter sled on the table saw to cut the miters with the blade at full height!!
The underside of the front moulding also contains a 'pocket' that is one half of the miter lap joint.. This will make more sense when we see the side mouldings in the next photo..
Next with the side mouldings, we cut a giant 2" wide by 7/8" deep rabbit in the top of the side moulding, seen being cut on the table saw..
The side moulding with the finished rabbit.. The rabbited area will now fit under the case bottom and case side joints, the rabbit also allows the side mouldings to meet up with the front moulding that sticks out proud of the case bottom by....11/16"
The off to the trusty Kapex to cut the miter joints, the Kapex is nice in that it will cut a horizontial 45 degree miter both left and right, the Kapex also has a nice feature where the depth of cut can be limited as shown here..
Finally the finished front edge of the bottom side moulding (the right moulding shown here), notice how the stub tendon will fit into the pocket cut into the front bottom moudling (yeah yikes)
Next we are machining the bracket feet for the chest, the back are fairly straight forward, the Mahogany 1 3/8" back side feet are half blind dovetailed to the 7/8" thick Yellow Poplar back foot. The front foot, is a conglomeration of a Mahogany 1 3/8" front side foot mitered to a 2 1/4" thick front foot, the extra thickness is needed to allow the front feet to follow the blockfronting bulge on the front lower case moulding. The feet after being band sawn and spindle sanded..
The back side feet being dovetailed..
An assembled back foot..
Front feet receive a 1/4" dado that will contain a spline, notice how the miter is offset..the excess material will be cut off the front foot to match the profile of the front case molding after the foot is glued up..
Dado being cut with two outer blades of dado set, with blade set at 45 degrees
Front foot with spline test fit into the dado, now ready for glue up..
Now after the front feet are glued up, we need to go off to the bandsaw to profile the front of the feet, first we load a nice sharp 3/8" band into the bandsaw. The front feet are clamped to a jig that holds them 90 degrees to the bandsaw blade..
Next the front of the feet are bandsawn.. The first cut removes the flat area in the front of the feet...
Then the profile that follows the bottom of the case molding..
Next we need to miter the ends of the drawer blades (aka. dividers), the ends of the cock beading is mitered to receive the front case side mouldings, the front case side mouldings complete the cock beading up the sides of the drawer openings...
The best and really the only way to perform this job is with a block profiled to 45 degress clamped to the drawer blade and a nice super sharp paring chisel to pare the material, in this case my trusty Blue Spruce paring chisels are used..
Now the block is clamped to front of case side moulding and them we pare the miters after the center of the area is dadoed by sawing with a razor saw and removing the excess material..
One Completed miter job, 5 more to go..
Finally with the front side moulding glued into place..
Now we need to start the process for the drawer fronts, the drawer fronts are milled from 12/4 Mahogany stock to a finished thickness of 2 5/8". After the drawer stock is milled to length, width and thickness, we next need to start the actual shaping process, after the drawer fronts are fully shaped the final thickness of the drawer fronts will be 7/8" net!!...
First the ends of the drawers where the drawer sides are dovetailed to the fronts are milled much as if we were creating a mortise joint, first the tendon shoulders are cut (not pictured) then off to the tendoning jig on the table saw to mill the ends so they are 7/8" thick..
The very first and most important face to establish is the flat surface where the drawer sides meets the back of the front drawers..
Here is a shot after the face is cut..
After we have eastablished the face for the rear of the drawer then next cut establishes the front of the drawer..
One of the reasons why we have been using Sketch Up as late of is it allows us to create very intricate and accurate patterns needed for the more complicated pieces, like this blockfront chest. Now using the printed pattern affixed to Baltic Birch plywood to draw the profile of the drawers..
Now off to the bandsaw to first establish the shaped front of the drawer, the extra material on the rear of the drawer front makes it somewhat easier job at the bandsaw..
The the drawer fronts are cleaned up with carving tools, rasps, files and block planes (ice tea is optional)..
After completing the shaping of the drawer fronts it's now time to bandsaw and clean up the rear of the drawers... I found it best to stay clear of the very tight curve at each side of the rear of the drawers, instead we just established some 'steps' that makes the carving job a little less daunting..
Getting close to the final shape of the rear of the blockfront drawers, just need to clean up the flat areas..
Next we need to fit the hardware to the drawer fronts, whenever we get to this stage at LaPlaca Wood Works we know that we are getting close to the end of the building stage. The brasses for this chest are Chippendale style escutcheon pulls sourced from Londenderry Brasses, we used CH 70 pulls and CH 71A escutcheons. The posts for the pulls were too short for the 7/8" drawer thickness, so we needed to counter bore the rear of the drawer to receive the cast nut..
Couldn't help myself here is a shot of the drawer fronts with the fitted brass pulls..
After the building of the project has completed, the next step is finishing preparation. It has been said that after the building has completed, the craftsman is only 50% completed with the project, I am a firm believer in that age old saying, finishing takes that long.
First step the finishing preparation is completely sanding the project to 180 grit. After sanding to 180 has been completed, the entire case is then wiped down with distilled water. The distilled water step raises the grain, we need to perform this step since the case will be dyed with a water based dye. The raised grain is then smoothed with 220 grit sanding.
After the case has been sanded and grain raised, the next step is to treat and end grain with a stain blocker, I use 3/4 lb blond shellac as a stain blocker. The treated end grain is then smoothed with gray Scotch Bright pads. If the end grain is not treated, it will dye much too dark.
Last step in the process is mask off any areas that we don't want to be dyed, with Scotch Blue Painters tape.
Actually the most important step in the finishing process, is to come up with the entire finishing 'schedule' (or recipe) that one is going to use to finish the piece. This schedule should be performed on scrap pieces from the project (ideally), or at the very least on scrap pieces from the same species. For instance the water based dye we use a LaPlaca Woodworks to accent the color of the South American Mahogany used on the Boston Blockfront chest, contains no binders, so after the dye drys the wood takes on a completely different appearance, that usually is just terrible looking. Each successive step in the process changes what the final color will look like, so unless the complete finishing schedule has been pretested, the final outcome will be a surprise (maybe a good or bad surprise) at $15+ a board foot for Mahogany we would like to keep surprises to a minimum.
First we use a very diluted water based dye to accentuate the color of the South American Mahogany, as I previously mentioned the dye contains no binders. This means the dye can be moved and to an extent removed with simple water, to 'lock' the dye we brush on a couple of coats of 1.5lb cut blond shellac.
After the shellac has dried, the chest gets abraded with gray Scotch Bright Pad and then gets an oil based glaze based on a gel stain. The shellac serves two purposes here, one to bind the dye into the wood, secondly to keep the glaze coat from 'grabbing' the wood too aggressively, so the glaze can be moved about. The glaze accentuates the the dye and adds a dimension to the coloring that either product alone cannot achieve.
After the glaze has dried properly (in a couple of days), we then apply a couple of coats of shellac, in the case of this chest the shellac used is a garnet shellac at a 1.5lb cut. The garnet shellac helps to slightly color the wood (garnet shellac is reddish brown in color) additionally and adds chatoyance to the finish.
Finally we add a couple of very 'tightly' applied coats of Waterlox Original Finish to the chest, Waterlox is a very durable phenolic varnish that has a very nice semi-gloss glow after 3-4 weeks of curing..
The finished project is located here..