Thread: A George III Mahogany Cabinet-on-Chest

The urea I'm currently using came from Bunning's horticulture aisle (according to Mrs. Wood who purchased it). I haven't got the pack beside me, but I'm guessing it contains 500g., although I'm sure I've seen it in larger packs. 500g. would keep you going for a year or so.

As for the ratio... I adjust it as I feel the need. For some jobs I add heaps and other times I add more glue to quicken it up again. I'm not sure of exact quantities, but if I had to guess, I'd say 20%-30% urea would be a starting point. If you go much over 30% you end up with what's called 'liquid hide glue' which remains liquid at room temperature and which can be handy for quick glue-ups where you don't necessarily want to turn the glue pot on.

I would suggest adding some urea to your glue in increments and then test the results. The urea darkens the glue and I'm also guided by the shade of brown as to how quick or slow the glue is. I can also tell by how it brushes out how quick or slow it's likely to be. The urea dissolves readily, so it's not difficult or inconvenient to alter on the fly.

BTW, straight glue is considered a delicacy by most dogs and won't do them any harm, but don't let them eat any glue with urea in it... they could meet a sticky end!

Originally Posted by Woodwould

The urea I'm currently using came from Bunning's horticulture aisle (according to Mrs. Wood who purchased it). I haven't got the pack beside me, but I'm guessing it contains 500g., although I'm sure I've seen it in larger packs. 500g. would keep you going for a year or so.

As for the ratio... I adjust it as I feel the need. For some jobs I add heaps and other times I add more glue to quicken it up again. I'm not sure of exact quantities, but if I had to guess, I'd say 20%-30% urea would be a starting point. If you go much over 30% you end up with what's called 'liquid hide glue' which remains liquid at room temperature and which can be handy for quick glue-ups where you don't necessarily want to turn the glue pot on.

I would suggest adding some urea to your glue in increments and then test the results. The urea darkens the glue and I'm also guided by the shade of brown as to how quick or slow the glue is. I can also tell by how it brushes out how quick or slow it's likely to be. The urea dissolves readily, so it's not difficult or inconvenient to alter on the fly.

BTW, straight glue is considered a delicacy by most dogs and won't do them any harm, but don't let them eat any glue with urea in it... they could meet a sticky end!

Thanks WW
Bunnings would be a better source than my former customer Pivot

Do you cut your cockbeading with a beading plane, and tailed router in table, a scratch stock or some other ancient, black-art method?

Like the chest’s, the cabinet’s carcase is half-lap-dovetailed; combining mahogany on the sides with pine top and bottom. Before assembling the carcase, trenches were cut into the sides to accommodate the adjustable shelves.

During the eighteenth-century, cutting shelf supports from the solid was accomplished in one of two subtly different ways: The first method simply involved cutting trenches that encroached into the nominally 3/4" or 7/8" thick carcase sides, much the same as cutting dustboard trenches in chest carcases.

Circa 1780 mahogany secretaire-bookcase with 'cut-in' shelf supports.

'Worked-up' shelf supports required much thicker carcase panels for a more robust appearance. A rebate or moulding – the same depth as the proposed trenches – was first formed down the front interior edge of the panel, delineating a solid, unbroken carcase side panel. The worked-up shelf supports were then formed in the ancillary material in the normal way, giving the supports the illusion of being separately applied.

Circa 1790 mahogany bookcase with worked-up shelf supports.

Circa 1770 mahogany open bookcase with worked-up shelf supports.

Both these formats of shelf supports are found in ordinary and quality work alike and with this cabinet being relatively narrow (34" wide internally), I opted for cut-in shelf supports.

The 'cut-in' shelf supports.

The backboards on a chest of drawers (or bureau etc.) normally comprise several pine boards butted together (vertically or horizontally) and nailed onto the back of the carcase. Although rudimentary, these simple unobtrusive backboards serve the purpose adequately. Bookcase and cabinet backboards on the other hand are visible with the doors open and ordinary butted backboards with the usual gaps and splits would detract from otherwise fine cabinetwork. Before continuing with a solution, there's another aspect worth considering.

The carcase of a chest of drawers resists racking well; due largely to its dovetailed construction, but also in part, to its many internal structural ribs (the dustboards) and, to a much lesser extent, the drawers, but in truth, there aren't many shearing forces exerted on the average chest. However, a bookcase or (unfitted) cabinet with loose, book-laden shelves and heavy doors (especially if glazed) – whose mass shifts wildly as they are swung open – has much less to resist racking. Nailed-on, shrunken and/or split soft pine butted backboards offer little resistance to this potential degree of racking. The solution is surprisingly simple – a panelled back.

The panelled back meets both criteria; the construction is aesthetically, compatible with the associated cabinetwork and the jointed framework competently resists racking. As a bonus, the floating panels, being unlikely to split, better protect the valuable books contained within from the ingress of dust.

Circa 1790 mahogany bookcase-on-chest with panelled upper back.

My apologies; this has all been an apodictic but rather verbose justification for my adopting a panelled back for the cabinet!

The rebates in the back edges of the carcase sides were made deeper than those in the chest to accommodate the 3/4" thick pine panel framework. The fielded panels are each made up from two 1/2" thick boards, rubbed together with glue. Once glued and assembled, the panelled back was attached to the carcase, as tradition would have it, with screws rather than nails.

The panelled back.

Fielded panels.

Originally Posted by waveink

Do you cut your cockbeading with a beading plane, and tailed router in table, a scratch stock or some other ancient, black-art method?

I cut the 1/8" thick beading on the bandsaw and then shape the actual bead with an upturned block plane held in my hand. I support the beading on a finger and pull the beading over the blade a couple of times, varying the angle to create the arc. It then gets a swipe with a bit of 'paper and then burnished.

This stuff is very thin and a moulding plane or scratchstock will often shred the fibres rather than cut the profile cleanly. I use a scratchstock for 3/16" and above beading.

Originally Posted by Woodwould

I cut the 1/8" thick beading on the bandsaw and then shape the actual bead with an upturned block plane held in my hand. I support the beading on a finger and pull the beading over the blade a couple of times, varying the angle to create the arc. It then gets a swipe with a bit of 'paper and then burnished.

This stuff is very thin and a moulding plane or scratchstock will often shred the fibres rather than cut the profile cleanly. I use a scratchstock for 3/16" and above beading.

Thank you

Originally Posted by Woodwould

My apologies; this has all been an apodictic but rather verbose justification for my adopting a panelled back for the cabinet!

I am thoroughly enjoying your lessons in the background of your construction methods.
I've always suspected there are people out there doing the kind of work you do, but I've never had the opportunity to actually see this kind of work under construction.
The history lesson is a bonus on top.
Thank you for taking the time to share.
Cheers
Jim

I prefer a back with floating panels, for the same reasons as you've illustrated. Always a pleasure to watch and learn.

Originally Posted by Waldo

I prefer a back with floating panels, for the same reasons as you've illustrated. Always a pleasure to watch and learn.

From a technical stance, I would prefer panelled backs too, but being the punctilious Georgianite that I am...

I have a cabinet that I renovated and modified many years ago. It has floating panels and when I pulled the unit apart I was surprised by the very small tolerances that had been allowed for movement.

In couple of places, once all the old varnish had been removed, there were actually gaps that let light through. It took abit of rehashing to get things right.

I've often wondered whether the panels were originally cut were undersize or whether there was a huge amount of shrinkage over the years.

Hi WW,

Just a question, I've got a couple of days off and had a look at the construction detail of the lower chest in post 13 (https://www.woodworkforums.com/f187/g...4/#post1369981). It looks as though you've got the dust dividers as being two different thicknesses, wider where you've dovetailed them into the carcase end and thinner (7/16"?) where they're in the trench.

Typically, this board also acts as the kicker. On completion, do you shim out the underside edges of the dustboard so that the drawer has a kicker, or ignore it as it may be insignificant in the amount that the drawer will drop when opened?

Cheers,

eddie

As you point out, with these stepped dustboards, the drawers would drop and wear the edges of the dividers unless packers were installed to act as kickers. To this end, pieces of scrap were rubbed onto the underside of the boards after the boards were installed. Occasionally, the scraps were rubbed onto the underside of the dustboards prior to being installed and were then fitted into uniformly wide trenches.

Originally Posted by Woodwould

As you point out, with these stepped dustboards, the drawers would drop and wear the edges of the dividers unless packers were installed to act as kickers. To this end, pieces of scrap were rubbed onto the underside of the boards after the boards were installed. Occasionally, the scraps were rubbed onto the underside of the dustboards prior to being installed and were then fitted into uniformly wide trenches.

Ta WW

Makes sense.

During the first half of the eighteenth-century, cornices were simply extensions of the bookcase or cabinet carcase.

Cornice wrapped round upper chest carcase, c. 1720.

From around 1760, the cornice became a separate structure sitting atop the carcase. The giveaway is often a barely visible gap beneath an astragal, or other small moulding (the first element of the cornice), that was intended to disguise the break between carcase and cornice.

Circa 1780 mahogany bookcase with separation line visible below the bead-and-cove moulding.

The purpose of the loose cornice was two-fold: firstly, savings could be made in expensive mahogany (or other show wood) and secondly, the whole was much less prone to damage during transportation if the main elements were demountable. Breakfront bookcases are usually comprised of eight or more separate components and could not exist if not demountable.

Loose cornices consist of dovetailed (some were merely nailed together), box-like pine frames around which were applied the various moulded elements. The tops of the frames were either left open, or enclosed – which made it easier to dust the top of the piece and also provided a suitable platform on which to fashionably display an oriental vase or ginger jar.

An enclosed cornice I restored some years ago.

I knocked together a pine cornice frame and began working and attaching the composite mahogany mouldings.

The bottom astragal moulding and fluted section glued to the cornice frame.

Cutting the dentil moulding.