Tresoor of castle Hernen Part 9: The crown

This blogpost continues the story of the making of the dressoir or tresoor for Castle Hernen and concerns the top or crown of the tresoor. We were presented with new challenges with regards to the construction. For our tressor, we wanted to have a similar look and feel like the crown of the tresoor at chateau Langeais, however, photos from the outside do not provide much information of how this look is actually achieved. Demolishing a medieval dressoir would likely solve this, but of course nobody would allow us to do that - we also would be very reluctant to such a thing. 

Left: The top view of the Langeais tresoor. The top consists of three joined boards, whereby the top planks are integrated in the side decoration of the crown. Right: The side view of the crown with the decoration. Wooden pins are visible that fix the crown to the frame of the tresoor.

Our crown has a slightly different construction, as the top boards fit inside the decorative rails (For thee langeais tresoor the top boards are part of the decoration). The decorative parts of our crown consist of 5 pieces with a decorative profile and one flat one without decoration. The latter is at the backside of the tresoor. All these six parts have a rabbet on top on which the top boards rest, and a rabbet below to fir over the frame of the tresoor. First, some square oak stock was prepared, after which the rabbets were made with a router table. The rabbits had a similar depth, but a different height. Thus, we only needed to adjust the height of the router, while the guiding rails could stay at the same place.

The back rail had no decoration, and only the two rabbets.

Next the decorative profile needed to be created. This was more challenging as also stability of the oak stock when moving it across the router bit had to be taken into account. It is important to consider which part of the profile has to be routed first. We used a round bit as well as a V-bit for routing the profile, and finished it by hand using a scraper.

Left: The first rounds of routing have been finished. Right: the middle part has been rounded with a scraper.

The small decorative groove in the (round) middle was made with a V-bit. The stock was securely fixed between 2 guiding rails on the router table.

The finished profile of the crown.

We borrowed a crosscut saw to make exact 45 degree cuts. A fake multiplex frame was made onto which the parts of the crown could be temporarily fixed with screws. The holes made for the screw were later used for wooden pins to fix it to the real frame of the tresoor. 

Left: The fake multiplex frame. Right: the size of each part of the crown was measured and tried on the real tresoor as well.

Testing the pieces on the tresoor frame.

The fake frame with all the front parts screwed and clamped with diamond shaped pressing blocks (left), and with the back rail and a middle supporting rail added (right). 

We used two doublesided dovetails to fix the crown parts of the 45 degree angles together. At the backrail a normal single dovetail joint was used. An additional rail was added in the middle to stabilize the crown and support the top boards. This was fixed with dovetail joint on the one side and a mortise joint at the other side. 

(Left) A paper dovetail was used to mark the place for joining. (Right) The plan for the two doublesided dovetails. Due to the 22.5 degree angle of the joint, the doublesided dovetails also have different angles. Also the second dovetail is much smaller.

The angle ready for cutting. Some wooden blocks and an underboard were used to clamp the crown pieces and stabilize them for cutting with a chisel.

The fixed crown pieces from the side. The dovetail marking can be seen on the top.

A thin strip of oak was used to make the doublesided dovetails. These were sawn out and then cleaned up with a chisel. The doublesided dovetails were glued with hideglue to the crown.

The strip with the small dovetails (4 + one spare).

(Left) Sawing the doublesided dovetails. (Right) The 'raw' small dovetails.

Fitting the doublesided dovetail in the joint.

The crown with a mdf top board on the tresoor.

Next, the top boards needed to be added. The top consisted of three boards that were connceted to each other with a tongue and groove joint. The boards are not fixed and provide an alternative way to open the tresoor (for instance if the key is lost). If necessary they can be fixed with some pins. 

The top with a mock mdf top.

Two of the three oak top boards are ready.


The complete top boards of the crown.

The crown was fixed to the tresoor with pins using the same the holes (inside the frame of the crown) that were used for the screws earlier. On the outside of the crown, some extra pins were added to fix it vertically . 

The finished crown of the tresoor.