Handsome & Co Educational Taster: The Coopered Vessel
To cooper is the traditional craft of creating wooden ‘staved’ vessels for the transportation of goods, were a stave is the term given to each piece of timber which makes up the coopered vessel. Advances in material technologies such as plastics and cardboards has seen the art of coopering all but disappear from modern society, apart from the use in wine and spirit barrels. Throughout history the barrel has to be the most common of all the coopered vessels, the purposes of these vessels varied in accordance with their intended purpose and as such the level of craftsmanship also varied, a summary of these variations is as follows:
The most basic of these was the ‘dry’ style of coopering, these allowed for the transportation of bulky dry goods like fruit, cereal or nails. The next style was the ‘dry-tight’ style which were also designed for containing dry goods while keeping moisture out, primarily used for the likes of gunpowder or flour. Both of these versions of the coopered vessel were typically crafted from pine due to its quick workability.
The ‘white’ style of coopering saw the creation of straight staved vessels for the transportation of liquids, these were the likes of buckets and washtubs. The highest level of the coopered vessel is the ‘wet’ style, which are typically used for the long term storage and transportation of liquids like wine and spirits and in the most highly crafted versions could store liquids like beer under pressure. The latter style of coopered vessels are typically crafted from white oak as this best meets the requirements of porosity, workability, strength, weight and character. The rays which typically characterise white oak provide additional strength and bendability, while still retaining relative stability during (dry) shrinkage and (wet) swelling.
The cooper traditionally hand selected the trees for use in these highly crafted vessels as the shape of the tree and the growing conditions determined the textural quality of the wood fibres, the fineness of the grain and the tannin content found within. All of which contribute to the quality of the finished product stored within the barrels.
Once the tree has been selected and fell the logs were then split by hand in order to preserve the wood grain and not break any of the fibres, which was essential to making the barrels impermeable to outside influences that may affect the taste and aroma of the goods stored within. Once split, the staves would be air dried to reduce the moisture content in the timber, the maximum moisture content achieved via air drying is usually around 15% and was calculated for half a year per 10mm of softwood and 1 year per 10mm of hardwood. During the drying process the staves are left in the elements to allow for the harsher tannins and impurities to be purged from the timber. This process would typically take several years. Even with the implement of modern machines and materials, the barrel making process has remained relatively unchanged throughout history.
The process to create a version of a coopered vessel for this terms educational taster and make it achievable within the 3 hour class was a bit of a test and meant we had to streamline a few of the processes. Like most tasks within the furniture workshop the initial task involved accurately marking out the stock.
The marking out provides a reference for the 6mm thick plywood base of the vessel to slot into, the initial shoulders of which are cut by hand using a tenon saw and then cleaned up back to the marked shoulder and valley of the slot using a series of appropriately sized chisels, ie a narrow chisel and mallet to remove the bulk of the material down to the valley of the recess and a wider chisel without the mallet to pair back to the shoulders of the recess.
One of the process which has been streamlined in order to make the task achievable in the allotted 3 hours was the creation of the 22.5 degree angle needed to make the 8 staves meet back together, one side of each stave was was angle prior to the class which meant the students had on angle to create in each stave. To achieve this we used an angled support with a shooting board, a shooting board is an aid to allow you to plane smaller pieces of timber more consistently and accurately. The marking out for this was the other reference the students placed on the staves at the beginning. It is crucial at this step to not rush and ensure each stave is reduced to the same size and angle in order for the vessel to come together properly.
The students are then provided with a square piece of 6mm plywood which needs to be marked and shaped down to match the octogonal shape of the vessel. The dimension along the base/valley of the slot equals 26mm therefore each side of the base needs to be equal to this. Once marked out, the base is roughed out using the bandsaw and then refined to shape with the disc sander. Students also have the option to add an individual flourish to their vessel by adding a chamfer to the top edge of each stave. This process is also completed using the disc sander, the chamfer also provides a visual softening to the vessel as a whole.
The next stage is to give the internal faces of each stave a quick sand and complete a dry run to ensure the vessel will come together perfectly prior to the final glue up. To glue the vessel together, students placed all eight staves onto the bench with the internal faces all facing down and all the recessed slots to the same side. Then, using strips of masking tape along the top and bottom of each stave, they stuck all the staves together and by giving the tape a small amount of stretch while taping down meant the tape would help provide some of the clamping pressure needed during the glue up. Then by flipping the taped staves over the students could then apply a small amount of glue to each side of the staves and in the recess for the base, place the base in the slot of the first stave and wrap the vessel together. To assist in clamping pressure the students then utilised a couple of large rubber bands around the top and bottom of the vessel. After the clamping pressure allowed enough time for the glue to dry students could then remove the rubber bands and tape and give their new vessels a sand and coat of finish all ready to become a pencil case or utensil holder or whatever else they could envisage their new vessel becoming.