04 October 2021
Roll out this barrel of delight
We live in a country prone to droughts, but we also love colour on our patios and in our gardens… so what about this as a container for colour? It’s small enough for even a balcony, and very easily scaled up – or down.
This particular one has 12 staves (the vertical pieces that make up the sides of a barrel), and they are 450mm long, but you can scale the barrel up by using 15 (3 feet), 16 (4 feet), 18 (4 feet), 20 (5 feet), 21 (7 feet) or whatever number of staves suit you. Bear in mind, however, that the above numbers are governed by the number of feet you might want…
The one featured here has four feet, which are simply four of the staves at 360/0°, 90°, 180° and 270° left at their full length with the pair on either side of each foot cut away in an arch.
- Treated SA pine – 22x69mm – 4 lengths of 1.810m*
- Aluminium band – 2x19mm – one 2.5m length
- Stainless steel pan head screws – 22 of 10 gauge 19mm length; 6 of 10 gauge 25mm length
*The number of lengths mentioned here includes that required to make up the barrel’s base. As it happens, stock ran out, so I used a substitute, but when making one for yourself, include what you will need for the base. Also ensure that if you increase the diameter of the barrel, then extra timber will be required for the base. Take that into account.
- I cut the 12 staves each to a length of 450mm. this ensured that there was no waste at all, as I could cut four from each length of 22x69mm treated timber, allowing for +-2mm for the width of each cut, to use up the entire 1.81m length.
- When arranging your staves, it makes sense to arrange the cut ends to be the top of the barrel… so these will be the tops of the staves on the completed barrel.
- Get my point? The factory cuts have discoloured over time, and some are rough, but will be hidden if they are the ends at the bottom of the barrel.
- The easiest way to line everything up is clamp the first stave to the end of a sheet of hardboard, MDF or whatever, as purchased from your Mica…. The manufacturers cut at a very precise 90° – making it easy for you to line everything up properly.
5. Next step was to position all 12 staves, with 12mm gap between each (I used a few short lengths of a piece of timber 12mm thick for this), and then cut the first aluminium strip to length. Rather cut slightly too long and then trim if you have to. The strip has to overlap the first stave to its full width and the last stave to the equivalent of its full width – this will become clearer further down. Hence, the strip is 69mm longer than the total length of the staves so that one end of the strip slips under the other. Now bend what will be the upper end of the strip joint up about 30-40°. This lifted portion is 50mm long. Now put a 2mm spacer (a couple of washers will do, at the point of the bend and then bend the cranked 50mm portion down again so that you create a zigzag bend. Ensure that both bends are made at 90° to the strip length so that when viewed from directly above, the strip and 50mm raised end are exactly in alignment.
- This is how the end of the strip, with its bend is positioned at the other end of the strip will fit over the other end.
- Measure the distance from the bend to the end of the stave plus the 12mm spacer… this is the amount by which the other end of the strip overhangs the last stave.
- Cut the second length of aluminium strip from rest of the 2.5m length (in this case it left about 500mm over).
- Now bend it as you did the first… so that they match up as shown here. Note that the first end of the strip has been temporarily and loosely attached to the first stave with a 25mm screw just for setting the spacing and the strip in position.
- Now drill a pilot hole in the strip at its centre point, and the midpoint of the stave
- And secure each with a single 19mm screw. The screw length in this case is the length from the tip to the base of the pan head – so 19mm will not penetrate the other side of the stave. This is important as the barrel will be lined with 250 micron black plastic and you won’t want any screw tips puncturing it. To space the strip above what would be the bottom of the barrel, I simply used a length of the 22x69mm timber.
- This shows the 19mm screws used to attach the staves to the strip, and the 25mm screws used to secure the ends of the strip to each other, and to the stave.
- Another view to show how the strip is attached, a spacer between the first and second stave and the second stave fixed to the strip.
- At this stage, I clamped the cranked end of the second strip to the first (in an inverted position), and rounded off the ends of both. This is not essential, but the ends do look better when rounded off.
- I attached the top strip to the staves exactly as I did the first.
- Then I flipped the assembly over and brushed away any aluminium swarf (the curled bits of metal cut when the drill bit made when I drilled through the strips. This is essential so that nothing can puncture the plastic lining.
- Now I rolled the assembly roughly into a round barrel shape – now you can see clearly how the ends of the strips fit together… the end left squared will fit under the raised portion of the other end.
- A view from the top showing how the gaps between the staves close up, but not completely. Beware… if you do not leave a sufficient gap between each stave, they will not be able to be rolled into a barrel shape at all.
- I removed the loosely attached first stave and with the ends of the strap clamped as shown, set the gap between the second and last stave at 80mm. this would provide a gap of about 5mm on either side of the stave between it and its adjacent staves.
- This is how the ends of the strips come together. Neat!
- I used three 25mm screws to secure the last stave in position and the ends of the strip.
- Now comes the crafty bit… I measured the OUTER circumference and it was exactly 1000mm. so now to work out the diameter/radius of the base… so, a little geometry for you… come on, you remember it from school, right?
The circumference of a circle is arrived at by multiplying pi (π [3.142]) by its diameter or 2x its radius. Hence, if you know the circumference, you can calculate the diameter by dividing the circumference by 3.142. It this case it gives you a figure of 318,3mm (give or take a couple of points of a millimetre). Divide that by 2 and you arrive at a radius of 159,1mm.
That, however, is the OUTER radius, and the base fits within the barrel, so I subtracted 22mm per stave thickness on either side of the barrel to arrive at a radius for the base of 137mm.
- First step was to cut the pieces for the base.
- I checked before joining them that they would accommodate the radius of the base. Then I drew diagonals from corner to corner to establish the dead centre.
- I set the compass.
- And inscribed the circle for the base.
- I ripped some offcut wood to make two strips and fixed them to what would be the underside of the base…
- I ensured that no screw was even close to the cut line – jigsaw blades are quite expensive!
- Then I repeated the centring of the circle on what would be the top side of the base, and cut it out with a jigsaw.
- Then I inserted the base into the barrel from the underside, positioning it 69mm (I used a little offcut of 22x69mm timber as my space setter.
- Senior moment admission #1… I should have done this before forming the barrel, but at this stage, I created four feet… I used one section of the base leftover to mark off two arcs on four quadrants of the barrel.
- Then I used the jigsaw to cut them away.
- As shown here.
- I used four of the offcuts from this operation to act as supports for the base – I attached one each to each foot inner surface as shown. As it happens, the base was an extremely tight fit, and probably would not move anyway, but why take the chance?
- Senior moment admission #2… I should have drilled the 40mmØ drain hole in the middle of the base before fitting it… but didn’t. So I did it now. In passing the barrel is perfectly circular, but the cut-outs for the feet, when the picture is taken from directly above, give the impression it is now a square with 45° corners. It isn’t.
- Now for the plastic lining. I used 250 micron black plastic – it’s strong and highly durable (it’s used in buildings as a damp barrier for example) and cheap. I cut a section large enough for each side to overlap the top of the barrel. And then came the crafty part… I poured boiling water into the barrel, and topped up with water from the hot water tap. This softens the plastic and makes it easy to gently by using a length of wood (that water is hot!) to tamp the plastic into the shape of the base. At the same time, I used a 16mmØ dowel to indent the sheet over the drain hole. Then I left the water overnight to cool. This set the plastic’s shape.
- The next morning I syphoned the water out of the barrel and set it to one side for later watering of the plant that would go into the barrel. This shows the base with indent in the plastic sheet in the drain hole in the base.
- This is how the plastic looks from the underside of the base… a sort of cone shape.
- I used a heated bolt to make a hole in the middle of the plastic. This ensures that water draining out does not touch the base at all.
- Then I used staples to pleat and secure the plastic to the sides of the barrel. The stapling can be pretty untidy as it will not be seen and in any event, the staples will soon rust away. But in the meantime they would have done the job… keeping the plastic lining in place while the soil in the pot settled.
- I used a piece of 22mm offcut and a utility knife to trim the plastic neatly around the top of the barrel.
- I used some layers of shade cloth as filters to keep the drain hole clear and prevent soil loss.
- Cloth first, then some gravel.
- Followed by a couple more layers of shade cloth. These all act together to allow excess water to drain away, prevent the soil becoming waterlogged, and prevent soil being lost, or blocking the drainage hole. I finished off by adding potting soil to the barrel, planting the plant in it, and water from the plastic-forming process to water the plant well in.
How’s that for adding a little colour to the patio?
These materials are available at Selected Mica Stores. To find your closest Mica and whether or not they stock the items required, please go to www.mica.co.za, find your store and call them. If your local Mica does not stock exactly what you need they will be able to order it for you or suggest an alternative product or a reputable source.
TIME: two days
Jigsaw and/or circular cut-off saw**, drill/driver and 40mmØ spade bit, hacksaw, stapler, utility knife.
**You will need a jigsaw to cut the arches for the feet and to cut the circular base. You can also use it to cut the staves to length, but a circular cut-ff saw for the latter makes it far easier to achieve a very straight cut.