Monday 9 July 2018
The ring box started as a commission for architect Stuart Macalister, who, in true architect style, sent me some very detailed drawings of what he had in mind. The brief was that the box should be smooth, streamlined and fit beautifully in the hand – and as a box for an engagement ring, it had to look the part, too! During subsequent discussions the design evolved, the materials changed and this is what we ended up with. Pink ivory (Berchemia zeyheri) and African blackwood (Dalbergia melanoxylon) aren't the cheapest of woods to use, but others can be substituted if you want to reduce the outlay.
To ensure all the components were as stable as I could make them, all the blanks were cut and then left to acclimatise in my house rather than in my workshop, which, being unheated for most of the time, is not as dry as the house. The blanks were only returned to the workshop when the box was made. Hopefully this would ensure the lid remained a good fit after the box was completed.
I was trying to work out how the box could be made to hold the ring without it rattling around or falling out when the box was opened. My solution was to cut the bottom half of the slot slightly wider and line it with kid leather so it would give a little and grip the ring. The slot in the top insert would be slightly narrower to hide the edges of the leather.
Mount one of the box blanks in a chuck, cut the surface flat and cut a chuck spigot to fit your chuck jaws. My spigot was cut to fit 35mm dovetail jaws. You will see from the photo that my blank was octagonal. I sometimes cut blanks this way when the blade I have in the bandsaw is too wide to cut the radius of blank I am cutting. In practice, it only takes a couple of cuts on the lathe to get the blank round and it's also kinder on the bandsaw blade. Do the same with all the other blanks while you have chuck jaws mounted to hold them. Mount the first box blank in the chuck and cut the face flat. As this was side grain, I used the half-round scraper but the spindle gouge could also be used to do the same job
The next step is to use the square scraper to drill the first hole, which is 30mm wide x 14mm deep. You then need to check the sides of the hole are parallel using internal callipers. Adjust as necessary to get the hole to the right dimensions. Open up the wider hole – which needs to be 45mm wide x 6mm deep – to check the sides are parallel
Check the dimensions using Vernier callipers. Use the spindle gouge to cut the outside of the box to a straight cylinder just over 65mm in diameter. Make sure you don't run off the edge of the blank and potentially cause splintering of the edge
Once this is almost to size, take a few sheer cuts using the wing of the gouge. The shavings should be very thin and wispy. This should leave a good finish on the surface of the wood
Use the spindle gouge with edge trailing – as you would for a scraper – to bevel the corner of the box. Take very light cuts so minimal sanding will be needed. This will ensure the detail stays crisp and the corners stay sharp. Sand the surface of the box to 600 grit, making sure you don't round over the flat surface. Reduce the lathe speed when sanding; this will reduce the heat and avoid heat checks. Mount the 35mm blackwood blank in the chuck and clean up the surface with the round scraper. Check for flatness with a steel rule as before
Cut a section of the blank to 30mm diameter using the spindle gouge. Check the fit in the box
Use a pair of dividers to mark the end of the insert with circles of 20mm and 16.5mm diameter and also draw a line through the centre. These marks will be used to cut the slot for the ring later
Use the 2mm parting tool to part off the insert at 8mm thick. I found the easiest way to do this was to start parting off slightly wider and cut to the correct width before parting off all the way
Mount one of the 50mm blackwood blanks in the chuck. Cut the surface flat and cut the diameter to 45mm. Use the 2mm parting tool to define the depth of the insert but don't part off all the way. Use the round scraper to cut the semicircular hollow. As this is side grain, cut from edge to centre; this will leave a better finish
Once the hollow is the correct width and depth, round over the corners using the half-round scraper
You can now sand the surface and sides of the insert to 800 grit. Blackwood will show up any scratches left by coarser-grit abrasives so you need to go pretty fine and again, reduce the lathe speed when sanding
Part off the insert and mount it in the chuck – or jam chuck – so you can true up the back surface and mark it out for the slot. This one should have circles scribed at 20mm and 17mm and a centreline
The next step is to cut the slot in the 30mm insert to 3.5mm wide, using drills, piercing bits and files as required. Bevel the top edge of the slot so the edges of the leather will be hidden from above. Cut the slot in the 45mm insert to 3mm wide. These dimensions were for a ring with a 2.5mm wide band. The ring diameter was 18mm so the slot was made 20mm long
Use a scalpel or other sharp knife to cut the pieces of leather. There is one to go beneath the 30mm insert – so the pink wood at the bottom of the slot is hidden – one for each side of the slot and one for each end
Use the 75mm offcut to create a jam chuck for mounting the box. It needs to be a snug fit so the box can be turned on the jam chuck
Mount the box half on the jam chuck and use the spindle gouge to cut it to the final thickness of 20mm. Shape the box to the desired shape. Remember, as this is side grain, the cuts should be from centre to edge. Refine the surface using the spindle gouge in sheer cutting mode. This both removes any ridges and cleans up any torn grain so less sanding is needed. Sand to 600 grit
You can now mount the second half of the box in the chuck before cutting the surface flat, checking with the rule as before. Use the square scraper to hollow a hole in the centre of the blank, 15mm wide x 15mm deep
You are now ready to cut the wider hole to 9mm deep and 45mm wide, but check the fit of the blackwood insert in the first box half as that will be the joint between the two halves of the box. The two parts need to be a good fit but not so tight it takes two people to separate the box! At the final stages, I use the edge of the square scraper, which is also sharpened to a cutting edge, so I can take fine cuts – hopefully this reduces the chance of overshooting
Next, cut the outside of the box to 65mm and again, finish with a few sheer cuts, which will improve the surface finish on the item
Once this is completed you can sand the surface of the box down to 600 grit, remembering to slow the lathe down as you progress
Cut the inside of the box with the square scraper to produce the angled section between the 45mm and 15mm diameter sections. Bevel the edge of the box with the spindle gouge as before. Try to get the two bevels to the same size
You can now mount the last blackwood 50mm blank and cut the surface flat. Use the round scraper to cut the semicircular hollow. Next, use the 2mm parting tool to define the thickness of the blank and sand the surface to 800 grit. Don't worry about sanding the side as it will be hidden within the box. Mark a line on the side, 5mm from the front face. This will be used in the next stage of the project
Next, part off the insert and reverse in the chuck or use a jam chuck, then mark a 15mm circle in the centre and use the spindle gouge to cut from the 15mm circle to the 5mm line on the edge so it matches the recess in the box
Mount the second half of the box on the jam chuck, cut it to 20mm thickness and shape the outside to match the first half. You can use either a profile gauge or a card template to match the shape of the two halves. You can now sand the surface to 600 grit
To finish the box, use a three-stage buffing system. You need to buff the blackwood insert for the box lid before gluing it into the box
If the buffing wheels you have will not get into the hollow in the centre, use a small felt wheel on a rotary tool to buff those parts. The same compounds used on the buffing wheels can be used on the felt wheels
Also buff the other box components and finish with carnauba wax on the buffing wheel. Take care to keep hold of the parts being buffed and always work towards any edge rather than away from it, so there is less chance of it being caught by the wheel
Glue and assemble all parts and admire your handiwork!