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Turning with Pencils

Bob Chapman experiments with turning pencils to make various forms

Table of Contents

Making objects from glued-together pencils is not a new idea, and a search online will reveal many such items. Nevertheless, the idea has appealed to me for some time, and when the editor suggested I should try it for the magazine, I was only too happy to oblige – although I stressed that there would inevitably be a certain amount of experimentation involved.

Thinking about the practicalities of the project there were some obvious decisions to be made. Firstly, I needed a cheap source of pencils as I would certainly need a large number of them. And secondly, I needed to decide what adhesive I would use to glue them together and how I would hold the pencils together until the glue had set. Hexagonal pencils are space filling provided they are aligned carefully, but round pencils will fit together in any orientation, albeit with some gaps between them. In the end I purchased 72 hexagonal coloured pencils and 24 round ones and soon began playing at arranging them.

First thoughts

The good thing about hexagonal pencils is that they fit together perfectly with no gaps. Each pencil is 7mm across flats and 7.5mm from corner to corner. I wanted to get a cylinder at least 75mm diameter, and reckoned that a 12 x 12 block would be around 85–90mm, which would allow some wastage in turning the block to a cylinder. This is where actually playing with the pencils shows errors in thinking. Arranging 12 pencils side-by-side with flats touching gives a row 12 x 7mm, i.e. 84mm as expected, but adding a second layer on top of the first does not add another 7mm, because the corners of the second layer fit into the valleys in the first layer. The maths is complicated, but suffice to say that each additional layer adds a whisker over 6mm to the thickness of the block. Getting a block which is actually square in section would be tricky. Instead, I began to think in terms of 12 layers of pencils which would have alternately 12 and 11 pencils in each layer.

Hmm… a block has corners which get wasted when it is turned to a cylinder. Perhaps I could reduce this waste by simply making a bundle held together with rubber bands. Try it. As it gets bigger it’s actually quite difficult keeping all those pencils in the right place, and the thought of trying to do it when they were covered in glue… no, I think not. Back to the block idea.

Equipment and materials used

  • Epoxy resin
  • Bandsaw
  • 13mm bowl gouge
  • Skew chisel
  • 16mm Forstner bit
  • 6mm bowl gouge
  • 6mm straight scraper
  • Cranked scraper
  • Callipers
  • Leak Fix filler
  • Abrasives
  • Acrylic lacquer
  • Colouring pencils

Vase plan

Lidded box plan

The hollow form – hexagonal pencils

1. You need a diameter of around 80mm to make the hollow form. To create a block you could hold the pencils in a bundle with rubber bands, but holding them together while fitting the bands is not as simple as it might seem
2. Instead, you could construct a frame to hold the pencils in position. Glue two pieces of wood at right angles on a base board and lay the pencils out, side by side, before bringing up a third piece and gluing in place. A 12 x 12 pencil block needs 138 pencils
3. If making a square block the pencils at the corners will be completely wasted when turned to a cylinder. If you form a hexagonal block, it will reduce the wastage when turning to round. To do this cut two blocks from waste wood with the inside face at 60° to the horizontal and use them to make a frame as before. Trial and error showed that if I started with seven pencils in the first row and increased to a middle row of 13 before decreasing back to seven, the across flats ‘diameter’ of the block would be about 80mm
4. Choose your adhesive carefully. You need to have one that gives you enough open time to bond everything properly and allow you to assemble everything well. West System epoxy was chosen here as it gives a suitably long ‘open’ time and bonds to the pencils well. Once you have chosen your adhesive, line the mould with a plastic bag and apply the adhesive with a brush to each layer as the block is built up
5. After building to the middle layer of 13 pencils, hold them in place by laying a weighted board on top and leave to set
6. Now remove and unwrap the block. Unfortunately when the glued up block was removed and the hidden end of the pencils examined, several small gaps were evident. Obviously I’m not as good at cutting an angle of 60° as cutting at 90°, and some errors had crept in. There was nothing I could do about it except regret not staying with the square block, which I had made much more accurately
7. Use the same frame for the other half, from seven to 12 pencils, and then glue the two halves together to make the final hexagonal block. Use a weight on top to hold everything together until the epoxy sets. This method is much less wasteful of pencils and uses 127, leaving 17 half-pencils for any spares or repairs that might be necessary
8. Clean up the ends of the finished blocks on the bandsaw. Some small gaps between pencils could now be seen but there is nothing to be done about them at this stage
9. Mount the block between centres and turn it to a cylinder. A 13mm bowl gouge for this is gentler than a spindle roughing gouge
10. Using a skew chisel on its side, form a dovetailed spigot at one end so the block can be held in the four-jaw chuck. Use a 16mm Forstner bit to drill a hole down the block, stopping well short of the bottom to allow sufficient waste for parting off later
11. Start shaping the hollow form with a 6mm bowl gouge, resharpening frequently as necessary. The upper curve of the form can be taken to its more-or-less final shape, but leave the lower part oversized to give strength during hollowing. Note the pencil line that divides the blank in a one-third to two-thirds ratio
12. Start hollowing with a 6mm straight scraper, feeling down the central hole and gradually widening it out. This tool is ideal for the lower half of the form, but don’t remove too much at this stage. The aim is to widen the hole to enable the next tool to be used
13. In order to get under the shoulder of the vessel a hooked tool is needed, and I find this simple cranked scraper invaluable for this purpose. Hollow the upper part of the form and then using the two scrapers in turn – gradually open up the interior of the hollow form
14. Use callipers to keep an eye on wall thickness and complete the shaping of the outside and the inside, little by little, until the final shape is achieved, and the walls are a suitable thickness. Be very cautious not to make the walls too thin, as they may collapse suddenly if the glue fails
15. The form will have many small voids between some of the pencils and these can be filled with a black filler. This is ‘Leak Fix’ – a two-part black filler made by Plastic Padding, which adheres well to wood and sets very hard. Excess filler can be sanded away but, surprisingly, it is too hard to be cut with a HSS tool
16. Start sanding with 80 grit to remove the filler, then continue down to 400 grit to get a smooth, clean surface. Fine steel wool can be used, with the lathe off, to remove any smearing from the coloured centres
17. I used my vacuum system to hold the hollow form, using masking tape to stop any air leakage between the pencils. Partially part off and finish with a hacksaw to avoid any tear-out in the centre. Clean up and sand the bottom. Finish the hollow form by standing it on a small block of wood and spraying it with several thin coats of acrylic lacquer
18. When the acrylic has had time to cure thoroughly – after about a week – use a buffing compound on a soft cloth and work over the vase a small section at a time to bring it to a deep glossy shine. If all goes well, your finished vase should look something like this

Scarf ring – round pencils

1. My round pencils were 7mm diameter and glued together in three rows of 8, 7, 8 pencils, giving a block of approximately 56mm wide and a little less than 20mm thick
2. Cut a 56mm section from one end of this block and drill a 5mm hole through the centre pencil of the middle row. This is to take a 5mm diameter crossbar made from a spar from my grandson’s broken kite. Obviously any other similarly sized spindle would work equally well
3. While holding the block in a small vice, drill a 30mm hole through the middle. To avoid splintering, turn the block over once the point has broken through, and complete the hole from the other side
4. Push the block onto a mandrel as a tight push fit and turn to a round cross section. During this turning some of the coloured centres broke out and disappeared into the shavings. Fortunately, I had my stash of spare pencils and could cut out appropriately coloured centres to replace them, glued in with cyanoacrylate. These few spare pencils were invaluable for replacing lost centres in both this scarf ring and the earring box, which shed these coloured cylinders with alarming frequency. Remember, that it is not essential to replace a lost coloured centre with the same colour – no one will ever know.
5. After sanding and spraying with acrylic, glue the crossbar in place with cyanoacrylate. The finished scarf ring should look something like this. My wife knows several elaborate ways of tying a scarf with a ring like this. To me it looks like a belt buckle, but what do I know…?

Handy hints

1. The cheapest hexagonal coloured pencils I could find were £2.99 for 24 from Rymans Ltd, and the round pencils were £1 for 12 from PoundWorld. Top quality coloured pencils can cost well over £1 each.
2. West System epoxy is expensive unless you also have other uses for it, but a two-part epoxy adhesive such as Araldite could be used instead.
3. The wooden component of pencils is usually a very straight grained cedar, although other timbers are used. It cuts easily and sands well but is not an attractive timber.
4. The coloured centres of the pencils are actually quite hard and blunt tools quickly. Regular sharpening is needed to maintain a good finish from the tools.
5. Try to keep sanding to a minimum as the colours, especially the darker ones, can smear across the surface causing discolouration, which is difficult to remove
6. The centres of the cheaper round pencils tended to break out fairly frequently. This never happened with the hexagonal pencils. Keep all the little offcuts of pencils as a source of spare centres to replace any lost.
7. If you don’t have a vacuum system, make a jam chuck and use tailstock support while you part off.
8. Because the pencils had been bought specifically for the project there is a temptation – one I gave in to – to try to use up every last bit of pencil. This involves making smaller and smaller items as the remaining pieces are used up. It is almost certainly more cost-effective to stop at the main project and throw the
left-over bits away. Or you could always do a bit of colouring-in.

Earring box – round pencils

1. To make the final project the remaining section of the block of pencils was cut in half and the two halves glued side by side to make a shorter, thicker block about 55mm long. Cut this block to a square section, mount between centres and turn to a 40mm diameter cylinder with a small dovetail spigot at each end.
2. Mounted in the four jaw chuck, mark the lid section at about a third of the overall length and part off with your narrowest parting tool
3. Hollow out the body section using a spindle gouge and small scraper and sand to a good finish. Remove a small section from the rim, ready to accept the lid. Then replace the body with the lid, which is similarly hollowed. Cut a matching recess to fit the body
4. Fit the two parts together and remount between centres. Cut a very shallow curve into the sides to give the box a more attractive shape
5. Reinforce the body with masking tape and grip by expanding the jaws into the tiny lid recess. Expand the jaws very gently – just enough to grip the box. A slip here will almost certainly split the box apart. Wrapping masking tape (or sellotape if you don’t have any) around the box will help to prevent this from happening. With the tailstock in place clean up the bottom with a small gouge, removing the tailstock for the final, very fine, cuts. Hold the lid in compression on the lid spigot while shaping it to a dome with a small Gouge
6. Finish the box with spray lacquer and leave to dry before assembling lid and base together. When the lacquer is fully cured, polish with a buffing compound. Note that some voids between pencils have been exposed during turning. Unless you were very careful about filling the spaces between pencils, this is almost inevitable. I rather like them. They add a natural design feature to the box which reminds us that round pencils are not space-filling

Further reading

Finishing for Turnings

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