by Jo Miller
October CMW Virtual Demonstration – Tod Raines
N Dallas, Fort Worth area, Texas – woodturningtoolstore.com
Our October virtual demo featured Tod Raines who demonstrated turning a Piston Box.. In a Piston Box, the top is shaped as a hollow cylinder that fits into the base of the bowl/box. An opening is put in the top to hold small objects such as pills, sewing needles, toothpicks etc, and is small enough to fit into a pocket or purse. The shape is good for embellishment/texturizing/pyrography/painting and uses drill bits rather than hollowing tools that he feels makes it an easy project for any level turner
Tod begins with a blank of 1 ¾ x 1 ¾ x 8 inches. He prefers to use pine because he likes the smell and it is a good wood for pyrography. The blank is rounded off between centers. A chuck could be used at one end if the blank will fit into your chuck – otherwise you will have to make a tenon. The tail stock end should be cleaned up prior to drilling
You will be using 2 Forstner bits with a 1/8” difference between the two bits. This will produce a wall thickness of 1/16th inch. (Its possible to use 2 bits with a 1/4” difference between the 2 bits depending on the project and size of the blank. This will produce a wall thickness of 1/8”). For this demonstration, Tod used a 1 1/8” and a 1 ¼” forstner bit).
Using the smaller forstner bit (1 1/8”), drill into the blank to desired depth –in this case 2 ¼”. Sand the inside lightly using sandpaper wrapped around a dowel (80 and 150 grit so that it is smooth to the touch). Using a cone center in the tail stock and gentle pressure, cut down the blank to the diameter of the larger forstner bit, and the length of the “piston” – ~ 2 ¼” or the length of the drilled portion. To help with this step, Tod creates a “jig” as a check on the thickness. He uses a thin piece of wood with a hole the size of the forstner bit you are using (in this case the larger size – 1 ¼”). The inside of the hole is sanded slightly to make sure you will have a snug fit . The outside diameter of the blank is peeled down to the desired size (1 ¼”) just at the end – and using the jig to check the size. Then gradually peel the diameter away and inch or so at a time and use the jig to slide it along as you go. Sand lightly. Mark the thickness of your lid. Undercut the lid and part off of the blank
Next you will make the bottom of box.
Clean off the end and mark the center with a dimple
Use a jocobs chuck to hold the larger size forsner bit – in this case 1 ¼”. Drill to the depth slightly longer than the top. Use a finger on the drill bit to decrease vibrations and wandering. Go slowly. You want a tight fit between the top and bottom… Use a sanding stick to make sure the top will fit.
Use a parting tool to mark the end of the box (don’t part off yet). Smooth up the end and shape the bottom.
Shape the bottom: for a barrel shape, you want the middle to be the thickest part , so shape towards the ends. Make other shapes as you wish. Don’t part off yet
Sand to 180 grit – for pyrography – or as you wish.
To finish the top of the box
Insert the top of the lid in the box and shape the top of the box – ex dome shape for the barrel shaped box. He creates a slight indented rim with a dome shape in the middle – slightly lower than the edge.
Marking indexing lines or grooves for burning depending on your design
Part off the bottom of the box – leave the excess in the chuck to use as a jam chuck to fit the bottom of the box opening – tape it securely and part down the remainder to the size you want the bottom. He uses a slight indented insert with a slight dome at the bottom and top.
Create an insert to seal the top by putting the top opening onto the jam chuck. You will have to adjust the fit to create a 1/8”-3/8” tenon that will fit into the top as a plug. You might want the plug to have an angle in it if you are making a box for ex matches so that they will lean in the opening and be more accessible for removing Make sure this end has a clean cut. Glue the tenon into the top using a medium/thick CA glue (or yellow glud) making a “plug” and secure the top into the jam chuck using a “rubber chucky” in the tail stock. Part off the plug and sand the bottom and in top to create the kind of fit you want.
Create the opening in the box top:
Use a dowel with sand paper wrapped around it (150 grit)
Put the dowel between centers.
Choose where you want the opening – consider the grain or any markings on the wood
Sand completely through the 1/16th thickness of the top of the box and the length you need for the kind of object you want to hold in the box – i.e a smaller hole for pills, a longer hole (~2”) for needles, toothpicks opening upper half, etc.
Create indexing marks and grooves for burning before parting off the bottom. He usually makes 12 indexing lines and burns with a wire just above and below the top, and at the bottom.
Mark where your “hole” is inside the box so it can be opened without dumping the contents
Finishing: Tod does not finish the inside of the box (he likes the smell of pIne) – and to allow for easy opening and closing – just sand to smooth finish. Once pyrography etc is completed, he uses Minwas, or polyacrylic spray ( either satin or semigloss). For his Castle box, he uses a a sanded paint finish
Other considerations: If you want to make a longer cylinder – you may have to do it in two parts and glue the parts together due to limitations in the length of the forstner bits. You can use extensions but its important to prevent any wobbling or drift of the bit since the wall thickness is only 1/8th inch.