Shrink pot, and a shrink pot croze

I have been making shrink pots for a few years now. I love wooden boxes and containers and I feel very comfortable with the process and durability of these containers, compared with some of the other boxes I have made over the years.
For those of you who are wondering what a shrink pot is, wonder no more. Take a green or unseasoned branch of wood and hollow it out so it has an even wall thickness if about 10mm. You now have a tube. Make a groove near the bottom and insert a seasoned wooden plank. As the pot dries the tube shrinks around the plank holding it tight.
I was very chuffed when I entered the non-turned treen section at the Bodgers Ball craft competition at the weekend and my contemporaries voted my shrink pot first prize.

The pot is birch with a yew lid and the arrow is fiddle back willow. Only the yew is sanded and the rest is a fine tool finish. The pot is no higher than 10 inches.

I have also made my largest shrink pot so far. This one stands nearly 2 foot high and is over 12 inch diameter. Made from ash and western red cedar with an elm handle.

This one is not quite finished, the lid is, but I need to work on the pot. A pot this size will take a while to shrink and dry around the bottom plank. I was careful with this one to cut a ring off the bottom, taking it home and drying it so I could work out the amount of shrinkage. The last thing you want to do is to spend a day hollowing out a pot and making the bottom plank too large. If you do this, the side of the pot splits open as it dries out. How do I know? Well I have done it on a couple of large elm pots. This was in the days when I thought it best to have a really tight fitting bottom plank. Having a nice loose bottom plank is the way to go, you may have to check it a couple of times as it dries to make sure it it still oriented properly in the groove.  With a Scots pine pot I made, this drying process took months and it was a small one, only 6 inch diameter. I boiled it, I put it in the microwave and left it near the fire, and still the bottom was loose and rattling around in the groove. It just got left in the car for a few months, and finally when I retrieved it the pot had shrunk around the plank. Sticking a shrink pot in the microwave really does speed the drying process up, and is worth doing if impatient.

I have been asked what is the best way to make the groove on the inside of the tube or pot. I have designed and made a shrink pot croze. This has a flat bed and an adjustable height blade.
Just hold in a vice and run the pot around the knife blade.

I then use a Frosts Mora 106 to cut a V groove. I can cut a groove within a couple of minutes on a medium sized pot, and the top edge of the groove is of an even height and at 90 degrees to sides of the pot.
I will be selling these as set or as the finished item. I do not know the price yet and will post here another post when I am ready to sell and more detail about their use.

If you want to learn how to make shrink pots I will be running a 2 day workshop next March 17th and 18th 2012 cost £165. Get in touch if you want more info and a booking form. The workshop will be at my workshop in Devon, UK