On Shrink Pots..

This blog post has been written to accompany a video I filmed with Zed Outdoors to provide more information and links about the specialist tools I use to make shrink pots. 

Check out the video and Zed’s YouTube channel

Shrink pots are hollowed out logs with a base fitted.  The body of the pot is worked green, i.e. with a high moisture content, and by allowing it to dry and therefore shrink onto a base made from dry timber you end up with a vessel with an integral bottom.  Lids can be made once the pot is dry. 

Augers –
The term auger is used widely to describe an Archimedes screw style drill. They’re used for lifting water and agricultural materials as well as drilling holes in ice, soil and wood.  In relation to drills in wood there’s a division between bar augers and auger bits. 

• Bar augers such as the one being used in the shrink pot video are a single piece drill with an attachment at the top for a handle.  The attachment can either be a ‘tooth’ which fits into a handle or a ring into which a handle will fit – the latter often being referred to as Scotch eye or barrel eye augers. 
• Auger bits fit into a brace and bit or powered drill. 

The auger I own is a 1” Gedge or Cook pattern auger.  I am very lucky to have picked this up without knowing much about augers other than the one’s I had previously purchased weren’t great.. Here’s a great page summarising the various auger patterns by Ian Swain - The Luddite -   Searching for ‘Cook’ pattern augers led me to this interesting site showing some history and lots of photos of these types of auger bits - http://www.georgesbasement.com/braces/RansomCook/RansomCookPatentAugerBits.htm
 
Wherever you find an old auger or one which needs sharpening there are a few things to know –

• The lead screw is crucial to the good functioning of the auger – it’s the primary consideration in assessing/purchasing an (old) auger
• Don’t sharpen the outside surfaces of the auger since the diameter will be reduced
• Try not to alter the edge geometry too much
• Try to locate an auger file which has two cutting sides and two flat sides.  This helps to sharpen just the bits you want and not bite into the other parts of the tools anatomy.  You can make a good substitute using wood with strips of sand paper glued on

For shrink pots you’ll be cutting into end grain so it’s important to keep the auger sharp. 
 
Gouges –
Most gouges you will see will have a bevel on the outside of the shaft of the tool and a clean channel or flute.  Such gouges can described as an Out-cannal or Out-Wall gouge but are often just called gouges..  The more specialised type of gouges used for shrink pots are called In-Cannal or In-Wall gouges.  This is where the bevel is inside the flute (curve) of the gouge and the outside of the tool is flat. 
In-Wall gouges allow you to cut vertically downwards inside the shrink pot whereas an Out-wall gouges would get fouled and stop cutting since they need to be presented at an angle to the surface being cut. 
Finding good In-Wall gouges can be tricky.  The first one I owned was very small and had a short tang so didn’t last very long when making shrink pots.  Also, you will be striking the gouge handle so ideally the handle should be bound – both at the bottom with a standard ferrule (band of metal) but also at the top of the handle with another ferrule to strengthen it. 
The gouges you see me using in the video are the Two Cherries brand – 16 and 22mm which I ordered from this website -
Part number - 1481000
http://www.kirschen.de/en/Mortise_Firmer-gouges_p4.html
The flat handle option allows you better grip for twisting the gouge if (when) it gets bound.
It is possible to convert a gouge from an Out-Wall to an In-Wall with care and some specialist tools, check out this article on the Axminster Website - https://knowledge.axminster.co.uk/using-in-cannel-gouges/
 
Flexcut scorp –
To cut the groove in the shrink pot which accepts the base I followed John Mullaney’s advice and use a Flexcut scorp.  There are other ways to cut the groove such as the tip of a knife to create a V-cut but the scorp cuts cleanly, quickly and consistently which is a boon to me.  You can find suppliers or Flex Cut tools online.  The tool I use in the video is a 5mm Right handed version - https://www.flexcut.com/home/product/kn22-316-5mm-right-handed-scorp. 
 
Shrink pots are a great, fun project to have a go at.  I hope I have inspired you to locate some tools and enjoy making..