12 Feb Slab Building Exercise – Tall Bottle
Slab building can be a great way to create forms that are uniform and smooth in shape but hard to throw on the wheel. This is a method for making a tall narrow bottle using slab and coiling techniques.
Select a tube that is the width you would like to make your bottle. Roll out a slab just wider than the circumference. 
Wrap a piece of newspaper around the tube so that the clay won’t stick to it. 
While the clay is still soft, roll the clay slab carefully around the paper and the tube 
Make sure the clay overlaps. Leave the slab loosely wrapped around the tube and let the clay firm up a little – to a ‘cheese hard’ state 
When the clay is ‘cheese hard’, make sure the clay is snugly wrapped around the tube and use a potter’s knife to cut through where the slab overlaps. Remove the excess clay from both edges 
This will leave you with a slab that fits the tube closely 
Score the edges of the clay where they meet and add slip or water then score again to create a good joining surface 
Carefully firm the scored edges together to form a strong join. Take care not to dent or deform the slab surface 
Use a rubber kidney or similar tool to smooth over the join once it is secure 
Roll out a small slab of the same thickness as the bottle slab to make a base. Draw around the bottle to mark the bottle’s base without cutting through just yet 
If your bottle is not completely round, make a mark near the bottle base and a corresponding mark on the base slab so that you’ll know where to rejoin them 
After marking the bottle base on the small slab, score and slip where they will join 
Score and slip the base of the bottle, then gently slide the cardboard tube out from the clay and remove the newspaper lining 
Before adding the base or neck of the bottle, smooth over the join on the inside using a wooden tool, taking care not to distort the round form 
Turn the clay tube over and do the same from the other end 
Join the clay tube and the base, gently rocking or wiggling the two together to create a good join. Don’t do this until the clay tube is firm enough to stand without distorting (cheese hard) 
Once the base is firmly attached, use a brush to smooth the slurry from the join 
Using a potter’s knife, cut around the base, just wider than the bottle (about 1-2mm will be enough) 
Remove the excess clay 
Use a kidney to merge the small excess of clay up against the bottle base to create a good join 
Any small flare out can be tidied up when the clay is leather hard 
When the clay is leather hard, use a kidney to tidy the base. Here I have cut a notch into an old credit card to create an undercut on the base which will look smart when the bottle is completed 
You can slide the shaped card around the base to form the shape of the foot for the bottle 
This is the undercut of the foot ring created by the shaped card. 
Once the base is complete you can start on the neck of the bottle. If the clay tube is firm, score and slip the top before adding the first coil 
Roll a soft coil to join to the top of the tube. The coil should be a bit thicker than the tube walls 
Add the coils to the top, making each one just a little narrower in circumference than the tube top and placed on the inside edge, so that the neck of the bottle will taper inwards as you coil 
merge the coil to the tube, inside and out 
Use a wooden tool to smooth out the join 
Add decreasing coils to create the neck, smoothing roughly as you go. The final surface can be smoothed more finely when the clay has firmed up a little to cheese hard 
As the neck narrows it can be harder to smooth the inside but use your fingers to create a fairly smooth interior. 
When you want to create the bottle neck, the next coil can start to go straight up instead of narrowing in 
Make the neck as tall/narrow as desired, cutting a level top if the rim has become uneven 
Use a serrated kidney and then a smooth kidney on the clay when leather hard to tidy the finished surface and complete the bottle
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