Tuesday, June 21, 2011

How to carve a cup

I always talk about carving a piece but have never showed the process to how it's done. So for this post I'll show the step by step process of how to carve a cup.
I will use one of the cups I made last week as my example.

Before carving you must decide if your cup will have a handle or not, if it will make that first so while you're carving the handle can harden up and dry a little so it won't droop when attached.

The handles' design is basically up to you, round, flat square whatever. The only thing you have to watch out for is making sure it's not too thin. You will be holding your cup with it so if it's too brittle it will snap.

I decided to go with a basic coil handle for 5 of my cups. Coil handles are super easy; just roll out, cut and shape.

Although I only need 5 handles I made a bunch so I would have a lot of choices later on. I made thick/thin and long/short sizes. While carving the cups I placed them on some dry wall to help them dry faster. (Make sure to flip them every 10 min so they don't get too dry on one side)

Now it's time to start carving...
Before starting it's essential to measure the thickness of the bottom. Using two rulers I measured the outside like this.
Height was 102mm

Then I measured the inside like this.

Height was 85mm

So to get the thickness 102-85=17mm of thickness, which is quite a lot. Ideally between 5-7mm is what's desired.

Now it's time to flip over your cup and center it on the wheel. While the wheel is stopped, place the cup in the center then slowly start turning the wheel. Unless you're super lucky the cup should appear wobbly and off center. To get it to the right spot is quite tricky; while one hand slightly touches the cup the other hand gently taps the cup to bump it to the correct spot. This takes at least a year or practice to get down.

Prepare a coil long and thick enough to wrap around the base of the cup and that will reach above 2 fingers. Now you're ready to station the cup.
The coil you just made will wrap around the base like this.

While wrapping and pressing down on the coil make sure you always keep one hand slightly pressing down from the top onto the cup so your it won't move from the center.

Once finished it will look like this. Now it's time to get your tools ready.

I have 4 carving tools I like to keep handy. The one closest is the most versatile and used tool I own. The others are for special areas like corners or flat edges. I also keep a needle tool on hand for signing the piece once it's done.

Now it's time to carve

Starting from the center of the cup use the tools corner and apply slight pressure. Work your way slowly to the edge.

As you do this a curly Q of clay will start to form. Then repeat.

After a few times it's time to carve the clay sticking out on the side. This is relatively similar to above, but instead start farther out and work out to the side. You can't apply too much pressure since it will throw the cup off balance.

After a few times you can see the side getting reduced.

After a few more tries it should look like this.
Notice how the edges and top are all flat, if it's lumpy the cup will not stand up straight.

After the cup gets cleaned up a bit I like to measure it again to make sure I don't make any mistakes.
It looks much better but is still heavy, after measuring I still had about 4mm left to carve.

After measuring, centering and coiling the base again it was time to make the cups bottom rims.
I used my needle tool to draw guidelines so I would know where to stop carving. I carved the inside and outside until there was a 4mm thick rim at the base. Carving the rim is pretty simple, start from the middle and work your way to the line. Opposite for the outer layer. It's hard to give good direction at this part since everyone has their own way and technique which works best for them. But everyone will need a steady and patient hand.

2 hours later I had finished all 5 of my handle cups. They turned out well.

After scoring, applying liquid clay and smoothing out the edges the handles had been attached...
This was the last step so now the cups will dry under a towel for 7-10 days and get bisque fired...Can't wait to glaze them!

Until next time :)

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