Wednesday, June 20, 2012

The Dreaded Threaded Vessel Challenge

Once every three months, my Etsy Metal Clay Heads team holds a challenge.  I haven't entered many of them, for various reasons, but decided to this time around.   The challenges have two parts:  a style part and a technical part.  This challenge called for some sort of a vessel with a threaded top with a 1920s-1930s look.

I've done threaded pieces before with success, so I thought this would be a great challenge for me to do.  As practice for working towards the Metal Clay Master's Registry, I made a threaded vessel a couple of years ago, and I was quite happy with it.

So I figured the challenge wouldn't be too hard, but I wasn't counting on the unpredictability of bronze clay.   I didn't want to make a round piece and drew out a texture on scratch foam for the sides that had an Art Deco feel.  I planned on a four-sided piece.

But, I also didn't plan on how difficult it would be to construct a four sided piece around a round thread.  I wanted the threads to be set on the inside of the bottle and have the stopper screw down into it, which is the exact opposite of what most bottles are, I realized after looking at many.

The first piece looked pretty good before I fired it but I fired it on its side and it warped.  I also fired the stopper separate from the bottle, which was the same technique I used for the silver vessel.  Unfortunately, once the bottle warped, there was no way I could get the stopper in and it was too hard to bend it back into shape.

So back to the drawing board I went, this time with a bit of knowledge under my belt.  This time I chose copper clay instead of bronze.  I've had better luck with it.  I constructed the piece a bit differently as well.  It's still four-sided with the same design, but I added upside down triangles to fill in the gaps instead of untextured clay.  I also took the bottom tips of the design to decorate the top. Lastly, I fired the stopper in place this time, after having coated it with paper clay powder.

In the first firing, the bottle sintered and the top seemed okay, but when I went to unscrew it, it simply came off and left the threaded part inside the bottle.  Keeping my fingers crossed, I re-attached the top to the part that was still in the bottle with some thick slip and refired.  This time it worked and the top stayed together when I removed it.  It still didn't feel fully sintered in the middle (I made it hollow) so I fired just the top one more time.

I'm pleased to say it worked and I finally have a piece that is fully sintered and doesn't look too bad.  It's just under an inch an a half tall and about a half-inch wide.

You can find a few more pictures of it, as well as pictures of it before it was fired here.

Even taking the pictures was a challenge.  I must have taken well over 300 pictures and managed to winnow them down to less than a dozen that were clear enough to use.  And the bottle looks much more like bronze than copper in the pictures but nothing I have tried seems to get the color true.  I guess there is a reason why they are called challenges.