[SKYDANCER]

any tips on extruding cone 10 porcelain tubes, how to prevent warping during drying.

[bciskepottery]

How long are the extrusions? Are you altering the shape after extruding, or just using the tubes straight from the extruder?

[SKYDANCER]

bciskepottery, on 28 January 2013 - 08:25 PM, said:

How long are the extrusions? Are you altering the shape after extruding, or just using the tubes straight from the extruder?

The extrusions are about 16" long, and they are to be used in our Flute making, so they are not altered, just tuned at a leather hard stage.

[bciskepottery]

Maybe try a dowel that matches the interior of the extrusion . . . either extruded directly over the dowel, or inserted after. I'd either put plastic or newspaper under the extruded forms so they can shrink without binding/deforming on a bare wareboard or put a smaller dowel through them and suspend them so they air dry without laying flat on a board. Minimum handling.

[Mark C.]

I work 99% in porcelain for some time now.If you are making only a few extrude a tube and leave it hang till firmer-Which will keep it straight and easier to handle,then hold a board up to its length for support as you cut it-a helper would be good. I would have paper on the board and lay some soft fabric on each side for support as it dries under plastic slowly.
If you are production making them then I would have some more steps for you.
I used to make production porcelain extruded glasses but straight was not important.
Mark

[Ben]

You might get straighter results from slip casting.