Yesterday, alongside the goblet I also managed to slip cast my first tumbler using the three part mold I made last week. This mold worked perfectly and the final piece was much easier to release from the mold and clean up than the goblet. It was all over more structurally sound and I was very happy with the finished product. I have now left it to dry before bisque firing.
The two molds cast and waiting to dry for 15 minutes.
Cutting off the top edge with a potters knife.
With this piece I smoothed down all the inner and top edges with a sponge before taking it out of the mold. This kept the all over strength of the piece. I will be taking this approach with the run of all my final pieces.
This is the piece straight out of the mold with the messy seams.
This is the final result after cleaning with a sponge.
There was some discussion about how thin the tumbler is. I will be able to review this after firing.
Today I was able to take my first goblet finished sample finished with a tin glaze Out the kiln. I was very happy to see it standing, despite cracking at the base of the stem several times. I was fairly happy with the finish however parts of the glaze hadn’t stuck because I should have stirred it a little longer. I will sample more before choosing my final finish.
I also managed to get my 3rd goblet out of the mold today. I cut this to the edges at the top to the edge of the glass as apposed to round in my first sample.
So that the stem didn’t break I cleaned up most of the vessel whilst it was in partial parts of the mold to support it. This approach worked very effectively. The stem only wobbled slightly when I was putting the finishing touches to the piece.
I finished of cleaning up this piece with a wet sponge which made this piece far neater than my previous two samples. I feel that I am now heading towards the quality I am aiming for in my final pieces.
Today I finished off making my tumbler slip cast mold. I started my filing down the two parts I had made last week. I keyed in 3 lock holes and the cleaned and soft soaped the top surface. Instead of drilling into the top section after casting as I had done with the previous mold, I built a clay cone on top.
I then clamped around the wooden walls and sealed the edges with clay.
After drying, I took off the wooden walls and then filed the sides down and scraped with a kidney.
I am very pleased with the accuracy of this mold. It has worked much better than the goblet mold as it was far less complicated to make. I have left the mold to dry for three days before I will try using it for slip casting.
I slipcast another Goblet last Friday. As I had problems with the last one breaking I decided to cut the top section whilst it was still in the mold. I had less problems with this one because the stem was stronger being cut in the mold.
This time instead of cutting the top round I cut the top in line with the walls which I think looks much better and will be more prcticasl cleaning.
I have started to make the mold for the tumbler. This was much simpler than the goblet design as it had much less undercuts within it. The tumbler mold will only have to be in three parts as apposed to the five parts needed for the goblet.
Building the first side wall
Building and clamping the wood walls and sealing sides with clay
The first pour.
The first mold taken apart.
Cleaning up the first mold and adding the key holes.
Building the wood walls and sealing for the second pour.
Yesterday I decided to 3D print myself a clay extruder from my home printer. The first one I printed had a large internal area to hold the clay. This would have taken 24 hours to print. I re-designed it to take 12 hours and left this to run. The print failed in the middle of the night when it had almost completed. This was due to the plastic reel getting stuck.
I went back to the drawing board and reprinted another which was again a little smaller. This took about 3 hours to print at the lowest quality.
The extrusion nozzle didn’t stick too well when printing, so I repaired this with my 3D printing pen.
I also realised that the pusher wasn’t strong enough with the flimsy stick I had added. I eventually managed to extrude the clay with my thumb but this was quite difficult and so I will be making a much stronger pusher.
I put together a few shapes with the clay I had extruded using some slip I made up. This is just a sample, however it could be used as a tea-spoon rest. I will fire and glaze this sample over the next few weeks.
I left this to dry a little and carved into it to smooth of the areas of leftover slip and lines from the printer. A small section broke off where I didn’t join the pieces too well with slip.