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.
I have spent two days this week preparing the slip cast mild for my goblet. Because of the undercuts in the piece I had to make a mold with five sections so that I will be able to remove the piece after casting.
First I marked out on the print where I would build the walls out to make the mold. Or essentials where the seems would be. After marking out two sections it quickly became clear that 3 walls were needed in order to get the piece out of the mould.
I covered two thirds of the piece in clay leaving just the third visible that would be cast first.
I then smoothed out the clay walls.
I clamped wooden walls around the piece, filled any holes with clay and poured in plaster.
Once dry I took apart the mold and cleaned up the plaster a little. The I drilled in a half dome so that the next part of the mold would lock in.
I washed the plaster three times with soft soap. This was wiped off with a sponge and would keep the next plaster pour from sticking.
I then built the second wall and built up the wooden boards.
This was the result of the second pour after removing the walls and clay.
The process was repeated a third time to create the third wall.
This is the three walls completed and the process took about seven hours to get to this stage.
The top of the mold was then planed back.
Lock holes were drilled into the three walls at the top.
I then built walls around the mold and sealed for the pour.
This process was repeated for the bottom.
The five parts were then planed into one nice block.
This is the final reveal as I took out the 3D print.
The mould has now been placed in the drying cupboard and will be ready to use hopefully in three days time.
i got my 3D printed resin jig back a few days ago. It has been nearly ten years since I printed my last jig on the SLA resin machine at RCA. This one was printed on a much more modern machine called a form lab which can print in various types of resin. My model had to be scaled down slightly to fit the bed size of the machine. The result of this has been that the tube sizes were too small and closed up making the jig unusable. Although it looks great as an object I will need to rebuild this in CAD.
This afternoon I have been building a 3D model of a design for a drinking tumbler. Because of the height of the piece I will find this hard to press from a mould so I am going to try and slip cast this along side the wine goblets. The CAD model is just over 16cm which I am hoping will give a good size after taking into account shrinkage during the firing process.
I am going for a similar design to my whisky glasses as I wish for the same theme to run through out the collection that will be used in my kitchen. These pieces will be smooth all over as apposed to the whisky vessels which have texture down one side.