Here are some pieces with this enamel:
I wanted to obtain a fish-scale glaze. The literature on the Internet indicates that this can be obtained starting from diagram 46 (see Daniel de Montmollin's book). On a first scan, I obtained the following result:
A first result close to laminated plaiting (what we call snowflakes or fish scales) appears. I decide to select sample no. 3 and test it with greater thicknesses:
The result is quite catastrophic! Craters appear, and it even looks as if the clay has been eaten away by the glaze. I'd never seen that before.
I'm going to give it another try by adding more silica (I can't remove any because I'm already at the minimum silica level in the recipe).
A lamination appears, but there's still a strange effect on the sample's periphery.
I'm trying it on a large piece of enamel to see if the effect isn't simply due to the smallness of the sample:
I like the result, but there's a lack of glaze around the edge of the pot, so I'm trying to glaze a second piece with a thicker glaze:
The greater thickness doesn't solve the problem - on the contrary, the same phenomenon occurs as before. At this stage of my research, I'm quite baffled and wonder how to solve this problem!
I decide to resume my initial sweep but spread the zone further apart:
After this trial, which didn't seem conclusive at first, I carried out 2 new separate searches, changing the raw materials in the recipe quite radically, while remaining in the same place on the diagram. These 2 searches didn't yield anything very interesting, so I won't go into them here. It was only after these two "failures" that I came back to the above result.
I looked at the result in the top right-hand corner and noticed that there was no "crater" formation around the edge. I reproduced this test by increasing the thickness:
On the plus side, the rim is once again correct. A flaky effect can be seen, even if it's not very obvious, and there's also a lack of homogeneity in the fusion, no doubt due to the glaze application.
So I decided to test this formula on a large workpiece by dipping to see what I could get:
the result is satisfactory. The edges look good, there's no "crater", and the laminated effect appears. I decide to make another thicker piece:
The enamel edges are just as good! (Phew!) The layered braiding also appears.
I perform my usual thickness test:
The result doesn't really appeal. I decided to do some research on this type of enamel, called fish scale for example. During my research, I came across 2 recipes that I decided to try "just to see":
I'm not interested in the right-hand sample. On the other hand, the test on the left contains things that interest me at the bottom of the sample. I decide to carry out a test on a larger piece:
The test was inconclusive. Perhaps a thickness problem? I'll do another test on a larger piece, increasing the thickness:
The result is starting to look very interesting. However, I decided to do a few tests to improve the recipe a little. I start by making a variation on lithium carbonate:
The sample (red dot) that doesn't contain lithium carbonate is closer to what I'm looking for.
Here are some more tests of raw material variations:
These tests do not improve the recipe.
I decided to experiment with thicknesses, here with the basic recipe:
and here the same thickness test but with the modification made by removing the lithium carbonate:
The result is less transparent and whiter. I like it better!
I'm doing a final test on a larger room with this recipe:
Impeccable! We approve!