The development of armature based ceramics using South African raw materials
- Authors: Luyt, Michelle
- Date: 2018
- Subjects: Pottery -- Research -- South Africa , Pottery craft -- South Africa -- Technique Ceramics in interior decoration -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/22618 , vital:30028
- Description: The purpose of the research was to develop a procedure by which South African ceramicists can use locally sourced ceramic materials to create armature based art forms, without having to rely on the importation of raw materials. The study also investigated the suitability of wire armatures as well as variable temperature ranges applicable to this investigation. It was found that commercial clay slip bodies purchased from South African suppliers tended to crack when coated over wire armatures during the firing process. It was shown that by substituting South African ceramic raw materials in the John W. Conrad’s C25 casting slip and Jeremy Dubber’s Ascent casting slip formulae with the addition of paper pulp and potassium feldspar, reduced the problem of the clay cracking when applied to wire armatures. The addition of paper fibres gave the clay bodies strong adhesive qualities which allowed the clay them to adhere onto the wire armatures which prevented the dry clay coatings from chipping off prior to and after firing. The addition of potassium feldspar helped with the maturing point of both the clay bodies and helped fuse the clay particles together which strengthened the clay coatings after being fired to their respective maturing temperatures. A further application of hydrochloric acid 30% or Pro Grip Key Coat ® to the three wire armature types, being galvanized binding wire, galvanized diamond mesh and Kanthal wire prior to coating with the above two formulae improved the adhesion of the clay slips to the armatures. This prevented them from the tendency to slide off the wire during the dipping and pouring process and helped eliminate any cracks that formed during the firing process. However, the glazing of the clay slips above proved to be problematic where it was sought as a further enhancement of the clay coated wire armatures. A general-purpose earthenware glaze caused the fired clay coating to crack probably due to the increased tension between the wire, clay body and the glaze. This problem was solved by developing a low firing transparent glaze. Other decorative effects were achieved by the inclusion of 0.5% cobalt oxide into the low firing transparent glaze which produced a blemish free deep blue colour. A further effect was achieved using binding copper wire over the bisque ware and then glazing with the low firing transparent glaze. A smoke firing technique as well an application of a copper oxide wash to the bisque fired ware and then re-firing to the required maturing temperature produced pleasing results.
- Full Text:
- Date Issued: 2018
- Authors: Luyt, Michelle
- Date: 2018
- Subjects: Pottery -- Research -- South Africa , Pottery craft -- South Africa -- Technique Ceramics in interior decoration -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/22618 , vital:30028
- Description: The purpose of the research was to develop a procedure by which South African ceramicists can use locally sourced ceramic materials to create armature based art forms, without having to rely on the importation of raw materials. The study also investigated the suitability of wire armatures as well as variable temperature ranges applicable to this investigation. It was found that commercial clay slip bodies purchased from South African suppliers tended to crack when coated over wire armatures during the firing process. It was shown that by substituting South African ceramic raw materials in the John W. Conrad’s C25 casting slip and Jeremy Dubber’s Ascent casting slip formulae with the addition of paper pulp and potassium feldspar, reduced the problem of the clay cracking when applied to wire armatures. The addition of paper fibres gave the clay bodies strong adhesive qualities which allowed the clay them to adhere onto the wire armatures which prevented the dry clay coatings from chipping off prior to and after firing. The addition of potassium feldspar helped with the maturing point of both the clay bodies and helped fuse the clay particles together which strengthened the clay coatings after being fired to their respective maturing temperatures. A further application of hydrochloric acid 30% or Pro Grip Key Coat ® to the three wire armature types, being galvanized binding wire, galvanized diamond mesh and Kanthal wire prior to coating with the above two formulae improved the adhesion of the clay slips to the armatures. This prevented them from the tendency to slide off the wire during the dipping and pouring process and helped eliminate any cracks that formed during the firing process. However, the glazing of the clay slips above proved to be problematic where it was sought as a further enhancement of the clay coated wire armatures. A general-purpose earthenware glaze caused the fired clay coating to crack probably due to the increased tension between the wire, clay body and the glaze. This problem was solved by developing a low firing transparent glaze. Other decorative effects were achieved by the inclusion of 0.5% cobalt oxide into the low firing transparent glaze which produced a blemish free deep blue colour. A further effect was achieved using binding copper wire over the bisque ware and then glazing with the low firing transparent glaze. A smoke firing technique as well an application of a copper oxide wash to the bisque fired ware and then re-firing to the required maturing temperature produced pleasing results.
- Full Text:
- Date Issued: 2018
The development of a translucent low fired porcelain casting slip using South African raw materials
- Authors: Ruiters, Mellaney Bualin
- Date: 2017
- Subjects: Arts -- Research -- South Africa , Pottery -- Research -- South Africa , Ceramics -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/20004 , vital:29026
- Description: The purpose of the research was to develop a translucent low fired porcelain casting slip using South African raw materials, due to the ever increasing electricity tariffs in South Africa as well as the physical deterioration put on the elements and brickwork in electric kilns when fired to traditional porcelain temperatures. Traditional porcelain bodies that can be purchased from South African suppliers are required to be fired to between 12000C and 13000C. The commercially prepared porcelains when tested produced white vitrified bodies but were lacking in translucency. Local ceramic artists are therefore compelled to import their porcelains from overseas suppliers if they require a white translucent porcelain but this is still requires a firing temperature well above 12000C. It has been shown that by using South African ceramic raw materials and adjusting a Parian ceramic formula using a selected frit; a low fired translucent porcelain can be made that matures below 12000C. The addition of paper fibres to the non-plastic porcelain was necessary to reduce the high shrinkage rate and prevented the clay from cracking and tearing in the firing process. With the further adjustments to the formula by the addition of calcium triphosphate true white translucent porcelain was produced. Without this last adjustment the porcelain would be an off-white colour due to the impurities found in the South African ceramic raw materials which are mainly contaminated with iron oxide. It was found that the following formula produced a white translucent porcelain which vitrified at 11900C and satisfies the original concept in the title stated above.
- Full Text:
- Date Issued: 2017
- Authors: Ruiters, Mellaney Bualin
- Date: 2017
- Subjects: Arts -- Research -- South Africa , Pottery -- Research -- South Africa , Ceramics -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/20004 , vital:29026
- Description: The purpose of the research was to develop a translucent low fired porcelain casting slip using South African raw materials, due to the ever increasing electricity tariffs in South Africa as well as the physical deterioration put on the elements and brickwork in electric kilns when fired to traditional porcelain temperatures. Traditional porcelain bodies that can be purchased from South African suppliers are required to be fired to between 12000C and 13000C. The commercially prepared porcelains when tested produced white vitrified bodies but were lacking in translucency. Local ceramic artists are therefore compelled to import their porcelains from overseas suppliers if they require a white translucent porcelain but this is still requires a firing temperature well above 12000C. It has been shown that by using South African ceramic raw materials and adjusting a Parian ceramic formula using a selected frit; a low fired translucent porcelain can be made that matures below 12000C. The addition of paper fibres to the non-plastic porcelain was necessary to reduce the high shrinkage rate and prevented the clay from cracking and tearing in the firing process. With the further adjustments to the formula by the addition of calcium triphosphate true white translucent porcelain was produced. Without this last adjustment the porcelain would be an off-white colour due to the impurities found in the South African ceramic raw materials which are mainly contaminated with iron oxide. It was found that the following formula produced a white translucent porcelain which vitrified at 11900C and satisfies the original concept in the title stated above.
- Full Text:
- Date Issued: 2017
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