Overblog
Suivre ce blog
Administration Créer mon blog

Earth of fire

Actualité volcanique, Article de fond sur étude de volcan, tectonique, récits et photos de voyage

Publié par Bernard Duyck
Publié dans : #L'art sur les chemins du feu

Used for over a century, enamelled lava will be first used for signage street signs , ladders low water, to certain outputs of the Metro in Paris (Porte de la Chapelle) / France, for roads signs of Michelin in France , or orientation tables published by the Touring club .

Today , this beautiful product is used for worktops for kitchens, wall coverings, decorative panels or art trinkets.

Jules Jolivet (1794-1871) Decorative panel "The Trinity " - Painting enamelled lava - 110 x 240 cm Paris , Saint- Vincent -de- Paul - Photo: Didier Rykner

Jules Jolivet (1794-1871) Decorative panel "The Trinity " - Painting enamelled lava - 110 x 240 cm Paris , Saint- Vincent -de- Paul - Photo: Didier Rykner

Viewpoint in Ajaccio " The Genoese city " - photo agency Méliades .

Viewpoint in Ajaccio " The Genoese city " - photo agency Méliades .

Michelin quadrangular road sign , combining information and advertising - photo auto Forum

Michelin quadrangular road sign , combining information and advertising - photo auto Forum

Production of  the plates :

Slices of lava, most often Volvic lava , a trachy - andesite , are calibrated in thickness and debited to the desired format ( water-cooled diamond tool ) . After surfacing to smooth the cutting traces and chamfering of the edges , the imperfections of the stone are engobed  with a mixture of silica , feldspar and clay . Once dry , the plate is sanded with cork and baked at about 980 ° C.

The drawing is referred to the graphite mine , and enamels , mainly based on iron oxides and derivatives, applied with a marten brush . Everything is vitrified between 940 and 960 ° C. A possible additional passage in the oven is when gilding brush, annealed to 700 ° C. The lava stone is the only supporting these repeated firings.

The enamel surface has crazing , cracking which can be explained by an expansion coefficient higher for the enamel than lava. In cooling , the difference in shrinkage leads to the appearance of this phenomenon of microcracking .

Manufacturing of the enamel plates of lava - Extract from the "official monthly magazine of the auto -club- Ardennes " , Number 11 November 1935.

Manufacturing of the enamel plates of lava - Extract from the "official monthly magazine of the auto -club- Ardennes " , Number 11 November 1935.

Enameled lava plate on concrete substrate - A6 Darvault / Company motorway Paris -Lyon

Enameled lava plate on concrete substrate - A6 Darvault / Company motorway Paris -Lyon

Its features allow you to create a product of unparalleled quality. The natural appearance of the lava gives a unique visual rendering, brightness and exceptional color depth .

The sustainability of the product comes from his insensitivity to heat, cold, salt air and wind erosion by blowing sand , and high resistance to damage , scratch , puncture , or graffiti (which may be removed by pressure hose , or with acetone )

Only drawback, offset by the longevity of the product , its price avoisinne 3,000 € ht / m².

 

Sources :

- Histoire du panneau Michelin - link

- Ce qu'il faut savoir sur la lave émaillée - link

Articles récents

Hébergé par Overblog