A Theoretical Approach To The Restoration Of Azulejos By Re-Firing

LNEC found, as a by-product of another research project, that in at least some cases, glazed ceramic tiles (azulejos) could be restored by re-firing. The re-firing of facade glazed tiles as a viable alternative to their outright dumping should, in principle, present no doubts. However the mere idea of restoring in the kiln brings forth methodologic arguments unparalleled in other restoration techniques. The present communication discusses the re-firing of azulejos based on theoretical restoration principles, aiming to demonstrate that it cannot be discarded straightforwardly without considering individually its advantages and possible applications. However, and although no damaging consequences where identified, the eventual application of this method to azulejos that are not considered as industrial products still requires complementary studies regarding its long-term dangerousness.