Cleaning and sealing terracotta tiles in Sway, Hampshire. Tiles were damaged by oven cleaner. I removed the damaged boiled linseed sealant using Mylands Perfecta Stripper followed by Evans Sure Strip high alkaline cleaner. Back to re-seal tomorrow when dry. For sealing I will use a base of Tile Doctor “Seal and Finish” followed by a coat of LTP Stone Oil to match the surrounding tiles as closely as possible. If the tiles aren’t completely dry I will use a heat gun to eliminate any residue of moisture before sealing for best results.
Even without splashed oven cleaning fluid terracotta in front of ovens often suffers from stains caused by hot cooking oil which can penetrate the sealer and sink in to the tile. Best to use a cooking mat to avoid this. When it happens the only solution is to remove the sealer on the affected tile and then steam and use a Spid brass wire brush to remove the mark before drying and re-sealing.