Strip out old, mouldy sealant around your sink or worktop and lay a clean, watertight new bead in one session.
RS-01Clear the area and open a windowEmpty the sink and move anything sitting near the joint on the worktop. Open a window or door, as sealant remover and fresh silicone can smell strong in a closed kitchen. Keep a bin bag close by for the old sealant strips.
RS-02Cut out the old sealantRun a sealant removal tool or a sharp craft knife along both edges of the old bead, then peel it away in strips. Work slowly so you don't scratch the worktop or scuff the sink finish. Pick out stubborn bits left in corners with a plastic scraper.
RS-03Remove the leftover residueDab methylated spirit or a proprietary silicone remover onto a cloth and rub along the gap to lift the old film. Check the joint is bare, with no grease, mould staining or crumbs of old sealant left. Let it dry fully before moving on — a hairdryer on a cool setting speeds this up.
RS-04Treat any mould stainsIf black staining remains in the gap or grout, spray with a mould-and-mildew remover and leave for the time given on the bottle. Rinse well with clean water and dry thoroughly. Skip this step if there's no staining to deal with.
RS-05Mask both sides of the gapRun masking tape along the worktop edge and along the sink edge, leaving a 3-5mm gap between the two lines for the new bead. This gives you a crisp, straight finish and keeps sealant off the surfaces either side.
RS-06Cut the nozzle and apply the beadCut the sealant tube nozzle at a 45° angle for a bead roughly 5mm wide. Load it into a sealant gun and run a steady, unbroken bead along the gap, keeping the gun angle constant. Use a kitchen and bathroom sealant with mould resistance, in a colour matching your worktop or sink.
RS-07Smooth the beadWet your finger or a sealant smoothing tool with a little washing-up liquid diluted in water. Run it along the bead in one continuous stroke to press the sealant into the gap and lift off the excess. Wipe the tool clean between strokes so you don't drag sealant back out of the joint.
RS-08Peel off the masking tapePull away the masking tape straight away, while the sealant is still wet, folding it back on itself at a shallow angle. This leaves a neat, straight edge. Don't wait until the sealant has started to skin over, or it will drag and tear.
RS-09Leave it to cure before using the sinkLeave the new sealant completely untouched for the time stated on the tube — typically 24 hours before running water or washing up, and longer before full immersion or leaving a wet cloth on it. Avoid hot water or harsh cleaners on the joint while it cures.
RS-10Clean tools and tidy upWipe the sealant gun nozzle and any tools with methylated spirit before sealant cures on them, then re-cap the tube tightly for next time. Bag up the old sealant strips and offcuts, and give the sink and worktop a final wipe over.
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