How To Remove Old Silicone From a Benchtop
How do you replace perished silicone sealant between a gas cooktop and a stone benchtop?
Cut the old silicone away with a sharp blade or knife. Once the bulk is off, use Selleys Sealant Remover on the thin residual film that is left — spread it over the residue and leave it to soften, then take the softened silicone off with a scraper. Clean the area, let it dry thoroughly, and apply a new bead.
Around a cooktop, use a sealant with real temperature resistance. Selleys' guidance for this job names a sealant with excellent temperature resistance up to 150°C. Among the Selleys wet-area sealants, the one whose technical data sheet gives that figure is Selleys Wet Area Matt Silicone, with a service temperature range of −40°C to 150°C — and, importantly for a stone benchtop, it is a neutral cure product.
Why the residue matters more than the bead
Cutting the visible bead out is the easy half. What defeats most resealing jobs is the film that stays behind — a haze of silicone keyed into the pores of the stone and the edge of the cooktop, invisible from a standing position.
Fresh silicone bonds poorly to cured silicone. If that film is still there, the new bead is gripping the old residue rather than the benchtop, and the joint fails again along that interface. This is the same reason you cannot simply run a fresh bead over an existing one.
Selleys Sealant Remover — what the technical data sheet specifies
| Property | Selleys Sealant Remover |
|---|---|
| Appearance | Light beige smooth paste |
| Pack size | 375g tub |
| Removal time | 10 minutes |
| Layer thickness | At least 5mm spread evenly over the old sealant |
| Residual sealant depth before applying | Less than 5mm |
| Works on | Silicone, acrylic, SMP/hybrid and polyurethane sealants |
| Suitable surfaces | Ceramic tiles, porcelain, glass, grout, most metals, brass, laminate, most plastics, masonry, coated timber, most painted surfaces |
| Clean up | Mineral turpentine |
Indicative data only, not intended for the preparation of specifications.
A note on dwell time. The current Sealant Remover technical data sheet (version 1.0, March 2025) specifies leaving the product for at least 10 minutes, with a second application if required. Some Selleys advice for this job quotes a longer dwell of at least 2 hours. The technical data sheet figure is 10 minutes; if the residue is thick or the room is cold, a second application is the approach the data sheet gives rather than a longer single soak.
Removing the old bead, step by step
- Wear protective gloves, avoid breathing vapours, and work in a well-ventilated area — the remover's own safety directions.
- Cut along both edges of the bead with a sharp blade to break its bond with the stone and the cooktop, then lift the silicone away in as long a strip as you can. Long strips come off far more cleanly than short stabs.
- Scrape or cut the remainder back so only a very thin layer of less than 5mm depth is left. A sealant remover tool makes this easier, and the more you take off mechanically, the better the remover penetrates.
- Stir the remover if necessary, then use a scraper or brush to spread a layer at least 5mm thick evenly over what is left.
- Leave it for at least 10 minutes. A second application may be needed.
- Work a scraper or sealant remover tool backwards and forwards to lift the softened sealant off the surface.
- Clean any residue and your tools immediately with mineral turpentine.
- Let the joint dry completely before you seal. Stone is porous at the cut edges and holds moisture longer than it looks.
Choosing the new sealant for a cooktop-to-stone joint
Two requirements pull in the same direction here.
Temperature. A gas cooktop puts heat into the surround. Wet Area Matt Silicone's published service temperature is −40°C to 150°C. Selleys Silicone 401 goes considerably further — −60°C to +205°C, tolerating short periods at 260°C — but it is an acid cure product developed for form-in-place gaskets and industrial sealing, and its listed substrates are metal, glass, ceramic, some rigid plastics, painted and wood surfaces, not stone.
Cure chemistry. Selleys' guidance for natural and engineered stone is a neutral cure silicone. Neutral cure products do not release acetic acid as they set, which is why they are the recommendation for granite, marble and engineered stone. Wet Area Matt Silicone is neutral cure; Silicone 401 and Glass Silicone are acid cure.
Put together: for a stone benchtop, a neutral cure silicone rated to 150°C is the combination to look for.
Limitations to check
- Sealant Remover is not suitable for rubber, EPDM or polycarbonate. If the cooktop trim includes any of these, keep the remover off it.
- It may affect some surfaces — test compatibility in an inconspicuous spot before use, and do not leave it on porous materials or acrylic-painted surfaces for extended periods.
- It will not remove staining caused by silicone oils that have already penetrated the stone. That is a different problem and no remover reverses it.
- Wet Area Matt Silicone is not paintable (complete painting 7 days before sealing), and is not suitable for PP, PE or PTFE, for aquariums, for food or drinking water contact, or for permanent water immersion.
- Check with your cooktop manufacturer as well. Appliance makers often specify how the unit is to be sealed into the benchtop, and their instructions take precedence.
Common questions about replacing silicone around a cooktop
Can I just run a new bead over the old one?
No. Fresh silicone does not adhere well to cured silicone, so the joint fails again along the seam. See applying another bead after the first dries.
How long do I leave the Sealant Remover on?
The technical data sheet says at least 10 minutes, with a second application if the first does not do it. Cut the bulk of the sealant away first so there is less than 5mm of residue to work on.
Will the remover damage my stone benchtop?
Masonry is listed among its suitable surfaces, but the data sheet also says the product may affect some surfaces and that compatibility should be tested before use, and that it should not be left on porous materials for extended periods. Test an out-of-sight area first.
What should I clean the joint with before resealing?
Mineral turpentine is what the remover's clean-up instruction specifies, and it is also what the silicone data sheets call for before application. Then let it dry completely.
Why does the joint have to be bone dry?
Silicone will not bond reliably to a damp surface. The wet-area silicone data sheets require surfaces that are clean, dry and free of dirt, grease, oil or water.
Can I use Silicone 401 around the cooktop?
Its temperature performance is the highest in the range, but it is an acid cure silicone and stone is not among its listed substrates. For a stone benchtop, a neutral cure product is the safer choice.
How long before I can use the cooktop again?
Let the bead cure before subjecting it to heat. Silicone sealants of this type cure at roughly 2mm per 24 hours, so cure time depends on how deep the bead is in the joint.
What about the joint between the benchtop and the wall?
That is a related but separate question — see sealing a kitchen benchtop.
Is there a general guide to removing old sealant?
Yes — how to remove old sealant covers the technique in more detail, and how temperature resistance affects silicone sealant performance covers the heat side.
How do I remove old silicone from a benchtop?
First, scrape away as much of the old silicone as possible using a sharp knife or scraper, leaving only a thin layer of less than 5mm. Then apply Selleys Sealant Remover evenly over the remaining silicone in a layer at least 5mm thick, using a scraper or brush. Let it sit for about 10 minutes (a second application may be needed for stubborn residue). After that, use a scraper or sealant remover tool in a forward and backward motion to remove the softened sealant. Finally, clean any remaining residue and your tools immediately with mineral turpentine.
What product does Selleys recommend for removing old silicone sealant?
Selleys recommends using Selleys Sealant Remover, which softens old sealant for easier removal without the need for excessive scraping.
How long does Selleys Sealant Remover take to work?
Selleys Sealant Remover is fast-acting and works in approximately 10 minutes, though a second application may be required for stubborn residue.
Is Selleys Sealant Remover safe to use on benchtop surfaces?
Yes, Selleys Sealant Remover will not harm most surfaces and finishes and is suitable for use on ceramic tiles, laminate, glass, most metals, and most painted surfaces—common materials found in kitchen benchtops.
What should I use to clean residue after removing old silicone?
Clean any remaining residue and your tools immediately with mineral turpentine for best results.
Does Selleys Sealant Remover leave any residue behind?
No, Selleys Sealant Remover leaves no residue once the old sealant has been removed.
Can Selleys Sealant Remover be used on both horizontal and vertical surfaces?
Yes, Selleys Sealant Remover is suitable for use on both horizontal and vertical applications.
What tool can make the initial removal of old sealant easier?
A sealant remover tool can make the initial cutting and scraping of old sealant easier before applying Selleys Sealant Remover.