How To Remove Old Sealant
What is the easiest way to remove old sealant?
Cut away as much as you can with a blade, then soften what is left with Selleys Sealant Remover and scrape it off. The good news is that whether you are removing sealant from a glass shower screen, a metal laundry tub or a tiled splashback, the process is the same.
The part worth getting right is the last 5%. A visible bead comes away easily; the thin film that stays behind, keyed into the glaze and the texture of the grout, is invisible from a standing position and it is the reason replacement beads fail early. Fresh silicone bonds to that residue rather than to the tile.
What you need
- Selleys Sealant Remover — 375 g tub
- A sharp blade or a sealant remover tool
- A scraper
- Mineral turpentine
- A cloth or rag for cleaning
- Protective gloves
The process
- Cut away the worst of the sealant using a sharp blade or a sealant remover tool. Run the blade along both edges of the bead so it lifts in long pieces. The aim is to leave only a very thin layer — less than 5 mm deep. Cutting away as much old sealant as possible lets the remover penetrate more easily, which is why this step is not optional.
- Make sure the surfaces are completely dry.
- Apply Selleys Sealant Remover over the remaining sealant, spread evenly with a scraper or brush to a layer at least 5 mm thick. Test a small area first.
- Leave it at least 10 minutes. It can take significantly longer if the sealant was not cut back first, and thicker residue may need a second application. Make sure the remover does not dry out while you wait.
- Scrape the softened sealant off using a scraper or sealant remover tool, working in a forward and backward motion.
- Clean any residue and your tools immediately with mineral turpentine. Do not use water.
Wear protective gloves, avoid breathing the vapours, and use it only in a well-ventilated area.
Sealant Remover at a glance
| Property | Typical result |
|---|---|
| Appearance | Light beige coloured smooth paste |
| Density | 0.83 @ 23 °C |
| Removal time | 10 minutes |
| Packaging | 375 g tub |
| Sealant types | Silicone, acrylic, SMP/hybrid and polyurethane |
Indicative data only, not intended for the preparation of specifications.
It sticks vertically, which is what makes it usable on a shower screen join rather than only on horizontal work, and it is applied easily with a scraper or brush. It leaves no residue and will not harm most surfaces and finishes.
Where it can and cannot be used
Suitable for baths, sinks, vanities, showers, tiles, ceramics, laminate, window frames, masonry and roofing — and for use on ceramic tiles, porcelain, glass, grout, most metals, brass, laminate, most plastics, masonry, coated timber and most painted surfaces.
Limitations:
- Not suitable for rubber, EPDM or polycarbonate. That rules out a polycarbonate shower screen panel and any rubber seal in the area — mask them off if they are close to the work.
- Product may affect some surfaces — test compatibility before use.
- Do not leave it on porous materials or acrylic-painted surfaces for extended periods. On a porous stone or an acrylic-painted wall, apply, watch it, and remove it on time rather than leaving it to work while you do something else.
- It will not remove staining caused by old penetrated silicone oils. If the grout or stone has darkened where the bead sat, that is a stain in the substrate, not residue on it, and removing the sealant will not lift it.
Why "10 minutes" and not longer
Selleys Sealant Remover is a fast-acting product — its published removal time is 10 minutes, and it is designed to work in a single application. It is worth knowing this because older Selleys guidance for this job quoted several hours, and people still wait that long out of habit.
Waiting longer is not a free improvement. The product needs to stay wet to keep working, and on porous or acrylic-painted surfaces extended contact is specifically discouraged. If ten minutes has not softened the material, the usual cause is that the bead was not cut back far enough — the fix is more cutting and a second application, not a longer wait.
Finishing the surface before you reseal
Once the softened sealant is off, clean the joint down with mineral turpentine on a clean cloth. This lifts the last of the softened residue along with body oils and soap film, and it flashes off without leaving anything behind.
If there is any sign of mould in the joint — black spotting in what is left of the bead, or in the grout — treat it before you reseal. Selleys recommends spraying Selleys Rapid Mould Killer into the gap to kill any residual mould, then drying the area thoroughly. An established colony can penetrate a new seal even where the new product contains mould inhibitors, so a joint that is not properly treated is a joint that will need doing again.
Replacing your sealant — four steps
- Mask. To ensure a neat finish, use masking or painters tape to mask both sides of the joint before applying sealant.
- Apply. Gun Selleys No Mould into the joint, making sure the sealant is pushed into the joint rather than laid across the surface.
- Tool. Smooth the sealant with a spatula dipped in detergent water within 5 to 10 minutes of application. Remove the tape as soon as possible, before the product has a chance to skin.
- Clean up. Clear any residual excess sealant with turps.
No Mould is an acetic cure silicone with a skin time of 20 minutes and a cure rate of 2 mm per 24 hours. It is waterproof and shower ready 1 hour after application, and needs at least 48 hours to cure fully, during which the bead must not be touched. If the joint touches a mirror edge or stone, use a neutral cure product such as Selleys Wet Area Silicone instead, which cures in 72 hours.
For the full resealing method, see how to replace old silicone. For a caulking gun refresher, see how to use a caulking gun.
Common questions about removing old sealant
How thick should I spread the remover?
At least 5 mm, evenly, over sealant that has already been cut back to a layer less than 5 mm deep.
How long does it take to work?
At least 10 minutes. Significantly longer if the sealant was not cut back first, and a second application may be needed.
Do I clean up with water or solvent?
Mineral turpentine. Do not use water.
Does it work on anything other than silicone?
Yes — it is suitable for silicone, acrylic, SMP/hybrid and polyurethane sealants.
Will it damage my tiles?
It will not harm most surfaces and finishes, and it is listed as suitable for ceramic tiles, porcelain and grout. Test compatibility on a small area first, and do not leave it on porous materials or acrylic-painted surfaces for extended periods.
Can I use it on a plastic shower base or a rubber seal?
Not on rubber, EPDM or polycarbonate. Most other plastics are fine, but test first.
The grout is still stained where the old bead was. What now?
That is staining from old penetrated silicone oils, which this product will not remove. It is in the substrate rather than on it.
Do I have to remove every trace?
Yes. New silicone will bond to residue rather than to the surface, and any mould left in the joint becomes the start of the next failure.
What size does it come in?
A 375 g tub.
Can I use it on a vertical joint?
Yes — it sticks vertically and is suitable for both horizontal and vertical application.
Is there a version of this guide for tiles specifically?
What are the main steps to remove old silicone sealant according to Selleys?
According to Selleys, the steps are: 1) Cut away the worst of the sealant using a sharp blade. 2) Ensure the surfaces are completely dry. 3) Apply Selleys Silicone Remover on the surface of the old silicone, layering it about 3mm high (test on a small area first). 4) Allow 2-4 hours for thin beads of sealant to soften, noting this can take longer if the silicone wasn't cut back first and may require multiple applications; make sure the remover doesn't dry out while waiting. 5) Once the remover has softened the silicone, clean the residue up with methylated spirits – do not use water.
What tools and supplies are needed to remove old sealant?
The supply needed is Selleys Silicone Remover, and the tools needed are methylated spirits, a sharp blade, and a cloth/rag for cleaning.
How long does the whole process of removing old sealant take?
The total time for the process is listed as 240 minutes (4 hours).
How long should Selleys Silicone Remover be left on the sealant before cleaning?
You should allow 2-4 hours for thin beads of sealant to soften, though it can take significantly longer if the silicone was not cut back first, and multiple applications may be required.
Can water be used to clean up silicone residue after using Selleys Silicone Remover?
No, water should not be used. Once the remover has softened the silicone, the residue should be cleaned up with methylated spirits instead.
Why is it important to cut back old sealant before applying the remover?
Cutting away the worst of the sealant with a sharp blade first is important because it allows the remover to work more effectively; according to the knowledge base, leaving only a thin layer (less than 5mm) allows the chemical remover to penetrate more effectively into the remaining material, and skipping this step can make the softening process take significantly longer and may require multiple applications.
How thick should the layer of Selleys Silicone Remover be when applying it?
The sealant remover should be applied on the surface of the old silicone, layered to about 3mm high, and it's recommended to test on a small area first.