Wet Area Speed Seal Silicone Curing Time
Can a hair dryer speed up the curing of Selleys Wet Area Silicone?
No. Selleys Wet Area Silicone requires atmospheric moisture to cure. Using a hair dryer will have no effect on the cure time and could hinder the curing process.
That is worth understanding rather than just accepting, because it runs against the intuition almost everyone brings to the job. Silicone does not dry the way paint dries. Paint loses a solvent or water carrier, so heat and airflow help. Silicone cures — it undergoes a chemical reaction with water vapour drawn from the surrounding air, forming a rubber from the outside inwards. Warm dry air holds less moisture at a given relative humidity, so a hair dryer removes the one ingredient the reaction needs.
What actually helps is ordinary ventilation at normal room humidity. Open the window, leave the door ajar, and let the joint alone.
When can you use the shower?
This depends on which product you used, and the two answers are quite different.
| Selleys Wet Area Silicone (neutral cure) | The shower can be used 24 hours after application. By then the sealant has developed a sufficient skin and a watertight seal — provided it has not been disturbed by touching. Its technical data sheet states the sealant cures in 72 hours. |
| Selleys No Mould (acetic cure) | The shower can be used 1 hour after application, as it will have skinned over sufficiently. Its technical data sheet states the semi-cured sealant must not be touched until fully cured, at least 48 hours. |
In both cases the same rule applies through the whole curing period: do not touch or disturb the bead. Water running over a skinned bead is fine. A finger pressed into one is not.
Skin, watertight, cured — three different states
Most confusion about silicone timing comes from treating these as one thing. They are not.
Skin forms first. No Mould skins in 20 minutes; Wet Area Silicone in 5 to 10 minutes at 25°C and 50% relative humidity. This is the tooling deadline — after the surface skins, tooling tears it rather than smoothing it.
Watertight comes next, and it is what the "shower ready" figures describe. One hour for No Mould, 24 hours for Wet Area Silicone. The skin is thick enough to keep water out of the joint, but the material underneath is still reacting.
Fully cured is last: at least 48 hours for No Mould, 72 hours for Wet Area Silicone. Both cure at approximately 2mm per 24 hours, so a deep bead takes proportionally longer than a shallow one. That per-day rate is why a published cure time is always a minimum rather than a guarantee — it assumes a normal bead.
What genuinely affects cure speed
- Humidity. The published figures assume 50% relative humidity. Drier air slows the cure.
- Bead depth. At 2mm per 24 hours, an 8mm bead needs four days to cure through.
- Ventilation. Air movement at normal humidity brings fresh moisture to the surface. Warm dry air does the opposite.
- Being left alone. The most common cause of a failed new bead is someone testing it with a finger.
Getting the joint right in the first place
- Spray Selleys Rapid Mould Killer into the gap to kill any residual mould before applying new sealant.
- Thoroughly clean the surface with turps and dry it.
- Cut the nozzle at a 45° angle, cut the cartridge tip and fit the nozzle.
- Place the cartridge in a caulking gun and apply with steady pressure, pushing the sealant into the joint.
- Tool with a spatula dipped in detergent water — within 10 minutes for No Mould, within 5 to 10 minutes for Wet Area Silicone.
- Clean up with turps before the product skins.
- Leave it undisturbed for the full cure period.
- Clean off soap scum and dirt regularly afterwards, since these encourage mould growth.
Limitations on both products
- Not paintable. Complete painting seven days before applying sealant.
- Not suitable for aquariums.
- Not suitable for food and drinking water contact.
- Not suitable for permanent water immersion.
- No Mould is not suitable for metals other than aluminium and stainless steel, because it is an acetic cure silicone.
- Wet Area Silicone is not suitable for use on PP, PE or PTFE.
Common questions
Will a hair dryer make silicone cure faster?
No. Wet Area Silicone needs atmospheric moisture to cure; a hair dryer has no effect on cure time and could hinder it.
What about a heater or a fan?
Ventilation at normal room humidity is what helps. Adding heat lowers relative humidity, which works against the cure.
How soon can I shower after using Wet Area Silicone?
24 hours after application, provided the bead has not been disturbed.
How soon can I shower after using No Mould?
1 hour after application. It will have skinned over sufficiently, but do not touch it.
How long is a full cure?
Wet Area Silicone cures in 72 hours. No Mould needs at least 48 hours, per its technical data sheet.
Does the thickness of the bead matter?
Yes. Both cure at approximately 2mm per 24 hours, from the surface inwards.
How long do I have to tool the bead?
Within 10 minutes for No Mould, within 5 to 10 minutes for Wet Area Silicone.
What happens if I touch it while it is curing?
You break the skin and disturb the joint. The instruction on both products is that the semi-cured sealant must not be touched until fully cured.
Why does No Mould smell of vinegar?
It is an acetic cure silicone, so it releases acetic acid as it cures. That is also why it is not suitable for metals other than aluminium and stainless steel.
Is there a full guide to resealing a shower?
Yes — how to replace old silicone, and how soon can I shower after Wet Area is applied.
Will a hair dryer make silicone cure faster?
No. Wet Area Silicone needs atmospheric moisture to cure; a hair dryer has no effect on cure time and could hinder it.
What about a heater or a fan?
Ventilation at normal room humidity is what helps. Adding heat lowers relative humidity, which works against the cure.
How soon can I shower after using Wet Area Silicone?
24 hours after application, provided the bead has not been disturbed.
How soon can I shower after using No Mould?
1 hour after application. It will have skinned over sufficiently, but do not touch it.
How long is a full cure?
Wet Area Silicone cures in 72 hours. No Mould needs at least 48 hours, per its technical data sheet.
Does the thickness of the bead matter?
Yes. Both cure at approximately 2mm per 24 hours, from the surface inwards.
How long do I have to tool the bead?
Within 10 minutes for No Mould, within 5 to 10 minutes for Wet Area Silicone.
What happens if I touch it while it is curing?
You break the skin and disturb the joint. The instruction on both products is that the semi-cured sealant must not be touched until fully cured.
Why does No Mould smell of vinegar?
It is an acetic cure silicone, so it releases acetic acid as it cures. That is also why it is not suitable for metals other than aluminium and stainless steel.
Is there a full guide to resealing a shower?
Yes — how to replace old silicone , and how soon can I shower after Wet Area is applied .