Just dip your finger into the liquid (make sure it's slippery) and then, with as little pressure as possible, run your finger along the line of silicone, smoothing it out as you go.
After removing any old sealant, cleaning and drying the surface, lay the silicone as normal. Next, grab your glass cleaner and spray over the fresh sealant. This won't mix with the silicone, allowing you to smooth it out without sticking to any unwanted surfaces. Then all you need to do is leave it to dry.
Smooth the Caulk Bead
Some professionals will use their finger to smooth caulk while others go back over their work with a damp rag. Whichever method you use, the overall goal is to smooth the bead and not to remove excess caulk.
It is fine to put another layer of silicone over an existing bead. The main consideration to remember is if the old bead is not fully cured you do not want to break the skin it has formed. Sometimes it is best to wait 2-3 days before putting any new product on so the old one has enough time to dry.
An index finger works fine when tooling a bead of water-based caulk. An ice cube is another alternative. It's best to tool silicone and polyurethane joints with a plastic spoon or a caulk tool. For poly caulk, wet the tool surface with solvent to get smooth results with this super-sticky material.
Just dip your finger into the liquid (make sure it's slippery) and then, with as little pressure as possible, run your finger along the line of silicone, smoothing it out as you go.
Sometimes, people touch the caulk before it has cured and then inadvertently touch their mouth or eyes. In general, caulk is only a mild irritant. If it has already cured and a child swallows a piece of it, it could pose a choking hazard depending on the size of the piece and might also cause a mild stomach upset.
Yes, some caulks can be smoothed by sanding once dried. However, silicone or decorators caulk cannot be sanded. To smooth this kind of caulk, you'll need to use either denatured alcohol or mineral spirits. You'll need 80- and 100-grit sandpaper to smooth dry caulk.
When the caulk gets wet, it will not cure properly. The formula that makes up your caulk will not be able to dry and cure or bond to the surface to that you have applied it. Not being able to dry in a timely manner will prevent the caulk from creating a proper seal.
Wet fingers work fine for regular caulk but silicone caulk requires alcohol or similar.
Siliconing tools offer an easy solution to providing a professional finish when sealing. Sometimes referred to as caulking tools or sealant tools they help smoothing out and shaping applications of a newly applied silicone finish.
It might seem that certain shower sealants or caulks are dry to the touch quickly after application, but they actually take around 24 hours to properly cure fully. The curing process can be sped up or slowed down in accordance with the level of humidity within the shower enclosure, and the home in general.
When the sealer is applied too heavily, the air displaced through the surface can't escape, and it forms a bubble in the sealer surface. Bubbling of a sealer can also occur if application is done in hot weather, or if the concrete is in direct sun.
Smooth the Joint
Wet your finger with either rubbing alcohol (for silicone caulk) or water (for latex caulk). Also, dampen a corner of a cloth rag with either water or alcohol, as appropriate. The alcohol or water will serve as a lubricant and thinning agent as you smooth the joint.
Can I apply new silicone atop, or alongside old silicone caulk? It is recommended that any old silicone is removed. While new, freshly applied silicone can be applied & will bond to old silicone – the bond isn't as strong as if it were applied to a clean surface.
You can use either a heat gun or a blow dryer to soften the silicone. Ideally, you want to apply the heat to all areas of the silicone for at least thirty seconds and no more than two minutes. You can then test the silicone material to see if it is soft enough to remove.
Silicone sealant generally cures within 24 hours. If it has been over 24 hours, check the silicone sealant “Use By” date on the package.
Warmer temperatures generally lead to faster curing times, partly due to the fact that they usually involve higher humidity. However, regardless of the ambient temperature at the time you undertake your project, it's not a good idea to try to help the silicone cure faster by applying direct heat to it.
For any stubborn caulk that remains, start by rubbing butter all over your hands. It's best to cut off a piece of butter rather than using the whole stick if you plan to use the butter for culinary purposes later. Next, apply baking soda to your hands and rub them together.