The caulk that has the utmost adhesive properties and flexibility is 100% silicone caulk. This caulk is excellent for use in places like around a tub. The drawback to 100% silicone caulk is that the material is so sticky it can be very hard to get a smooth bead.
You can smooth silicone caulk and make it lie perfectly flat against the surface. One method of making the caulk smooth is to use alcohol in a spray bottle.
What You Need for Smooth Silicone Caulk
After you place a bead of caulk in the area where you need it to use the spray bottle and spritz the alcohol on top of the bead. You only need a fine mist so do not get carried away applying the alcohol.
Take your index finger and run it along with the bead of caulk gently applying pressure as you go. You will notice that the caulk is not sticking to your finger as badly as it would if you had not applied the alcohol.
You must move your finger in a slow but steady pace while you are doing this. If you try to go too fast your results will not look as precise or smooth.
You will have some caulk adhere to your finger so you are going to need to stop from time to time and wipe the excess material off of your finger.
When you finish wiping your finger return to smoothing the caulk by starting about one inch above the area you stopped in. This will allow you to make a smooth bead that does not have humps where you stop and started.
If there is any excess silicone above or below the line you created you need to quickly clean it away before it starts to harden. You can put alcohol on a soft cloth and wipe the excess away. When you are finished you will need to discard the cloth so use a cloth that you do not mind throwing away.
If the caulk dries before you can get it removed you can still get it off but it will be harder to do. If the caulk dries you will have to have a razor blade to cut the excess material away. Be careful using the razor blade because it can scratch or cut the surface of your tub, or area that you are removing caulk from.
A razor blade can also cut you so be careful with this sharp item. When you dispose of a razor blade make certain you place the blade into something like an old bottle that has a lid that you can fasten. Do not simply throw the blade in your trash bag, and do not wrap the blade in paper and then throw it in the trash.
Use Masking Tape to Smooth Silicone Caulk
One of the easiest ways to get silicone caulk around your tub in a smooth line with no caulk left on the tub or tub surround is to use masking tape.
You take the masking tape and place it on the tub surround just a fraction of an inch above the location you want the caulk line to be. Then you place a line of masking tape around the top edge of the tub leaving a small crack between the two lines of masking tape.
Put your bead of caulk in the area between the two lines of tape. Use your finger to apply steady pressure to the caulk and make the caulk smooth.
Smooth with Your Finger
You can moisten your finger with plain water or use water in a spray bottle to dampen the top of the caulk before you run your finger across it. Use a slow and steady pressure. It is best if you work in small sections rather than working all the way around the tub at one time. The caulk can be hard to work with after it begins to dry.
When you have your caulk smooth you simply remove the sections of tape and throw them in the trash. This is best if it is done before the caulk dries completely.