How to Recaulk a Tub


One thing I keep on meaning to make an entry about one of these days is the current mindset of this expectant father. The theme is something like this – “I know I need to do something, but I don’t know what”.

Well, I’ve been finding myself motivated to do stuff – all sorts of stuff, and once I get it in my head, it seems really important I get it done now, lest I be a bad, bad father. The other day, that thing was recaulking the tub. As you’ll see in the pictures, though it really was no place for an infant before the recaulking.


I should point out that the following documentation is based on instructions I found here

What You’ll Need:

  1. Utility knife with regular blades and hook-shaped blades
  2. Vacuum Cleaner with Crevice Tool
  3. Silicone Remover
  4. Isopropyl Alcohol
  5. Masking Tape
  6. Caulk
  7. Caulking Gun
  8. Paper Towel

Step 1 – Buy a Property with a Really Gross Tub


This part is harder than it might seem. Not all properties will have a tub of the required disgustingness to really make you feel good about doing this job. If you get a place with a tub that is only mildly disconcerting, for example, you endanger yourself to the risk of never getting around to it. My standards are so low, we managed to live here for 5 months before I motivated myself to get this done.

Step 2 – Remove the Old Caulk with a Utility Knife


I found a few techniques that worked well in different spots. In most spots, I could carve out a V shaped groove and just whittle it out along the seam.


Along the edge of the tub, there was frequently thin film of caulk on the tub. In those cases, scraping at it with the edge of the utility knife blade flat on the surface worked well to remove it.


In other spots, the old caulk had gotten very hard with age. (Ahem.) In those places, this hook shaped knife was helpful in loosening it off, and then pulling it out. Otherwise, it had a tendency to get pushed in further.


When I was done, the edge looked messy, but void. There was just a big dark gap between the tile and the tub.


Step 3 – Clean Up The Old Caulk Bits


After going at it with a knife, there was a satisfying amount of grody old bits in the tub. They’ll just get in the way for the next few steps though. I used a vacuum cleaner to remove them, and then with the crevice tool attachment on, went at the join. There were a lot of bits in there that the vacuum got out that I don’t think could have been removed otherwise.

Step 4 – Use Silicon Remover


I bought Dap Silicone-Be-Gone at Home Depot. It worked well to get the little filmy bits off that I couldn’t with the knife. The jar comes with a brush, and you basically just brush it on, leave it for a couple of hours, and then clean it all off with soap and water.

I think it is important to clean it off really well – this stuff is meant to dissolve silicone, and after it’s cleaned off, that’s exactly what is re-applied!

Step 5 – Clean the Edge Thouroughly

After removing the silicone remover, I washed the tub with comet scouring powder, and finally with isopropyl alcohol, just to be sure the surfaces were free of any residue.

Step 6 – Mask The Join


Using painter’s tape, mask off on area about 1/4 inch away from the edge on both sides – the tub and the the tile. I rolled my eyes when I read about this step, thinking that I could lay a bead of new caulk down without making a mess, but found that to be completely untrue. Whoever did this job before didn’t use masking tape, and it showed. Filmy bits of silicone were everywhere. Masking prevents that entirely.

Step 7 – Fill the Tub with Water

Water is heavy, and the tub is flexible. Filling the tub with water will increase the size of the gap, and filling with it at it’s maximum size will prevent pulling on the caulk (ahem) later.

Step 8 – Apply the New Caulk


I used GE Silicone II Kitchen and Bath in White. Make sure to look at the colour when you buy it. I didn’t – I bought clear and had to go back and exchange it. I also bought the gun, and would recommend getting the better model instead of the cheaper one. I’ve used cheap ones in the past, and trust me, it’s worth the $2-$5 upgrade.


The nozzle should be cut at a 45 degree angle. After the nozzle is cut, poke the membrane in the tube with the poker on the caulking gun (mine is on the handle).

There is no easy way to tell you how to caulk the tub without making a mess – I’ll just warn you that it is a messy business and give you these tips:

  • have paper towel handy. It will help you to clean the tip of the tube after you are done, and any spot you might dribble while going through this process.
  • with the slanted nozzle cut against the tub, gently squeeze the trigger and move the gun along, with the nozzle pointing reverse to the movement of the gun
  • if you see you’ve left a gap, just keep moving in a long smooth motion. You can fix it later, but stopping to mess around mid-stream will apply the caulk more unevenly than going back now.
  • you can always lay down a second pass – don’t worry if you don’t lay as much as you’d like on the first one. It’s better to err on the side of not enough on the first pass.

Step 9 – Clean the Edge with a Wet Fingertip

I think the wetting is supposed to keep the silicone from soaking into your skin. I’ll be honest, by the time I was done, I don’t think it made much of a difference.

Having just applied a bead of caulk into the gap, now you’ll want to smooth that edge out and press the new caulk down to fill that gap more by running your finger along it. This is where the masking tape shows it’s usefulness – if you find you have excess, it can be squeezed onto the tape to be removed later.

Step 10 – Remove the Masking Tape

Wait about 15 minutes to let the caulk set partway, then remove the tape. Be sure to pause to admire your beautiful work!

The caulk should be tack-free in 3 hours, but isn’t fully cured and shouldn’t be used as a shower or bath until 24 hours has passed.

In my tub I went from this:


To this:


This was gratifying, but you might note the paint peeling off of the tile where I cleaned up the edge. I know what you are thinking – paint on tile? That’s crazy! It might be, but that’s how it was when we bought the place. I’m was too lazy to replace the tile, so I just laid another coat of paint on top. That’s another story, but if you are looking for paint to apply to tile, it was recommended I use Melamine paint, and I did, and it seems to have worked well. Melamine is actually a type of plastic. It’s oil based and therefore stinky, but it’s very, very sticky, and was a lot easier than replacing the tile!

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