Butyl caulk: Fill the gap

• Butyl caulk: What is it used for?
• How to apply butyl sealant
  

With a large number of different sealants on the market right now, butyl caulk has carved itself a niche as the go-to choice for filling in gaps that are larger than your standard household joints. As well as being easy to apply, it reaches full strength within minutes, meaning you can handle items in a just a short amount of time.

It is the speed with which it cures that gives butyl rubber caulk its standout quality: water resistance. Combined with a high degree of elasticity that enables it to withstand the expansion and contraction of materials that come with different temperatures, butyl sealant is ideal for use with door frames, drains, windows and other external applications.

Despite all its positive qualities, butyl rubber sealant can be untidy to apply without the correct technique. In order to avoid a messy job and get it done right, observe the following steps:

1. Warm. Cold butyl rubber caulk can harden, making it difficult to squeeze from its tube and apply accurately. Before using, submerge the tube in warm water and leave it to soak for around 20 minutes.
2. Prime. Use a utility knife to cut the tip off the tube at a 45-degree angle, starting smaller first. Load the tube into a caulking gun and test it out on a piece of scrap material – if the bead produced is too small for the gap or joint you are looking to fill, cut a larger aperture. Keep in mind that dried butyl caulk will shrink down slightly.
3. Apply. Holding the caulk gun at a 30-degree angle and starting at one end of the gap or joint, slowly squeeze the trigger and apply an even bead until you’ve reached the other end. If you do need to smooth the bead into the gap or joint, this will need to be done immediately, given butyl sealant’s quick hardening time.
4. Let it dry. Although butyl sealant hardens and reaches full strength quickly, allow it to dry for at least two days if you want to paint over it.