Can You Stain Caulk?

We recently published an article on the question of staining wood filler.  Most of us use nails or screws in our work, although the more talented woodworker will prefer joints that do not use a mechanical element to hold them together.

We always marvel at Japanese woodworkers and house builders that will use building and joining techniques that do not include nails, screws, or any other mechanical devices.  

Today we want to consider caulk, a cousin of wood fillers.  We’ve all likely used caulk, at least in our bathroom, but also probably in the kitchen and perhaps around windows and doors.  It serves the same purpose as wood fillers in that it acts as a sealant.

It’s waterproof (thus bathrooms and kitchens) and used to seal cracks and spaces between trim and walls, for instance.

Wood fillers fill nail and screw holes, as well as scratches and cracks, so you can see the family resemblance.

What is Caulk?

As we have just said, it is a sealant and waterproof filler that, well, seals and fills gaps between things:  tiles and tub, for instance; countertop and backsplash, for another; window or door trim and walls, another still.  

While caulk and silicone are related, and there are silicone caulk products, they are not the same thing.  Caulk is composed of silicone material but differs from silicone in that the latter has an elastic quality to it.  Silicone sealants will provide some flexibility as they will expand and contract more freely than non-silicone caulk.

Caulk is typically made from latex and acrylic materials and, as such, will tend to be more rigid and firm, as well as prone to shrinking as it cures.  Other sealants, like silicone, will give a more elastic quality to sealing jobs and a greater water resistance.

Caulk will be long-lasting on static and unmoving surfaces; but will not provide the elasticity of silicone, something you will want in your bathroom and kitchen where the moisture content is higher.  So, use silicone along the tub/tile line in the bathroom, for instance, rather than caulk.

However, do not use silicone on wood or painted surfaces; that is the province of caulk. 

How Is Caulk Used?

You would want to use caulk to seal leaks through cracks, gaps, or joints, especially when less than a quarter inch wide.  For instance, cracks, gaps, or joints around windows or doors and along baseboard trim, where the building materials are pretty stationary, would be an appropriate purpose for caulking.

However, with doors and windows that open, in other words, they move, the better choice would be weatherstripping.

Use a gun to apply the caulk, and run a wet finger to smooth it in and along the gap for a smooth and uniform application.

Is It Okay to Use Caulk Over Caulk?

Maybe, yes.  Just like you don’t want to be painting over paint that is chipping, you don’t want to caulk over caulk where the bottom layer of the caulk is moldy or in some way damaged.  You’d want to make sure the old caulk is clean and dry and has been degreased.

The better approach is to remove the old caulk and replace it with new.  This will create a better seal, and that is why we use caulk in the first place.

Can You Colorize Caulk?

Sure, and that includes staining it.  There are a few things to keep in mind, but yes, you can colorize caulk.  Staining is one way to do that.  Painting is another. Of the types of caulk, you want to make sure of your choice.

You want to make sure you are using the right types of caulk, a latex caulk (acrylic latex caulk) and not silicone caulk, as silicone will not accept color.  You also want to make sure you are using the right kind of stain. By colorizing caulk, we want to distinguish between painting it and staining it.

For our purposes today, we are discussing using stain as a colorant for caulk, as distinct from the paintable caulk.

Separate and apart from the regular (for lack of a better term) type of caulk, there are also stainable caulks, caulks that are made specifically for use with stain.  Think baseboard trim, or window trim, for instance, and sealing any small gap between the wood and other building materials like drywall.

Some caulks are pre-colorized, also.  Sashco is a brand name that comes to mind in this category and offers a variety of colors to match some of the more common wood stains and paint colors. It’s available at the big DIY stores, your local hardware stores, and the major online retail stores.

Stainable caulks take the guesswork out of adding color to a caulk, of course.  However, this is not to say that a latex acrylic caulk can not accept stains well.

Unlike wood filler, which does not take stain well, latex acrylic caulk will accept stain colorization to match the color of the stain on the wood you are using the caulk with to seal a gap. There are a couple of ways to colorize it:

Add the stain with a paintbrush.  A straight-edge paintbrush with a small head will work best for you to keep the stain from the surrounding surfaces.

Make sure the caulk has both completely dried and completely cured, and wipe any excess stain off after a few minutes, being careful not to spread the stain beyond the caulk.  You want to ensure that the gap has been fully and tightly sealed before you begin applying stain to it.

Plan on two coats of stain, also being sure to allow plenty of time for the first coat of stain to dry fully.    

Mix stain and caulk together before applying.  Be sure you are using a stainable caulk, a caulk made specifically to hold the stain.  This will not be a latex caulk, as latex caulk will not hold stains.

Mix it well and fully so there are no white streaks in the caulk and apply it to the gap as you would normally.  As you can imagine, this is preferable to simply painting the stain on, as the color is mixed throughout the caulk uniformly.  It’s the difference between stain on caulk vs stain in caulk, and uniform color throughout will always be better than color just on top.

Using the same stain to mix with the caulk that you used on the wood will match the color of the caulk with the color already there.

Be sure to use a solid stain.  You have a solid stain, a semi-transparent stain, and a transparent stain to choose from, and always choose the solid stain for coloring caulk.

The semi-transparent and transparent stains will turn yellowish on caulk rather than hold their color.  A solid stain will not turn color, especially when you add two coats or, better still, mix it well with the caulk.

Again, when choosing the solid stain to mix with your caulk, use the same color as you used on the wood. To repeat, stain in caulk is better than stain on caulk.

Video Comparison of Caulks

This fellow does a good job explaining the differences among the various types of caulks available to choose from for filling your gaps.  

It’s pretty much what you need to know to make an informed choice for your needs.  

Can you colorize caulk?  Yes, you can.  There are choices, so learn and make the right choice.