Introduction to Caulking Guns and Accessories

Caulk guns have been a necessary jobsite tool for more than 125 years. When first invented in 1894, a “puttying-tool” looked more like a pastry chef’s device than a contractor tool. In its original design, caulk was placed into a pouch from which workers pushed the material out with a hand crank to fill in voids.

Caulking guns have evolved from a tool for filling to an instrument used for sealing. This first great technological leap occurred in the 1930s when inventors replaced the hand-crank with a ratchet-like device that powered a more consistent dispensing action. And now with the introduction of new power drives that can be matched to the material being dispensed, craftsmen of all trades are using caulking guns to perform a wide variety of applications.

Many caulk guns can now dispense more than caulk. By upping the caulking gun’s power and equipping it with the proper accessories, you can apply construction materials including sealants, adhesives, and firestop materials. Recently, tool manufacturers have upped the dispensing capacity to enable workers to place stiffer materials such as mortars and masonry grouts.

It may be time to upgrade that caulking gun in your toolbox. You can now choose from a wide array of tools and accessories to generate greater job efficiencies, higher quality applications, and reduce user exposure to fatigue and repetitive motion conditions. Your White Cap professional can help you match the right tool for any job and material.

Placing the Perfect Bead

While caulking guns are used for multiple tasks with differing materials, their design goal is to help you position a perfect bead of material on the surface or substrate on your first pass. Pros define the perfect bead as a material placement that is consistent in both diameter and height, free from gaps, and shows no air bubbles.

Achieving the perfect bead isn’t easy. First, not all bead geometries are the same. A bead’s diameter, height and even shape should change to match the application. For example, a bathroom seal requires a small thin bead, while adhesives often require wide, flat beads.

Second, you must overcome jobsite conditions. The quest for the perfect bead is complicated by weather, product temperature, and substrate preparation. You need a caulking gun that allows you to adjust the product placement on an almost continuous basis.

Third, you need to be productive and avoid product waste when placing that perfect bead. To eliminate wasted motion, you might want to select caulk guns with larger containment units. Some projects require the ability to change tubes very quickly. Some larger projects are best performed with sausages that allow you to keep moving without stopping. You know you’re on target and have selected the best grip when you’re not tired from triggering, even on a long day.

 

The Right Amount of Pressure

Along with a steady hand, a perfect bead is created with the proper combination of the force by which the material is ejected from the gun’s containment unit and the nozzle’s configuration. Thrust is the term manufacturers use to describe the amount of force the caulk gun’s mechanism applies to the material.

You will be the most efficient and comfortable when you match the power of the tool to the viscosity of the material. Choose your dispensing tool power based on the material and application.

When comparing drive systems, it is important to remember that the required force to dispense thin (low viscosity) materials is much less than the force needed to gun thicker (higher viscosity) materials. Long nozzles generate significant back pressure and require more force. Materials like acrylic latex, silicone, and polyurethane work well with guns that offer thrust between 290 and 375 lbs. For stiffer materials, such as cold polyurethane, you’ll want a caulking gun that can provide up to 700 lbs. of thrust. When you’re dealing with very stiff materials such as 2-component sealants that require a mixing nozzle, or applications that require a long nozzle, you’ll want a tool with a thrust capacity of around 900 lbs.

How Caulking Guns Work

To create the proper thrust, the three core components of a caulking gun must be in balance. You can spec out the caulking gun’s drive, material containment unit, and nozzle to meet your specific application needs. 

Drives are the mechanisms that create force or thrust. There are three primary types available: 

1.     Manual drives have hand-operated mechanisms. When you select the proper gear ratio that matches the material’s viscosity, you avoid trigger fatigue. (For example, select a caulking gun with a lower gear ratio for adhesives.)

2.     Air-powered drives are commonly used for manufacturing or industrial applications where there are few materials being applied. These drives require an air compressor, regulator, and hose. Air-powered drives come in two styles:

      a.  Single Action Air-Powered Drive: Air power allows for smooth dispensing and requires manual loading for maximum control

      b.  Dual Action Air-Powered Drive: Air powers both the dispensing and loading 

3.     Cordless drives are becoming more popular as lithium technology delivers more power and longer lasting endurance. The drives on these tools are powerful, responsive, and reduce fatigue. For standard-duty, choose caulking guns with a 12-volt battery system, or an 18-volt system for a heavy-duty option.
 

When should you opt for a powered gun versus manual?

Caulking guns with powered drives provide a good return on your investment when placing:   

• Large volumes of material, i.e., wide joints or extensive adhesives
• Long smooth beads (eliminating tooling)
• Thick and sticky materials
• 2-component materials that require a static mixing nozzle
• Materials that require the use of long nozzles

One important note: Because cordless tools are designed to dispense at a continuous rate, they are not recommended for crack injection. Air powered guns are a much better choice for that type of application. 

3.  Cartridge MCU’s might the simplest option but the material cost is the highest in cost per ounce.

The nozzle determines the size and shape of the material to be dispensed. You have a wide array of nozzle types to choose from to create that perfect bead. Remember that as the diameter of the nozzle decreases and its length increases, you’ll need more pressure inside of the MCU to dispense the material. 

 

Other common caulking gun options to consider

Many manufactures offer some built-in options that help you maintain efficiency when on the job. The most important option is a cleaning rod that allows you to quickly clear material if it clogs. Two other handy cartridge-related options are a cutter and a seal puncture tool.

Two options that are very useful when working on a ladder or in tight conditions are ladder hooks and revolving barrels that provides extra maneuverability for dispensing caulk around corners.

Be sure to tell your White Cap experts about your project needs and material types to allow them to help you select the caulking gun configuration that aligns the power drives, MCUs and nozzles you’ll need to place that perfect bead efficiently and economically.