AST GMP 025 Vs. SealBoss® JointMaster®: Which Joint Filling Dispensing System Should You Choose?

Table of Contents

• AST GMP 025 Product Specs
• SealBoss JointMaster Product Specs
• Side-by-Side Comparison
• Why Contractors Choose the AST GMP 025 for Joint Filling
• Why Some Contractors Choose the JointMaster for Joint Filling
• How to Choose
• FAQs

There are a few dispensing systems on the market for joint filling, but selecting the right dispenser can have a direct impact on the quality and efficiency of your work.

Having been in the dispensing industry for over 50 years, our team has worked with contractors who have used a wide range of equipment to dispense materials for joint filling. Two popular products in the U.S. market are the AST GMP 025 and the SealBoss JointMaster Pro2 G3i Digital. To help you decide, our team takes a closer look at both products and compares the two.

AST GMP 025

The AST GMP 025 dispensing system for joint filling is a two-part, precision GMP metering pump with tolerances down to one thousandth of an inch that supports fixed ratios of 1:1 to 4:1. It has a continuous flow up to 0.3 gallons per minute, handles fluid pressures up to 750 psi, and is compatible with materials up to 5,000 cps. The joint filling system also has a 1/4 HP DC drive motor and a manual dispense manifold. Two 6-gallon stainless steel tanks are available as a feeding option.

The dispensing system is also a smart cost-saving solution for contractors who want reliable and consistent results without a high price tag. Its simple design skips unnecessary bells and whistles that can not only increase costs but also be more complicated for workers and require more maintenance. Consequently, contractors are able to get high-performance results while keeping operational costs low.

With both a rugged and compact design, it is a dependable and affordable option for contractors and their crews working in demanding jobsites where durability and portability are equally important.

SealBoss JointMaster

The SealBoss JointMaster Pro2 Pump is a high-output, two-component, joint filling dispensing system with a rotary gear-driven pump. It has a 1:1 by volume ratio standard, but a 2:1 ratio is available. The flow rate is anywhere from 0.1 to more than 1 gallon per minute depending on the material, allowing for maximum throughput. The dispensing system also has a 1/2 HP AC drive motor, is compatible with viscosities from 50 to 4,000 cps, and features 6-gallon stainless steel tanks to supply material to the pump.

With a digital interface display and a handle-mounted control on the applicator wand, operators can make adjustments during long runs. With its high flow capacity and long-run performance, the JointMaster joint fill machine is ideal for contractors who prioritize speed and throughput for large-scale and high-volume, continuous joint filling applications. The system does require daily pump teardown and cleaning to maintain optimum performance.

Side-by-Side Comparison of GMP 025 & JointMaster

While both the SealBoss JointMaster and the AST GMP 025 joint filling dispensing systems are used for many of the same applications, there are some notable distinctions between the two machines. Our team outlined some of the most important similarities and differences between the GMP 025 and the JointMaster.

Why Contractors Choose the AST GMP 025 for Joint Filling

One of the biggest differences between the JointMaster and the AST GMP 025 joint filling system is the pumps themselves. AST has the unique advantage of having its own machining centers and manufacturing the gerotor pumps itself, instead of getting catalog pumps from an outside source. Consequently, its products, like the GMP 025, can maintain tolerances down to one thousandth of an inch for tighter and more precise on ratio dispensing. This precision can help reduce the risk of soft joints, brittle cures, or rework. If accuracy and precision are important for your team, then the GMP 025 joint filler dispenser is likely the right choice for you.

Another benefit of the GMP 025 over the JointMaster pump is the easy end-of-the-day maintenance requirements. The last thing any crew wants to do after a long day of work is break down the pump, clean it, repack it with grease, and put it back together. The GMP 025 concrete joint filler machine has a special lubrication chamber with a grease circuit on the top and a bleed port on the bottom. All the crew needs to do at the end of the day is put a few squirts of grease in the lubrication chamber. This small design change not only reduce maintenance time but also helps lower repair costs and increase the lifespan of the equipment. If you want a machine that stays productive without extensive upkeep, the GMP 025 offers a noticeable advantage.

Although the GMP 025 joint fill machine does not match the maximum output of the SealBoss JointMaster, many contractors find the flow rate more than adequate. They also prefer the simple and compact design that makes operation intuitive.

Other beneficial features of the GMP 025 joint filler pump include:

• Telescoping wands for adjustable length
• Wheel guide
• Silicone gasketed tank lid for overnight material storage
• Customizable design options
  
• Affordable cost

Why Some Contractors Choose the JointMaster for Joint Filling

The SealBoss JointMaster pump filler system is a popular premium option mostly because of its very high-volume capabilities. With its high flow rate sometimes over one gallon per minute, the JointMaster is designed for very high-output, industrial applications. The JointMaster is also the heftier and burlier option compared to the GMP 025 dispensing equipment.

The equipment also has a programmable logic controller with a digital display. This feature can be beneficial for consistent line speed over long runs. Routine pump teardown and cleaning after every shift is also recommended for optimum machine performance.

The JointMaster joint filler system is generally viewed as a higher-cost, premium industrial system. If your primary focus is maximum volume and speed rather than budget, it can be a good fit. For many contractors, however, these additional capabilities are not essential for their typical project requirements.

Other beneficial features of the JointMaster joint filling machine include:

• 5-gallon or 6-gallon tank options
• Low-voltage signal line to the applicator
• Low-voltage control wiring
• Swivel wheels and brakes

How to Choose Between the GMP 025 and SealBoss JointMaster

If you are trying to decide between the AST GMP 025 and the SealBoss JointMaster there is a lot to consider. Every contractor’s needs are different, so understanding what your team values most will help point you in the right direction.

1. Identify the scale of your average job.
If your work involves very high-throughput production and cost is not a concern, the SealBoss JointMaster’s higher output may be beneficial. If you handle a range of job sizes, the GMP 025 often provides all the performance you need without the additional cost.

2. Evaluate how important ratio accuracy is to your results
The GMP 025’s precision machining helps ensure consistent mix ratios. This is especially valuable when you are working with cure-sensitive polyureas and urethanes. The SealBoss JointMaster performs well for most applications, but the looser tolerances of an off-the-shelf pump can introduce variation over time.

3. Consider how much maintenance your crew is realistically willing to perform.
If you know your team will not tear down and repack a pump every day, the GMP 025’s lubrication chamber saves time and can extend pump life. Contractors who follow strict maintenance schedules can get good results from the JointMaster, but the required daily teardown should be factored in.

4. Determine which features are most important to you.
If you are interested in all the bells and whistles, then the JointMaster may be a better option. If you want a system with practical features you can trust to get the job done, the GMP 025 is likely the way to go.

It is worth noting that both machines have their strengths. The JointMaster excels in very high-volume environments, while the GMP 025 is engineered for accuracy, simplicity, and low operating costs.

Still Have Questions?

Choosing between the SealBoss Joint Master and the AST GMP 025 depends on your job requirements and goals. You want a machine that supports both your workflow and your bottom line. If you have more specific questions or just want to learn more, feel free to contact our team.

Dispensing.com is not affiliated with SealBoss®. SealBoss® is a registered trademark of the SealBoss Corp.