Milwaukee M18 Cordless Caulk Gun Review

Milwaukee Cordless Caulk Gun window

Last Updated on July 23, 2022

The Milwaukee Cordless caulk gun runs on the M18 RedLithium battery platform and is designed to apply both caulk and other tube or cartridge-based adhesives.

With 950 lbs. of force at the tip of your forefinger, you’re ready for the highest viscosity materials. This is not just a one or two-speed trigger; you get the feel of the true variable speed control.  The six-setting maximum speed dial allows you to optimize the flow rate of the Milwaukee cordless caulk gun (0-21 Inches Per Minute), and the Constant Flow Technology keeps the material flowing without oscillation. It’s claimed that over 200 tubes of 10oz construction adhesive can be dispensed on one battery charge using the included M18 RedLithium battery…that’s a ton of work accomplished on one charge. What’s more, you can dispense those materials in the cold weather—there’s enough force to get them flowing.

Meet Our Pro

When you’re testing the most powerful cordless caulking gun of its kind, who wants to see a simple job of caulking windows or a bathtub?  No, we want to see a tool like this put to the test—in the hands of a Pro in a real-world scenario. I just so happen to have one in the family.

Milwaukee Cordless Caulk Gun

Meet Jimmy Johnson (no, not the race car driver), owner of Highland City Glass since 1981. By the name, you would think of a normal glass shop where you can buy your custom-cut window glass or have your windshield replaced.  Yes, it’s that, and much more. Located in Central Florida, a large portion of the world’s phosphate supply is mined right here. With that comes a lot of heavy equipment: bulldozers, payloaders, draglines, cranes, control rooms, and pit cars (Pit cars are steel-plate sheds built on sleds that are used to blast the phosphate rock, being dug by the draglines, with hi-pressure water that creates a slurry sent to the plant for processing.)

Through the years, much of this heavy equipment glass has gone from being mounted with rubber gaskets to being glued in with various materials, such as urethane. Urethane is the same product used in most auto windshields. Highland City Glass has been servicing heavy equipment in the mining industry since the late sixties.

Milwaukee M18 Cordless Caulk Gun Testing and Use

All urethanes, like the commonly-used Dow Betaseal Express adhesive, have a set time of just minutes. This means that, once you start applying the material, you have to finish the application and set the glass before your set-time window passes. If you’ve ever had the privilege of squeezing out a tube of urethane with a manual-style caulking gun, you quickly appreciate the opportunity of using a cordless tool to do this work for you—it’s a lot of work.

Milwaukee Cordless Caulk Gun window installation
Tim Johnson assists Jimmy by installing a replacement side glass window into a CAT excavator.
Milwaukee Cordless Caulk Gun urethane

Unboxing and using the Milwaukee 2641-21CT cordless caulk gun was not a totally new concept to Jimmy. He’s been using the old 14.4v platform of the Milwaukee cordless caulk gun for several years now—albeit, the little 14.4V model is a bit tired now.  Right away, we noticed the power delivery of the M18 was sufficient—in fact, it was initially dialed into more than was needed—but you can easily dial it back to get that perfect flow. What’s nice is that the tool has a variable speed trigger, so what you’re setting with the dial is your maximum flow—allowing you to back off as needed to make corners or when you come to the end of a line or seam.

Long Run-Time

With the Milwaukee M18 platform, there’s no need to charge the battery in the middle of the day—even with a compact M18 battery. You can use the tool all day and still have plenty of juice left when you put it up. To give you some perspective, it will dispense over 200 10-oz tubes of construction adhesive on a single charge!  If 10 oz tubes aren’t big enough for you, then you can opt for the 20 oz Clear Barrel Sausage Conversion Kit (48-08-1094) or the 20 oz Aluminum Barrel Sausage Conversion Kit (48-08-1093).  Both of these options are interchangeable on the gun within minutes.

Milwaukee Caulk Gun install window

Milwaukee M18 Cordless Caulk Gun Eliminates Drip

Milwaukee Cordless Caulk Gun truck

We loved Milwaukee’s Anti-Drip mechanism which instantly stops excess material from oozing when you release the trigger. In simple terms, you can be moving at a fast pace, laying a long bead of urethane or other adhesive, and when you come to a seam (where the end of your bead meets your starting point) you let off the trigger. The Milwaukee 2641-21CT instantly reverses the plunger to relieve the pressure. No more tapping the manual back release switch and hoping for the best… Another nicety is the rotating collar that allows you to keep hold of the machine while turning corners and making transitions, all while still in control of your perfect bead.

Milwaukee 2641-21CT M18 Caulk Gun Pricing

The street price of the Milwaukee 2641-21CT M18 Caulk Gun is about $329 for the kit—a very fair price when you amortize the number of uses you’ll get from this tool over its life.

Milwaukee M18 Caulk Gun 2641-21CT Specifications

  • Battery: Compact M18 RedLithium
  • Charger: M18 and M12 multi-voltage charger
  • Length: 18.5″
  • Weight: 5.8 lbs
  • Charge time: 1 hour
  • No-load speed: 0-21 IPM (inches per minute)
  • Force: 950 lbs
  • Carriage: 10 oz cartridge (quart carriage & 20 oz. barrels optional)
  • Warranty: 5 years (tool); 2 years (battery)
  • Price: $329 (kit)

Milwaukee 2641-21CT Caulk Gun Conclusion

Milwaukee 12V caulk gun liquid nails

If you’re in the glass business, or really any trade that requires you to extrude substrate from a tube in a consistent and smooth manner, then a Milwaukee caulk gun kit should be on your truck. You can get it in the 10 oz model we tested, or even purchase it configured for use with 20 oz tubes or with a quart carriage (and those systems can be purchased later as accessories to your existing 10 oz cordless caulk and adhesive gun). The only other question will be whether you want the M18 model or the smaller, more nimble M12 cordless caulk gun. The M12 model is perfect for when you don’t need to do as much work (perhaps general construction applications when you want to deliver Liquid Nails or caulk siding). The M12 model is also better for when you’re not working in cold temperatures.

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