Astro Pneumatic Air Caulking Gun #405 - Professional Heavy Duty Sealant Applicator for Construction, Automotive & Home Improvement Projects

This pneumatic caulk gun really was a spectacular upgrade over a normal hand-powered version and a fraction of the cost of an electric version or some of the other pneumatic units. I was able to neatly apply 8 tubes of caulk in less than an hour around the base of the garage wall, a major improvement over the manual styles.Mechanically simple and reliable. Worked flawlessly. It uses the existing piston in the tube combined with compressed air. No moving parts besides the trigger. As straightforward as it gets.Excellent value, costing what it should for what it is.Some notes:-The trigger is designed for a single finger and doesn’t lend itself to any other pull method besides the pad of your trigger finger. Hooking your finger around the trigger gets uncomfortable quickly. It’s a minor gripe but one to be aware of. It does have some feathering capability, allowing a user to adjust dispensing speed without changing a regulator setting.-Tube-to-tube viscosity changes will impact the width of your bead and how long it takes to apply a full tube even with the exact same opening in the nozzle. This is not an issue with the gun but can be easily addressed with a mini regulator at the tool. Same batch of tubes, same manufacturer, same nozzle opening size and a couple tubes were much runnier than others, changing the dispensing speed dramatically.-For most silicone caulk I found 20psi to work well, though I had to back it off or adjust my technique depending on the qualities of the tube currently being dispensed.-The threads for the tube and end cap are wide and fast to spin, but can be a little fiddly to get started. Your mileage may vary on that factor.-Because it uses your normal tube of caulk for all its functions, there is nothing to clean. Toss the empty tube and put the gun into your toolbox and move on with life. Perfect!Overall- 5 solid stars. Wish I would have bought it years ago.