I BOUGHT ONE OF THESE RIDGID CAULKING GUNS 18VOLT AND USED IT ONCE I THOUGHT IT WAS WORKING WELL UNTIL I WENT TO CHANGE THE TUBE AND SEEN THAT THE CAULKING HAD BACKED UP AND CAME THROUGH THE PLUNGER SIDE OF THE TUBE PUTTING ADHESIVE ALL OVER THE GEARS. I CLEANED IT UP AND ATTEMPED SEVERAL TIMES WITH THE SAME RESULTS. I WAS USING THE BIG TUBES. CANT FIGURE OUT WHY IT KEEPS DOING IT. WHAT IT DOES AS WHEN THE PLUNGER PUSHES ON THE BACK OF THE CAULKING TUBE IT PUSHES AT AN ANGLE CAUSING THE CAULK TO COME OUT OF THE BACK SIDE OFTHE TUBE MAKING A HUGE MESS. WHEN YOU PULL THE PLUNGER BACK IT THEN GETS CAULKING ON THE GEARS AND RIGHT UP INTO THE GUN WHICH MAKES IT ALMOST IMPOSSABLE TO CLEAN AND IF IT DRYS IN THE GEARS THE GUN WONT OPERATE AT ALL.