I WAS HAVING FUN WITH, MY DAD I WORKED TOGATHER ON HOMES 25 YEARS. SO I GOT THIS IT WAS GOOD FOR 6 TUBS, I MADE SURE IT WAS CLEN, AIR PSI, WAS RIGHT. THEN IT  STOP,, IGOT SAMS TUB OUT OF AIR GUN PUT IT IN A HAND GUN, TUB CAULK WAS WORKING GOOD. ALL TUBS OF CAULK I GOT AT LOWES AND LOOKED AT THE DATES ON EACH ONE.  THIS BAD THING NOT BECOUSE IT STOP ON ME I READ ALL ABOUT IT WHAT WAS SAID HOW THAY USED IT. I HAVE $40.000.00 TOOLS, BUT THIS ONE GOT ME TDHILL.