Just bought a used seal-rite 700 trailer unit. Came with the melter attached to the front of the trailer. Guy I bought it from left some crackfill in it. I hooked the torch up to my 20 lb propane bottle and it took forever to heat up. I left it going for probably an hour and a half and it only got up to 200 degrees. The torch didn't have the regulator on it that I see on seal-rites website. Do I need the regulator or am I doing something else wrong? Maybe a larger propane tank?