In my idiolect, those two words are homonyms. When I worked construction, you couldn't ask someone for caulk without raucous laughter. http://dictionary.refere

In my idiolect, those two words are homonyms. When I worked construction, you couldn't ask someone for caulk without raucous laughter. http://dictionary.reference.com/browse/caulk http://dictionary.reference.com/browse/caulk this link seems to agree, with the word represented in IPA as [kɔːk]