I never said anybody else should torch their hardy. I said, "I would". Screenzies has already determined that the hole is plug welded, a few seconds of preheat flame would verify "to me" that it is metal, and not some cob webs. I am, however, a bit of a pyro, and torch class was among my favorites in school.
Side note; on my lab rat, I accidentally welded my pritchel hole shut, because copper tube is just not heat resistant enough. Hard face rod is a real pain to try to drill through.