Radical Eggnog

Hey all. I got everything assembled, kicked it on, and for some reason the burner is sputtering. It is very odd, and I can link to a video if need be. It seems like some gas is escaping from where the mig tip connects to the compression fitting. The tip is screwed in there tight, but it is still happening. I'm not sure what could be causing it, so thought that I would toss is to you folks and see what you could make of it.

First off, great guide. It helped a lot. I'm in the process of building my first forge (build the burner today, the actual forge next weekend.) I was wondering how you connected the propane to the burner. Just trying to ensure I do everything properly (and safely!)