Are these two "air" holes in the weld something I should be concerned about? Thanks.

I'm no welder, but that bead looks horrible.

Worry about? No (but Frank might be along to correct me). But certainly not something I would want on a frame.

Is that a production frame?

there are lots of bikes out there with pits like that. That's a pretty ugly bead though.

You will occasionally see a crack from something like that, but usually because the penetration is bad on the whole weld.

Thanks for the replies. Yes, it is a production Schwinn Madison and obviously came this way from the factory as it was like this when I got it (about a month ago). I certainly don't want a future crack - what can I do to prevent that? FWIW, it is a 4130 frame and if the picture isn't clear it is at the top tube / seat tube connection.

I think that mountain bikes are much more likely to have seat cluster cracking problems than a road/track bike. I think you'll be fine. Is that the worst looking weld?

Thanks. It is. I looked over the rest of the welds are they all look ok.