Any insurance pros want to field this handyman welder question?

I have started a "handyman" buisiness and will need liability insurance. First, why are so many companys not willing to quote? Second, I have a welder, I cant find anyone willing to quote for that at all, why not? Finaly, with regards to welding, I have heard the term "insured and bonded" how do you get bonded and what is it for?