Sub frame welded by a local mechanic?

Recently a local mechanic welded it for me. Prior to having the sub frame welded by a local mechanic. I visited a Car-X shop that told me while I was getting a oil change. They told me I was driving a dangerous vehicle because previous welding done to the sun frame near motor had rotted away. Although, one nice Russian guy I visited his local auto shop over two years ago. Had told me the motor won't fall out. And that would just here noise. Although the mechanic o recently visited, that I trust. Had told me his welding the area would last a while. He did same if the welding came lose or rotted again. That he suggested I look for another car.