If you haven't welded in over 5 years, you probably don't have a welder waiting for you to use it. In this case, buying or renting a welder can be very expensive and a waste of time if you don't have the necessary welding skills. Even if you plan to rent a welder, the deposits you have to pay can be ridiculous. Also, paying this cost doesn't really help you save money, and the quality of the work won't be as good as that of the professionals. Also, the weld you create won't be as strong and defeats the whole purpose of the weld in the first place.
Welding is dangerous work for many reasons. You could be seriously burned if you are not wearing the correct protective equipment or are not careful. Also, the light emitted from the welding process can cause you to lose your eyesight. A professional welder must go through a lot of safety and technical training before being certified and know how to protect themselves and those around them. If you have not received this training, you are endangering yourself, your family members, and the site you have chosen to weld.
Welding looks easy on TV, right? Why can't I do this myself? Yes, welders with 20 years of experience make welding look easy. as easy as you think. There's a reason welding schools exist, but it's not something you can learn with a weekend at the house of your friends who have welded in the past. It takes years of experience and practice to become a good solderer and your project is unlikely to be successful without experience.