The project you describe is possible as long as you know the angles just support the member to be welded at the correct angle and tack it together and add all the members and view what you have if you like it weld it if you need to change any thing just break the tack weld and make the adjustment. One thing though don't use re-bar it will break. A solid piece 3/8 or 1/2 inch works well and is easy to bend or cut. islandwelder@earthlink.net