Abstract: A method for forming a solar collector includes a panel provided with an inner bore and a deformable metal tube inserted in the bore and mechanically secured thereto by passing a plug or bullet through the tube to deform it outwardly into intimate contact with the panel such as to maximize the heat transfer therebetween and to substantially eliminate any possibility of corrosion by keeping the tube in constant compression. The tube can carry a liquid, such as water or glycol, which is heated by the panel exposed to radiant solar heat. The so formed solar collector typically uses a copper tube and an extruded aluminum panel. A number of parallel conduits connected at their opposite ends to common main inlet and outlet copper pipes may be provided with the panels of adjacent conduits mating together while allowing for relative movement therebetween but without the forming of gaps therebetween.