yes, weld-on is a solvent
we are both saying the same thing and you are right, the joint should not come apart if done properly.
definition of chemical weld:
A Chemical weld occurs when you dissolve together the two faces of each surface to be joined (in a controlled fashion) with a welding chemical. The welding chemical is a volatile solvent that is blended to control the speed at which it dissolves the surface of the material and to control its rate of evaporation. The welding chemical is brushed, poured, or squirted onto the surfaces before they are pressed together. By carefully pressing the semi-dissolved surfaces together a bond is formed that is very similar to the bond we would get if we heated the surfaces using thermal welding. The solvent "flashes off" or evaporates, and after about 24 hours you have a homogeneous weld with no foreign material between the two surfaces.