Method of making a magnetic toy fish

A method of constructing a toy fish formed from two preformed half-shell sections with each half-shell section defining one half of the fish structure, which comprises:

• bringing said preformed half-shell sections into alignment with each other, sealing said two preformed half-shell sections to form air tight seal joints, said sealing being carried out by applying sonar energy to the half-shell sections across their entire lengths, at a frequency of from about 18,000 Hz to about 20,000 Hz, a pressure of from about 15 p.s.i. to about 20 p.s.i., and a welding time of from about 0.5 second to about 0.9 second to effect the air-tight seal between said half-shell sections.