Abstract: The time required for the erection of large-diameter fiberglass-reinforced tanks is reduced greatly, and tank quality much improved, by providing fiberglass-reinforced joint rings exteriorly adjacent the abutted ends of the tank sections, bonding and sealing the joint-ring edges to the tank section walls, and introducing large amounts of thermosetting bonding resin into the resulting large annuluses. Fiberglass-reinforced joint means are also bonded to the section ends interiorly thereof. This is accomplished by mounting corrosion-barrier joint rings interiorly adjacent the abutted ends in such manner as to create annuluses, and injecting bonding and corrosion-prevention resin into such annuluses. Each exterior joint ring is first mounted on a tank section above the end, then such end is caused to abut an opposed end, and then the joint ring is dropped onto stop means prior to the above-mentioned bonding-sealing and resin-introduction steps.