Provided is a method of manufacturing a perhalogenated elastomer comprising using an onium compound to coagulate a latex comprising polymer particles, the polymer particles consisting essentially of interpolymerized units of one or more perhalogenated comonomer(s) and at least one cure site monomer, wherein the coagulation is performed essentially free of metal ions and metal salts. Also provided is an elastomeric composition comprising a curable perhalogenated elastomer comprising interpolymerized units derived from a nitrogen-containing cure site monomer and coagulated with an onium compound, wherein the elastomer is capable of curing without adding further components and wherein the composition is essentially free of metal ions and metal salts. Also provided are fluoropolymer articles and methods of making fluoropolymer compositions and articles.