701—26.48 (422) Vulcanizing, recapping or retreading. Prior to May 18, 1984, persons engaged in the business of recapping or retreading tires for any vehicle or vulcanizing any type of product for others are rendering, furnishing or performing a service, the gross receipts from which are subject to tax. For the purposes of this rule, vulcanizing shall mean the act or process of treating crude rubbers, synthetic rubber, or other rubber-like material with a chemical and subjecting it to heat in order to increase its strength and elasticity. On and after May 18, 1984, the sale of vulcanizing, recapping or retreading is treated as a sale of tangible personal property. See rule 701—16.51(422,423) for the effects of this change and for certain changes in the treatment of vulcanizing, recapping or retreading for the period beginning January 1, 1979, and ending May 17, 1984.