A sealant template for use in sealing a joint between a component and a vessel to which the component is attached comprises a support member on which are adhesively adhered inner and outer template sections. The inner template section has a ring-shape having an outer profile similar to but smaller than the periphery of the base of the component, and the outer template section has a ring-shape having an inner profile similar to but larger than the periphery of the base of the component. When the inner template section is adhesively adhered to the base of the component and the outer template section is adhesively adhered to the vessel surface, a ring-shaped gap exists between the inner and outer template sections at the joint between the component and the vessel to facilitate application of sealant to the joint. The inner and outer template sections may be provided with tabs to facilitate removal of the template sections from the backing member and adherence thereof to the component and the vessel. The inner and outer template sections may be provided with weakened regions to enable separation of the template sections into plural template section pieces to simplify adhering the template sections to the component and the vessel. The weakened regions may be formed by perforated lines or score lines.