{"product_id":"permatex-ultra-copper-rtv-silicone-gasket-maker-3-oz-tubes-2-pack-high-temp-oil-resistant-sealant","title":"Permatex Ultra Copper RTV Silicone Gasket Maker 3 oz Tubes (2-Pack) — High-Temp, Oil-Resistant Sealant","description":"\u003cp\u003e\u003cstrong\u003ePermatex 81878 Ultra Copper RTV Silicone Gasket Maker is a high-temperature, copper-colored silicone sealant in a 3 oz tube sold as a convenient 2-pack for creating dependable, oil- and coolant-resistant gaskets and repairs.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis two-tube package of Permatex Ultra Copper RTV is formulated to form flexible, durable gaskets where metal-to-metal seals are required and where high heat and exposure to oils or antifreeze are expected. It cures to a firm, copper-colored silicone that withstands engine temperatures and provides a reliable sealing surface without the hassle of premade gaskets. Use it for new gasket fabrication, maintenance repairs, or as a replacement where custom-fit sealing is needed.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this product perform under high heat and chemical exposure?\u003c\/h3\u003e\n\u003cp\u003eThe Ultra Copper RTV is engineered for high-temperature environments and resists degradation from oil, coolant, and common automotive fluids. It remains flexible after curing, tolerating thermal cycling without cracking or shrinking, which helps maintain a long-lasting seal under repeated engine heat-up and cool-down cycles.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRated for elevated temperatures common in engine bays\u003c\/li\u003e\n  \u003cli\u003eResistant to oil, water, coolant and many automotive chemicals\u003c\/li\u003e\n  \u003cli\u003eThermally stable and flexible after full cure\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I apply the 3 oz Ultra Copper RTV correctly?\u003c\/h3\u003e\n\u003cp\u003eSurface prep is critical: clean and dry mating surfaces, remove old gasket material, and ensure no oil or debris remains. Apply a continuous bead from the 3 oz tube, assemble parts within the recommended skin time, and allow proper cure time before exposing to fluids or full operating temperatures.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eClean surfaces thoroughly with solvent and scrape old gasket\u003c\/li\u003e\n  \u003cli\u003eApply bead size appropriate to flange design from the 3 oz tube\u003c\/li\u003e\n  \u003cli\u003eAssemble within skin time and follow Permatex cure recommendations\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill Ultra Copper RTV work for both stationary and dynamic sealing applications?\u003c\/h3\u003e\n\u003cp\u003eYes — it is suitable for both static flange seals and certain dynamic applications where slight movement occurs, because cured silicone stays resilient and resists extrusion. For heavy dynamic sealing or extremely tight tolerance moving parts, check application guidelines to confirm compatibility.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIdeal for static flanges like valve covers, oil pans, water pumps\u003c\/li\u003e\n  \u003cli\u003eAcceptable for light dynamic joints with minimal movement\u003c\/li\u003e\n  \u003cli\u003eNot intended for high-pressure rotating seals without verification\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the packaging and sizing details I should know?\u003c\/h3\u003e\n\u003cp\u003eThis listing contains two 3 oz tubes of Permatex Ultra Copper RTV (Permatex 81878), making it convenient for tackling multiple repairs or keeping a spare tube on hand. The compact 3 oz tubes fit easily in toolboxes and allow controlled bead application for precision projects.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eTwo 3 oz tubes included (2-pack)\u003c\/li\u003e\n  \u003cli\u003eCompact tubes for accurate bead control\u003c\/li\u003e\n  \u003cli\u003eCopper-colored silicone for visible, professional-looking seals\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Permatex 81878 Ultra Copper RTV in a 2-pack is aimed at DIY mechanics, professional technicians, and restoration enthusiasts who need a reliable, high-temperature silicone gasket maker for engines and mechanical assemblies. It’s ideal when custom-fit sealing is required, for maintenance jobs, or when keeping a spare tube ready for emergencies. If you need a copper-colored, oil- and coolant-resistant sealant that cures to a flexible gasket, this product is designed to meet those needs.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: How long until Permatex Ultra Copper RTV cures fully?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Skin forms in minutes; full cure typically requires 24 hours, depending on bead thickness and temperature.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this RTV with engine oil and coolant?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. Ultra Copper is formulated to resist oil and coolant once fully cured, suitable for many automotive sealing tasks.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Permatex","offers":[{"title":"Default Title","offer_id":48084348174494,"sku":"B01LZ7WZAT","price":32.63,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/permatex-ultra-copper-front-packaging.jpg?v=1785851193","url":"https:\/\/northtrailauto.ca\/products\/permatex-ultra-copper-rtv-silicone-gasket-maker-3-oz-tubes-2-pack-high-temp-oil-resistant-sealant","provider":"North Trail Auto","version":"1.0","type":"link"}