--- product_id: 1934494 title: "Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube" brand: "permatex" price: "R389" currency: ZAR in_stock: true category: "Permatex" url: https://www.desertcart.co.za/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker store_origin: ZA region: South Africa --- # Max temp 700°F intermittent 8x more flexible than cut gaskets 3x more oil resistant than silicones Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube **Brand:** permatex **Price:** R389 **Availability:** ✅ In Stock ## Summary > 🔥 Seal the deal with ultra copper power! 🛠️ ## Quick Answers - **What is this?** Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube by permatex - **How much does it cost?** R389 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker) ## Best For - permatex enthusiasts ## Why This Product - Trusted permatex brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Flexibility That Lasts:** Eight times more flexible than traditional cut gaskets, ensuring a durable, vibration-resistant seal. - • **Sensor-Safe & Low Odor:** Formulated to be sensor-safe and low odor, keeping your workspace comfortable and your engine components protected. - • **Oil-Resistant Powerhouse:** Three times more oil resistant than conventional silicones, maintaining integrity in harsh environments. - • **Unmatched Heat Resilience:** Handles extreme temps from -75°F to 700°F intermittent, perfect for high-performance engines. - • **Universal Fit for Pro Mechanics:** Ideal for exhaust manifolds, valve covers, oil pans, and more—trusted by professionals for precision sealing. ## Overview Permatex 81878 Ultra Copper RTV Silicone Gasket Maker is a top-tier, high-temperature sealant designed for demanding automotive applications. It offers superior adhesion, exceptional oil resistance, and extreme flexibility, making it the go-to choice for turbocharged and high-performance engines. Sensor-safe and low odor, this 3 oz tube gasket maker withstands temperatures from -75°F to 700°F intermittent, ensuring reliable, long-lasting seals on exhaust manifolds, valve covers, and more. ## Description Permatex Ultra Copper. For 4-cylinder, turbocharged or high-performance engines. The most advanced, high temperature RTV silicone gasket available. Sensor safe, low odor, noncorrosive. Superior adhesion. 3 times more oil resistant than conventional silicones; 8 times more flexible than cut gaskets. Temperature range -75 deg. F. to 700 deg. F. intermittent; resists auto and shop fluids and vibration. Suggested Applications : Exhaust manifolds/headers, valve covers, oil pans, timing covers, water pumps, thermostat housings. 3 oz tube. Carded. ## Features - Most Advanced, High Temp Rtv Silicone Gasket Available.Fit Type: Universal - Three Times More Oil Resistant Than Conventional Silicones; Eight Times More Flexible Than Cut Gaskets - Sensor-Safe, Low Odor, And Non-Corrosive With Superior Adhesion - Temperature Range -75F To 700F Intermittent ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0002UEOPA | | Best Sellers Rank | #1,868 in Automotive ( See Top 100 in Automotive ) #5 in Gasket Sealers | | Brand | Permatex | | Customer Reviews | 4.8 4.8 out of 5 stars (3,375) | | Date First Available | June 3, 2025 | | Exterior | Painted | | Is Discontinued By Manufacturer | Yes | | Item Weight | 3 ounces | | Item model number | 81878 | | Manufacturer | PERMTX-LOCKT | | Manufacturer Part Number | 81878 | | Model | Permatex 81878 | | National Stock Number | 8030-01-598-1435 | | OEM Part Number | PMT81878 | | Product Dimensions | 8 x 4 x 2 inches | | Special Features | Forms a superior bond on oil contaminated metals and maintains outstanding oil resistance | ## Product Details - **Brand:** Permatex - **Color:** Copper - **Full Cure Time:** 24 Hours - **Item Weight:** 85 Grams - **Liquid Volume:** 3000 Milliliters ## Images ![Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube - Image 1](https://m.media-amazon.com/images/I/81freAdVPGL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Can this be used on a valve cover gasket to get a better seal?** A: Yes. It is better than OEM gaskets in that it conforms to any warpage, dents, dings, & other incongruities, whereas OEM gaskets are designed for factory new, perfect valve covers without flaws. Withstands 700 degrees. **Q: Can I use this product to seal several non-moving parts of a wood burning stove instead of the standard gasketing material?** A: This gasketting goop is absolutely incredible for sealing wood stove parts. I’d certainly never use it on the fire box. But it can and will hold to moving parts in high temperatures. It lasts for several years on one application. **Q: can I use this to seal radiator tubes to a heat exchanger in my gas furnace? Gaskets no longer available for it.** A: Greetings! As I don't know this application, specifically, I can say that say that Ultra Copper is excellent for sealing liquid coolant surfaces in truck/auto repairs. Temperature, up to about 800*F and pressures exceeding 15 psi will remain sealed with this product. U.C. remains a pliant sealing silicone "glue", but it won't harden, as epoxy does. If you need a sealer that also hastens, look elsewhere. If this is for a flange or any flat, secured surface, you're good-to-go. NO acetic acid in this product, if that's a plus for you. **Q: Can I spread this on outside of exhaust manifold leak like you would caulk something or does it have to go between parts? F150 '04 V8** A: It is too much pressure and heat to use any caulk or rtv. Even muffler cement doesn't work. You might have a lean fuel mixture to cause the problem in he first place. Exhaust bolts rust solid from heat erosion, use the right amount of points on the socket to get bolts out(6 sided bolt--6 sided socket) Copper metal exhaust gaskets work well. Mr. Gasket brand. ## Frequently Bought Together - Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube - J-B Weld 37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz - Permatex 80335 Muffler and Tailpipe Sealer, 3 oz., Plastic, 1 Count (Pack of 1) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.za/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker](https://www.desertcart.co.za/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker) --- *Product available on Desertcart South Africa* *Store origin: ZA* *Last updated: 2026-07-10*