--- product_id: 1934494 title: "Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube" price: "81.65 DT" currency: TND in_stock: true reviews_count: 13 url: https://www.desertcart.tn/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker store_origin: TN region: Tunisia --- # Max temp 700°F intermittent 8x flexibility vs cut gaskets 3x oil resistance vs standard silicones Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube **Price:** 81.65 DT **Availability:** ✅ In Stock ## Summary > 🔥 Seal the heat, skip the leaks — the pro’s choice for engine toughness! ## Quick Answers - **What is this?** Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube - **How much does it cost?** 81.65 DT with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker) ## Best For - Customers looking for quality international products ## Why This Product - 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 durability under vibration. - • **Sensor-Safe & Low Odor:** Formulated to be non-corrosive and safe for sensitive engine sensors with minimal fumes. - • **Superior Oil Resistance:** Three times more resistant to oil contamination than conventional silicones for lasting seals. - • **Unrivaled Heat Endurance:** Handles extreme engine temps up to 700°F without breaking down or shrinking. - • **Universal Fit for High-Performance Engines:** Perfect for turbocharged, 4-cylinder, and high-performance applications including exhaust manifolds and valve covers. ## Overview Permatex Ultra Copper RTV Silicone Gasket Maker is the industry-leading high-temperature sealant designed for demanding automotive applications. With a temperature tolerance from -75°F to 700°F intermittent, it offers superior adhesion, exceptional oil resistance, and unmatched flexibility. Sensor-safe and low odor, this 3 oz tube is the trusted solution for turbocharged and high-performance engines, ensuring durable, leak-proof 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. Review: Good go to - Works great. My badly made NEW rear catalytic converter with a warped flange was leaking and it was giving me a code. Tried several time with different gaskets, but ended up using this silicone and a donut gasket/ Haven't got a code since. Good stuff. Review: The Only RTV for High-Heat Engine Jobs - If you're working on anything high-heat, like an exhaust manifold or turbo application, this is the only gasket maker to use. The Ultra Copper RTV is a workhorse—it handles maximum temperatures without breaking down, shrinking, or leaking. It goes on smoothly, cures quickly, and forms a super durable, tight seal. I've used it on headers where standard RTV would just burn up, and this holds strong. It's the professional choice for reliability under extreme heat. Essential for engine work. ## 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 | #1,671 in Automotive (See Top 100 in Automotive) #4 in Gasket Sealers | | Brand | Permatex | | Customer Reviews | 4.7 4.7 out of 5 stars (3,325) 4.7 out of 5 stars | | Date First Available | June 3, 2025 | | Exterior | Painted | | Is Discontinued By Manufacturer | Yes | | Item Model Number | 81878 | | Item Weight | 3 ounces | | 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. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good go to *by A***R on February 10, 2026* Works great. My badly made NEW rear catalytic converter with a warped flange was leaking and it was giving me a code. Tried several time with different gaskets, but ended up using this silicone and a donut gasket/ Haven't got a code since. Good stuff. ### ⭐⭐⭐⭐⭐ The Only RTV for High-Heat Engine Jobs *by M***O on October 11, 2025* If you're working on anything high-heat, like an exhaust manifold or turbo application, this is the only gasket maker to use. The Ultra Copper RTV is a workhorse—it handles maximum temperatures without breaking down, shrinking, or leaking. It goes on smoothly, cures quickly, and forms a super durable, tight seal. I've used it on headers where standard RTV would just burn up, and this holds strong. It's the professional choice for reliability under extreme heat. Essential for engine work. ### ⭐⭐⭐⭐⭐ Good gasket repair! *by J***Z on May 11, 2026* The installation of the exhaust manifold went well! Time will tell if the repair holds or not. ## 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.tn/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker](https://www.desertcart.tn/products/1934494-permatex-81878-ultra-copper-maximum-temperature-rtv-silicone-gasket-maker) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-06-21*