

🔥 Seal the heat, own the street!
Permatex 27038 Optimum Red is a premium high-temperature RTV gasket maker designed for professionals and serious DIYers. It delivers maximum heat resistance up to 750°F (399°C), is OEM specified and sensor-safe, and offers a non-toxic, low-odor formula that resists aging and cracking. Ideal for sealing exhaust manifolds, headers, and turbochargers, it ensures a reliable, long-lasting gasket seal under extreme conditions.











| ASIN | B08CRYCZ91 |
| Best Sellers Rank | #836 in Automotive ( See Top 100 in Automotive ) #2 in Gasket Sealers #1,026 in Oils & Fluids |
| Brand Name | Permatex |
| Color | Optimum Red |
| Customer Reviews | 4.7 4.7 out of 5 stars (424) |
| EU Spare Part Availability Duration | 5 Years |
| Included Components | Optimum Red High Temperature Gasket Maker |
| Item Thickness | 0.2 Inches |
| Item Type Name | Permatex Optimum Red High Temperature Gasket Maker 3.35 oz |
| Manufacturer | Permatex |
| Material Type | Silicone |
| UPC | 686226987631 686226270382 |
| Unit Count | 1.0 Count |
| Upper Temperature Rating | 750 Degrees Fahrenheit |
J**K
Works amazing
This stuff is great. You must follow the instructions though. Don’t just apply and go.
G**G
Excellent high temp rtv on manifold.
Used to seal exhaust manifold gasket on tractor. Several months with no leakage. If using on manifolds, just put a thin bead on both sides of gasket, just around the ports. Also used to seal exhaust studs on tractor that penetrated coolant jacket. No coolant leaks.
S**M
Kamado joe glue !
Awsome stuff for fixing kamado joe gaskets ! Can't ever seem to find it locally.
G**.
High temperature gasket sealer.
Haven't used the caulk gun size tube yet but I've used the same product from a squeeze tube size container and I'm very pleased with the performance. I've used it on exhaust system welds to inhibit rust and on a John Deere tractor that was leaking from the oil pan gasket. Just applied it externally without removing the oil pan and surprisingly it stopped the leak and saved me from removing the engine. Two months later and not a drop of oil has leaked out. So happy. Great sealing agent.
M**E
works great thin walls
i think works great gave it 4 starts because when rolling it up to squeeze out it popped a hole in it, just threw the rest of the tube away
S**B
Fast delivery! Great Gasket maker! Very Impressed
Great quality high temp gasket maker, Using for a Diesel heater. I would Buy again, Great Brand
J**D
Excellent
Really good stuff
K**N
Good sealant
Good gasket sealant
J**N
I recently used the Permatex 27038 Optimum Red RTV Silicone to install my intake manifold, and I’m incredibly impressed with its performance! This silicone sealant was very simple to use, applying smoothly and evenly without any mess. It formed a strong, reliable seal that held up perfectly under high temperatures and pressure, ensuring my intake manifold installation was rock-solid. The product lived up to its promises, providing excellent adhesion and durability. I highly recommend this RTV silicone for any automotive sealing needs!
S**Y
All good 👍
Trustpilot
Hace 1 mes
Hace 3 semanas