Understanding RTV Drying Times

Understanding RTV Drying Times and Vehicle Service Readiness

When it comes to automotive maintenance and repairs, one of the critical components often discussed is the use of RTV (Room Temperature Vulcanizing) sealants. These sealants are commonly employed in applications such as gaskets for engine components, oil pans, and transmission housings. Given their importance in ensuring a leak-free operation, it is vital to understand RTV drying times and the implications for vehicle service readiness, particularly regarding oil filling and returning to the road.

Understanding The Differences in RTV Drying Times Between Products in a Squeeze Tube and Those in Pressurized Cans

Fluid Refilling Time and Returning to Service

Don’t confuse the RTV products that come in tubes with the products that come in pressurized cans— they are different formulations and have different drying and return-to-service times.

In almost all cases, the RTV in pressurized cans has a much faster drying time and can often be refilled with fluid and returned to service immediately. RTV products in squeeze tubes, on the other hand, require a cure time of 24 hours or as little as 90 minutes, depending on the product.

When you can apply final torque also varies by product

Most squeeze tube RTV products require hand tightening and a pre-determined drying time before applying final torque. The pressurized RTV products can often be torqued to specification immediately.

Which color RTV is best for the job

According to Permatex, the RTV colors denote their uses

Black RTV is highly resistant to oil. It is used on oil pans, transmission pans, timing covers, and differential covers.
Grey RTV is used where rigidity and high torque loads are required. It is used on valve covers, water pumps, and intake manifold end seals.
Red RTV for high-temperature applications. Use on headers exhaust manifolds, turbochargers, slip-fit exhaust.

Permatex has made specialty RTV gasket makers for Water Pump and Thermostat applications. This product is non-corrosive and has the highest glycol resistance. Use with modern organic acid based coolants.

Permatex Gear Oil RTV for gear oil and transfer case applications.l

Black RTV Products: Application, Assembly, and RTV Drying Times (Return-to-service) Times

Ultra Black RTV Gasket Maker in a squeeze tube

1) For best results, clean and dry all surfaces with a residue-free solvent,
2) Apply with a 1/16″ to 1/4″ (2 to 6 mm) bead.
3) Apply a continuous and even bead of silicone to one surface, surrounding all bolt holes.
4) Assemble parts immediately and tighten to finger tight until the RTV material begins to squeeze out around the flange.
5) Allow to dry for one hour, then retighten 1/4 to 1/2 turn.
6) The product dries in 1 hour and fully cures in 24 hours. Allow more time in cold or very dry conditions.
7) Allow 24 hours to cure before filling with fluids or returning to service.

Optimum Black RTV Gasket Maker in a tube

1) Surfaces should be clean and dry.
2) Apply a continuous 1/16″ to 1/4″ (2 to 6mm) bead of silicone to one surface, surrounding all bolt holes.
3) Assemble parts immediately while the silicone is still wet and tighten to finger tight until material begins to squeeze out around the flange.
4) Let the product dry for one hour, then tighten it to torque specifications
5) Allow 24 hours to cure before filling with fluids or returning to service.

The Right Stuff Black RTV Gasket Maker in a squeeze tube

1) Surfaces should be clean and dry.
2) Apply a continuous 1/16″ to 1/4″ (2 to 6mm) bead of silicone to one surface, surrounding all bolt holes.
3) Assemble parts immediately while the silicone is still wet, and finger tighten until the material begins to squeeze out around the flange.
4) Let dry for one hour, then tighten to torque specifications. The product cures in 90 minutes.
5) Allow 90 minutes to cure before filling with fluids or returning to service.

The Right Stuff Black RTV Gasket Maker in a pressurized can

1) Clean and dry parts.
2) Push the nozzle sideways to dispense the product.
3) Apply a continuous 1/8″ to 1/4″ bead to one surface, surrounding all bolt holes.
4) Assemble parts within five minutes, tightening bolts to recommended torque levels.
5) Equipment can be returned to service immediately

Grey RTV Products: Application, Assembly, and Cure (Return-to-service) Times

Ultra Grey RTV in a tube

1) For best results, clean and dry all surfaces with a residue-free solvent,
2) Apply with a 1/16″ to 1/4″ (2 to 6 mm) bead.
3) Apply a continuous and even bead of silicone to one surface, surrounding all bolt holes.
4) Assemble parts immediately and tighten to finger tight until the RTV material begins to squeeze out around the flange.
5) Allow to dry for one hour, then retighten 1/4 to 1/2 turn.
6) Silicone will skin over in one hour and fully cure in 24 hours under normal conditions. Allow more time for cold or very dry conditions.
7) Allow 24 hours to cure before filling with fluids or returning to service.

Optimum Grey RTV Gasket Maker in a tube

1) Surfaces should be clean and dry.
2) Apply a continuous 1/16″ to 1/4″ (2 to 6mm) bead of silicone to one surface, surrounding all bolt holes.
3) Assemble parts immediately while the silicone is still wet and tighten to finger-tight until the material begins to squeeze out around the flange.
4) Let the product dry for one hour, then tighten it to torque specifications
5) Allow 24 hours to cure before filling with fluids or returning to service.

The Right Stuff Grey RTV Gasket Maker in a tube

1) Clean and dry parts.
2) Push the nozzle sideways to dispense the product.
3) Apply a continuous 1/16″ to 1/4″ bead to one surface. A 1/8″ bead is usually sufficient for most applications. Apply a continuous and even bead of The Right Stuff 90 Minute to one surface, first tracing the internal areas of the gasket configuration, then all surrounding bolt holes
4) Assemble parts within five minutes while The Right Stuff is still wet, tightening bolts to recommended torque levels. The product cures in 90- minutes and a re-torque is not required
5) Equipment can be returned to service after the 90-minute cure time.

The Right Stuff Grey RTV Gasket Maker in a pressurized can

1) Clean and dry parts.
2) Push the nozzle sideways to dispense the product.
3) Apply a continuous 1/8″ to 1/4″ bead to one surface, surrounding all bolt holes.
4) Assemble parts within five minutes, tightening bolts to recommended torque levels. The product cures in 1 minute.
5) Equipment can be returned to service immediately

Red RTV Products: Application, Assembly, and Cure (Return-to-service) Times

Ultra Red RTV in a tube

1) For best results, clean and dry all surfaces with a residue-free solvent,
2) Apply with a 1/16″ to 1/4″ (2 to 6 mm) bead.
3) Apply a continuous and even bead of silicone to one surface, surrounding all bolt holes.
4) Assemble parts immediately and tighten to finger tight until the RTV material begins to squeeze out around the flange.
5) Allow to dry for one hour, then tighten to torque specifications.
6) Silicone will fully cure in 24 hours under normal conditions. Allow more time for cold or very dry conditions.
7) Allow 24 hours to cure before filling with fluids or returning to service.

Optimum Red RTV Gasket Maker in a tube

1) Surfaces should be clean and dry.
2) Apply a continuous 1/16″ to 1/4″ (2 to 6mm) bead of silicone to one surface, surrounding all bolt holes.
3) Assemble parts immediately while the silicone is still wet and tighten to finger-tight until the material begins to squeeze out around the flange.
4) Let the product dry for one hour, then tighten it to torque specifications
5) Allow 24 hours to cure before filling with fluids or returning to service.

The Right Stuff Red RTV Gasket Maker in a tube

1) Clean and dry parts.
2) Push the nozzle sideways to dispense the product.
3) Apply a continuous 1/16″ to 1/4″ (2 to 6mm) bead of silicone to one surface, surrounding all bolt holes.
4) Assemble parts immediately while The Right Stuff is still wet. Finger tighten until material begins to squeeze out around flange.
5) Let the product dry for 1 hour. Then tighten to torque specifications.
6) Equipment can be returned to service after the 90-minute cure time.

The Right Stuff Red RTV Gasket Maker in a pressurized can

1) Clean and dry parts.
2) Push the nozzle sideways to dispense the product.
3) Apply a continuous 1/8″ to 1/4″ bead to one surface, surrounding all bolt holes.
4) Assemble parts within five minutes, tightening bolts to recommended torque specifications. The product cures in 1 minute.
5) Equipment can be returned to service immediately

©, 2024 Rick Muscoplat