Best sealants, thread lockers and gasket compounds
Posted: Wed Jul 22, 2020 4:00 pmThere is a huge assortment of thread lockers and sealants available for use on our planes and engines, and determining what to use for any particular application can be difficult. The following products have proven to be good choices, and are recommended by many builders. In some cases these are specifically called out for use by a product manufacturer, and in other cases they are "fan favorites".
Thread Lock Compounds:
Loctite 243 "blue loctite" - general purpose thread lock; medium strength for parts that will need to be disassembled at some point; oil-resistant; built-in primer.
[Similar products: Permatex 24200, Loctite 242 (non oil-resistant, slightly lower strength)]
Loctite 263 "red loctite" - high strength, permanent bond for parts that are not planned for disassembly (requires heating to 500+ deg); oil-resistant; includes built-in primer for best strength.
[Similar products: Permatex 27100, Loctite 262 (slightly lower strength), Loctite 271, Loctite 272 (slower-curing, higher-temp 271), - all these can be improved by also using Loctite primer]
Loctite 620 - Used on the Jabiru flywheel cap screws as a super-strength thread locker; "glues" the screws in place and requires heat to remove.
Loctite 7471 Primer - used to clean and prime hardware before assembling with loctite; especially useful for critical high-strength parts, on nickle plated, zinc plated or stainless steel hardware. Also speeds up the curing process.
Notes:
- Loctite and Permatex are interchangeable products. You'll notice that the Permatex part number looks very similar to the Loctite product number (Loctite 242 vs Permatex 24200).
- Loctite products that have similar numbers (e.g. 242 vs 243): the higher number is typically the "new and improved" version. Functionally, both are very similar.
- The Aerovee Assembly manual calls out Loctite 242 and 271 for the majority of thread locking tasks. The Jabiru overhaul manual specifies Loctite 242/243 and 262.
- Always clean the threads before applying thread lock (use a non-residue cleaner like alcohol or laquer thinner).
- See the Loctite application guide for even more info: https://www.ellsworth.com/globalassets/ ... ocking.pdf
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Fluid Fitting Sealants:
Loctite 565 - white paste sealant that includes PTFE (teflon); useful on fuel and oil system fittings with NPT threads
[Similar products: Loctite 567 (higher-temp 565), Permatex PTFE thread sealant]
Loctite 545 - gas and oil safe thread sealant; cures like regular loctite; designed for pressurized systems.
Gasoila E-Seal - liquid thread sealant with PTFE; gas and oil safe; non-hardening formula.
Notes:
- Discussion on various sealants used on fuel tank fittings: viewtopic.php?f=21&t=5768
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Gasket Compounds:
Permatex Red High-Temp RTV - Used for AeroVee real main seal, intake manifolds (optionally), sealing baffle leaks, other hot-area sealing tasks.
Permatex Ultra Black RTV - Used for general sealing, airframe penetrations, antenna mounting base, forward windshield edge, etc. Also works well for gluing platic and aluminum, such as eyeball vents, NACA scoops, snap bushings, etc.
Permatex Aviation Form-A-Gasket #3 - Non-hardening sealant for case halves, machined flanges, etc. Used by AeroVee case halves.
Loctite 515 - Gasket replacement sealant; use on machined mating surfaces (cover plates, mounting flanges, etc). Jabiru uses this to seal the crankcase halves. A favorite case-half sealant for other engine builders as well.
[Similar products: Loctite 518 (newer, faster curing, built-in primer)]
Keywords: thread lock, threadlock, loctite, locktite, permatex, case sealant, flange gasket, fuel tank fitting sealant, NPT thread sealant
Thread Lock Compounds:
Loctite 243 "blue loctite" - general purpose thread lock; medium strength for parts that will need to be disassembled at some point; oil-resistant; built-in primer.
[Similar products: Permatex 24200, Loctite 242 (non oil-resistant, slightly lower strength)]
Loctite 263 "red loctite" - high strength, permanent bond for parts that are not planned for disassembly (requires heating to 500+ deg); oil-resistant; includes built-in primer for best strength.
[Similar products: Permatex 27100, Loctite 262 (slightly lower strength), Loctite 271, Loctite 272 (slower-curing, higher-temp 271), - all these can be improved by also using Loctite primer]
Loctite 620 - Used on the Jabiru flywheel cap screws as a super-strength thread locker; "glues" the screws in place and requires heat to remove.
Loctite 7471 Primer - used to clean and prime hardware before assembling with loctite; especially useful for critical high-strength parts, on nickle plated, zinc plated or stainless steel hardware. Also speeds up the curing process.
Notes:
- Loctite and Permatex are interchangeable products. You'll notice that the Permatex part number looks very similar to the Loctite product number (Loctite 242 vs Permatex 24200).
- Loctite products that have similar numbers (e.g. 242 vs 243): the higher number is typically the "new and improved" version. Functionally, both are very similar.
- The Aerovee Assembly manual calls out Loctite 242 and 271 for the majority of thread locking tasks. The Jabiru overhaul manual specifies Loctite 242/243 and 262.
- Always clean the threads before applying thread lock (use a non-residue cleaner like alcohol or laquer thinner).
- See the Loctite application guide for even more info: https://www.ellsworth.com/globalassets/ ... ocking.pdf
---------
Fluid Fitting Sealants:
Loctite 565 - white paste sealant that includes PTFE (teflon); useful on fuel and oil system fittings with NPT threads
[Similar products: Loctite 567 (higher-temp 565), Permatex PTFE thread sealant]
Loctite 545 - gas and oil safe thread sealant; cures like regular loctite; designed for pressurized systems.
Gasoila E-Seal - liquid thread sealant with PTFE; gas and oil safe; non-hardening formula.
Notes:
- Discussion on various sealants used on fuel tank fittings: viewtopic.php?f=21&t=5768
---------
Gasket Compounds:
Permatex Red High-Temp RTV - Used for AeroVee real main seal, intake manifolds (optionally), sealing baffle leaks, other hot-area sealing tasks.
Permatex Ultra Black RTV - Used for general sealing, airframe penetrations, antenna mounting base, forward windshield edge, etc. Also works well for gluing platic and aluminum, such as eyeball vents, NACA scoops, snap bushings, etc.
Permatex Aviation Form-A-Gasket #3 - Non-hardening sealant for case halves, machined flanges, etc. Used by AeroVee case halves.
Loctite 515 - Gasket replacement sealant; use on machined mating surfaces (cover plates, mounting flanges, etc). Jabiru uses this to seal the crankcase halves. A favorite case-half sealant for other engine builders as well.
[Similar products: Loctite 518 (newer, faster curing, built-in primer)]
Keywords: thread lock, threadlock, loctite, locktite, permatex, case sealant, flange gasket, fuel tank fitting sealant, NPT thread sealant