Gasketing sealants
General purpose, semi-flexible, rigid machine-flange sealant
This general purpose, semi-flexible anaerobic-curing gasketing product is ideal for sealing close fitting, rigid machine flanges made of aluminum, iron or steel.
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- Description
- Technical specification
- Rating & reviews
- Question & answer
LOCTITE® 518 is a general purpose, primerless, semi-flexible, form-in-place anaerobic flange sealant. It cures – even in the presence of minor surface contaminants – to seal close fitting joints between rigid metal flanges, and will flex with minor flange movements. It provides resistance to low pressures immediately after assembly of flanges, and is ideal for use on aluminum substrates where you need very good flexibility. Typically used as a form-in-place gasket for pumps, thermostats, compressors, transmission housings and axle covers, it not only works on active metals (e.g. mild steel) but also on passive substrates, such as aluminum with a low copper content. You can expect gap performance to 0.01" (0.25mm).
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Semi-flexible anaerobic flange sealant
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Adapts to surface irregularities & gap fill up to 0.01" (0.25mm)
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Forms an instant low-pressure seal
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Cures on inactive surfaces without primer
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NSF registered
- Product category:
- Gasketing sealants
- Technologies:
- Acrylates, anaerobic cure
- Application method:
- Dispense system,Manual
- Applications:
- Rigid assembly gasketing,Sealing
- Chemical basis / base:
- Dimethacrylate ester
- Color:
- Red
- Cure type:
- Anaerobic cure
- Fixture time, Steel:
- 25.0 min.
- Gap fill, Unprimed:
- 0.25 mm
- Key characteristics:
- Fluorescent,For machined, rigid flanges,Immediate low pressure sealing,Strength: medium strength,Surface contamination-tolerant,Thixotropic
- Number of components:
- 1 part
- Operating temperature:
- -55.0 °C - 150.0 °C (-65.0 °F - 300.0 °F)
- Physical form:
- Gel
- Recommended for use with:
- Metal: aluminum,Metal: iron - cast iron,Metal: passive metal,Metal: steel
- Specific gravity, @ 25.0 °C:
- 1.1
- Storage temperature:
- 8.0 °C - 21.0 °C
- Viscosity:
- 750000.0 mPa·s (cP)
How to use
Apply LOCTITE® SF 7200/SF 790 and use a wooden or plastic scraper to remove any residual/cured gasketing material. Remove any burrs that may create shimming between the flanges. It is recommended to use LOCTITE® SF 7063/7064/7070 to degrease and clean surfaces prior to applying the adhesive.
If cure speed of LOCTITE® 518 is too slow due to passive metals or low temperature (below 5°C), use activator LOCTITE® SF 7240 or LOCTITE® SF 7649 (see cure speed vs activator graph in the TDS). Allow to dry.
Apply a continuous bead of sealant onto one flange surface. Place the bead close to the inner rim of the flange and encircle all bolt holes. Small surface scratches will be filled by the adhesive. LOCTITE® 518 can also be applied by roller onto larger flanges.
Assemble flanges and tighten bolts as soon as possible. Wipe away any excess squeeze-out, as this will not cure when exposed to air due to sealant's anaerobic curing properties.
Disassemble bolts with standard hand tools. Use jacking-screws, cast-on bosses or recesses to lift flanges apart. Once disassembled, apply LOCTITE® SF 7200 or SF 790 on old sealant and use a wood or plastic scraper to remove residues from flange surfaces.
For corroded or seized parts, use LOCTITE® LB 8040 Freeze and Release.
FAQ
Use a LOCTITE® gasketing adhesive (silicone or anaerobic depending on your application) to: completely fill voids and surface variations; replace or augment traditional gaskets; overcome typical issues of over-torqueing bolts and gasket relaxation; as well as reducing inventory with a ‘one size fits all’ solution.
Yes, Henkel anaerobic adhesives become highly resistant thermoset polymers once cured, making them suitable for a vast number of applications. Consult the online product resources or contact our technical teams for further information.
Henkel has several products available with varying levels of NSF® and WRAS® approval, amongst others. Please contact the Henkel sales or technical teams with your requirements.
Both silicones and SMP adhesives provide excellent flexibility and gap-filling properties together with high adhesion to a wide range of substrates, making them ideal for elastic bonding & sealing applications. Silicones have superior thermal resistance for high-temperature applications whereas SMP adhesives are suitable for applications that require over-painting. There are a range of properties available for each technology type. Please speak with a Henkel representative regarding your application to determine the best available grade.
LOCTITE® Silicone adhesives such as LOCTITE® SI 5920 or LOCTITE® SI 5990 have been specially formulated for high temperature engine sealing applications. However due to the very high temperatures generated in the combustion chamber care should be taken when specifying liquid gasketing materials around the cylinder head or exhaust manifold. Please consult the Henkel technical team for further advice where necessary.
All necessary H&S measures and PPE (personal protection equipment) requirements can be found on the product material safety data sheet, all of which are available via our website.
