Surface Preparation: Anaerobics
Hernon Primers are surface preparation agents for all Hernon
anaerobic adhesives and sealants. Primers are optimized for each
family of anaerobic products: Nuts N' Bolts, Cylinlock, Dripstop,
Gasket Replacer, HASA, and Ultrabond UV cure systems. Please
refer to the appropriate comparison chart or technical data sheet
for specific recommendations.
Primers provide the necessary chemical assistance to:
- Reduce fixturing time
- Accelerate full cure
- Assure predictability of cure on inactive surfaces
- Bolster production rates
- Expand adhesive gap filling abilities
- Clean part surfaces
- Restore cure parameters at low temperatures
Primer provide the necessary chemistry to initiate polymer
formation at the part surface. This action is initiated by catalysts
contained in the formulation. The solvent in the primer formulation
evaporates leaving a thin film of the catalyst. Since different
anaerobics require different catalysts, Hernon offers a variety
of formulations.
Surface activity level may necessitate the use of primers.
Active Surfaces:
Anaerobics generally cure well on "active" metallic
surfaces:
|
Steel |
Copper |
|
Iron |
Manganese |
|
Brass Bronze |
|
-
- Inactive Surfaces:
Primers provide the anaerobic adhesives the needed ions
to cure with predictability on "inactive" or "passive"
surfaces:
|
Aluminum |
Passivation Coatings |
|
Anodic Coatings |
Silver |
|
Cadmium |
Stainless Steel |
|
Ceramics |
Thermoset Plastics |
|
Gold |
Titanium |
|
High Allow Steels |
Zinc |
Fixturing and curing times are dramatically reduced with primers,
allowing faster line processing, reduced clamping and higher
throughput production rates.
Gap filling ability is enhanced by primers because the adhesive
cure is initiated quicker. Since less liquid migrates or flows
away from the joint, more adhesive is retained at the bondline.
Applying primers, and indirectly their solvents, helps remove
oils from the part surface, promoting better part cleanliness,
and better cures.
More predictability in the cure of the adhesive means less
variation due to human factors, part tolerances, part cleanliness,
etc.
Temperature has a direct effect on the cure rate of anaerobic
adhesives. Higher temperatures promote faster cure times. Primers
restore predictability to adhesive cures when temperatures are
less than normal room temperature levels, 70 degrees Fahrenheit.
Without priming, cures in very cold temperatures extend into
days, not hours.
Each Primer formulation offers additional processing flexibilities
with it "on-part life." Depending on the primer, you
can prime parts a week or more ahead of time, before assembly.
Long on-part life allows batch treating of sub-assemblies ahead
of time. Baskets of parts can be dunked or bond areas preprimed
to speed assembly with less assembly line integration needed.
To apply primers - spray, dip, brush, dispense, or drip on
part. Allow solvent (if present) to flash-off (evaporate) fully.
Apply adhesive to mating surface and assemble parts.
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