The mixing ratio involves -
100 gms of adhesive per 5 gms of hardener

Providing higher coverage in a cost effective way
Providing superior bonding strength, thus ensuring of a quality output
Allowing more open time that meets production cycle needs
Provides for uniform performance
As it does not contain benzene, it saves human life from cancer possibility

Pre-application Safeguards

Metallic surfaces need to be free of oils, grease as well as other contaminants
Here, it should also be ensured that rust and mill scale are removed through sand blasting process to NACE #2 (for this profile of 2-3 mils is preferred)
The cured rubber should have all mould release agent removed as well as buffed with stiff bristled wire brush of 24 grit
This should be done at speed that does not burn the rubber surface

Application

Apply first coat to each surface in a scrubbing like motion
Allow coat to dry for around 1 hour at 25oC
After required drying time, second coat is applied to each surface
Let this dry until tacky and then compress both surfaces through stitch down/applying pressure
Maximum bond strength would develop in around 21 days (however sufficient initial bond strength will be achieved after 24 hours that makes it ready for most services)

Pre-application Safeguards

Rubber, if cured in sheet form need to be solvent cleaned as well as buffed as described before application of the first coat of adhesive

Application

Allow first coat to dry for at least 1 hour or longer
After required drying time, second coat is applied
When still tacky, stitch two components together/or apply pressure

For adherence to other elastomeric materials/special environmental conditions, please undergo trial so as to determine -
Suitability of product with individual materials
Determine the preferred method of application