Rubber to Steel Bonding Issues

[IFSG]

Greetings!

We've been facing some issues in the bonding process of a NR bush to a Zinc-Nickel plated steel part.
We prepare both parts using Lord's primer and then apply a Lord adhesive to the bushing.
Right now we are performing a few tests in order to replicate this bonding failure but haven't been able to achieve it so far.
Does anyone have a direction of where we could conduct our tests?

 

[TugboatEng]

What cleaning was performed prior to priming?

What primer is being used?

What adhesive is being used?

 

[IFSG]

For the bushing it self we've been performing a hot bath in deionized water (which is the process standard for any bushes we perform the adhesion process), we've concluded that cleaning the steel part does not produce any significant influence on the bonding performarce.

Primer is Lord's 7701 and Adhesive is Cilbond's 24.

 

[TugboatEng]

A hot bath in deionized water doesn't do well to remove non-polar contaminants such as oils and greases. The TDS for Lord 7701 specifically calls out a solvent cleaning which you have not done.

The TDS for Clibond 24 does not recommend a proper and does not list zinc-nickel as recommend surface prep.