Selective solder flux blocking nozzle.

We are using Mulicore MF101 flux and a Vitronics selective soldering machine on a lead-fee assembly and are having trouble with nozzles blocking even when the nozzle aperture is increased. Has anyone come across this problem before using fluxes with a high solid content of above 5%? Another issue is the flux in the canister separating after a week when we do our lead-free production runs. The flux canister is pressurised to 0.5bar. Are the two issues related? I would like to know temperatures (stored and use), Pressure (stored and use) and timing of storage. We would like to retain the same flux because of approvals but if you know better then a change will have to happen. We have used manufacturers recommendations and now throw it open to the knowledge base of the real world.

Steve.

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