Introduction
If one wants to change over to another flux than the flux that is presently in the fluxing system, the fluxing system has to be cleaned first. For that it is advised to make use of a special draining hose that can be coupled to the end part of the flux supply hose, that originally is connected to the fluxer head. The right cleaning method depends on the flux type that was previously used in the fluxing system.
Emptying the fluxing system
The present flux in the fluxer tank and the supply hoses should be drained off as much as possible. The tank can than be rinsed with flux solvent of the flux type that was originally in the flux tank.
Alcohol based flux
E.g. when the system contained a alcohol based flux, the tank should be rinsed with alcohol, so that all flux components such as resin and activator are rinsed off. Remove the supply hose from the fluxer head and connect a special draining hose to that supply hose. Guide the end of that drainage hose into a canister that can collect the flushing liquids used for cleaning the flux supply system. Next the fluxer tank must be filled with alcohol to flush the supply hoses from flux remainings. Now the fluxer head should be connected to the original supply system and the fluxer head should be rinsed by activating the fluxer for a sufficient time. After that, the flux system should be drained off again and allowed to dry before filling with new flux.
Water based flux
When the fluxer contained a water based flux the tank should after the flux is drained off be first cleaned with water, so that all flux components are rinsed off. Remove the supply hose from the fluxer head and connect a special draining hose to that supply hose. Guide the end of that drainage hose into a canister that can collect the flushing liquids used for cleaning the flux supply system. Next the fluxer tank is filled with water to flush the supply hoses from flux remainings. Now the fluxer head should be connected to the original supply system and the fluxer head should be rinsed by activating the fluxer for a sufficient time. Finally the water is removed from the flux tank and it should be filled with alcohol. Now the system should be flushed with alcohol to remove all remaining water from the system. After that, the flux system should be drained off again and allowed to dry before filling with new flux.
Approximate volumes of supply hoses
The volume of the supply hoses and pipes for the Delta wave soldering machine is about 160 cc. For the Selective soldering machine this is about 225 cc. For both systems it is advised to use at least twice this volume for the flushing solvent(s) after drainage of the flux from the system; e.g. 0.5 litre clean water and/or 0.5 litre alcohol.
Materials handling and safety aspects
Flux residues and the used flushing liquids should be handled as chemical waste and be treated accordingly. See also the materials safety data sheets from the flux suppliers of the fluxes and solvents involved.
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