Fault
|
Possible cause
|
Diagnostic clue
|
Corrective action
|
No plating at all
|
Electricity not flowing in the plating circuit |
No amps are flowing through the plating circuit. |
Check the workpiece connection, anode connection, leads, jig/contact points and all electrical connections. Clean contact points if necessary. |
| Reverse polarity |
Current may still flow, but tin does not deposit onto the workpiece. The workpiece may show signs of anodic attack. |
Correct the polarity: workpiece negative (–), anode positive (+). |
Plating is slow
|
Amps too low |
Plating takes longer than expected and the amps are below those recommended for the surface area being plated. |
Check the workpiece surface area and set the amps to the value recommended by the Tin Tank Plating Calculator. |
| Poor electrical contact |
Amps are lower than expected or unstable despite the correct setting. Electrical contact points may become warm. |
Check and clean the workpiece connection, jig and other electrical contact points. |
| Tin concentration depleted |
Gassing occurs at the workpiece under conditions that would not normally produce significant gassing. |
Replace the depleted Tin Tank Plating Solution. |
| Anodes excessively worn or passivated |
The MultiPlater shows a red dot, or a third-party power supply requires excessive voltage to maintain the required amps. |
Check the tin anodes. Replace excessively worn anodes; clean/reactivate passivated anodes as appropriate. |
Plating is patchy, uneven or has unplated areas
|
Inadequate cleaning or activation |
Tin deposits normally on some areas but poorly or not at all on others. |
Degrease and prepare the surface using the appropriate Tin Tank Process Sequence, then replate. |
| Surface is porous, heavily scratched or poorly mechanically prepared |
Tin preferentially deposits on some parts of the surface while other areas remain poorly covered. |
Mechanically finish the surface appropriately before repeating the preparation and plating sequence. |
| Poor or intermittent electrical contact |
MultiPlater: green/red light fluctuates during plating. Third-party power supply: amps and voltage fluctuate. |
Check and clean the workpiece connection, jig and all other electrical contact points. Ensure the connection remains secure throughout plating. |
Deposit is dark or burnt
|
Amps too high |
The tin deposit becomes dark or burnt, particularly on edges, corners, points and other high-current areas. |
Check the workpiece surface area and reduce the amps to the value recommended by the Tin Tank Plating Calculator. |
| Article too close to the anode |
Burning is concentrated on the area of the article nearest the anode. |
Move the item in the beaker or rearrange the anodes to increase the distance between the article and the anode. |
| Too little agitation |
Burning occurs even though the amps are correctly set, particularly in higher-current areas. |
Increase the agitation of the plating solution. |
Deposit is rough
|
Small particles of tin entering the solution from the anode |
The deposit develops small rough projections or a gritty surface. Tin particles may be present in the solution. This is commonly caused by tin particles escaping from the anode bag, or by plating without an anode bag. |
Make sure the tin anodes are enclosed in suitable anode bags and check the bags for holes, damage or poor fitting. Filter the solution occasionally by batch filtration using a filter funnel and filter papers, or continuously using a filter cartridge and tubing connected to a peristaltic pump. Spa Plating supplies the filtration equipment for both methods, but not the peristaltic pump. |
Plating is peeling or blistering
|
Inadequate cleaning or activation |
The tin deposit initially plates, but subsequently blisters, peels or can be rubbed away from the underlying surface. |
Remove the poorly adhered tin completely. Degrease and prepare the surface using the appropriate Tin Tank Process Sequence, then replate. |
| Incorrect preparation method for the metal being plated |
The tin deposits but subsequently blisters or peels from the underlying surface. |
Check the Process Sequences tab and use the correct preparation and plating sequence for the metal being plated. |
| Existing plating layer is poorly adhered |
The tin peels or blisters together with a previously plated layer underneath it. |
Remove all loose or poorly adhered plating back to a sound surface before preparing and replating. A new tin layer cannot improve the adhesion of an unstable coating underneath it. |
Incorrect plating thickness
|
Incorrect plating area estimated or calculated |
The measured tin thickness differs from the required thickness even though the calculated amps and plating time were used. It is easy to underestimate irregular shapes, edges, recesses or multiple surfaces. |
Estimate the total surface area being plated as accurately as possible and repeat the calculation using the corrected area. Use the Tin Tank Plating Calculator. If you are unsure how to estimate the surface area, ask our Technical Assistant for help. |
