1: Repeat the test, ensuring that test specimens are clean and dry

2: Recalibrate the micrometer or thickness test instrument using standards of proper phosphorus content

3: If necessary, confirm the thickness microscopically on a cross section of the coating

1: Calibrate, repair or replace the temperature controller if necessary

2: If electrically heated, check that the voltage, current, and resistance are correct

3: If steam heated, check the steam supply, including solenoid, strainer and trap for proper operation

4: Ensure that the temperature sensor is in the solution and not damaged or leaking

5: Measure the temperature of the agitation air, and if necessary preheat the air

1: Measure the bath's pH with a calibrated pH meter and increase it to its proper range(generally between 4.8 and 5.2 pH) with50% ammonia or potassium carbonate

2: Recalibrate the pH meter or check the accuracy of pH papers used to monitor the bath

3: Eliminate any sources of acid drag in, such as blind holes and poor rinsing

4: Check the pH of DI water added to the bath, especially after regeneration

5: Confirm that the proper ratio of hypophosphite to nickel replenisher is being used (for self pH regulating baths)

1: Analyze the bath's nickel and reducer content and increase them to their proper range

2: Check the EDTA solution used for nickel titrations against a standard to ensure its accuracy

3: Ensure that only deionized water is used for nickel titrations

4: Ensure that the plating tank's volume, used to determine replenishment amounts, is correct

5: Ensure that the proper ratio of hypophosphite to nickel replenisher is being used (generally either 1:1 or 2:1)

1: Analyze the solution for poisonous metals(stabilizers) like lead, cadmium, bismuth and tin

2: Dummy the solution electrolessly or electrolytically at low current density and large cathode area to remove contaminants

3: Carbon treat the solution by circulating it through carbon cartridges or a packed filter

4: Dispose of the bath if or are not successful and make up a new one

5: Identify and eliminate the source of contamination. Look for: Racks or barrels that have been used in incompatible processes like cadmium; contaminated rinses; dragged in solutions in bind holes or pores; parts plated with poisonous metals; incompatible maskants; drippage from adjacent equipment; steam coil leaks; impurities in agitation air or process water

1: Check that bath loading is above 0.25ft2/gal or 0.6 dm2/L (for some heavy metal stabilized baths)

2: Put dummy panels into the bath to raise the loading to about 0.4 ft2/gal or 1 dm2/L

3: Increase the number of parts in the bath to obtain about 0.4 ft2/gal or 1 dm2/L

1: Confirm that the proper ratio of hypophosphite to nickel replenisher is being used

2: If possible, discard part of the bath and adjust it to bring it into balance

3: If not, dispose of the bath and make up a new one

1: Analyze the solution for nitrates by wet analysis (diphenylamine methoor by specific ion electrode

2: Nitrate contamination is usually due to inadequate rinsing after passivation

3: Treat the solution with 1-2 g/L of sulfamic acid which will convert nitrates and nitrites to nitrogen over time

4: Improve rinsing after passivation

5: Test the rinse water after passivation with nitrate test papers to confirm their absence

1: Reduce air to the minimum required for solution movement (for some heavy metal stabilized baths)

1: Check bath records or analyze the bath for orthophosphate to determine the bath's age

2: Depending on formulation, baths typically slow down as they get older

3: If older than normal range for bath (often equals 1 or 2 mol/L of ortho), dispose of the bath and make up a new one

1: Confirm that the bath was made up correctly.Adjust, if possible, or dispose of the bath

1: Measure the bath's temperature before and after the parts are introduced to determine the amount of cooling

2: Preheat the parts in the soak cleaner or heated rinse prior to placing them in the plating tank

1: Confirm that the proper pretreatment has been used, especially for hard to activate alloys like high alloy steels

2: Low thickness can result if plating does not initiate immediately

1: Accumulation of zinc from zincated surfaces and organic acids will cause many baths to slow down

2: Dummy the solution electrolessly with steel wool in a filter bag to remove zinc

3: Dispose of the bath if is not successful and make up a new one

4: Install an ammoniacal strike bath before the electroless nickel bath

1: The EDTA used to titrate nickel solutions is a very strong chelator and will slow a bath

2: Dispose of the titration samples in some other way

3: Dispose of the bath and make up a new one

1: Repeat the test, ensuring that test specimens are clean and dry

2: Recalibrate the micrometer or thickness test instrument using standards of proper phosphorus content

3: If necessary, confirm the thickness microscopically on a cross section of the coating

1: Measure the bath's temperature with a calibrated thermometer and reduce it to its proper range (generally 185-195 Deg F or 85-90 DegC)

2: Calibrate, repair or replace the temperature controller if necessary

3: If electrically heated, check that the voltage, current, and resistance are correct

4: If steam heated, check the steam supply, including solenoid, strainer and trap for proper operation

5: Ensure that the temperature sensor is in the solution and not damaged or leaking

1: Measure the bath's pH with a calibrated pH meter and reduce it to its proper range(generally between 4.8 and 5.2 pH) with 50% sulfuric acid

2: Recalibrate the pH meter or check the accuracy of pH papers used

3: Eliminate any sources of alkaline drag in, such as blind holes and poor rinsing

4: Check steam coils or heaters for leaks and repair or replace if necessary

5: Check the pH of DI water added to the bath, especially after regeneration

6: Confirm that the proper ratio of hypophosphite to nickel replenisher is being used (for self pH regulating baths)

1: Analyze the bath's nickel and reducer content and reduce them to their proper range through dilution or continued plating

2: Check the EDTA solution used for nickel titrations against a standard to ensure its accuracy

3: Ensure that the plating tank's volume, used to determine replenishment amounts, is correct

1: Check that bath loading is below 0.75ft2/gal or 1.9 dm2/L (for some heavy metal stabilized baths)

2: Reduce the number of parts in the bath to obtain a bath loading less than 0.75 ft2/gal or 1.9 dm2/L

3: Ensure that the bath is not plating out on the plating tank or its components

4: Recalculate the surface area of the parts being plating, accounting for increased surface due to roughness, to confirm that nickel usage is not normal

1: Confirm that the bath was made up correctly.Adjust, if possible, or dispose of the bath

1: Confirm that the proper ratio of hypophosphite to nickel replenisher is being used (generally either 1:1 or 2:1)

2: If necessary, adjust with the needed replenisher to bring the solution into balance

1: Measure the bath's pH with a calibrated pH meter

2: Recalibrate the pH meter or check the accuracy of pH papers used to monitor the bath

1: Eliminate any sources of pretreatment chemicals (acids and alkali) drag in, such as blind holes or high barrel loading

2: Improve rinsing

1: Check that bath loading is below 0.75ft2/gal or 1.9 dm2/L

2: Reduce the number of parts in the bath to obtain a bath loading less than 0.75 ft2/gal or 1.9 dm2/L

3: Install an automatic pH or bath controller to add neutralizer as it is needed

1: Transfer the bath to another clean tank through a 1 micron filter bag

2: Strip and passivate the tank and equipment with room temperature, 30% nitric acid

1: Return the bath's pH to its proper range(generally between 4.8 and 5.2 pH) with 50% ammonia or potassium carbonate

2: Add additional buffering agents to the bath(for some simple bath formulations)

1: Measure nickel concentration of rinse after the plating tank and calculate the amount of bath being lost

2: Reduce drag out by draining or spray rinsing the parts over the plating tank before placing them in the rinse tank

3: Add small amounts of make up concentrate(typically 1-2% per bath cycle to replace the buffers being lost

4: Excessive Nickel Consumption

1: Repeat the analysis using fresh reagents, ensuring that the procedure is carefully followed

2: Check the EDTA solution used for nickel titrations against a standard to ensure its accuracy

3: Ensure that only deionized water is used for nickel titrations

1: Transfer the bath to another clean tank through a 1 micron filter bag

2: Strip and passivate the tank and equipment with room temperature, 30% nitric acid

1: Recalculate the surface area of the parts being plating, accounting for increased surface due to roughness, to confirm that nickel usage is not normal

2: Check that bath loading is below 0.75ft2/gal or 1.9 dm2/L

3: Reduce the number of parts in the bath to obtain a bath loading less than 0.75 ft2/gal or 1.9 dm2/L

1: Measure nickel concentration of rinse after the plating tank and calculate the amount of nickel being lost

2: Reduce drag out by draining or spray rinsing the parts over the plating tank before placing them in the rinse tank

1: Carefully measure the plating rate with properly prepared panels

2: Reduce the plating time to obtain the proper thickness

1: Observe solution for rapid gassing and the presence of dark grey or black particles

2: Quickly cool the bath and transfer it to another clean tank through a 1 micron filter bag

3: If the bath is still usable, add replenishers and neutralizer to return its concentration and pH to its normal operating range

4: Dispose of the bath if is not successful and make up a new one

1: Measure the current flow to the cathodes to confirm that the system is operating in its recommended range

2: If the current is above normal (typically 1-3 amperes), reduce the voltage to the recommended range

1: Inspect the tank, its piping, pumps, heaters and filters for drips and leaks

2: Repair or replace leaking components

1: Analyze the nickel replenisher or liquid nickel sulfate to confirm that its nickel concentration is normal

2: If low, examine the bottom of the replenisher drum for crystals or precipitates

3: If necessary, adjust the bath with additional replenisher to bring it into balance

4: Excessive Reducer Consumption

1: Repeat the analysis using fresh reagents, ensuring that the procedure is carefully followed

2: Check the iodine and thiosulfate solutions used for hypophosphite titrations against standards to ensure their accuracy

3: Ensure that the sample stands in the dark for 30 minutes prior to the titration

1: Keeping a bath at operating temperature without work increases reducer consumption

2: Install a heat exchanger or coil to cool the bath rapidly after its is used

1: Ensure that the plating tank's volume, used to determine replenishment amounts, is correct

2: Ensure that the proper ratio of hypo to nickel replenishers has been used(generally either 1:1 or 2:1)

1: Check reducer component drum for solids and for stratification

2: After heating to recommended temperature, stir the solution to redissolve solids and make homogeneous

3: Store reducer component drums at a temperature above that recommended by its manufacturer

1: Analyze the reducer replenisher to confirm that its hypophosphite concentration is normal

2: If low, examine the bottom of the replenisher drum for crystals or precipitates

3: If necessary, adjust the bath with additional replenisher to bring it into balance

1: Oxidizers, like nitrates and permanganate, will react with hypophosphite and consume it

2: Analyze the solution for nitrates by wet analysis (diphenylamine method) or by specific ion electrode

3: If present, treat the solution with 1-2 g/L ofsulfamic acid which will convert nitrates and nitrites to nitrogen over time

4: Identify and eliminate the source of contamination. Look for: Racks or barrels that have been used in incompatible processes; contaminated rinses; dragged in solutions in blind holes or pores; impurities in agitation air or process water