TROUBLESHOOTING OF ALKALINE ZINC PLATING BATH

TROUBLESHOOTING OF ALKALINE ZINC PLATING BATH 

SURCURE TECHNOLOGY PRODUCT ALKAZIN 111 PROCESS

Condition	Possible Cause	Corrective Measure
Blistering/poor adhesion	Poor cleaning	Check cleaning cycle
	Oil in acid pickle	Change acid add
	High brightener	Electrolyze add only Alkazin 111 Carrier A Maintenance until balanced
	Low temperature	Raise bath temperature above 65oF
	High carbonate level	Reduce carbonates
	Metallic impurities	See impurity chart
Dullness in low current density	Alkazine 111 Carrier A Up too low	Add in .05% increments
	Low temperature, under 65oF	Raise temperature to 75oF
	Low caustic:  zinc ratio	Increase caustic content or lower metal
	Low purifier	Add in 0.5% increments appropriate  Alkazin 111 Purifier C
Poor throwing power	Low caustic:  zinc ratio	Add caustic or lower metal content
	Bath temperature over 90oF	Lower temperature
	Low addition agent	Alkazine 111 Carrier A
High additive consumption	High temperature	Lower temperature
	Heavy drag-out	Check drag-out and adjust addition rate
	High carbonates	Treat to reduce
	Metallic impurities	See chart
Gray or black blotches in low current density	Metallic impurities	Add in 0.05% increments appropriate ARP purifier Dummy at LCD
Porous/rough high current density	Alkazine 111 Carrier A	Add in 0.1% increments
Deposit darkens when bright dipped or chromated	Copper contamination	Dummy under 10 ASF until removed. For high copper concentration, treat with zinc dust.
	Cadmium contamination	Dummy under 10 ASF Zinc dust 3 lbs/100 gals
	Iron contamination	Filter to remove
Zinc metal content decreasing	Low anode area	Increase anode area
	Polarized anodes	Check anodes.  If anodes are filmed, remove and clean in mild HCl
	Titanium baskets	Replace with steel baskets
	Low caustic content	Increase caustic content
	Low bath temperature, under 65°F	Raise temperature to 75°F

 

Zinc metal content increasing	High zinc anode area	Replace with steel
	High caustic content	Lower caustic content
	Zinc anode left in idle bath	Remove anodes if not working solution
Overall roughness in deposit	Insolubles	Filter electrolyte
	High current density burning	Lower current
	Low anode area	Add more anodes
Overall dullness with no brightener response	Grease/oil impurities Brighter overload	Filter to remove grease Carbon treat if necessary
	Low ARP 36 (hard water)	Add in 0.05% increments
	High carbonates	Treat for carbonates
High current density burning/gray	Alkazine 111 Carrier A	Add in 0.5% increments
	Low metal concentration	Add anodes or raise caustic
	Low bath temperature, under 65°F	Raise temperature to 75°F
Overall dull deposit	Low metal concentration	Add anodes or raise caustic
	High bath temperature over 95°F	Reduce solution temperature
	Alkazine 111 Carrier A	Add in 0.05% increments
	(hard water)	Add in 0.05% increments
	Alkazine 111 Conditioner-D Metallic Impurities	Add in 0.05% increments appropriate ARP Purifier
Streaked or pitted deposit in the mid to high current density	Low metal concentration	Add anodes or raise caustic content
	Low caustic concentration	Raise caustic content
	Alkazine 111 Brightener B	Stop adding additives and dummy plate
Grainy deposit in mid to high current density	Particles or high carbonates High caustic concentration	Filter solution Discontinue additions
Low cathode efficiency	Low zinc metal	Add anodes or increase caustic content
	Low caustic content	Raise caustic content
	High Carrier concentration	Stop adding additive and dummy plate
Streaky, haze deposit	Poor cleaning	Improve cleaning
	Hard water drag in	Use 12 oz/gal caustic predip
	Sludge in bottom of tank	Decant & filter
	High carbonate	Reduce by treatment
Caustic Misting	Poor ventilation	Improve ventilation and use for a foam blanket
	Alkazine 111 Carrier A	Reduce additions.  Look for impurities
	High caustic >20 oz/gal	Reduce addition

High carbonates High temperature operation Reduce temperature Air agitation Discontinue

                                     Air leak in filter pump      Repair leaks

                                 Filter hose above solution    Move hose

                                                                      METALLIC IMPURITIES

Impurity	Source	Tolerable Limit	Effect	Treatment
Cd	Impure anodes	1 ppm	Dull and darkened deposit in LCD	Zinc dust 2 g/ltr LCD dummy (under 10 ASF)
Cu	Anode and cathode bars Racking wire Brazed areas	20 ppm	White streaking darkening after bright dipping	Zinc dust 2g/ltr LCD dummy (Under 10
Cr(VI)	Chromate drag-in	2 ppm	Blistering HCD Skip plate Milky deposit	Sodium Hydrosulfite 1g/ltrPb
Pb	Leaded substrate anodes Soldered components	1 ppm	Dull gray plate mid to high CD	Zinc dust 2g/ltr LCD dummy (under 10 ASF)
Sn(II)	Soldered component	10 ppm	HCD dullness	.25% volume 30% Hydrogen Peroxide then LCD dummy