plating, anodizing, & finishing Q&As since 1989
Looking for an alternative for Black Chrome
Q. We are a manufacturer of zinc die-cast locks. We are in dire need of a black cosmetic finish that has similar wear characteristics to that of Black Chrome. This is a cosmetic part that requires high lustre with a maximum plating build up of .0015 per side. Our customer will not allow any oil or oil residue on the parts after plating. Our experience thus far has been that oil must be used on black chrome to produce a lustre. Any suggestions would be greatly appreciated! Our parts are zinc die cast (Zamak #3). They are approximately 1/2" diameter by 2" long.Mitch M [last name deleted for privacy by Editor]
- River Grove, Illinois, USA
A. A black chromate over zinc or a zinc alloy is an alternative. (Black over an alloy - such as zinc/iron - may be preferable since it won't contain silver and won't discolor over time.) The lusters of these chromates are very pleasing and they are offered by many finishing houses. Black nickel is also an option. We have a process that produces jet black coatings and is highly useful in decorative applications. One word of caution, however, is that black chrome is less susceptible to scratches and marring than these alternatives.
- Syracuse, New York
A. I've seen some real nice black nickel finishes out there , I would suggest contacting finishers within your shipping area and requesting samples of parts they already process in black finish , for your customers approval ....Ron Landrette
plating equipment supplier - Bristol, Connecticut
A. Mitch - Another alternative is to polish and/or buff the part and then do a hot black oxide finishing process. This will provide a durable and attractive finish. Also, there will be no dimensional change to interfere with assembly.Dan Brewer
chemical process supplier - Gurnee, Illinois
A. My shop has the capability of doing black e-coat on zinc die castings. Our black e-coat can be matte, semi-gloss, or glossy and has a maximum build-up of .0012 on all surfaces. Thickness of the e-coat is extremely uniform.Brad Smith
- Evansville, Indiana
Q. I have a question to Brad Smith, what pretreatment do you use to prepare zinc die casting to e-coat? I assume you do not use phosphate as for steel.