Posts by DaveO
Posts by DaveO [ 6 ]
Re: Question about aluminum oxide abrasive [ Started by a57chevytruckman in Electroplating : 4 replies ]
OK. You are prepping buffed steel for plating. What is the typical cycle? Remove compound in a diphase cleaner or in a power wash or some such cleaner. The next step is probably soak/electroclean. Next is a pickle, use a hydrochloric acid solution about 30% to 40% by volume. The aluminum or aluminum oxide is dissolved, and voila! No more problems. It works.
Now, even if there WERE small smears of aluminum metal or aluminum oxide, how would that corrode after it was encapsulated by the relatively thick deposits involved in decorative plating?
Re: Heaters plating up [ Started by D.T. in Electroplating : 15 replies ]
Bipolarity is also a potential factor. Is only one end being plated? That is the simplest way to check for bipolarity. I still think he needs to check the potential above ground first. How much current is there?
If this is such a problem, how come we're the only ones talking about it?
Re: Difference between Nickel Sulphate, Nickel Chloride, Nickel Sulfamate, Nickel Bromide [ Started by blurguy in Electroplating : 3 replies ]
Dustin has pretty well summed up the reasons for Nickel Sulfate and Nickel Chloride. They are components in the Watts bath. Nickel Chloride is also used in a formulation called a Woods Nickel strike which is used to activate stainless steel alloys for subsequent electroplating.
Nickel Sulfamate and Nickel Bromide are used in baths which employ high current densities, and fast build-up such as used in reel-to-reel plating, high build-up baths such as those employed in electroforming and baths to repair aircraft parts, where a high-ductility, low stress deposit is required for final machining. The Nickel Bromide is used as an anode corrosion promoter in a sulfamate bath, by the way, Dustin.
Blurguy, you need to get yourself to an Electroplating school such as those sponsored by many NASF Branches or to one of the commercial ones offered, then things will not be so "Blurred".
Re: Question about aluminum oxide abrasive [ Started by a57chevytruckman in Electroplating : 4 replies ]
You ask if aluminum oxide abrasive will cause corrosion problems on the "base" metal when it is plated over.
Do you MEAN "BASE" metal such as sodium or potassium, or do you mean "BASIS" metal which is the basis for the plating? Don't mix these terms up.
Be very specific. What basis metal do you refer to? What is the metal you will be plating over the basis metal? What kind of corrosion do the doomsayers say you will encounter? It will be a whole lot easier to solve the problem when you say what the problem is or may be.
Re: Heaters plating up [ Started by D.T. in Electroplating : 15 replies ]
Guys,
RIPPLE is NOT superimposed AC, as your replies indicate. Ripple is defined as "...the extent to which the DC (from a rectifier) deviates from the ideal..." (ref. ELECTROPLATING by Frederick A. Lowenheim pp. 160). By nature of the alternating current being rectified (converted to DC) and by the nature of the filtration of the rectified current, the "Ripple" can be as much as 50%, or very close to 0. Dr. Lowenheim goes on to relate that ripple is normally of little importance in electroplating operations. In chrome plating, ripple is a problem. It is not a problem in copper plating. Superimposed AC could cause problems in bright acid copper plating.
It should also be noted that ripple is not gonna cause heaters to plate out nor will superimposed AC! Stray DC current probably would. Take a milliammeter, and measure the current potential between the heater and the ground. That won't tell you WHERE the current is coming from, but it will tell you how big the leak is. When you know h …
Re: Hard Chrome Anodes? STEEL? [ Started by overchrome in Electroplating : 9 replies ]
The stock answer for a maximum metallic impurity level is 0.5 ounces per Gallon. This can be fudged a little by increasing your chromic acid concentration. Doing this will allow higher levels of contamination before burning occurs. Burning is an indication of metallic impurities going over the limit and reducing CE.
Dustin Gebhardt has the correct answer... porous pot(s) run regularly will easily control metallic impurities and allow the use of techniques like steel anodes and reversing before plating... handy tools!
