David S. Peterson
How to Implement Ambient Temperature Cleaning
Q. How can we find an ambient temperature spray cleaner to implement for our five-stage pretreatment line used prior to powder coating? Cleaning expert David Peterson has the answer.
Read MoreHow to Identify Substrate or Paint Defect
Q. Over the past several years we have had a coating defect anomaly randomly show up on painted parts...Cleaning expert David S. Peterson takes a close look at cleaning processes to identify the root cause.
Read MoreHow to Use Pretreatment to Improve Salt Spray Hours
Q. Our goal is to have our gas regulators pass ASTM B117 for 500 hours. We use an epoxy powder coat; parts are treated with zinc phosphate first, then powder coated. We are seeing the internal parts of the castings rusting prematurely. Which spec could I call out to increase corrosion protection, MIL-DTL-16232G Type Z, class? Or TT-C-490, Type I?
Read MoreHow to Strip Zinc Phosphate Without Using Chromic Acid
Q. I want to remove zinc phosphate from hardware parts after cold heading. Typically to remove zinc phosphate, I would soak in chromic acid at a high temperature, but this is not a viable or safe method for bulk treatment. Can I just hit the parts with a higher concentration of potassium hydroxide at a higher temperature to remove the zinc phosphate?
Read MoreIntermittent Phosphate Line Usage
Q. I inherited a cleaning and phosphate line and over the last two weeks, we have lost our phosphate solution twice. I am told it is because we have lost iron in the solution. Is there an additive that can be used to help maintain the solution as the tank is not in constant use?
Read MoreCan Aqueous Alkaline Cleaner Be Used on Aluminum?
Q. Should I not use the same bath to process aluminum and stainless steel? Can aqueous alkaline cleaner be used on aluminum?
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Parts Cleaning Clinic: Cleaning of Inconel
Q. What cleaning methods are recommended for finishing Inconel 718?
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Parts Cleaning Clinic: Phosphate Coating Problems
Q. We electrocoat sheet metal, iron castings (machined and non-machined) and aluminum castings (machined and non-machined surfaces) and are having problems with poor phosphating on aluminum substrates. We maintain the free acid at 0.7-1.1 points and total acid at 20-24 points, and the total fluoride at 1,500 ppm. Bath temperature is 40°C to 45°C. Any suggestions?
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Parts Cleaning Clinic: Pretreatment Equipment Suppliers
Q. I am researching manufacturers of aqueous part washers and phosphate pretreatment systems for powder coating, looking for companies that build conveyor systems, washers and treatment systems; not parts washers. The parts to be cleaned are various sizes of steel, stainless and aluminum fabrications from stampings, cut to length steel tubing, and sheet metal fabrications up to 6 feet long and 3 feet wide. What are my options?
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Parts Cleaning Clinic: Zinc Shot Blasting, Zinc Plating Alternatives
David S. Peterson talks zinc shot blasting, zinc plating alternatives, and advantages to reducing the heating of alkaline cleaners.
Read MoreParts Cleaning Clinic: Cleaning Oxygen-Free Copper
Q. Could you share with me how to lower or eliminate this defect and how to utilize automatic cleaning?
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