Q & A

by Mike Hobday, Technical services supervisor

In this newsletter, I will answer the most common questions, coming from distributors and customers.

Q. Is there a specific way to use a Cortec rust remover?
A. Yes, there is. When you want to remove corrosion from a surface there is a basic process you must follow. First, the part should be cleaned of any oil and/or debris. This gives the rust remover easy and direct access to the corrosion on the surface of the part.

After cleaning the part should be placed into a bath, or coated with the gelled version, of the rust remover you have chosen for the task at hand (Cortec's staff will be happy to help you select the proper product for your application). Once the part is free of rust it should be rinsed with an alkaline cleaner to help neutralize the surface. This step is critical as rinsing alone may not get all of the acid off of the surface, and acids can be corrosive over time. Once neutralized the part is ready for further processing.

Q. My data sheet says to apply VCI-386 at 1.5 to 3 mils DFT. What does DFT stand for and how do I know if I have put down the right coating thickness?
A. First off, DFT stands for dry film thickness. You may also see the abbreviation WFT for wet film thickness. Second, there are two ways to determine if you have the proper coating thickness on your part. The first method for determining film thickness is to use an electronic thickness gauge.

This unit is used after the coating is dry, and is simply placed on a painted surface and electrically determines the thickness of the coating. These units have good accuracy, but can be expensive and can't be used until the coating is dry. A better tool for most customers is a wet film gauge. Wet film gauges do not cost much, sometimes as low as a few dollars, and are used while the coating is wet. This allows you to add extra paint if there is too little on the part. To use a wet film gauge you must know what wet film thickness is required for desired dry film thickness. For help determining what WFT you need contact one of Cortec's Technical Service Engineers. They will be happy to help.

Q. Does it matter what cleaner I put in my recirculating pressure washer, or will they all work?
A. It matters quite a bit what cleaner you use for pressure washing applications where the cleaner is recirculated through the unit. Some cleaners are made to have good foaming action, which can be very helpful in some applications. This same cleaner put into a recirculating pressure washer would foam up and out of the unit, kind of like the commercial where the kid puts too much soap in the washing machine. For any circulating pressure application you want to use a non-foaming cleaner like VCI(tm)-418. This will give you clean parts along with corrosion protection with out foaming out of the parts washer.

Q. My customer wants an ESD bag. What is an ESD bag and how does it differ from an ordinary plastic bag?
A. ESD bags are used by the electronics industry to protect sensitive electronic parts from electrical damage that can be caused by a normal plastic bag. ESD bags are different in that they have special additives in their plastic to prevent this type of damage. They protect parts in two ways. One, the surface of the bag will not generate a static charge when a part is rubbed across it. Two, the additives also allow the plastic to dissipate a charge across the surface of the bag. A charge can be dissipated by the bag rather than through the electronic part, which, could damage or destroy it.

Q. Who can I contact if I have questions about what Cortec product best fits my application?
A. Anytime you have a question feel free to contact one of our Technical Service Engineers for prompt, accurate technical to any of your questions.