By Eng. Carlos F Molina

The following article is about API RP 652 for the API 653 certification exam. What do you think is the difference between a lining and a coating? Between a coating and a paint?….. Before you continue reading, share your thoughts in the comment section.

As far as I know,  paint is a liquid or paste that, when applied in a substrate, coats a layer over the surface, protects it and then gets to be known as a coating. Any material applied to the internal surfaces of a tank to serve as a barrier to corrosion and/or product , it is known also as a lining. Right now we are going to study linings. If you are preparing to take the API 653 certification exam, do me a favor an read the 652 RP. (more…)

By Eng. Carlos F Molina

As any person in a project knows, consumables control is difficult, and critical. And while there are some calculators and guides in the internet and literature for things like control of welding and safety consumables, there is not much for painting consumables. In fact, a google search for “abrasive performance” has little results, and a search for “paint control” yields almost no result. For people in charge of paint control, this can be a nightmare.

I haven´t found any paint control strategy on the web. I am sharing one I have used before with success. It is mainly useful in large surfaces that are going to be painted by the airless spraying method.
I am aware this might not be the only nor the best approach there is to the subject. But maybe it will serve as a catalyst for debate in the subject. I am open to criticism. I know there are many experts in the field already. And finally, this is not my creation only, but the work of others put together as an overall strategy.

NOTE 1: In this article, I use the word paint for a) the liquid in the buckets before applied b) the act of painting, and I use the word coating when referring to the product applied and already dry over the substrate.
NOTE 2: In this article, I use the example of a project where you have to paint the inside of  tank with a single coating and the exterior with a 2-coat arrangement.
NOTE 3: In this article, I assume all paints are 2-part (a resin and a hardener). However, it serves with single component paints.
NOTE 4. In this article, I talk about the possibility of being untrue to specifications of a paint job in very small areas. Take the advice at your own risk. (Remember: any standard is a form of risk reduction, so your professional criteria should always be used.)
NOTE 5. Finally, none of this information can be used to blame me later about anything. This is not a contractual document anyways, but only an strategy. (more…)