The types of “rust preventive oil”
As you may know, there is (1) painting and (2) plating as a permanent means to protect metal products from corrosion. But, it will not be used to paint and to plate on metal products when you want to temporarily protect them from corrosion.
In this column, I would like to cover the way to protect metal products from corrosion temporarily. There are “rust preventive oil”, “VCI treated paper” and “anticorrosive polymer film” as a means to protect temporarily metal products from corrosion. At first, I would like to talk about “rust preventive oil”, which is the most major means among broadly classified.
1) The types of “rust preventive oil”
In the classification of “rust preventive oil”, there are various types being from low viscosity type to make hard film. In view of their raw material, it can be said that whether it is made by adding the film-forming agent(film formation assistant), and the rust preventive additive, etc. to the oil.
Then, “rust preventive oil” can be roughly divided into three types, saying (1) lubricating oil type, (2) solvent cutback type and (3) petrolatum type.
In the classification under JIS, the lubricating oil type is divided and being the VCI oil independent, and the solvent cutback type is divided and being the finger print remover type independent so that the types are divided to 5 in total. Please take note that the VCI oil and finger print remover type of the rust preventive oil can be referred as the functional classification.
Lubricating oil type
The lubricating oil type rust preventive oil is made by adding rust preventive additive to the lubricating oil, but not adding any film-forming agent. The reason why not adding the film- forming agent is that the lubricating oil itself has originally film-forming function. Different viscosity types can be made depending on what viscosity of the lubricating oil employed, because the lubricating oil are composed by the variety of viscosity level, although the lubricant oil can be roughly referred.
The lubricating oil type rust preventive oil seems to be main stream as far as reviewing catalogs made by various companies. In the JIS classification, the lubricating oil type rust preventive oil is subdivided to 8 types, but actually more numbers of type has been available in the market. It means there are so many variations in the lubricating oil type rust preventive oil.
Solvent cutback type
On the other hand, a number of the solvent cutback type rust preventive oil with the different character in function has been produced by employing the different film-forming agent. It is possible to produce the different nature of film, ranging from soft to hard, which is created after vaporizing of the solvent.
In the JIS classification, the solvent cutback type rust preventive oil is also subdivided to 6 types, but many other types have been available in the market other than these 6 categories.
The third, petrolatum type rust preventive oil is specified 1 type only in the JIS classification, as the base material is petrolatum.
Next time, let me explain about what quality these rust preventive oil are on the basis of the items specified in JIS.