De-greasing is an essential part of the metal preparation process. A degreaser removes any dirt, grease, and oil on the metal, so there is nothing to attack the paint when it is applied. An even more important process is to remove the tramp oil from the surface of the degreaser. Tramp oil could be anything from oil that collects under a weld to oils transferred onto a part during the machining process.
Surface preparation: Why it is essential to degrease metal before painting
When it comes to metal painting in industrial paint shops, the first step is always degreasing. The main goal of this process is to prepare the surface of the metal by removing any dirt and grease that can cause adhesion problems during the painting process.
Degreasing is necessary because dirt and grease can cause the paint to chip away from the metal after the painting process. It can also cause the paint to run down the metal during curing. If you do not remove these contaminants, they will eventually cause corrosion in your metal parts.
Why remove tramp oil from your degreaser or pre-degrease bath in an industrial paint shop?
It’s a question we get asked all the time.
The simple answer is that it helps keep your degreaser tank clean and free from contaminants, preventing contamination of incoming parts.
Tramp oil can be released into the degreaser by many sources. However, most commonly, it is from the incoming metal surfaces. These parts have been subjected to press lubricants and cutting fluids to allow the metal to be formed without damage and cut without burring. This process will leave a thin film of oil on the surface of the metal that will float on top of the degreaser or pre-degrease tank.
Disadvantages of leaving the tramp oil in the degreaser bath during the metal degrease process
When washing metal, the degreasing and cleaning solution must be perfect. The degreaser must not contain excessive amounts of tramp oil. The question is: why do we still see such bad results, especially in industrial paint shops?
The main reason is that people are unaware of how big this problem is. The other reason is that companies do not test their degreaser regularly. As a result, they are unaware of how much tramp oil accumulates in the bath over time.
Some disadvantages of leaving the tramp oil in the degreaser tank during the metal degrease process.
- Tramp oils can cause poor cleaning action by forming a protective film on parts during the cleaning process.
- Tramp oils can reduce effective cleaner bathing and cause foaming in the cleaner tank, which will result in short bath life.
- Tramp oils can cause rusting or corrosion on a part’s surface by sealing off oxygen from reaching protected areas of parts during the drying process.
- Tramp oils can contribute to skin irritation and health hazards because they combine with other contaminants like dust and dirt.
It all comes down to cost. Perhaps the most expensive component in a painting operation is reworking. After all, you can only get out of it what you put into it. Tramp oil build-up in your degreaser or pre-degrease bath destroys your good quality paint operation. Then you have just used extra man-hours, paint, electricity, compressed air through your system to achieve desired quality. Please click here to read how a vehicle manufacturer learned that investing in an Innovation Filter System’s coalescer-oil separation system almost eliminated their paint rework problem.
Suppose you want to avoid these costly rework issues. In that case, we recommend investing in excellent quality, well-designed tramp oil separation system like the coalescer. To understand how the coalescer works, please click here.
