Our pocket-sized penetrant system

by R. Dörn, New Business Development, MR-Chemie

"Hello, I've got a problem," is how a conversation for our application experts in the field sometimes start a conversation. In this particular case, it was reported that a small circular weld needed to be inspected. Our dye penetrant system consisting of dye penetrant, intermediate cleaner and solvent-based developer is used for this. The issue that has now been described on the phone is when circular weld is wetted with the penetrant from the spray can, more agent ends up in the air than on the component (overspray). The same applies to treatment with the developer.

As a manufacturer with a close relationship with our customer, we are aware of this issue and our experts have practical solutions for reduce or eliminate overspray. We would be happy to advise you on which solutions might be suitable for you. Perhaps the same solution as the presented here.

Our pocket-sized penetrant system is the ideal solution when only small areas need to be inspected, the environment does not allow for contamination or known areas need to be inspected quickly. In this case, it was a small surface on the one hand and a very sensitive environment on the other that led us to the pen system in our dialogue. The workpieces consist of several mostly round profiles and are clamped in testing machines for fatigue tests. Previously, the workpieces were removed after a certain dynamic load and taken to a separate room for PT testing. After a successful test, the workpieces were clamped again to continue the test. With the pens, the test is simply paused and the relevant areas are inspected for cracks with our Piccolo pens in the installed position. This saves a huge amount of time in the testing process, reduces parameter falsification and increases employee motivation. A clear win-win situation. Our customer has an optimised inspection process and we have a satisfied customer. Because that is what we value at MR Chemie.

How does the application work and what do you need to look out for?

Firstly, we offer some of our penetrants, intermediate cleaners and developers in Piccolo and Jumbo pen formats in addition to the classic delivery forms. The pens are suitable for precise application without over-spray, as you would expect from everyday felt-tip pens. The penetrant, fluorescent or coloured, can be applied to the area to be tested as with a felt-tip pen, precisely and without any over-spray. After sufficient penetration time, the penetrant is removed from the surface as usual. Either completely wash off with water or first remove the excess penetrant with a dry and lint-free tissue and then clean the surface further with water or with another tissue to which the intermediate cleaner has been applied until no penetrant is visible. If the intermediate cleaner from the Piccolo pen is used for this purpose, press the felt onto a dry cloth several times until it is sufficiently wet.
Figure 1: Treat the area to be tested with the Penetrant MR® 68 C Piccolo-Pen.
Figure 2: Intermediate cleaning with water.

Once the surface is dry after intermediate cleaning, the developer is applied. A difference must now be made in the application. DIN EN ISO 3452 specifies very precisely how a wet developer should be applied. Application with a pen is not taken into consideration in the standard. Therefore, if you need to carry out the process in accordance with the application standard, you should use our classic delivery forms, e.g. the spray can. If you are allowed to deviate from the standard, the developer in a piccolo or jumbo pen is ideal. A small additional tip: do not try to “colour in” the areas, but simply brush over the surface once or twice in the same direction. This will give you a thin and even developer film. The crack indicators, if present, will appear as usual!

Figure 3: Application of the developer with the MR® 70 Piccolo-Pen. Always stroke in the same direction.
Figure 4: Viewing the ads after development.

For myself, the small piccolo and jumbo pins are great pocket-sized problem solvers. Whether in the industrial sector, engine restoration or crack testing at critical points on high-performance bicycles. In other words, wherever cracks need to be found in small areas.

Figure 5: Comparison of piccolo & jumbo pens

Feel free to share your experience with us, where you have already used our pens or where you can imagine using them. Either simply write to us at post@mr-chemie.de or post a photo on your social media channel and link to us.

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Your contact

Picture of Roman Dörn

Roman Dörn

New Business Development

02303 95151-42


With high quality products for
Non-Destructive Testing, 3D Laserscanning
and the hygienic sector


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