Why do I need a contrast paint:
by T. Elias, Technical Sales Manager, MR Chemie
The main criterion for deciding to use a background color is usually insufficient contrast formation between the workpiece surface to be tested and the magnetic particles in the test equipment used. However, as is often the case in NDT, it is precisely these contrasts that enable us to reliably evaluate our tests.So what else is there to say about contrast paint? Quite a lot!
The individual requirements for a contrast paint:
In addition to the time factor due to the additional work step and the cost factor – including the post-processing of the test pieces using cleaners, for example – the required drying time, temperature resistance and covering power are often mentioned as further criteria when using contrast paints. Employee protection due to hazardous or odor-tainting ingredients and the environmental compatibility of the products are also always discussed. All of the points mentioned here are undoubtedly justified and have been used by us, among others, as an opportunity to adapt our contrast paints to a large number of test requirements and internal company regulations.
The alternatives:
First of all, unfortunately we don’t have one for all cases. But with our wide range of contrast paints, we are well equipped for these and other problems. If, for example, you need to carry out a component test above 100 °C, our MR® 72 undercoat paint is also ideal for this. It offers short drying times, as does our MR® 72 LS, which can also be easily welded over up to a layer thickness of approx. 30µm (see also test report no. 13090 from SLV Berlin) and can also be painted over. If you would like to save yourself the additional work step of a more time-consuming subsequent cleaning, our MR® 727 could be the right product of choice, as it is easy to wipe off. Odour nuisance, which is of course always perceived individually, can be minimized with our MR® 72 AF variant (AF = acetone-free) or MR® 725 and MR® 726. High covering power is also achieved with our MR® 72 TF, which does not contain titanium dioxide. And last but not least, our MR® 721 is also available as an environmentally friendly, water-based alternative. In addition, we often offer a choice of application method, as most products are available in an aerosol can or in a container. Of course, we also offer a solid selection of accessories for our container variants, such as suitable spray guns and paint spray guns.
Conclusion:
For all those who cannot do without a contrast paint, we offer complex solutions for the most gentle but safe and effective MT daylight testing possible. Certainly not all aspects have been covered in this article, but perhaps we have been able to provide some suggestions and your interest has been aroused. If so, please feel free to share your experiences or specific requirements with us and let us work together to find the right solution for you.
