A fully new design: a penetrant from Asia!

April 2010

Among our many readers, the world over one took the opportunity to ask us about a very specific penetrant.

This reader let us know that product he uses, that is purchased from an ASIAN COUNTRY, is being checked for cracks with a “penetrant” which is made up with 1 gram of fuchsine with 1 liter of an undisclosed percentage of alcohol and water.

John T. Davis, an inspector, sent this letter:

‘‘I would enjoy my "case" to be presented if it would help others to be aware and to gain insight. It would be beneficial to let the world of NDT know that there are multi-Million Dollar Companies, we will reach a Billion Dollar level soon, that may not have “any idea” of the technological advances available in NDT, nor may not realize, that just because someone conducts a test on a product, that the test is "officially" accepted by the STANDARDS, or that the "official" STANDARDS for these tests even exist. Or how to find them?”

This is the case, in our vendor using the fuchsine dye for porcelain crack checks, and stating that it is the standard, and "everyone" does it.

The lack of clear, simple, and straightforward knowledge needs to be made available, and you and your colleague Pierre have risen to this occasion. I only wish there were more with your heart and mind and soul for this effort, for the world to experience.

Thank you for filling the void in the vessel of knowledge in this area. Should we never meet or write again, think of this meeting as a seed that is planted to produce an abundance of fruit to be shared. I am honoured and humbled in gratitude.’’

We are here with a supplier who uses a so-called penetrant to detect flaws and porosities in porcelain. Is this the right product for this application?

After having been involved in Penetrant Testing for ca 40 years we think we have seen every possible mistake, we have heard every “incongruity”. We were wrong! But…it did not come as a surprise for us!

John has faced a lot of troubles due to the porosities and the cracks (see photographs below) for the last few months. No wonder we believe him!

Large cracks as seen with naked eye / Porcelain (dark area) stained by fuschine dye solution supposed to detect cracks.

As written in our paper titled ‘‘PT in France in the good ol'days of Rock and Roll’’ in the ‘‘Oldies but Goodies’’ series on our Website:

- ‘‘In the '50s PT materials were kind of similar to our Grand-Ma's recipes: formulae were published and every man in charge of PT had his own recipe.’’

Obviously here we are still in the ‘50s!

By the way fuchsine is a dye used in bacteriology and cytology, i.e. for biological applications, but in NO WAY for crack detection.

The right choice for this specific application is to use a penetrant specifically designed for such an application as explained in a paper previously published on our website(*).

As an other choice, a Type 1, Method A, Level 2 penetrant may be used generally without any developer. Users may choose among many penetrants listed in the Qualified Products List (QPL) annexed to the American SAE-AMS 2644 specification.

When will we ‘‘meet’’ the next ‘‘so-called penetrant’’?
Every new opportunity may lead to a new paper on our site!

Note

(*) Patrick DUBOSC and Pierre CHEMIN - Chapter 10: - Fluorescent particles in suspension in hydrocarbons as a fluorescent penetrant - Special products for PT - DPC N°017- October 2009.