Metal finishing Q&As since 1989

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Fading problems of particular shade in powder coating

We have been suppling all leading Oil companies their requirement of various shades in powder coating. Unfortunately, recently we have started getting field complaints of fading of colour on pumps. In particular it has been observed that P.O. Red shade made by M/s Marpol is getting faded in field after coming in open atmosphere for some time of around 2 to 3 months.

Request to please give solution of the above to avoid such problems in future.

Shailesh Dhanani
Mercantile & Industrial Development Co Ltd - Ahmedabad, Gujarat, India
2004

Shailesh Dhanani,

Your question is incomplete , Pl write the full specification of powder using i.e., EP or PP Epoxy only.

But again this problem can be solve by using the Powder (Ultra voilet resistance).Pure Polyester.

Rakesh Sharma
Minda - Delhi, India
2004

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Dear Mr. Sharma,

Thanks for your response. in fact I forgot to mention that the one what we are using is Pure Polyster Powder. You may please suggest.

Shailesh Dhanani
Mercantile & Industrial Development Company Limited - Ahmedabad, Gujarat, India
2004

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Dear Sirs,

Unfortunately red & yellow pigment dyes (used in surface coatings) have poor resistance to ultra violet light � some are better than others. Maybe your powder mfgr. is using a locally produced red dye that may not be suitable for your process. One of the worlds most respected red pigment mfgr. does have offices in India- phone them up for advice and then ensure your mfgr. uses the pigment that is recommended by them. Ask your powder supplier to carry out and show you the results of test panels subjected to 500 & 1000 hours in a UV cabinet-- this will show the discolouration to be expected from different red pigment blends. Expect to pay a little more for your product.

Terry Hickling
Birmingham, United Kingdom
2004