Hello, A yellow chromate on Al should meet 168 hrs exposure test per Mil-C-5541C ask your supplier. IF YOUR SUPPLIER CAN DO THIS THEN GET ANOTHER SUPPLIER THEY ARE BETTER ONES AVAILABLE. There are also ASTM specs that are available on the nternet( http://www.ASTM.org search in the specification section) Also the Am. Electroplater and Surface Society has a publication on Chromates in you need it 407-281-6441, "Chromate Conversion Coatings" Let me know if you need more. We can arrange for a conference call to your supplier if you need it. Richard Haynes -----Original Message----- From: [log in to unmask] <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: Friday, September 04, 1998 2:45 PM Subject: [TN] Fwd:Alodine washing off *** TFS Evaluation Copy of module : cc:Mail *** ____________________Forward Header_____________________ Subject: Alodine washing off Author: CharlesC Date: 9/3/98 6:02 PM We are having a problem on a PCB which has an Aluminum stiffener/ heat sink bonded on the component side. When we recieve the board the Alodine is quite dark but after aqueous cleaning the finish lightens enevenly and after three or four washings we have what appears to be bare aluminum. The board manufaturer tells us that indeed the finsh has come off. This is only happening on one part number PCB, the other board from the same manufacturer does not exhibit the problem. We do try to minimize washings but due to the nature of the assy. four washings is about as low as we can go. We use an inline aqueous cleaner our saponifier contains monoethanolamine, the water is R.O. and the temperature is 160deg.F I have the following questions: 1. Has anyone else had this happen.? 2. Does a high PH remove the Alodine? 3. Do you know of any reference sources? 4. Got any other ideas? Thanks Charles Caswell Process Lead, Printed Circuit Board Dept. Frontier Electronics Systems ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################