Here in India, automotive painting workshops use what they call a car-patch to fill up minor dents before painting. The main component is green, and the hardener is white (to be used in a mix of about 10:1). This stuff is extremely cheap, gets rock solid in about 15 minutes on mixing, and shows excellent electrical characteristics for this application. I have used this for potting even 240 volt operated boards. Regards, Anand ----- Original Message ----- From: "Omega Software" To: Sent: Saturday, February 28, 2004 4:14 AM Subject: Re: [EE]: that black substance..? > At 22.34 27/02/2004 +0100, you wrote: > >Hello, > >I saw some hybrid circuits drowned into a black, very hard substance, > >I guess to hide their "secrets". > > > >Now I need to do something similar.. I have to borrow some circuits to > > Correction: I meant "lend", not "borrow".. of course. > > > >a customer, but I don't want him to reverse engineer them. Not only I'm > >gonna cancel signs/labels from the ICs, but I also (for some added > >security) I would like to drown most of it into this black, very hard, > >substance. I guess that if he tries to remove it, the circuit board will > >be damaged. The circuits will return to me, so I'll know if he tried to > >be too smart. > > > >Could anybody give me some pointers / directions, please? For a good > >start, I would need to know the name of this substance (to then try to > >translate it into my own country language). > > > >Thanks! > >Andrea > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.