Don, I don't know whether it is applicable to your application, but a traditional method is to immerse the part to be tested in a hot fluid (say 70°C) and observe for bubble streams. The choice of fluid is difficult. It must have a low surface tension and low viscosity; it must be stable with time at the chosen temperature; it must not evaporate; it must not be reactive with anything on the assembly; it must not affect the electrical properties; it must be easy to clean off; it must be cheap; it must not pollute; it must be non-toxic and non-flammable; etc. Unfortunately, this miracle liquid does not exist but there are some which come quite close. These are perfluorocarbons. They fill these functions bar two: they are polluting and they are damned expensive. In this application, the expense part can be minimised by good housekeeping and recovery of drag-out losses. Notwithstanding, there will be losses due to evaporation and these products are amongst the most global-warming substances known to man, about 10,000 times worse than CO2. This means that 1 kg lost is equivalent to 10 tonnes of CO2 and 10 tonnes of CO2 may be produced by burning 16 tonnes of motor fuel, which is equivalent to about 20,000 litres, sufficient to run a modern car 200,000 km, or more than the average lifetime of a car. See what I'm getting at? Recover every milligram you can. That having been said, I guess you may be in Deutschland and there may be regulations regarding the use of PFCs in your country, either in force or proposed. Check carefully. Hope this helps. Brian "Steffen, Don E" wrote: > > Technetters > > I am a Quality Engineer on a Safety Product that has a Leak Test > requirement. We are using a die cast aluminum housing that has a > porosity issue. I want to find out if there are any one in the TECH > NET world that might have some experience in leak detection methods. > Water is out of the picture. Because of the vertura effect, water can > be sucked into a housing. I am presently using water for > troubleshooting purposes, but everything that is applied to water is > scrap. I have tried Helium gas but this is not always reliable and > repeatable. Is there anyone out there that can help me out in this > dilemma? > > ----------------------------------------------------------- > This Mail has been checked for Viruses > Attention: Encrypted Mails can NOT be checked ! > > *** > > Diese Mail wurde auf Viren ueberprueft > Hinweis: Verschluesselte Mails koennen NICHT geprueft werden! > ------------------------------------------------------------ --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------