another outgassing question

[PCT17522]

I read the post under Tips and Tricks and some others about the subject, but I'm still curious. The statement was made that sometimes it takes more than one outgassing to remove all of the trapped air. Is multiple heating and cooling more effective than a longer dwell at temperature? I've heard that outgassing lasts for approximately 24 hours before it's necessary to do it again, is this accurate? I have hundreds of small stainless steel castings (I'm not sure what kind of casting) that need to be masked before they are coated. The masking won't stand up to a prolonged dwell at an elevated temperature. (So they need to be masked after outgassing and before coating...thus the 24 hour question.) The parts are coated using a hot-dip fluidized bed process. I've tried outgassing them with some success, but there are some parts that just won't outgas entirely. Any suggestions, or just general knowledge that might help?

[nuttyman]

OGF primer or OGF additive. the outgas debate will live on forever!!!

[BottleFed70]

You should not need to re-outgass unless the piece is exposed to some form of contamination (oil, polishing compound, etc).

You could always do a test run... also, fresh castings are a lot better than old/used castings that have had a lot of time to soak up the oils, etc.

[PCT17522]

This OGF additive says that it can be used with any powder. I wonder if this refers to any thermoset powders, or really any powder. I am coating these castings with a thermoplastic nylon. Does anyone know off hand if these are compatible? Perhaps I'll just get a sample and try it. It seems useful, even if not in this application.