Ok. Why viton? Regular gum rubber and buna nitrile will take a vacuum just fine.
-Jerry > On Aug 29, 2014, at 8:36 AM, Nathan McCorkle <[email protected]> wrote: > >> On Fri, Aug 29, 2014 at 5:48 AM, John Griessen <[email protected]> >> wrote: >>> On 08/29/2014 03:29 AM, Nathan McCorkle wrote: >>> >>> looking to make a vacuum container wire feed-through, thinking I'll >>> drill a hole into an existing aluminum blocking plate >> >> >> How about buying a ready made terminal with plastic around it to silicone >> into >> a hole in a plate, or hole in a rubber stopper? > > All the terminals I've seen that mention anything about vacuum or > hermetically sealed seem to ring-in in the hundreds of dollars. > > Also I'd like to try and keep the chemical list down to a minimum, as > certain materials like to off-gas for a very long time and that > behavior can foul the vacuum and imaging system contained therein. > >> >> Or, the spark lighting electrodes from gas grills (like piezo sparkers come >> from)... > > Hmm, I haven't look at one of those in a while, I've got a box of > gas-leaked-out piezo hand-held lighters but they've just got a > plastic-insulated wire. Do you have a certain brand? > >> They look like a glass to metal assembly that might be fairly hermetically >> sealed >> just by accident... They're 0.25 inch diameter and would fit in a stopper >> hole also. >> I think there's one of those just down the street at the moment... > > I'd really like to try the Viton stopper approach, NASA seals walk-in > vacuum chambers with doors >15ft wide using Viton o-rings (or used to > at least). The rest of the vacuum system uses Viton, which may not be > required as this doesn't go through temperature swings or harsh > chemical treatment. But I have only really scratched the surface on > o-ring vacuum sealing technology, so I'm not sure which rubber > compound would be second-best (in terms of how flexible, and also in > terms of off-gassing). I know off-gassing can differ between different > kinds of RTV silicone, as I've researched the various types of those > available for potting electronics. > > I'll take a look at the grill lighters for sure when I go to the > hardware store to look for stoppers. > > Thanks! > _______________________________________________ > dorkbotpdx-blabber mailing list > [email protected] > http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber _______________________________________________ dorkbotpdx-blabber mailing list [email protected] http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber
