On Apr 9, 11:53*am, "Existential Angst"
wrote:

It's an old-style union (flat mating faces), immediately on my compressor,
with the controls and fittings on that.

Should be a quick job, if it will work... will save me a trip to the store.
Plus it would be but another DIY thrill.... *

Alternatively, can I just putty/dope the faces up?

If it ever needs disassembly, the 'just dope' solution has flaws.
Why not get out the razor knife and some oaktag or gasket material
and cut yourself a gasket?

Someone did a dope-but-no-gasket replacement on my car's water
pump. When it needed replacement, I found that the housing parts
were glued tight and couldn't be budged. No gaskets meant that the
attaching bolts were a couple of turns tighter, and went into the
engine
block past the fully-cut-thread length (so the bolts broke, of course,
at disassembly time).