That is really interesting - I wonder why it matters so much? It seems to me that the ground glass joints seal pretty well to begin with - and the addition of anything else would easily seal it.

Vesp, I've noticed numerous times that even with a liberal application of white pet. after a good bit of heat and vacuum the joints show little "islands" where there are gaps in the grease.  No such phenomena was noticed with silicone grease

The people at a glass shop squoze a big blob of vacuum grease onto a piece of foil for me. I've been
hoarding it and rationing it out very sparingly. It's a different beast from vaseline alright. A while back
I had a silicone grease that was an electrical product (dielectric grease?), anyway I'm going to look
for that when I run out of my gift grease. I read somewhere where somebody was comparing this very favorably
to the real mcoy. He couldn't tell them apart. But yeah, with the heat, vacuum, and time that vaseline
just starts to erode away. I've tried wrapping heavier duty teflon tape as well. I think that was ok, but lots of dicking around.

Frank one of ziggy's mates uses Dow Corning high vacuum grease and it is so fucking good. Yes its abit expensive, but fuck its good. Real clean, real good fit, only use minimal amount, and appropriately and it lasts for years, well it has me. I remember playing with vaseline and melting in rubber bands and it was shit. You get value for money with the couta stuff.

yeah it kind of does matter silicone handle heat better it is'nt as likely to contaminate the distillate.
vaseline is good for the homsexually inclined.
use vacum grease not ass grease

i used salt baths just table salt much easier than fussing with scolding hot oils.

i'm not sure i got your question can you come again?
if you want you can use metal filings for good heat transfer.
i hate using oil baths.

LOL
Jon is right,silicone is for glassware,veseline is for but pirates!
Vaseline is hydrocarbon and it will contaminate most solvents
and stronger oxidants.Howewer it's easier to clean!

I use Bayer silicone grease and it works great,only problem is
cleaning the scum it makes at high temperatures.
DCM dissolves it "good",actualy it dries it until you are left with white dry
powder that can be removed with brush,thats weird!

just explain rather than directing people away from vesp thats what the thread is for!

Cross posting is bad form on the internet      If you want information that's already been posted elsewhere you need to do what it takes to find it    There's no point in answering questions twice, perhaps you should rethink your demands 

Proper vac grease is great. Vaseline doesn't perform as well under tough conditions.

You also need that seal in complex glassware setups from which you need to exclude oxygen and/or moisture.

When I put in orders there are never enough innocuous things to fill the basket. That item is anti-suspicious. Ordering it shows you understand proper laboratory technique and will go for the necessary supplies to do things by the book. Chemists follow procedure and do things the right way. Drug cooks fly by the seat of their pants, don't give two shits about safety, completely ignore procedure, and order the same damn thing over and over again.