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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: curiouscat on May 11, 2013, 02:55:51 AM

Title: Ground glass joints: Grease for solvent application
Post by: curiouscat on May 11, 2013, 02:55:51 AM

Our regular grease seems to dissolve away leading to leaky ground glass joints. The reaction we are working on has MEK (methyl ethyl ketone) as a solvent and is heated to ~55 C.  Reaction runs for ~12 hours.

Any sugesstions for what grease might work? I was thinking of the silicones but wanted to get opinions from the real lab rats. :)

Title: Re: Ground glass joints: Grease for solvent application
Post by: discodermolide on May 11, 2013, 03:10:52 AM

I presume this is normal scale?
How about using a ptfe sleeve. I only applied grease to the very top of the joint.
Is the joint damaged in any way?

Title: Re: Ground glass joints: Grease for solvent application
Post by: curiouscat on May 11, 2013, 03:13:06 AM

Quote from: discodermolide on May 11, 2013, 03:10:52 AM

I presume this is normal scale?

Yep. 5 Litres or so.

Quote

How about using a ptfe sleeve. I only applied grease to the very top of the joint.

I'll try that. Never thought of it. Thanks.

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Is the joint damaged in any way?

Not visibly, no. It is old glassware though. Might be worn a bit.