Vaseline experience: don't use it !!!

[methlab]

Hi guys! For all those out there, who followed Brightstar's 'brilliant' hint: "...use vaseline to grease the joints...", i want to say: please don't do it !!! I did it and i got very bad results or nothing with it. Yesterday i got my high-quality BASF silicone-grease. This changed my live totally. I followed MM wacker and everything was perfect. I got 106.6g of double-distilled MDP2P from 178g of Safrole. I think this is a good result for a non chemist like me. Thank you very much to those guys, who told me, that i am burning my ketone, because of too high temperatures and bad vacuum. Last week i thought that i'm too stupid for this, but now i know, that i am not. I will never use vaseline and i can not recommend using it. Save your precursors and buy a good silicone grease.

[Mercury]

When you washed with 500ml of saturated sodium bicarbonate, how much water and sodium bicarbonate did you use to make 500ml?

[pirat]

If you have no better thing at hand, Vaseline work good enough. I get higher yields than you, and I always use Vaseline.

[methlab]

Did i use too less vaseline? Got some messages from other guys, who has the same experience like me. What kind of vaseline do you use, where is it prduced?
I am living in europe and my vaseline is normally used for the feet of my dogs (cause it's very cold out there now). Followed exactly MM wacker. When i distilled the MDP2P with my Vaseline, the temp was 160-180C, thus burning the nice keton. Using the BASF vacuum-grease decreases this temp to 125-130 C.
But maybe i should give it another try, or maybe i have used just too less.
What will happen, if some vaseline drops will fall into my DCM/Keton mix? Sorry, if i have annoyed some vaseline users out there, i just wanted to tell you my experience, which i share with other users...

[sYnThOmAtIc]

How about investing in some teflon coated joints!!! Talk about some expense. Interchangable teflon collars are cheaper. No need for messy grease or running out. Also, flexible teflon sleeves can be bought at a lower cost and are reusable also.

[biotechdude]

Vaseline can be ok, however dont smear it on like you're greasing your nanna's bum crack.  Just a little round the TOP of the joint.  This way it doesn't melt at high temps and come into your distillate.  If it does though; just cool it and the vaseline will precipitate out, then just scoop/pick it out.

However, good old plumbers thread tape is the handiest stuff so put a thin layer of that inside (around the joint) and an even thinner layer of your chosen grease.  This way the joint doesn't 'pop' open cos its TOO greased up (doh!).  It also is a snug (releasable) seal.  Not too much though; or it will absorbe product or be too fat and pressurise the glass socket.

HOWEVER, at the end of the day, high grade silicone grease can be obtained from most stores that sell rubber products.  This, combined with PFTE sleeves of your required joint size are the best option.

[Snakebyte]

Never heard that idea about the teflon tape. I'll give it a try though because my vacuum isn't what it could be. By the the Meth...how much pressure difference was there after changing to the silicon grease?