Sciencemadness Discussion Board

Springs and hooks and a Buchner with an issue

Organikum - 4-2-2013 at 18:43

The first attached picture shows these nice aluminium hooks to use together with springs instead of Kecks.
I knew this exists but I was unable to ever find a seller. Now I found this nice flask and hope somebody here can tell me an address where to get some 50 to 100 of these aluminium pieces - for a reasonable price, this can only cost a few cents a piece not more.

So if anybody is in the know pls tell.


The second picture shows a 20cm Buchner I got today for € 10.-, looks like new if not somebody had somehow applicated this black material what is elastic and probably rubber.

I did some small tests and thought to solve the problem by carbonisation, say to burn the shit off with a propane burner.
Any better ideas, warnings "Dont do this because...." tips?
Would be a pity if it got damaged, wouldn't it?

regards
/ORG



Aluhooks.JPG - 106kB

Buhuchner.JPG - 179kB

[Edited on 5-2-2013 by Organikum]

bahamuth - 5-2-2013 at 00:43

If you have a heating cabinet that goes to 250-300C. it will do most organic polymers after prolonged exposure. Otherwise I would try a sulfuric acid soak, with heating to about 100C. at first. If that don't work heat it harder in sulfuric acid. Heating locally with a blowtorch might crack the perforated plate..

I also want some of those hooks:)

Endimion17 - 5-2-2013 at 01:37

Rubber on smooth ceramics... I'd take a plastic utensil and scrap the shit out of it. Traces can be removed with some organic solvent on a cotton ball.

Those aluminium hooks, I've had two of them. Didn't last long. They could be made from a thin sheet...

[Edited on 5-2-2013 by Endimion17]

phlogiston - 5-2-2013 at 01:42

The aluminium hooks seem a bit elaborate to me. What is the advantage of these over other solutions?
If heat resistance: there are several types of steel snap-on clips for this purpose that should offer better heat resistance and are easier to install and remove and won't suffer from metal fatigue as badly as aluminum.

Regarding the rubber:

(1) Freeze it, so it becomes hard and brittle and non-sticky. Then mechanically remove it.

(2) Try dissolving it with methylene chloride or chloroform

[Edited on 5-2-2013 by phlogiston]

Doc B - 5-2-2013 at 04:54

I make similar fittings with those disposable steel pipe cleaners. The entwined fabric doesn't suffer from heat except applied flame and provides a soft contact to the glass which lessens the risk of damage. Once applied to all joints, I just twist to lock and unlock.

Maybe the rubber is a solution to ill fitting papers? If it doesn't dissolve it might be there to provide an edge seal with the filter paper. My Buchner is crap the liquids always creep under the edges.

Dr.Bob - 5-2-2013 at 05:19

When using a Buchner, always put the paper in the buchner , wet it with your solvent a moment before you use it, and then turn the vacuum on before pouring any solution in it. If you do this properly, it will be rare that your solids will leak under the paper. The real trick is wetting it and putting the vacuum on quiickly and then immediately pouring in some of the solution to keep the paper wet, and then don't ever let it get dry until done. Also, using thicker paper helps, as it does not bleed vacuum as fast, so it holds down better.