Chromatography Forum

What is the best method for removing vespel/graphite ferrules from the column nuts? The soft graphite are easy. but sometimes the harder ferrules are really difficult to remove. I've resorted to using an appropriately sized drillbit (the end without the cutting flutes) to force the ferrule out, but surely there is a better way?

What is the best method for removing vespel/graphite ferrules from the column nuts? The soft graphite are easy. but sometimes the harder ferrules are really difficult to remove. I've resorted to using an appropriately sized drillbit (the end without the cutting flutes) to force the ferrule out, but surely there is a better way?

If there is a better way I am yet to find it. Like you I use a flat-ended piece of steel rod, held in a pin vice, to shove the ferrule out.

Peter

Hello

I'm using dentist tools made from stainless V6. They are really sharp and tough and they can do the trick.

Regards

Tomasz Kubowicz

I had the smallest size precission flathead screw driver that fits through the hole on the nut. I put it on the hole, tap with a hammer and the ferrule usually pops out in one piece. On my 5890-FID I use the same graphite vespel ferrules in reverse (pointy end towards detector) and special column nut (similar to the inlet nut but with greater depth) getting the ferrules of of them is a real nightmare.

To remove the ferrule from the column nut that goes on the MS interface of the Agilent MS, I use a pushpin like is used on a bulletin board. I break off the column and insert the pushpin into the hole and push or tap until the ferrule pops out. For the inlet end I normally use my pocket knife blade.

A straight piece of a paper clip with gentle hammering will do the trick - I did this many times.

Thanks for the responses. I decided to buy a little pin vice from Amazon : https://www.amazon.com/gp/product/B0002 ... UTF8&psc=1

It comes with drill bits that and also nice little pointy tool that works pretty good for ejecting ferrules. I also ordered some sub-mm tungsten carbide rods from eBay and the combination should be perfect.

We at Aviv Analytical found a simple yet "magical" way to remove ferrules from nuts. Cut the column as short as conveniently possible around the column ferrule holding nut. Place the nut in a GC oven at 310ºC for a one-few minutes, cool down the GC oven to 40ºC and take the nut. The ferrule should now be lose and easy to remove. The reason behind this "trick" is that in unclamped nuts the ferrule expands to the open ferrule center and upward during heating and thus contract during cooling from the walls of the nut and become lose.