How clean can you get scoria?

[stillthinking]

Hi team,

If using scoria as a column packing how clean does it need to be/how clean can you get it?? Using a 4 inch copper column section 650mm long packed with scoria and a 450mm section above that packed with SS scrubbies.

Scoria has been flushed with the tap over a seive three times and allowed to dry, then boiled on the stove for an hour or so in a pot then did a vinegar run and a sac run with some feints. After the sac run the scoria was clean but the scrubbies held pink dirt when they came out and got cleaned in a bucked with fresh water.

Run was crystal clear, pulled 94% temp corrected too!

Is this ok/normal and to be expected??

[RC Al]

I would follow up with a full blast steam run just for giggles to clean the feints out a bit and give the rocks a bit more f a jiggle, the more dirt/dust you can pull out, the more open area the rocks will have

I wouldn't stress on any bits in the scrubbie, but would remove anything that has dropped in size below 10-12mm

I don't believe mixing mediums in column is a good thing - outside of adding a bit of copper to an all SS rig.

The column works best with an even temp gradient, where there is a change ie rocks to scrubbers, the heat required to keep that gradient changes, which disrupts the separation from there up.

[stillthinking]

Cheers Al, I’ll give it a blast. So I understand it’s not unusual for SS scrubbies to catch a bit of crap?

Mixed packing medium didn’t seem to worry it on the maiden run, very distinctive separation to tails when the ABV plummeted and column temp soared.

[Ned]

Hi team,

If using scoria as a column packing how clean does it need to be/how clean can you get it?? Using a 4 inch copper column section 650mm long packed with scoria and a 450mm section above that packed with SS scrubbies.

Scoria has been flushed with the tap over a seive three times and allowed to dry, then boiled on the stove for an hour or so in a pot then did a vinegar run and a sac run with some feints. After the sac run the scoria was clean but the scrubbies held pink dirt when they came out and got cleaned in a bucked with fresh water.

Run was crystal clear, pulled 94% temp corrected too!

Is this ok/normal and to be expected??

Hi Stillthinking, I have been using scoria 10mm in a 4" bubbler in a 500mm packed section for over 2 years and pulling 94%. I got the 20mm scoria from the bit green shed and hit it so it broke in half. I have since got some 10mm from a garden supply, but whilst its not broke I will not try to fix it. I was a bugger to clean. I just kept soaking it until the water was clean. I run it with a 1kg of packed section at the bottom than filled with scoria and a 500g packed section at the top. The 1kg and 500g are copper. I just boil it now and again to clean it. Very happy with my results. TFFV comes out a treat. Don't remember the pink dirt, but perhaps I did not see it in the copper. :-D