buchner funnel size?

Shop deals on ebay
Advertise with us
xelexo
shop deals on amazon
Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Moses

Moses

Well-known member
Joined
Mar 15, 2024
Messages
66
Location
Creswell Oregon
I'm going to buy a buchner funnel for filtering can anyone recommend what size pore it should be how small of micron size? I hope I'm describing it correctly, thanks Moses
 
Moses said:
I'm going to buy a buchner funnel for filtering can anyone recommend what size pore it should be how small of micron size? I hope I'm describing it correctly, thanks Moses
Click to expand...
I use 100mm buchner funnels and 600ml vacuum flasks.

If you want your funnel to have the built-in filter then you want a quartz fritted funnel.
I do not think they are very versatile, as in if you are filtering out a metal that can be easily dissolved with a cheap acid like hydrochloric acid it would be fine.

I do not have any experience with quartz fritz disks or fritted funnel but I have read that they can be a real pain to clean when they get plugged up.
I can tell you that a porcelain buchner funnel is easy to clean and it is very simple to get the paper filter out.
They can be bought on Amazon with the proper sized filter papers very cheap.

Maybe other members can tell you how well or not the fritted quartz funnels work.
 
Fritted funnels for general refining just don’t hold up. Sooner rather than later they will clog. And just sucking something to dissolve the clog isn’t as easy or effective as it sounds. Avoid the frits.

True, a fritted filter will never leak around the papers, and I know some who put paper on top of a frit. But eventually they clog. Putting a paper in a Buchner properly to be sure it seals is your best bet. And the papers are easy to remove.
 
I use an 11cm Büchner funnel and a 1L Nalgene vacuum flask. Had both for several years now and it would be hard to do without them. I have two smaller Büchner funnels and flasks but rarely ever use them. I also have another funnel similar to a Büchner funnel but much larger that I have never used. It will hold around one gallon of fluid but has a ground glass fitting instead of fitting in a rubber stopper. I also have various other funnels that I use at times it just depends on what I am working on and the volume.
 
Shark said:
try adding a piece of fiberglass window screen between funnel and filter.
Click to expand...
make sure the edges of the filter paper extend past the screening. The screening lifts the paper ever so slightly but the edge is where the seal must be complete. Keeping the circle of screening you cut out so it stays inside all of the holes when placed in the filter is sufficient. But when you wet the paper to test suction, make sure the screen hasn't shifted.
 
Shark said:
If you start to tear the holes out in the filter, try adding a piece of fiberglass window screen between funnel and filter. This can also help speed up filtering in some cases.
Click to expand...
I would say that for ease of work, always add mesh under the filter paper. There are very specific cases when I will just use paper without mesh underneath, but for these occasions, I would just use fritted glass filter.

Frits are handy thing to have in hand when refining, and I found them very beneficial mainly for silver refining. As frit isn´t nearly as badly attacked by alkali than paper :) As 4metals said, they tend to clog up - but this is hugely dependent on what you are filtering through them. Junky solutions always through Buchner. But things like AgCl, silver powder, AR gold solution from refining... Legit. Easily cleaned afterwards.
 
orvi said:
but this is hugely dependent on what you are filtering through them. Junky solutions always through Buchner. But things like AgCl, silver powder, AR gold solution from refining... Legit. Easily cleaned afterwards.
Click to expand...
Another key ingredient is an organized refinery and a staff that won’t just use the first thing they think will work. When the dreaded drip sets in all refinery hardware is apparently fair game in a lot of shops.
 
4metals said:
Another key ingredient is an organized refinery and a staff that won’t just use the first thing they think will work. When the dreaded drip sets in all refinery hardware is apparently fair game in a lot of shops.
Click to expand...
True. Big part of success is to use right tools and right stuff for the job.

I used to have dedicated frit for working with silver (ca 20 cm in diameter), separate tight porosity (S4) frits for filtration of gold solutions from ultrafine AgCl precipitates and one "dirty" frit for bulk work with random stuff. Usually these "dirty work" frits were just retired "clean" ones. Expensive glassware, but very handy for drying bulk silver or washing AgCl, since you can attach suction hose to it and just throw it into the suspension in a bucket :)
 
I prefer drying silver from a silver cell in a stainless steel spin drier, it's fast and the centrifugal motion gets the moisture off efficiently, better than a funnel with suction. A cascading rinse system followed by a spin.

Edit because mr spell check substituted centripetal for centrifugal, big difference.
 
I actually found a three piece set of Coors in 3cm, 5cm and a 110cm in a yard sell for $20. I would put those odds at “dang near never” of ever happening again.
 

Latest posts

Back
Top