# Home made Vaccum filter 60 bucks



## mlgdave (Feb 20, 2011)

I had the Buchner so didnt include that in the price.
1) Vaccumm pump for bleeding brakes - $40
2) 6 only 1/2 gallon canning jars - $11.00
3) Rubber reducing coupler - $4.00
4) #11 Rubber stopper - $5.00

Just brought the stuff home, drilled a hole in the stopper, reamed it with a knife to taper the hole, drilled a hole for the vaccum and voila!

This sucker works like a champ and I have 6 flasks to filter into, I just filtered 1 gallon through 4 media filters in the funnel in about 5 minutes!











mlgdave
ps.........im pretty sure I found my missing 4 grams from my first batch, I had some "solution" leftover and some filters from that batch, filtered, put in SMB and its dropping gold!


----------



## Anonymous (Feb 20, 2011)

Wait until you see the one barren is finishing up..... :mrgreen:


----------



## Barren Realms 007 (Feb 20, 2011)

mic said:


> Wait until you see the one barren is finishing up..... :mrgreen:



It's finished, I just need to find the time to finish the vacume tank. 8) 

He used the same kind of rubber stopper I used. :mrgreen:


----------



## mlgdave (Feb 20, 2011)

cant wait! I love mine and next thing im building is my hood and scrubber as I now know I will be taking this on seriously now!

mlgdave


----------



## lazersteve (Feb 20, 2011)

Remember to filter the solution until it is 100% free of sediment.

These types of filter setups are only as good as the filter paper you use in them. Poor quality or cheap papers will allow sediment through which will lead to double work requiring you to filter a second, third, or even fourth time before the solution comes through clean.

They are really great for quick drying of very clean gold powder or filtering out the colored salts from PGM solutions. They are also well suited to drying silver crystals from the cell.

The rubber you are using is susceptible to nitric acid vapors also. It also is quickly attacked by sulfuric acid.

I would feel more comfortable if the stem of the buchner was seated all the way down into the stopper. It looks kind of top heavy. The last thing you want is a spill of several ounces of gold in solution.

Steve


----------



## mlgdave (Feb 21, 2011)

thanks Steve, and yes I was thinking a little top heavy as well. As far as filter paper is there a specific grade or notation I should be looking for? I ordered mine on Ebay from a labware supplier

mlgdave


----------



## 4metals (Feb 21, 2011)

The problem with one of the hand pumping type of vacuum pumps is sooner or later you'll end up with a dripper that will take all day, you don't want to be squeezing all day. That's why I like a water eductor you can walk away and do something else and let it run. Shor sells one to hook up to a sink for 20 bucks. Beats squeezing.


----------



## Lou (Feb 21, 2011)

4metals,

I like these even better: http://www.amazon.com/Brinkmann-Recirculating-Water-Aspirator-Capacity/dp/B0017YFGV6


----------



## Oz (Feb 21, 2011)

Ouch! $1949.00

Lou, if you have used it and like it, I am sure it is a fine machine. But the price?


----------



## dtectr (Feb 21, 2011)

I've been reading some old assay/chemistry/ whatever manuals online (google). 
Anyway, a Buchner funnel, properly prepared is actually a form of "vacuum funnel". Hoke emphasizes wettiing the filter paper thoroughly, eliminating voids between funnel & paper, but doesn't really say why. In an old manual it explains that once the paper is prepared properly in the cylinder of the funnel, capillary action, with some help from gravity, within the funnel/cylinder literally "pulls" the liquid through the paper, creating a weak, but effective vacuum filtration.

It works well with the cheaper filters, like 3-4 coffee filters, producing a better result than from gravity alone. Here's a couple pictures of my HillBilly(R) Buchner - to take better advantage of these properties, the "cylinder" could be of smaller diameter & greater height. Make sure your hands are VERY clean, free of any oils or contamination. Rubbing alcohol would not be out of line.


----------



## Anonymous (Feb 21, 2011)

Jordan that is a redneck funnel if I ever saw one!Im sure barren is going to chime in on that one.Other than me,he is probably one of the biggest rednecks here.....lol.
The holes you drilled will help create a larger filter footprint for the solution to pass through.......however,Ideally,you need very little support to help hold the filter up,and could have ten times the surface area for the solution to pass through.Think of a tic-tac-toe board.If you used that style configuration under the filter to support it,you could increase the filtering surface area exponentially,allowing so much more solution to pass through,before clogging the pores of the filter and slowing down the filter rate.


----------



## 4metals (Feb 21, 2011)

Fiberglass window screening cut to a size less than the hole pattern diameter does just that. But you need suction.


----------



## Barren Realms 007 (Feb 21, 2011)

I'll give you an "A" for effort. But theory doesen't always work in pricticality(sp). When you fight with silver chloride or tin in your solution you will find out the hard way. Your funnel will be good for a small job where there are no contaminents. But if you try to do much volume at all you will find the fault's in your system. And if you try to put a vacume with coffee filters with the size holes you have you will have the possability of tearing the filter paper from the pressuer exerted on the paper. Also the sharp pieces around the holes can cause the same problem. You will also find that your system might be a little top heavy when filled with solution.


----------



## philddreamer (Feb 22, 2011)

I'm waiting for my filters to be delivered; so I had a bag of vacuum clenaner bags that I picked up @ a garage sale last summer for .50 cents. 
Made me some 3.625" circles, fit 2 of them in my 90mm Buchner with 3 coffee filter & it got the job done for now. 

I wouldn't use them with sulphuric, though...

Phil


----------

