The vacuum from the pump should seal that.
You use vacuum right?
Sreetips filters?
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You use vacuum right?
Dunkin Donuts has two sizes - Very Large and Colossal. Ask them for a few (I tell them I am doing a science experiment). You should probably buy some doughnuts, though.
When using a Büchner funnel it is key to wet the filter first, before adding your solution.
Set up your flask and funnel, apply vacuum, spray a mist of water over the filter, add your solution.
With out wetting the filter before hand some “trash” will find its way between the filter and funnel. This is assuming you’re using quality filters that fit your funnel correctly.
Set up your flask and funnel, apply vacuum, spray a mist of water over the filter, add your solution.
With out wetting the filter before hand some “trash” will find its way between the filter and funnel. This is assuming you’re using quality filters that fit your funnel correctly.
I am using a vacuum pump. I do mist it beforehand to let it seal better. I have a 120mm funnel with 110mm filters. And bigger of filter I would be unable to fit them in. I am new to vacuum filtration. I've always use coffee filter and normal funnels.
Maybe I'm just miss understanding something. Still would like to find them big ones like sreetips
Maybe I'm just miss understanding something. Still would like to find them big ones like sreetips
Golddigger76
Well-known member
Not only do I mist the buchner funnel I also give it a few sprays of water on the top of the filter paper once it's in place.
The only time anything gets by is if my pump sucks a hole in the paper.
The only time anything gets by is if my pump sucks a hole in the paper.
Skip to 16:07 to see how he makes his special filters....Like & subscribe to his channel.
Do you use coffe filters in the Buchner?
120 mm Büchner funnel should have 120mm filter paper. I have cut larger papers to size in the past when I found them on sale at a good price. Some of the very fine pore papers can run cheaper for the large ones than for the smaller sized of the same type.
Large coffee filters can be purchased at food service outlets like GFS, there are also iced tea brewer filters which are larger than food service coffee filters and cover large strainers well. The correct sized Buchner funnel filter paper is only a Google search away.
If decide to buy filter rounds for vacuum filtration, you have to be careful with the Slow flow filters. Slow flow or tiny pore size can fail easily under a high vacuum once they're loaded up.. That's one of the reasons I don't vacuum filter very much.
The 4 different types of filters I use
- Cotton makeup removers or cotton balls. These are great for cone funnels. The catch everything. Just push them in.
- Coffee Filters have a pour size of around 20 u (microns).
- Paper filters. These have a pour size 10 u and up.
- Filber Glass filters have pour size of about 0.2 u to about 2.0 u.
The problem with all cotton or paper filters are they don't handle acid well. Filber glass filters are made out of ... Glass. If you can use a glass beaker, you can use a glass filter. They even make borosilicate filters. Example. Amazon. Omicron 133047 borosilicate.
With bushner filters once the filter is in place, spray it with water to make the filter stick.
If you want to create a cup, like a coffee filter, use a 150 mm filter, push it in dry, make sure there are no gaps. Then spray it with water and re-inspect.
The are 2 main types of filters: Quantitative and Qualitative. The quantitative are flow faster flows as compared with other filters of the same type.
- Cotton makeup removers or cotton balls. These are great for cone funnels. The catch everything. Just push them in.
- Coffee Filters have a pour size of around 20 u (microns).
- Paper filters. These have a pour size 10 u and up.
- Filber Glass filters have pour size of about 0.2 u to about 2.0 u.
The problem with all cotton or paper filters are they don't handle acid well. Filber glass filters are made out of ... Glass. If you can use a glass beaker, you can use a glass filter. They even make borosilicate filters. Example. Amazon. Omicron 133047 borosilicate.
With bushner filters once the filter is in place, spray it with water to make the filter stick.
If you want to create a cup, like a coffee filter, use a 150 mm filter, push it in dry, make sure there are no gaps. Then spray it with water and re-inspect.
The are 2 main types of filters: Quantitative and Qualitative. The quantitative are flow faster flows as compared with other filters of the same type.
He has a video where he shows how he prepares his filters.
First time I've even heard of them. Amazon have them?
MapishPepperush
Well-known member
I don't know take a look
Yes, but they aren’t cheap compared to paper
I enjoy this community. Ask 1 question and then everyone goes off on different issues and solutions. It is helpful cause it'll answer other questions not asked. I really appreciate all if the feedback.
I haven't watched all of his videos I guess I will try to find the one where he makes his own. Guess I'll use a big coffee filter with a filter disc at the bottom.
And if you have a 120mm buchner funnel then try to fit 120mm filter disc it'll be to big.
Thank you everyone for all the information.
I haven't watched all of his videos I guess I will try to find the one where he makes his own. Guess I'll use a big coffee filter with a filter disc at the bottom.
And if you have a 120mm buchner funnel then try to fit 120mm filter disc it'll be to big.
Thank you everyone for all the information.
Did you not watch Sreetips video that was posted in this thread a little further up. I know it says "gold plated silver jewelry", but skip to 16 minutes an 7 seconds. He is very detailed on how he makes them.
I find new tricks in his video's from time to time... great channel.
I'm sure you wouldn't need 2 Buchner funnels to make them, just something that fits into the other.
Trying to buy the correct size filter circles used to confuses me with the whole cm/mm thing...I think I finally figured it out though.
I'm sure you wouldn't need 2 Buchner funnels to make them, just something that fits into the other.
Trying to buy the correct size filter circles used to confuses me with the whole cm/mm thing...I think I finally figured it out though.
