# How big is my cylinder?!



## viacin (Oct 20, 2008)

I have a conundrum. I am purchasing this 100ml graduated cylinder ( http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=120313272527&ssPageName=STRK:MEWA:IT&ih=002 ), and I would like to also purchase a glass funnel to neatly fit inside of it. 

However, I'm picky about my choices. *I do not want the stem of the funnel to touch the bottom of said cylinder*, so the funnel should rest on the top of the cylinder. I would also like the maximum top size to avoid spills. So here is my conundrum: Sadly, I do not know the height, or even a perspective of size for a 100ml cylinder. I tried contacting the seller, useless. I tried finding the dimintions through a web search, also useless.

My hope is that someone with more labware experience would recommend a approapriate funnel (top size x stem length). Here are my prefered choices (so I could buy from the same dealer and combine shipping):

50mm stem
60mm stem
75mm stem
100mm stem

all top heights are the same as stem length. They may ALL be too long, I do not know. In which case, I am a bumbing fool and request your corrections.

If you're bored and like to help, would you mind giving me your opinion? Many thanks will be in order.


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## Oz (Oct 20, 2008)

Buy a long stem funnel and cut it to length.


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## viacin (Oct 20, 2008)

That's plan B. And nothing sounds as official as a plan B. I tried it once, and broke the funnel part as well. So lets file this under "maybe".


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## qst42know (Oct 20, 2008)

This auction is the same Bomex cylinder only with dimensions.

Item number: 230294067632


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## viacin (Oct 20, 2008)

330 mm tall? Really? Wow, thats 10x's larger than I expected! Hmm, maybe 50ml would be better.

And yes, bomex is not my best friend, but for a last minute graduated cylinder it must do.

Ty for the effort spent searching qst, I've learned that you seem to always have a helpful answer.

hey Oz, I may not have to cut that long stem after all.


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## Harold_V (Oct 20, 2008)

Your approach is wrong. Do not rely on the receiving vessel to support your funnel. Purchase a stand and a couple rings that support the funnel. Then you have no problems making any funnel fit any situation. All of my filtration was carried out that way, not only for convenience, but safety. 

The greatest advantage is it's one hell of a lot harder to tip the funnel when it's filled with values. No way would I recommend you place a funnel on the rim of your container. 

Harold


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## butcher (Oct 21, 2008)

And break those beaker rims


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## lazersteve (Oct 21, 2008)

I use long stem funnels in my filtering.

I sometimes place a 'booster seat' over the beaker that raises the funnel up out of the flask. This booster is made of a PVC coupling that changes from 3 1/2" OD to 1 1/4" OD. This fits conveniently over my beaker and raises the funnel up enough so the stem doesn't bottom out in the beaker. 

I also have a ring stand like Harold mentioned. The ring stand is definitely the proper way to go. The one problem I have with the ring stand is corrosion. The pole tends to rust and can allow foreign debris into your funnel if you are not careful. Keep it clean and away from harmful fumes.

Steve


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## viacin (Oct 21, 2008)

ty for the advice everyone. I really don't like broken glassware, or spilled acids. Just goes to show that when you think you've got it all figured out, you still have a lot to learn.  

But I was actually planning on using the cylinder to measure my sulfuric acid (and whatever else might need measuring in ml), not to do any processing in or anything. I could have converted it over to standard and used some measuring cups, but I'm picky about accuracy like that.

In the long term, I will invest in a ring (ever seen a plastic one? It should handle the vapors better). But for this weekend, my hand will suffice.

Ty for the warning.


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## Harold_V (Oct 22, 2008)

viacin said:


> In the long term, I will invest in a ring (ever seen a plastic one? It should handle the vapors better).



The rings come finished, so rusting is not a problem. I would imagine they now come powder coated. As long as you don't use them for heating, there's no reason for them to degrade. 

The one problem is the stand. The base of the one I used was finished with wrinkle paint, and held up fine, but the shank, which is ½" diameter steel, slowly degraded and was coated with a light covering of rust. You could minimize that problem by replacing it with a length of ½" diameter 304 or 316 stainless. It would be very slow to corrode, and would not yield problems. Truth be told, even the steel model will serve quite well. It is a distance from your filtered materials, thus you risk very little in the way of contamination. 

The nice thing about using this system is that your funnel won't tip over your receiving container. The risks are too great to not make a similar setup. It can be something as simple as a rod bolted to the counter top. It need not be a moveable stand. Consider mounting a rod on a piece of 3/4" countertop material (with the laminate included-----think a cutout for a sink), large enough to accommodate four 4,000 ml beakers, one every 90°. That way you could use the station for multiple filtrations. Drill and tap the end of the rod, then fasten it to the material with a flat head bolt from the bottom side of the base. Once you have located a functional spot on your counter, fasten the material to the countertop, so it can't tip. Simple and very effective. Buy a few rings and you're in like a tall dog. 

Buy a few Nalgene long stem funnels. 

Harold


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## viacin (Oct 22, 2008)

I thought about the stand this morning, and decided to get one. They're just so handy to have, plus it will allow me to use my huge ace glass funnel (10" tall, 7" top OD) for my filters like I originally planned. I got this one:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=190260539524&ssPageName=STRK:MEWN:IT&ih=009

6"x9" base, 24" rod with 3 rings (3",4",5"), and a 5" square gauze heating screen with ceramic center. Not too shabby I must say. It should hold every funnel I have bought so far. I basically got the rings, heating screen, and ceramic center for free. That's at least a $40 savings  I love ebay  I'm thinking about replacing the rod with 316 S.S.

Thanks for giving me the idea, because I really wanted to use my ace funnel, and now I can! I'm happy again


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## Harold_V (Oct 23, 2008)

That's called "using your head". 

You won't regret the decision. 

Be careful with your beakers around the cast iron base. They break easily. 

Mine was a three-legged affair. Worked fine, as will yours. 

Harold


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