mikeinkaty said:
When siphoning liquids from one container to another using clear plastic tubing I find it helpful to use wooden clothes pins to secure the tubing to each container. This helps hold the tubing in place while getting everything ready preventing it from flopping out and scattering fluid everywhere. The clothes pins will hold the tubing in place but are not strong enough to pinch the tubing shut.
I've done this mostly moving beer mast around but it would also apply (maybe more so) to moving acids around.
(i've been watching Lazersteves video's all night!)
Mike
I'm a rabid siphoner. It's so much easier than filtering to let the solids settle and then siphon off the solution. Sometimes, I siphon 20 or 30 times in a day. Here's some things I've learned over the years from siphoning many thousands of times.
I prefer to use only a length of vinyl tubing with no siphon pump. I've found that siphon pumps just complicate things and, if you're not careful, they can stir up the solids while pumping them to get them primed. I have used spring clamps (similar to using clothespins) or small C-clamps to secure the tubing when siphoning from a drum but, here again, for the smaller stuff, I think they complicate things and can reduce the amount of solution that can be siphoned off. Generally, I prefer clear tubing without nylon threads in it because it is more flexible. The exception is when siphoning hot or warm solutions (which I rarely do). With warm or hot solutions, the plain tubing will tend to collapse more and this can slow down or stop the flow.
The tubing size is important to me and I use different sizes based on the amount of solution I'm siphoning. For small amounts, a liter or two, I use 3/16" ID tubing. For buckets, I use 5/16" and, for drums, about 3/4". The object of siphoning is to remove as much solution as possible without disturbing the settled solids. For this, I find a slower siphon, while continually adjusting the tubing depth, is better than a fast siphon. Using 5/16" tubing, it will take about 5 minutes, or so, to drain a 5 gallon bucket. A 3/8" tubing is faster but, in a bucket, it makes it harder to prevent sucking up solids when you get near the bottom.
The main problem I've found with vinyl tubing from the hardware store is that it is rolled on spools and this creates a permanent curl in the tubing. If you try to siphon with curled tubing, you will continually have to fight it. If you can straighten it permanently (I've tried everything), it is much easier to use and is much less likely to jump out of the lower container. I recently discovered how to do it. To take out the curl, I first cut off the length I need (about 4' for buckets, as I describe it below) and tie a string (I use butcher's string) tightly to each end of the tubing. I put a loop in each string - the top loop is to hang the tubing on a nail and the bottom loop is to hang a weight. I find that a claw hammer makes a convenient weight. I put some water in a pot on the stove and curl the tubing in the water until it is all submerged. I manipulate the tubing until it is mostly filled with water and slightly drape one of the strings over the top of the pot so it is easier to remove the tubing. I heat the water slowly until the tubing appears milky colored. Don't get the water too hot - I would guess about 150-160F. I then remove it, drain it, and quickly hang it on the nail while it is still hot and hang the hammer on the other end. The nail must be high enough so that the tubing hangs straight. I let it cool for an hour or so and remove the strings. There is usually a kink where the strings were tied and I cut off the tubing a little below each kink. The milkiness in the tubing disappears after it cools.
In siphoning, there's always a top container and a bottom container. The greater the distance between the two, the faster the siphoning. For my height (5'9"), I prefer the tabletop to be about 36" off the floor. I place a plastic tray on the floor and put the catch bucket in it. I'm right-handed, so I stand to the right of the containers.
No matter what size container I'm siphoning from, I first stir the solution well and then put something underneath the back of the container, in order to make it tilt towards me. I use about a 6" piece of 2"x4" for buckets. The front edge of the bucket should be near the front edge of the bench. That way, I can see into the container better and, when the solids are allowed enough time to settle well, they will settle in a pile at the front edge of the container, rather than settling over the entire bottom. I've found that I can remove more solution, that way, without disturbing the solids.
As a visual aide, I use a red magic marker to mark about 1"-1.5" of the top end of the tubing - instead of solid red, I make a series of horizontal stripes all around the tubing. The markings, especially with dark colored solutions, will prevent me from withdrawing the tubing out of the solution and losing the siphon. The red will fade and occasionally must be redone.
I place a good strong light a couple of feet above the top container so I can see down in the solution.. Those cheap aluminum work lights with a squeeze clamp work well.
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Since most of my siphoning is done in buckets, I'll explain how I do that.
To siphon, I stand on the right side of the containers and hold the two ends evenly together with my left hand, allowing the rest of the tubing to hang down in a loop. I fill the tubing brim full of water with a lab-type squirt bottle, making sure there are no air bubbles in the tubing. For larger tubing, I hold the two ends under a sink faucet. However, this will only work if there is no aerator on the faucet. An aerator will produce many air pockets in the tubing.
I use my left index finger to seal the tubing end on the left and grab the right end with my right hand about 2"-3" from the end of the tip. The right end doesn't need to be sealed if it's always kept a little higher than the sealed left end. I lower my left hand to the bottom bucket, still sealing the end. I plunge the right end into the solution in the top container a couple of inches and, only a fraction of a second later, release the left end of the tubing into the bottom bucket.
I then lean the tubing in the top bucket away from me a little bit and place the tip of the tubing against the front of the bucket. I continually watch the tubing in the solution and, as it siphons, I continually slide the tip down the front inside of the bucket. The red tip of the tubing helps me to control the depth and keep it submerged. I hold the tubing in my right hand during the entire siphoning process. To steady my right hand, I rest it on the bucket rim, about where my wrist starts (of course, I clean off the rim before starting, to keep any acid from burning my wrist - been there, done that).
When it gets near the bottom, I grab the top of the back of the bucket with my left hand and tilt the bucket towards me a little bit more. I do this very slowly and steadily to keep the solids from shifting. If I have someone working with me, I often have them carefully slip a second 2"x4" under the back of the bucket while I tilt it. That steadies it better than trying to keep it tilted by hand. By tilting the bucket more, I can remove a little more solution at the end. Even if the solution is dark, the color will thin out at the end and you'll usually be able to see the solids and the tubing. Keep your eye constantly on the tip of the tubing and pull it out quickly (or raise it a bit) if any particles start to move towards the tip.
If you're left-handed, stand on the left side of the containers and do everything oppositely.
For a good feel, I would suggest using thin surgeon type gloves to do this. I usually use no gloves when siphoning but I'm not going to recommend that.
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Sometimes, the fines won't all completely settle as fast as we want. After mostly settling, this can still be siphoned and then the siphoned solution can either be filtered or set aside in a bucket for a few days and then be siphoned again. Even if you filter it, it will go faster than it would if you had tried to filter the whole thing to start with, without any settling and siphoning.
I also start with water in the tubing when siphoning the sulfuric stripper solution. There's a slight sizzle when the sulfuric and the water combine, but it doesn't last for even a second. There's a little dilution but not enough to make any difference. If you try this, expect the sizzle and don't jump when you hear it. I do use heavy rubber, cloth lined gloves, when siphoning sulfuric, even if they are cumbersome and I hate using them.
Sorry I got carried away with this. I kept thinking of more things. Let me know if I've confused you. It's really very simple and I've surely complicated it. The time involved before it starts siphoning is about 2 minutes. Making a video on this is one of the things on my (bucket - no pun intended) list. The main things are to keep a constant eye on the the tubing in the solution and learn how to control the depth by sliding the tip down along the inside of the bucket with your right hand. Practice a few times with water and sand.
