DIY: Make your own flared gravel vacuum cylinder!
This is a Do It Yourself project that allows you to flare out the end of your gravel vacuum siphon very neatly so it no longer digs into your skin (ouch!). I just tried it after thinking about it for a long time and was pretty amazed at the results.
I think many of us have experimented with the gravel vacuum siphon like:
http://www.pets mart.com/global … D=1103272008319
These cylinders are cheap and effective. From my experience, I like the "Top Fin" brand because the cylinders are harder than some of the other brands I’ve seen. With Top Fin, you can’t squash the cylinder by squeezing it.
Unfortunately, I don’t have any pictures to put up so I will try to be as descriptive as possible.
The premise behind this project is to:
1. Heat up the tip of the cylinder
2. Using your hands, reshape the tip portion of the cylinder while it’s still hot (this is harder than it sounds) so it flares outward.
But you also want the flare to be neat and uniform. To achieve this, you need 2 "pipe clamps". Pipe clamps are these:
http://doityour … ore/6192884.htm
They are about a dollar each at home depot or automotive stores. Of course make sure to get the size that can completely wrap around your cylinder.
1. Screw on the first pipe clamp to the tip of the cylinder, but leave about 1/2 inch of the cylinder tip sticking out. This 1/2 inch portion is the part where you will "reshape" once heated. Make sure the clamp is nice and tight but don’t over do it and crack your cylinder ;-)
2. Screw on the second pipe clamp right above the first one. Make sure it’s as flush to the first one as possible. There is a reason why you need this second clamp. We’ll get into that later.
3. Bring about 1 inch of water to a boil in a small pot.
4. Stick the end of the cylinder into the pot, but do so at an angle so it’s not immersed uniformly. The idea is to heat only a small portion of the tip at a time. It’s OK to stick the first clamp into the water but be careful not to stick the second clamp into the water. If you do, this means your water level is too high.
5. Once this portion is heated (becomes malleable), take it out of the water quickly, then with a towel (so you won’t burn yourself), grab the tip with your thumb and fingers and try to bend out the heated portion outwards to create a flare against the first clamp. You only have a few seconds to do this before the plastic gets hard so do it quickly.
Now you see why we use the pipe clamp? The clamp ensures that you won’t bend further up than where you placed the clamp and also by the time you get all the way around the cylinder, it keeps the flare fairly uniform and straight.
Now repeat this process for the other portions of the tip. Be careful not to immerse the part you already flared out into the boiling water because this will bring it back to the original shape.
But why do we need a second clamp above the first one? Because if you noticed, the flaring action actually creates a taper right before where the flare begins. The taper means the circumference shrinks, so the pipe clamp gets a little loose. The second clamp prevents the first clamp from sliding up the cylinder. That’s why it’s important not to get the second clamp into the hot water because you don’t want that part of the cylinder to get all hot and malleable. You’ll notice that the first clamp is not tight anymore, so you’ll have to tighten it. The plastic at the tip is pretty soft so don’t over-tighten. Tighten just enough so that the clamp is not loose anymore. The clamp is HOT. Be careful!
You may have to do this a few times to get the flare out all around.
So far, you’ve managed to create a flare. But it may not be a pretty, uniform, perpendicular flare. So, we’ll have to readjust it a little.
Imagine what would happen if you did NOT have any flare and placed the cylinder into the pot with boiling water so it’s standing vertical, and you pushed down on it. The tip is soft but you’ll probably end up crushing the plastic into an ugly shape. But now you’ve created an all-around flare. It’s just not too uniform and doesn’t stick out completely perpendicular yet. But since you have the flare, imagine if you placed it vertically into the pot and pushed downwards. Now the flare will "flare out" more, neatly, uniformly, and perpendicularly! (BTW, the clamps are still on).
Be careful! Don’t press down too hard or you’ll end up disfiguring the tip!
Now, while you still have the cylinder pressed down, take the pot and cylinder to a sink, dump all the hot water out and immediately pour cold water. This will harden the cylinder and so it’ll retain the neat flare you just created.
Now we’re done! Well, almost… You can take the two clamps off at this point. But have you noticed something? There an indentation on the cylinder from a particular part of the clamp where the screw is. So let’s try to get rid of that. So, bring the water to a boil again. This time, the water level should be high enough so it’ll immerse the dent. Now quickly place the cylinder into the pot vertically and remember to apply downward pressure so you’ll retain the flare. Let the cylinder heat up. The heat should knock out most of the dent. Again, DON’T press down too hard or you’ll disfigure the tip. Now like earlier, take the cylinder and pot to the sink, while still applying downward pressure, dump hot water, replace with cold.
Now, you’re done. And your gravel vacuum siphon tube has a neat, uniform flare. Hope this works for you guys.
Last edited by manki : 12-17-2004 at .
