Introduction: High Capacity Easy Use Soap Dispenser Tank

Hi, in this instructable I will be showing you how to make a large, easily refillable, and leak proof tank for the type of countertop soap dispenser shown in the second image.

My entire family had been frustrated about the soap dispenser in the kitchen for years. First there was the tiny size of the stock soap tank (something like 12 oz), which required you to crawl under the counter, reach behind the sink to unscrew it, and then spill soap everywhere trying to pour it from a gallon jug through the small opening in the top of the tank about once a week because it ran out so fast. Later, after we switched to the plug and hose shown in the second image next to the dispenser, which is supposed to be inserted into the top of a gallon jug of soap, we experienced even more problems. The connection between the top of the hose and the dispenser was poor, causing it not only to leak soap, but also for air to get in and allow the hose to drain of soap, making you have to pump the dispenser 30 times every time you needed some. The connection to the gallon jug was also rather poor, the hose would often fall out of the tank and leak soap all over the inside of the cabinet. And to top it all off, there was no reliable way to keep the hose at the bottom of the gallon jug, so it would drift to the top and suck in air instead of soap every other time you used it.

Finally my Mom came into the kitchen one day, attempted (and failed) to get soap out of the dispenser, turned to me, and said something along the lines of "TJ, I have two jobs for you. I want you to fix this soap dispenser, I don't care how you do it, just fix it." She also told me to fix a defective door handle on her car, but that's a different instructable. I took a look under the counter and immediately decided that the current system was so bad that it was not worth even trying to fix, and so I set out designing a new one. What I came up with was a PVC cylinder with a removable cap which used brass nipples to make leak proof connections to the tank. I also added a rigid pipe to force the pump to draw soap from the bottom of the cylinder.

I apologize in advance for the rather poor visual documentation in this instructable; I didn't think to take pictures until after I finished the project.

Step 1: Parts List

Here's what you'll need:

I have included pictures of the fittings.

  • 1 - 24" length of 4" ABS pipe (ABS is black, PVC is white)
  • 1 - 4" ABS female threaded-unthreaded adapter
  • 1 - 4" ABS cleanout plug
  • 1 - 4" ABS cap
  • 1 - 24" length of 1/2" PVC pipe
  • 1 - 1/4" FIP Brass pipe coupling (female at both ends)
  • 2 - 1/4" ID x 1/4" MIP Brass hose barb (male at one end, barbed on the other end)
  • About 7 feet of clear vinyl tubing, chose whatever size will just barely fit into the bottom of your soap pump (you want it big enough that you have to use brute force to get it into the pump, it should not slide in easily). Make sure it will also fit onto your brass barb.
  • PVC cement
  • A drill with large diameter drill bits (auger bits work fine)
  • A saw, preferably a hand saw or a variable speed jigsaw or sawzall with a low TPI (tooth per inch) blade. I will explain why this is important later. If you don't have a low TPI saw blade, don't worry, it will still work.
  • A sharp knife
  • A tape measure
  • Spanner set (or adjustable spanner, or, if you don't have either of those, you can make do with a couple pairs of pliers (but if you don't have a spanner set, you should go buy one, it's one of those tools that everyone should have)
  • A soap dispenser (you probably already have one if you're reading this)

Step 2: Gathering Data

We want your soap reservoir to hold as much soap as possible, and because 4" pipe is the largest that is readily available, the only way to go is up. Keeping that in mind, we need to figure out the maximum height of your cylinder to still have it fit in the space under your sink. To do this, crawl under your sink and use your tape measure to measure the height of the space in one corner of the space under the sink. You want to put it in a rear corner so that it doesn't get in the way or get knocked over when you need to go under there to access cleaning supplies or whatever you store under your sink (I must point out, however, that knocking over your soap container will not be nearly as big a catastrophe as you think it would be, knocking it over will not spill soap everywhere, it will simply cause the dispenser to stop working once the container gets less than half full, and might cause a tiny amount of soap to leak out if you don't bother to return it to the upright position). Once you have measured the space under your sink, it's time to get building!

Step 3: Build the Cylinder

First, use your saw to cut your piece of 4" ABS pipe down to 4" less than the height of the space you measured in step 2 (if you measured 23", cut it to 19"). If the height of the space under your counter is more than 28", you do not need to bother cutting your pipe at all (a cylinder 24" tall will hold more than a gallon of soap). If you are using a power saw, limit the speed of the cut so that you do not melt the pipe. The lower the TPI of the sawblade, the faster you can cut without melting the plastic. If you do begin to melt the plastic, stop cutting immediately and wait 30 seconds for the plastic to cool off before you resume cutting. If you do not wait, the melted pipe will not only stick to your sawblade like glue and make it hard to cut, but it will also release toxic fumes if it gets too hot. You don't want that. If you are using a high TPI blade, cut in short bursts of a few seconds of cutting, followed by a few seconds of letting the pipe cool off.

After you have cut your pipe to the correct size, run your knife around the inner and outer edges of your cut to remove all the little shreds of plastic hanging off it (these shreds, if left in place, not only look ugly, but can fall off and be sucked up into your soap dispenser and clog it. Now use PVC cement to glue the end cap to one end of your pipe, and the female threaded-unthreaded adapter to the other end. Refer to the picture if you have questions. Make sure to firmly press the pieces together to ensure a good seal. After you are finished gluing, wipe off any drips of cement with a paper towel or rag (make sure it does not get on anything you care about, like your shirt sleeve, PVC cement does not come out in the washing machine).

Let the pipe sit and dry for a while. In the meantime, we can work on the rest of the build.

Step 4: Build the Cylinder Cap

Now it's time to build the top of the cylinder. First, grab one of your brass barbs and select a drill bit with a slightly smaller diameter than the brass barb. Now you want to drill a hole in the center of your cleanout plug. After you have drilled the hole, attempt to screw one of the brass barbs into the hole from the top of the plug. If your hole is too small, you will not be able to get the threads to start screwing in, and you will need to go up one size drill bit and enlarge the hole until the brass barb can be threaded into it. Once you get the thread to bite into the plastic, use your spanner (or pliers if you do not have an extensive tool kit) to screw the barb in as far as it will go. It will be extremely difficult to screw in all the way, this is normal and is because you are using the barb to cut threads into a hole which does not have any. If you have a C clamp, you can clamp your cleanout plug to an immovable surface to make it easier. Another way to make it easier if you are having trouble screwing the brass barb all the way in is to slide a piece of pipe over the end of your spanner to give it a longer handle so you can apply more torque. A third way, if you have 2 C clamps, is to use both of them to firmly secure the plug to a table or counter, and then take your drill and lock the barb into the drill in the same way as you would a drill bit, and use the drill to screw in the barb. Once you get the barb screwed in all the way, flip the plug over and screw the female-female adapter into the threads of the barb, which will be sticking out the other side of the plug. Once you have done that, screw the second brass barb into the remaining end of the female-female adapter. Make sure all connections are very tight.

Step 5: Build the Soap Intake Tube

Remember how I mentioned that one of the problems with the original dispenser was that the tube would float to the top and suck up air instead of soap? Well, we are going to make sure that doesn't happen with ours. Get your piece of 1/2" PVC pipe and place it inside your cylinder (the PVC cement should be dry enough for you to pick up the cylinder now). Mark the pipe where it is level with the top of the cylinder, and then make a mark 1 1/2" below that. Cut the pipe at the second mark. As before, use your knife to trim off any shreds of PVC. Now, cut 6 slits into one end of the pipe as shown in the picture. The slits should go down about 1". This will allow you to simply push the PVC pipe onto the brass barb and have it stay in place, forming a vertical tube which forces the pump to draw soap from the bottom of the cylinder.

Next, cut a piece of vinyl tubing that is 1-2" longer than the piece of PVC you just cut. Insert the brass barb on the bottom of the cap into the piece of vinyl tubing. Now insert the end of the tubing into the end of the 1/2" PVC pipe (insert it into the end which has the slits in it) and thread it all the way through (there should be about 2" sticking out, if there is more, cut the extra off, if there is less, don't worry about it). Push the end of the pipe over the brass barb so that it stays in place.

Now, cut another piece of vinyl tubing, this time about 5 feet long. Insert one end into the bottom of the soap dispenser head (you may have to cut the end of the tube so that it tapers inward to make it easier to force into the dispenser). Next, thread the tube through the hole in your counter and pull it out through the door to the space. Now insert the brass barb on the top of the cap into the tube and place your dispenser head back into it's hole in the counter.

Step 6: Finished!

Now all you have to do is fill it with soap (which is very easy and spill-free because the opening in the top is 4" across), screw the top on, stick it under your counter, and repeatedly depress the pump until soap comes out (you may have to push on it 40 or 50 times to prime it before soap comes out the first time, after that, soap will be dispensed on the first depression).

When you run out of soap (which will probably take 4-6 months), just take the cylinder out from under the counter (the tube is long enough that you do not have to detach it to remove the cylinder), unscrew the top, and pour in another gallon of soap.

Now revel in the knowledge that you will no longer have to crawl under the counter every week to refill the soap, nor will you have to clean up massive soap spills or deal with the frustration of having to press the soap dispenser 30 times to get soap to come out of it.