Introduction: Contactless Outdoor Handwashing Station for Less Than $50
UPDATED JULY 3, 2020 : Increased capacity by blocking overflow tube, fixed possible sources of leaks around valve, minimized waste with a PVC cap to slow outflow, changed PVC stirrup to lighter/cheaper PEX tubing.
A good friend of mine has been assisting some needy families during the COVID-19 pandemic. Recently, she asked me if I might be able to create a simple open project to help with hand washing and decontamination. The projects she'd been looking into were very large, and in excess of $300/ea and took hours to construct. She gave me an ideal price of $50, and challenged me to create a simple solution that could be assembled with minimal skill. Most of the expense of those larger systems (which are extremely robust solutions, just too expensive) involved pumping water with a manual foot pump. I decided that gravity could do that work, but needed a way to control flow. Then I realized that a toilet repair kit would be nearly ideal: Commodity, off-the-shelf, products available in nearly every hardware store - controls water flow cheaply, and requires a minimal amount of skill to install! One bucket (Bucket 1 : "White") acts like the tank in your toilet - it gets filled by the holding tank / water source (or you dump water in every few days). The second bucket (Bucket 2: "Red") holds to outgoing water and channels it to the outlet hose. I used different colored buckets in this instructable to make it easier to distinguish. The flapper is weighted, so only releases water when you depress the flushing stirrup with your foot.
For simplicity, this version is manual fill. My prototype requires another bucket to fill 4-5 gallons, which could get you 50-80 handwashings depending on how careful you are. In production, we'll use a manual transfer pump, and have the bucket sitting on a 55 gal drum... so once a week, you use the pump to refill it.
This bucket is my second iteration, but I believe good enough for deployment. See step "Alternate: Autofill" for a my previous version that includes a fill pipe (for $11 or so more for an actual toilet kit) that might be appropriate depending on your water situation. The autofill just added a lot of unnecessary complexity for our immediate needs.
This project, with all the parts on hand, took me about 35 minutes to build, and should last a few years at least.
NOTE ON THE "TOILET REPAIR KIT": I purchased the more expensive replacement kit because it includes the section where the flapper will seal with the hole in the bottom. You can probably get away with a cheaper kit, or just a flapper, but I was concerned about long-term stability and preferred a little more expense to make sure it would withstand some abuse.
- 2 X 5 gallon buckets (inner and outer) $4 ea. = $8.00
- 1 X bucket lid = $0.99
- 1 X Fluidmaster flush valve kit with 2" Flapper (K-507A-008) = $14.98
- 2 X 2.5 in Clothes line pulleys = $5.76
- 3 X ( 3/4 x 1/4in ) sheet metal / machine screws = $0.48
- 3 X 1/4in hex nuts = $0.21
- 1 X synthetic clothesline = $4.98
- 1 X iron corner bracket = $3.10
- 10+ X galvanized washers = $1.02 OR 4 X copper sleeve/couplings = $2.00
- 1 X pea gravel / aquarium stone= $3 (I had some in my yard to use)
- 4 in of rubber hose or aquarium tubing = $0.50
- 5 ft blue PEX tube (Sharkbite) = $1.98 (or get 1 ft cut for you for ~ $0.50)
- 2 in. threaded PVC cap = $2.55
- Silicone Tub and Tile Seal (100% Silicone) = $3.99
The Fluidmaster flush valve kit (or ones like it) can be found for as low as $9 online.
Bucket prices seem to vary wildly, but so far, smaller regional hardware stores seem to offer them fairly cheaply. Lowes, while low priced ($3.50) was out in my area, while Big R (Now Stock & Field) had them for around $4, Menard's for $2.50.
You may need to adjust the number of washers depending on the length of your flush cord or the flush stirrup.
Washers are sold by weight in my local hardware store.
The PVC tubes (or any plastic tube) should be as light/thin as possible.. doesn't need to be PVC, but should be rigid enough to get stepped on without bending much. These will be the stirrup/footpedal. I think the ones I chose might be too heavy.
If you can't find PVC/PEX tubing, look in the sprinkler section for a 6 inch "Cut-Off Riser", it has a texture that will help as a foot stirrup, and should only cost $0.80 or so.
It is recommended to add copper coins or pipe in the upper tank to help control mosquito larvae. Depending on the weight of your flusher you might be able to use copper pipe sleeves instead of washers, but I think the washers will be most effective as weights. Just adding a handful of pennies to the bottom of each tank should help.
- Dremel with cylindrical sander
- Carpet knife
- Screwdriver or Ratchet (depending on the bolts you choose)
- Power drill
- 3/4 in. paddle drill bit
- 1/8 in. drill bit
Step 1: Prepare the Valve
(ADDED JULY 3, 2020)
The step will ensure that the valve doesn't stay open too long (we'll also be adding some weights later), just letting water through when we step on the stirrup. The silicone will allow our bucket to hold up to 5 gallons of water. You may opt to use a rubber stopper instead, this is just fine. I had silicone.
- Remove any extra thick rubber gaskets and cardboard, most valves have some kind of "top" rubber gasket that should be kept, and some thick red or black gaskets that can be saved for another project.
- The valve has an overflow tube sticking up the top. Fill the bottom of this with silicone, or otherwise plug the tube. If you don't you'll only be able to use about 2 gallons of water in your bucket, as it will spill out the bottom
- Cut the bulb off your valve. We DON'T WANT it to float. We just want it to seal, so be careful to only cut the bulb and not any of the surrounding rubber that will form our seal.
Step 2: Inner Bucket (White) - Water Reservoir / Flushing
The Inner Bucket works like the tank in your toilet - holding water until it is needed. The flush mechanism will control outlet (more on controlling that outlet in a later step).
- Mark out the hole based on the size of your flush valve thread pipe. be precise, but we're looking for the outer edge.
- Use the paddle drill bit to drill out the main part of the hole.
- Trim the excess with a carpet knife
- Dremel around in a circle, slowly widening the hole and testing your valve pipe for fit
- There should be a little space around the thread, as the valve's seal is shaped to fill this space, so even an inexact hole is ok.
- The gasket should fit flush to the surface.
- Install the valve from the inside of the bucket
- Add a bead of silicone around the valve base to ensure a good seal. This is optional, but recommended - we've noticed leaks if this step is skipped.
- Use the included valve seal screw from the outside to seal. Hand tighten so it won't leak.
- Drill 1/8 inch hole in a 2 inch PVC cap. This will limit how much water is used when the valve flushes, making about 1 cup per use, which will give around 16 uses per gallon... up to 80 per 5 gallons.
- Mount the cap on the base of the valve. if your bucket won't flush (the cap is pressed to the bottom), place a bead of silicone on part of the face to create a spacer/buffer.
- If the outflow is too restricted, use a slightly larger drill bit 3/16 in. and test again.
Step 3: Outer Bucket (Red) - Counter Weight / Outlet
The red bucket gives our handwashing station a flat base, a place to install the outlet "spigot" and is filled with rock to provide some weight so it won't tip over when the water level is low. This rock will also take up some space so we don't have a lot of excess water sitting in the bottom section.
- Hold the outer bucket up to the light to find the bottom edge
- Mark hole placement
- Choose a drill bit slightly smaller than the hose you want to use
- Drill hole and insert hose
- (optional) Use a little silicone to seal around the hole. my tube is fairly flexible and makes a reasonable seal.
- Fill the bottom 1-2 in with river rock / pea gravel / aquarium rock (careful not to block or crimp your tube).
- you may need to make a little room for the PVC cap.
I probably should have used more, but wanted to show you some rocks in the bottom for completeness.
Step 4: Flushing Mechanism (Pulley System)
The flushing mechanism provides a better angle and stand-off for the flushing cord. this prevents wearing out the plastic and reduces friction. The mechanism is made from two clothesline pulleys and an angled piece of metal.
- Place the angle bracket inside the bucket, with one arm sticking out over the lip
- Mark the location of the holes
- Drill through the two marked holes
- You may need to drill through on the other side, as it may have contacted the threads
- Insert the bottom bolt so the thread is pointing INTO the bucket (or they won't nest properly)
- Tighten the bottom bolt with a hex nut. Add a dab of silicone if you worry about it moving
- Thread the top bolt through the bucket and bracket (direction unimportant), and continue through one of the pulleys.
- Tighten the top bolt with a hex nut.
- Attach the other pulley to the bracket with the last nut/bolt
Step 5: Flushing Mechanism (Cord, Weight, Stirrup)
- Cut your tube(s) into two 3 in. pieces and one 6 inch piece.
- run one end of your cord through the tubes (Short / Long / Short)
- Tie a knot after tightening, this will form the stirrup- you may need longer pieces for larger feet. You can also use a single piece about 6 inches wide if you have two longer strings coming up.
- Measure cord to your expected height ( Water barrel + (washing station X 2)) as the stirrup should rest about 3-5 inches above the ground, go up through the pulleys, and down to the flush chain. Add about a foot to give you room to work.
- Cut cord
- Drill a hole in the lid with your 3/4 in. paddle drill about 4 inches from the edge (directly above the flapper)
- Cut a notch 1 inch wide and 2.5 inches deep pointing at this hole, this will provide room for the pulleys.
- Thread the free end of your flusher cord over the pulleys and through the hole in the lid
- Add a number of weights (washers OR copper sleeves) to the flapper chain. The weight should rest directly on the flapper. looping the wire through again may also help prevent weights from sliding off.
- Tie the cord to the flapper chain hook with a fisherman's knot
Here's Video of the finished mechanism (without lid) in action:
Step 6: Done!
The completed handwashing station must be manually refilled, or you can sit it on a rain or water barrel and add a manual transfer pump (ULINE has them for $15). You may need to experiment with the amount of weight required to prevent full flushing, as we count on those weights to force the flapper back down to reseal when the foot stirrup is released.
(Note the stirrup here is the heavier PVC that was replaced by blue PEX)
Also, our labcat Kelda, because the Internet demands such things.
Step 7: Alternate: Autofill
You can purchase a complete kit with refill valves for around $25, and do a similar installation to add a refill tube ($7) shown in the images. I'm not satisfied with the hole/silicone, so you may consider getting the proper connectors and making a tube that can pass through the wall of the PVC - this was just my original proof on concept, and is included for completeness. The fill hose could be connected to a raised tank or traditional plumping source.
Step 8: FAQ
Why not just use a "Tippy Tap"?
(A tippy tap is a jug, pedal, and string arrangement that tips the jug or pail when you want to wash your hands)
The tippy tap is great, but the lid/refill capability provides a lot of contact opportunities for people to get sick, especially if used by a number of families. Additionally, many (buckets) don't have reliable covers.
Our goal was to remove much the contact required by the tippy tap for multiple families to use the system with a large (55 gal) barrel and transfer pump not pictured. With a transfer pump or gravity feed (see the alternate version), you can have hundreds or thousands of washes without contact with the water in the drum, only the transfer handle (followed by a handwash)
Additionally, a tippy tap would need a structure to be built (wood frame, bars, buckets). If you were to deploy 1000 (one of the goals of this project), you'd still need to build *something* to standardize the deployed project - you'd probably be designing a wooden or similar frame that could be dropped in place, and you'd have a comparable cost and time of assembly. It might be a good idea to build them in the long run, as a multiple-decade-durable solution (with metal buckets), but that raises a lot of costs as well. We've added this idea to our phased implementation roadmap.