When building lapidary equipment at home, or when modifying manufactured equipment, one of the largest problems which confronts any mechanic is how to feed water to grinding wheels which require cooling and lubrication to grind. This handy unit is easy and inexpensive to construct, and can be put together at minimum cost. Also, it is easily moved about, so that one unit will service many machines. A common household pump-sprayer normally used to spray pesticides is modified with some copper tubing and clear flex-hose, to direct a steady pressurized stream of water to any grinding operation. This unit even works at drill presses and hand grinding operations, as well as grinding wheels.
The first thing you will need to acquire is a plastic pump sprayer, and it pays to buy the best you can find, although any unit of decent construction will work fine, even used units. You will also need about two feet of rigid copper tubing whose outside diameter is the same as the inside diameter of the port at the top of the pump sprayer. This is the future water output of this tool, and the flex hose will connect to it, so make sure the copper fits tightly into the port in the pressure tank. When installing this, a little silicone caulk will lubricate a very tight fitting connection, then harden to further waterproof and glue it.
So the piece of copper tubing will be fit snugly through the hole at the top of the tank, after the entire original hose assembly is removed. The rigid tubing needs to be inserted deeply into the tank, to within an inch or two of the bottom, and about two inches or so needs to protrude outside the tank, at the top. This tubing is, of course, where the pressurized water will flow from. The fitting needs to be airtight, so the right sized copper tubing is a must.
Once the rigid copper tubing is inserted into the tank and is made fast, all that is required is a five or six foot length of clear plastic tubing to plug onto the copper tubing sticking out of the tanks top. Coupling nipples for this plastic tubing are readily available wherever the tubing is purchased, and most hardware stores, aquarium supply stores, or auto parts stores carry these parts. Use a coupling nipple to hook to the copper tubing at the top of the tank, and use another coupling at the far end of the plastic hose, to hook to a stop-cock type brass faucet, which can also be purchased at hardware stores, or an aquarium supply store. The plastic nipples fit tightly over copper tubing with just hand pressure. You may have to flare a small length of copper tubing and affix it to the input end of the brass faucet, in order to have something to hook this nipple to, but this is very simple and can be done for you at most auto parts stores or machine shops if you cannot accomplish it yourself. Again, a little silicone caulk may work wonders at this scenario.
On the output end of the mini-brass-faucet you can affix a hypodermic needle casing for a fine stream, or even leave the needle of the hypo intact, for a very fine stream. Be careful if you do that though as the needle is sharp and may rust over time. Your particular situation will dictate just how fine your water stream needs to be, and some experimenting will of course be necessary. It is always best to start with the smallest stream available, and modify from that point upward. You can make the stream larger easily enough, but making it smaller many times entails more work and materials.
The business end of your flex hose can be easily clamped in place with a tent clamp, clothes pin, or other clamping device, up to and including specially made units which are magnetic and are marketed for just such situations. You will necessarily evolve what is best for you, and its probable that you will use different clamping apparatus for different situations. Just be sure not to pinch your hose shut when clamping!
Now all that is needed is to pump the sprayer several times to build pressure within the tank.
The water stream itself can be easily adjusted by opening the stopcock faucet in various degrees, from nearly closed, to wide open. The wide degree of adjustability ensures you will have just enough water for all situations, and you will be hard pressed to find a more handy tool once this becomes a member of your workshop.
