If you have an underground sprinkler system, you have likely had the experience of having to replace some of the sprinkler heads from time to time either due to lawnmower damage or perhaps just the ravages of time on a piece of plastic that is exposed to the elements year round.
Often these cracked or broken sprinkler heads announce themselves with a ten foot tall plume of water or a neighbor calling you with the good news. In our yard the broken head is usually buried in ground that would challenge a jackhammer, so I always hope that just the cap of the head is the only part damaged and I can simply unscrew that part and replace it. But more often than not, the head itself is also cracked. Trying to remove it with some vise grips or other tool frequently just destroys the plastic head piecemeal. Thus, in order to get a grip on the head down in a more solid, or unbroken, part with some large Channellock pliers, it generally requires digging around the entire unit.
A few years ago, I saw a fellow on late-night TV advertising a fairly large contraption for removing sprinkler heads without digging. The apparatus looked complicated and it was not cheap- at least for something that you might use once or twice a year. Since I have never seen anything mechanical that I did not think I could improve upon (at least a little bit), I decided to build a better or, in this case, simpler mousetrap.
Most brands of sprinkler heads share something in common. They have one or more plastic splines on the internal cavity which permits you to adjust the direction of spray made by the riser (see photos). These splines are very helpful because they allowed me to fashion a simple (and inexpensive) tool that would fit between the splines and snugly into the broken sprinkler head while it was still embedded in the ground. Then I could use a screwdriver to screw the head out of its fitting on the water line without benefit of a shovel or trowel.
Step 1: How It Works
1. I use a large pair of Channellock pliers to remove the sprinkler head cap and riser to expose the cavity and the splines. I then insert the appropriate sized removal tool as far down into the head as it will go just by pushing with my bare hand. I don't use too much force, nor do I hit it with another tool. I want to keep the sprinkler head as intact as possible so that it will come out of the ground easily. I insert the tool so that the end with the hole is protruding from the head.
2. Next I insert a screwdriver into the hole in the tool and twist it in a counterclockwise fashion. I back the sprinkler head out slowly, here again, to reduce the possibility of doing any more damage. Most often the head brings with it the nipple that connects it to the T-fitting on the water pipe.
3. At this point I use a flashlight to inspect the hole in the ground and see if any dirt has gotten into the T-fitting in the water line. If it is minimal, I just take a small wire “bottle brush” and clean out the threads in the connector. If a lot of dirt has caved into the connector, then I turn on the water valve to that line and flush out the dirt. This leaves some water in the hole but that will not affect our re-insertion of the new head. If I have not disturbed the integrity of the hole in general, when I put the new head into it, the nipple will be guided to the T-fitting and be ready to screw in.
4. Normally if the old nipple is in good condition, I remove it, clean it off, and attach it to the replacement sprinkler head before inserting the removal tool into the splines of the new head. When I insert the new head into the ground, I use the screwdriver to twist the head back onto the T-fitting in the water pipe.
5. And finally, I re-insert the riser, adjust the nozzle to make sure that it is pointing in the proper direction, and screw the cap onto the head.
Step 2: Tool Description
In my own sprinkler system I have two different sizes of sprinkler heads: the Rainbird Sure Pop series and the Rainbird 1800 Series. I found the Sure Pop heads needed a 1.308 inch width tool and the 1800 Series needed a 1.43 inch size. You may need to make your own removal tool a different width depending on the ID (or internal diameter) of the sprinkler heads you employ in your irrigation system.
I made a blade that would insert into the sprinkler head with a fairly tight fit. This simple tool was easy to make, but it did require a little bit of trial and error to realize that if it fit too loosely into the head, it would break off the splines or simply not get a good purchase. On the other hand, if the blade was too wide, I could not insert it into the cavity of the sprinkler head. Therefore, the only critical element of the tool was making its width relatively precise.
Step 3: Making a Sprinkler Head Removal Tool
1. Use either some 3/32 or 1/8 inch thick aluminum sheet. It will need to be at least 4 inches long and the width will be determined by the sprinkler heads that you have in your system- or approximately a 2 x 4 inch piece. If there is an old-fashioned hardware store or a Metal Super Market near you, there are usually small remnant pieces of aluminum sheet in their "drop bin" and they will often either just give you one or charge you some small nominal fee. An alternative is to go to Home Depot and buy a 1/8 x 1 1/2 x 36 inch length of flat aluminum bar for $8.47.
In truth, this tool does not have to be made from aluminum. It is just easier to work with- and will not rust. You could make this blade out of steel or some other material.
2. With the cap off the sprinkler head, you can use either a finely graduated ruler or a digital caliper to measure the ID (or internal diameter) of the head, as pictured in photo in Step 2.
3. On a suitable piece of aluminum, use a Sharpie to mark the outline of the tool. If you have a scratch awl or an ice pick, you can mark out the more critical dimension, i.e., the width of the tool. Although I made my removal tools in my small machine shop, you can fashion these devices in your garage workshop with some fairly simple equipment.
4. Cut out the tool with either a band saw or a hacksaw. Make sure that you leave about a 1/8 inch margin on the width dimension- that is to say, make your cut about 1/8 inch OUTSIDE the line you have drawn. In my situation, I then used a milling machine to refine the width dimension to ~1.43 inch for the tool intended for the Rainbird 1800 series heads. If you are still over 1.43 inches, the blade probably will not go into the head. If you are a few 1/100's of an inch below your target number, it likely will not make much difference.
Alternately, you can use either a grinder or a mill file (with the unfinished tool mounted in a vise with the tool's lateral edge turned upward). If you are using either of these methods, measure your tool's width ever so often with a caliper OR by simply pushing it into a sprinkler head to see if it will insert easily with a “snug fit.”
Step 4: Making a Sprinkler Head Removal Tool (Continued)
5. Use either a drill press or an electric hand drill to bore a 3/8 inch diameter hole that is horizontally centered in the blade and ½ inch from the top. (See photo)
6. Use either a belt sander or a mill file to burnish the sharp edges on the blade and, likewise, to put a small radius on (round off) all four corners of the tool to make it more user friendly to your hands.
7. It is probably better to make a couple of extra tools now while you have everything at hand. Once your neighbors see this device in action, they will want one for their tool box.