Rain Barrel Connections
The Best Method
Determining the best technique to achieve leak-free rain barrel connections can be a difficult task. I know, as I’ve tried them all. When I refer to “rain barrel connections”, I’m talking about those fittings that connect your garden hose to your rain barrel...those fittings that are used to connect rain barrels to each other, to route the stored rainwater to those areas for irrigation, and to route excess rainwater when the barrel is full. After much investigation and experimentation, I’ve determined that the various methods are appropriate for two situations: (1) for various types of rain barrels, and (2) for the various skill levels of the person “constructing” the rain barrel. Let’s now discuss the various techniques you can use for leak-free rain barrel connections:
Lock Washer technique
This is the easiest technique to utilize, and can only be used for open-head rain barrels – because you have to reach inside the barrel. With this technique, you insert a threaded adaptor into a pre-drilled hole. The hole should be drilled small enough to require some screwing in of the adaptor, but the tightness of the hole does not determine if the barrel will be leak–free. To achieve that task requires a rubber washer. The adaptor should be secured with a rubber washer on the outside of the barrel and a “nut” on the inside. It’s important to apply the washer on the outside of the barrel. Otherwise the barrel will still leak, as the water will travel around the threads. The use of Teflon/plumbers tape around the threads and a bead of silicon caulking or epoxy glue around the outside of the opening will ensure an even tighter seal.
This method is the most difficult to perform, but it’s the only method that can be utilized for rain barrel connections with closed-head rain barrels. With this method, and the other two methods, you can drill your hole with either a Forstner or Spade bit. The nature of the Forstner bit makes it a bit difficult to move the bit through plastic or wood. For this reason, there's a certain technique to using a Forstner bit on plastic to prevent it from binding. You have to pre-drill a small starter hole and wiggle the Forstner bit from side to side as you drill. With a Spade bit, you need to press down hard right at the end as it may buck as it breaks through, chewing an extra chunk out of the edge of your nice neat hole. You might also try stopping just before it breaks through and pushing the rest out with a screwdriver. In any case, keep both drill bits perpendicular to the surface of the rain barrel, so the adaptor
washer will seal properly. Although both drill bits are a bit tricky, I prefer to use a spade bit, since it’s a little easier to use. With this method, the hold you drill should be the correct size for the use of a pipe tap. You can obtain the proper size pipe tab from your local hardware store – to match the fittings for your rain barrel connections. Before working on your rainbarrel, you may want to practice threading a few holes with the pipe tap. This technique will create the tightest fit with your adaptor. Also, it's important to keep the tap exactly lined up with the direction of the hole (i.e. also at a right angle to the surface). If your threads are at an angle, your fittings will not screw in snugly and are more likely to leak. You may want to use two crescent wrenches pointing opposite to each other, to turn the pipe tap without pushing it out of line.
A variation of this method is to screw an adaptor into a pre-drilled hole, without any lock-nut or washer – without using a pipe tap. Then, to solidly secure the adaptor to the barrel, and to prevent leaking for your, just apply a bead of epoxy glue/putty around the seam where the rain barrel meets the adaptor fitting.
Many rain barrel connections, some older than three years old, have gone through freezing temperatures, and still have had no leaks. However, if you can't get a pipe tap or just prefer not to do it, and you don’t want to use the Lock-Washer technique described above, you can use the Bulkhead Fitting method described below – as long as you have an open-head rain barrel.
Bulkhead Fitting technique
This technique for establishing leak-free rain barrel connections is very effective and very easy, but can only be used for open-head barrels. This alternate technique doesn't need threaded holes, or extensive washer / lock-nut / caulking and/or gluing procedures. Instead of the threading technique described above, you can use a ½ or ¾ inch bulkhead fittings to be found at most local pond equipment stores.