Introduction: Grain Silo Bird Feeder
I saw this funnel and I was inspired to make an awesome bird feeder out of it. I wanted it to look like something my grandparents would have bought at the feed store in the 1930's. With a little searching, I was able to find the rest of what I needed to complete it with the look I envisioned. This is an easy to build project from ready-made parts that can be sourced at most home or hardware stores. It can be completed in an hour or two with simple tools. I like the farm store/industrial/grain silo look and I know that it will look good for lot longer than most feeders you can buy.
Step 1: Tools
The Tools you will need are as follows.
step drill bit or a set of drill bits 1/16" to 3/16"
flexible measuring tape
dull side cutting pliers
grinder with cut off blade (not sawzall as pictured, more on this later)
tubing cutter (optional)
Step 2: Materials
Here are the materials you will need.
big metal funnel (tractor supply has these)
8x6 duct reducer (any home store should have these)
pie plate from the thrift store (it should be of smaller diameter than the funnel so water won't drip in)
1 3/8" fence cap (you might have to get this at a fencing store, the home stores don't carry it)
1/4" copper tubing 6"-8" long
1/16" cable (old bicycle brake cable will work)
small fender washers
3/16" x 1/8" rivets (aluminum)
metal plumbing tape (pre-punched holes means no drilling or measuring)
Step 3: Fitting the Cap
First we need to cut the end of the funnel off so that the cap will fit. It also makes the opening bigger so that it is easier to fill the feeder with birdseed.
An easy way to transfer the diameter of the cap to the funnel is to make a template out of card stock. After you have traced the circle make sure to draw the actual cut line about 1/4" to 3/8" higher so there will be something sitting inside the cap.
Cutting with a sawzall was not the best way to do this. It jumped around and shook and made a pretty uneven cut. I have used a grinder with a cutoff wheel on something like this before and would recommend it as a much better method. A hacksaw might work if that's what you have.
Step 4: Drill the Holes for the Hanging Cables
Using the center punch, mark two points where you want to drill holes for the cables that will suspend your feeder. Look inside before doing this to avoid drilling through the thick part of the funnel neck. Now drill with a bit slightly bigger than the cable.
Step 5: Make the Cable Spreader
This is the part that keeps the cables separated so they don't hit the top of the feeder. Cut the tubing long enough so that when it is bent to the desired width, the ends will point straight down. Six to eight inches is about right. I used a tubing cutter and a reamer but a hacksaw would work. Next bend it around a round object that is the size you need. I used the front of my drill.
Step 6: Install Hanging Cable
Pass the cable through the cable separator. Push the cable end into the funnel. Put a washer and a ferrule on it. Crimp the ferrule with a pair of cutters, the duller the better, you don't want to cut, you want to smash. Do this on both sides.
Step 7: Divide by Three
Unfortunately, there will be math on this project. Measure around the duct, divide by three. Whew, I'm glad that's over. I used the metric side of the tape to make it easier. Mark the three points with a sharpie. Use the square to mark 3/4" down from the top to keep things even. Now use a square to transfer the measurement to the bottom of the duct so you don't have to do math again!
Step 8: Prepare the Straps
Plumbers tape breaks with a little back and forth bending. Bend a piece that has three small holes. Break it off and repeat. You'll need six pieces the same size. If the rivets are a little bit too big for the holes, ream them so they fit.
Step 9: Punch, Drill, Rivet
Center punch the three marks at the top of the duct. Using the step bit, drill to 3/16". It's pretty easy to drill too far in sheet metal and make a hole bigger than you wanted, so when it starts to go through the metal, stop pushing. For some reason the 3/16" rivets didn't fit in the 3/16" hole I drilled so a half twist with the reamer made it work. Now pop those straps on.
Step 10: Center and Mark the Top
For this step it's helpful to put the funnel in a can, bucket or flower pot to hold it while you work. Use a square to center the duct on the funnel. The trick is to keep adjusting until it's the same measurement all the way around. When it looks like it's centered, make some marks so it will be easy to put it back. Make a dot with the sharpie in the center of each end hole in the strap. When you're satisfied with the marks, punch and drill just like before.
Step 11: Rivet the Funnel to the Duct
Put the top and bottom together and push a rivet through the holes. You can put one hand inside and hold them together while you squeeze the rivet tool with the other hand. Make sure the strap is pushed all the way down on the rivet before you squeeze the handle.
Step 12: Mark the Holes in the Duct
The duct should hang a little below the rim of the pie pan so it will stay full of seed but not spill out. To do this, we will first bend the straps in the solid part just above the small hole on the end. Pliers make this easier. Now hold one of them against the bottom of the duct with the distance of the desired gap sticking out. Mine was about an inch, yours will depend on the depth of the pie plate you found. Make a dot on the duct in the small hole at the top of the strap. Use the square to transfer this measurement to the other marks. Punch and drill just like before.
Step 13: Mark the Pie Plate
To center the duct on the pie plate, use the same trick with the square from step ten. Transfer the three marks from the duct onto the plate. Now measure in a about 1/2" from where you marked the duct. (I used the holes in the plumbers tape as a tape measure.) This is where you will drill.
Step 14: Drill the Pie Plate
Center punch and drill three holes. Test to see if the rivets fit, ream if necessary.
Step 15: Attach the Straps
Rivet the straps to the inside of the duct with the bent part facing down.
Step 16: Rivet the Pie Plate on the Bottom
For the last step, put the funnel in the can like in step ten. Lining up the holes can be tricky because you can't put your hand inside at this point. It will help if you put a rivet in the holes one at a time. It takes two squeezes to pop a rivet. I did one squeeze on each rivet and went back around a second time and finished it. For a finishing touch, clean off the sharpie with a Q-tip and alcohol.
Step 17: Hang It Up and Enjoy!
There you have it, a bird feeder that looks cool and will last forever. The best way to fill it is with a funnel. If you worry about moisture getting in you could put a tiny blob of silicone on the holes where the cables go through, then pull them tight while it dries. I didn't feel the need to do this as the steep roof will shed water quickly. I remember in the past 3/16" rivets fitting into the holes in plumbers tape, maybe things have changed or my memory is wrong, but it's not too hard to make them fit.