Bird Feeder from Wire & 2-Liter Bottle
Here is a simple way to reuse a 2-liter bottle to provide a 'smorgasbord' for our fine feathered friends.
2-Liter Bird Feeder takes steel wire and a 2-liter bottle and through some twists and turns of wire bending a bird feeder is created.
2 Liter Bottle
Galvanized Steel Wire (I have found that suspended ceiling (t-bar ceiling) hanger wires work great. They are 6 feet long, 12 gauge and come 10 to a pack for about $4 at home improvement stores.)
Fine galvanized wire ( 24 gauge; 0.58mm)
Flux coated brazing rod
Handheld MAPP Torch
Step 1: Wire Bending
The 2-liter bottle for this bird feeder is held in a wire 'cage' (how appropriate for a bird feeder - sorry I couldn't resist.). The cage consists of a loop under the bottle with two rings around the bottle.
The wire perches give a landing spot for the birds to roost while eating and also hold open the 'bump-in' openings in the bottle for the bird seed to be exposed.
The cage is formed from bending the galvanized wire and brazing it in position. I think this is about my second brazing job and I'm not that great at it. I tried soldering, but I was having problems with getting the soldier to stick (I think the galvanization is the problem), so I opted for brazing. I used flux coated brazing rods with a handheld torch running on MAPP gas.
For this project we will need bend the wire into the following shapes:
A. Two rings the fit the circumference of the 2-liter bottle.
B. One U-shaped loop that passes under the bottle and supports it.
C. Two 'feeding station' perches
For those with access to CNC wire bending tools here are the SVG files (My first try at SVG files so please be forgiving). I do not have such tools so the files are included as the starting point from which to generate your final files. (I hope they help!)
Step 2: Bending Rings
Fill the 2-liter bottle with water and put the cap on tight. This gives a semi-ridged form to wrap the wire around.
1. Wrap one of the steel hanger wires around the 2-liter bottle 3 or 4 times. This might seem like a bit of a waste but having extra wraps lets the first and last wrap be a bit odd shaped and lets the middle warps be more nice and round.
2. Create rings by cutting the wrapped wire so that there is about a half-inch of overlap.
You need two of these rings - one will be positioned near the top of the bottle and one near the bottom.
Step 3: Bending U-Shaped Support Loop
Take a 3-1/2 foot length of wire and center it on the bottom of the 2-liter bottle. Then bend the wire up the sides parallel to the bottle. It's better to have extra wire extending past the top of the bottle rather than to be a bit short. The wire length can be trimmed later if needed.
Step 4: Assembly and Fit
Now its time to loose-fit everything together. The most important is to have the rings fit snugly around the bottle. Ultimately the rings will fit over the supporting loop too. To get the rings to fit nicely around the bottle may take some bending and flexing and test fitting on the bottle several times until they are nicely round and fit well.
Step 5: Bending Perches
The perches consist of a ~6-inch length of wire (you can cut it down later if needed) attached to the bottom ring. This connection is made by bending a small hook in the end of the wire and crimping it over the ring wire. These perches are installed on the bottom ring spaced between the support loop so that the vertical wires (support loop and perches) are all spaced evenly around the bottom ring.
The perches have a 90 degree bend in them so that they run parallel to the bottle and then jut out to form the perch for the birds. The 90 degree bend will ultimately be decreased to make an acute angle (a little less than 45 degrees) so that after the bottle is installed the top half of the perch pushes the bottle side inward to expose the birdseed.
Step 6: Wire Wrapping / Fastening
I thought the easiest way to hold everything together for brazing was to use fine gauge (24AWG) steel wire to tie all the wire intersections together.
I used the 'saddle tie' style of wrap - I looked up the types wraps to tie rebar together for concrete work - a bit of overkill but it gave good direction and examples. Make sure to get it really tight so that the wires stay in position while brazing.
Test fit the 2-liter bottle into the cage and make sure that the rings are parallel and the support loop vertical and spaced appropriately around the bottle (180 degrees for support wire; 90 degrees for support wire and perches).
This 24 AWG (0.58mm) wire is almost too small of gauge for this use. As I was brazing the wire would burn through, but usually after the joint was well underway. It might be wise to go a gauge larger.
Step 7: Brazing
This step involves brazing. So make sure to work safely:
TAKE NECESSARY PRECAUTIONS TO PREVENT SPREAD OF FIRE, BURNS, PROPERTY DAMAGE AND LOSS OF LIFE. Make sure to work on a non-flammable surface in a well ventilated area. Galvanized materials give off toxic fumes when brazed or welded. Have fire extinguishing materials available. Wear eye protection, welding gloves and other personal protective gear. Make sure to keep others away. Use common sense and don't attempt anything you are not familiar with. Seek professional assistance if you are not qualified.
Wow, sounds like I'm a lawyer (I'm not one, nor do I play one on television).
I used flux coated bronze brazing/welding rod. MAPP gas works pretty good and has just enough heat to actually braze. Make sure the molten brass fills in around the wires to give a strong bond.
Step 8: Hanging Loops and Hook
The bird feeder is designed to be hung from above so it needed some way to hang. I bend the top ends of the U-shapped support wire into 1/2-inch diameter rings. I bent the top portion of the U-shaped support wire inward, starting at about 12-inches up from the bottom of the bottle, so that the rings overlapped and could be supported by a convienient length of wire with hooks at both ends.
Step 9: Paint
I sprayed my cage flat black since color wasn't important and I will be filling the feeder with black sunflower seeds and black wires blend in nicely with the seed color.
Step 10: Prepare Bottle
The 2-liter bottle had a mold parting line about 1-3/4 inches up from the bottom of the bottle. This horizontal parting line runs the circumference of the bottle (at least on mine). I took a utility knife an cut approximately 4 inches along this parting line on opposing sides of the bottle. (So two cuts on opposite sides - each horizontal cut about 4-inches long).
Slide the bottle into the cage. Bend the perch wires inward to push in the portion of the bottle above the cut so that the bird seed will be exposed when filled.
You will need to drill a small hole in the bottom of the 2-liter bottle to allow rain water to drain. If the bottle has a 'scalloped' bottom you will need to drill holes in the bottom of each 'scallop'.
Step 11: Fill the 'Wire and 2-Liter Bottle' Bird Feeder With Seed
Now you can fill the bird feeder with seed. A funnel helps speed the process up.
Now you can hang your feeder and have all the feathered friends in the neighborhood visit for a snack.