DIY Project

DIY Suet Log Feeder

A drilled log is the closest thing in backyard feeding to a natural foraging surface, and it is a one-hour build from a storm-fallen limb. The details are the bit size and the hanging point.

A suet log is a section of hardwood limb with large flat-bottomed holes drilled into it and packed with a firm fat mix. Birds that feed by clinging to bark, which is most of the woodpeckers plus nuthatches, chickadees and creepers, use it more readily than a wire cage because the posture is the one they already know.

Build time is about an hour, most of which is drilling. The materials cost is a fallen limb, one screw eye and a batch of suet.

Three things separate a log that works from a log that splits and falls: the bit you use, the spacing of the holes, and whether the hanging hardware bites into end grain or passes through the log.

Materials and tools#

Materials

• One seasoned hardwood log, 3 to 4 inches (7.5 to 10 cm) in diameter and 14 to 18 inches (35 to 45 cm) long, with the bark intact.
• One 1/4 inch (6 mm) stainless or galvanized screw eye, or a 1/4 inch by 5 inch (6 by 127 mm) stainless eye bolt with a washer and nut for the through-bolt version.
• A galvanized S-hook or 12 inches (30 cm) of light chain.
• Suet plug ingredients, listed further down.

Tools

• A drill, corded or a decent cordless. This build asks a lot of a small drill.
• A 1-1/4 inch (32 mm) Forstner bit, or a spade bit if that is what you have.
• A 5/32 inch (4 mm) bit for the screw eye pilot, or a 5/16 inch (8 mm) bit if you are through-bolting.
• A clamp or a vise, or a helper. Do not hold the log by hand while drilling.
• Tape measure, pencil, safety glasses.
• A butter knife or narrow spatula for packing.
• A saucepan and a bowl for the suet.

Choosing the log#

Look for a limb that came down in a storm or a piece of firewood you have had for a year. Seasoned hardwood with tight bark is ideal: oak, maple, birch, hickory, ash, cherry or old apple. The wood should ring solid when you knock it, not sound hollow or crumble under a thumbnail.

Avoid these:

• Pressure-treated or painted wood. The preservatives are toxic and have no place under food.
• Resinous conifers. Pine and spruce gum the bit and weep pitch in warm weather, which can foul feathers.
• Punky, rotten wood. It will not hold a screw eye and the holes crumble.
• Green wood cut from a living tree. Standing dead wood is worth more to birds where it is, as covered in snags, dead wood and leaf litter.
• Firewood hauled from far away. Moving cut wood long distances is one of the main ways wood-boring insect pests spread. Use something local.

Hole layout#

For a 16 inch (41 cm) log, this layout gives five feeding holes with a solid 3 inch (7.5 cm) head for the hanging hardware.

The 3 inch (7.5 cm) vertical spacing and the 120 degree rotation matter for two reasons. Birds at adjacent holes stop displacing each other, and no two holes ever come close enough inside the log to break through into one another or to create a split line.

Never drill deeper than half the log's diameter. On a 3 inch (7.5 cm) log, 1 inch (25 mm) is already close to the limit.

Step by step#

Allow about one hour, plus chilling time for the suet.

1. Cut the log to length (10 minutes)#

Cut it square at both ends at 14 to 18 inches (35 to 45 cm). A square top end matters because that is where the hanging hardware goes.

2. Mark the holes (5 minutes)#

Run a pencil line down one side of the log as your reference. Mark hole centers at 3, 6, 9, 12 and 15 inches (7.5, 15, 23, 30 and 38 cm) from the top, rotating the log a third of a turn for each successive hole.

3. Set the depth stop (2 minutes)#

Wrap a strip of tape around the bit 1 inch (25 mm) up from the cutting edge. Drilling by eye into a curved surface produces holes of five different depths.

4. Drill (20 minutes)#

Clamp the log so the hole you are drilling faces straight up. Start slow until the center spur bites through the bark, then run at a moderate speed with steady pressure. Back the bit out once or twice per hole to clear chips. Repeat for each hole, re-clamping between them.

5. Clean the holes (5 minutes)#

Blow out the chips and run a fingertip around each rim. Snap off any loose bark tags around the openings; loose bark is what birds pull off and drop, and it takes the suet with it.

6. Fit the hanger (10 minutes)#

For a light log, drill a 5/32 inch (4 mm) pilot into the center of the top end grain and turn in the 1/4 inch (6 mm) screw eye until the shoulder is tight against the wood. For anything over about 4 pounds (1.8 kg), or if you want it to last, drill a 5/16 inch (8 mm) hole crosswise through the log 1-1/2 inches (4 cm) below the top and fit an eye bolt with a washer and nut. End grain is the weakest direction in wood, and a screw eye pulling out of a wet log in January is the standard failure of this build.

The suet plug recipe#

This packs firm at room temperature and stays in the holes into the 70s Fahrenheit (low 20s Celsius).

• 1 cup (240 ml) rendered beef suet or plain lard
• 1 cup (240 ml) plain unsalted peanut butter, no added sugar
• 2 cups (475 ml) yellow cornmeal
• 1 cup (240 ml) quick rolled oats
• 1 cup (240 ml) black oil sunflower seed or chopped unsalted peanuts

Melt the suet and peanut butter together over low heat, stirring until smooth. Take the pan off the heat, stir in the cornmeal and oats, then the seed. The mix should be stiff enough to hold a spoon upright as it cools. Let it firm for about 20 minutes, then pack it into the holes with a butter knife, pressing hard so there are no air pockets, and level it flush with the bark.

Chill the loaded log for an hour before hanging. The recipe makes far more than one log needs, so freeze the rest in an ice cube tray: each cube is close to one hole's worth and can be pressed in straight from the freezer. Variations and the rendering method are in homemade suet recipes, and the background on fats is in the suet guide.

Hanging it and who shows up#

Hang the log vertically from a branch, a shepherd's hook or a pole arm, 5 to 6 feet (1.5 to 1.8 m) up and 10 feet (3 m) from any launch point. Vertical matters: it forces the natural clinging posture and keeps rain out of the holes. Under an eave or on the shaded side of a tree extends the life of the fat considerably. General siting advice is in where to hang a bird feeder.

Expect downy woodpeckers within a week or two, hairy woodpeckers and red-bellied woodpeckers where they occur, white-breasted nuthatches working head-down, and black-capped chickadees taking a crumb and carrying it off. Brown creepers occasionally use one. If woodpeckers are the goal, the fuller strategy is in how to attract woodpeckers.

Warm weather, cleaning and lifespan#

Pull the suet or switch to a commercial no-melt dough once daytime highs pass about 85°F (29°C). Soft fat runs down the bark, coats feathers, and turns rancid within days. High-fat foods do their real work in cold weather, which is the argument in best high-energy foods for cold weather.

Between refills, scrape the old residue out with a spoon and scrub the holes with a stiff brush and hot soapy water. Do not soak the log; it will swell and check. Let it dry a full day before repacking. The general routine is in how to clean a bird feeder.

A hardwood log lasts three to five seasons. It is done when the bark starts sloughing off in sheets or the wood around a hole crumbles when you press it. At that point it is a good addition to a brush pile rather than trash.

Common mistakes to avoid#

• Holes too small. A 1 inch (25 mm) hole holds so little suet it is gone in a day. Use 1-1/4 in (32 mm).
• Drilling too deep. Past half the diameter, the log splits along the grain the first time it freezes.
• Soft peanut butter alone. Safe, but it slumps. Cut it with cornmeal.
• A screw eye in wet end grain. It pulls out. Through-bolt anything substantial.
• Hanging it horizontally. Rain sits in the holes and the fat goes off in a week.
• Leaving rancid fat in the holes. Scrape it out. Birds will refuse the whole feeder, and a cage-style suet feeder has the same rule.