Processing Gnarly Logs

Waste not, want not.

Gnarly logs are especially difficult to process. They’re knotted, twisted or misshapen in appearance, with deep ridges, irregular bumps and complex grain patterns. With their grain twists, burls (knotty tumor-like growths) and crotches where limbs meet the trunk, gnarly logs are notoriously difficult to split. But that doesn’t mean they can’t be processed into firewood.

Gnarly logs resist clean splitting because:

• Grain direction changes every few inches, so force doesn’t travel straight.
• Knots act like internal wedges, stopping tools cold.
• Twists store tension that releases unpredictably when opened.
• Irregular shapes roll, tip or bind during bucking and splitting.
• Crotches and forks create intersecting grain planes that don’t separate cleanly.

Cutting Gnarly Logs With Tools

Cutting and splitting gnarly logs with hand tools like hand saws, axes and mauls can be extremely challenging, and at times even dangerous. Many professionals don’t recommend splitting gnarly logs with hand tools.  

Splitting gnarly logs with power tools such as chainsaws and powered splitters also presents several challenges. Following these best practices can help:

1. Follow safety guidelines

It’s important to wear proper protective gear like chaps, gloves and eye protection before you begin. Remember to keep your hands clear of the splitter beam at all times to avoid injuries.

2. Buck shorter than standard stove length

Bucking means sawing the log into smaller lengths. Shorter rounds reduce the amount of twisted grain you must force apart.

• Mildly twisted: 14–16 in
• Heavy knots or spiral grain: 12–14 in
• Crotches, forks, burl sections: 10–12 in

Shorter rounds also sit more securely on a block or splitter table.

3. Stabilize the log before cutting or splitting

Stability is safety with irregular shapes.

• Use a tire ring or bungee strap on the chopping block.
• For chainsaw work, crib the log with smaller rounds or wedges.
• Position the log so the flattest face is down.

This prevents rolling, pinching and unexpected movement.

4. Read the grain and identify the weak line

You’re looking for:

• Natural checks or cracks.
• The “open” side of a crotch.
• Where knots cluster (avoid splitting through them).
• The direction of twist.

The weak line shows where the wood wants to split.

5. Use the chainsaw strategically

For the worst pieces, the saw becomes your primary splitter.

• Rip a relief cut down one side to create a flat surface.
• Quarter the round with the saw when a maul won’t start a split.
• Slice off knot clusters instead of trying to drive through them.
• Kerf cuts (narrow slits, 1–2 in deep, made along the top surface) can guide wedges and reduce binding.

This is standard practice among professional firewood processors.

6. Split from the outside in

Instead of trying to halve the round:

• Pop off slabs from the perimeter.
• Work around the log like peeling an onion.
• Once the outer material is removed, the core becomes manageable.

This method avoids fighting the densest, most chaotic grain all at once.

7. Use steel splitting wedges to walk the split

Steel wedges are essential for gnarly wood.

• Start in a natural check.
• Drive the first wedge until the crack opens.
• Add a second wedge to “walk” the split across the round.
• Keep wedges sharp; dull wedges bounce and wander.

This gives you controlled, predictable separation.

8. Let the hydraulic splitter do the heavy lifting

Even a 20–25-ton unit handles most gnarly pieces if you:

• Present the flattest face to the wedge.
• Rotate the round until the wedge hits the weakest grain path.
• Use the four-way only after the piece is quartered.
• For crotches or heavily interlocked grain, start with the open side facing the wedge. This prevents the splitter from stalling or the wood from kicking unpredictably.

Hydraulic force is most effective when aligned with grain, not knots.

The Easier Way to Cut Gnarly Logs: Firewood Processors

To save time and effort, consider a full-process, hydraulic-powered wood-processing attachment like the Halverson Wood Products’ firewood processors and grapple saws. These processors accomplish the entire process, including log lift, transportation, cutting and ejection into a storage area or container, all from the safety and comfort of your host machine’s cab.  

Each Halverson wood processing attachment addresses the seven steps listed above:

1. Buck shorter than standard stove length – All six Halverson firewood processing attachments can be set to buck log lengths from 16 to 22 inches, although the processor’s table, hydraulic-powered grab arm and heavy-duty chain and bar can handle most gnarly logs without having to sacrifice firewood length.
2. Stabilize the log before cutting or splitting – The hydraulic-powered grab arm and solid steel table fully secure most curved and knotted logs.
3. Read the grain and identify the weak line – Using the processor to maneuver the log onto the table allows the grab arm to securely grasp even gnarly logs. The heavy-duty saw cuts the log, and the 28,000-lb. to 43,331-lb. splitter force drives even gnarly wood through solid steel 2-, 4-, 6-, or 8-way wedges without needing to sacrifice firewood length. 
4. Use the chainsaw strategically – The hydraulic-powered saws on these processors can cut through gnarly wood without issue while you control them from the safety of your host machine’s cab.
5. Split from the outside in – No need for additional cuts or multiple trips through the splitter.
6. Use wedges to walk the split – Wedges are essential for gnarly wood, and 2-, 4-, 6- and 8-way solid steel wedges are available for the Halverson firewood processors.
7. Let the hydraulic splitter do the heavy lifting – The Halverson firewood processors literally do all the heavy lifting, from log lift through transportation, cutting to size, splitting and discharging to your firewood pile or container. You control the entire process from the safety and comfort of your host machine’s cab.

Difficult Wood Meets Its Match

Gnarly logs don't have to mean lost time, wasted firewood, or extra risk. You control the entire process from the safety and comfort of your host machine’s cab. Talk to our sales team about which Halverson processing attachment will be best for your situation.