What should you not put in a wood chipper?

Wood chippers are useful property maintenance tools, but not every material is safe to chip

Operating a wood chipper demands careful attention to safety and proper material selection.

Being able to turn brush, tree branches and other yard waste into a pile of chips is an incredibly useful tool for any property owner.

And while wood chippers have a number of safety controls and features to ensure the wellbeing of the user, a degree of caution is always advised. Feeding the wrong material into your chipper can result in serious injuries, cause equipment damage, or create dangerous projectiles flying from the infeed chute.

For both PTO and gas-powered wood chippers, knowing what materials to avoid is crucial for operator safety and equipment longevity. This comprehensive guide of safety tips will help you protect you and your investment when operating a wood chipper.

It's important to know what not to put in a wood chipper

Wood chippers work by feeding material through the feed chute and into either in-feed rollers, or directly into the flywheel, where sharp blades spin quickly and chip up the woody or leafy material.

The result is a pile of wood chips you can use around your property. It's always advised to wear hearing protection, safety goggles and follow all safety guidelines outlined in the product owners' manual.

You must also always be cautious about what you feed into your wood chipper, as any unintended materials are fed into a rapidly spinning steel disc which could have unintended results. Improper materials can cause severe damage to cutting blades and mechanisms. This may mean operator injury, costly repairs or total equipment failure. Real-world damage examples include:

• • Metal objects can damage or break chipper blades

  • Rocks can crack the flywheel housing

  • Vines can wrap around and jam the drive shaft

  • Wet materials can clog the discharge system

What you can safely put in a wood chipper

 Most tree waste is safe for chipping. Examples include:

• • Fresh branches up to the specified diameter

  • Dry wood within size limits

  • Clean brush and twigs

  • Tree limbs free of foreign objects

Materials you should never put in a wood chipper

While wood chippers are durable machines, it's always advised to follow the best practices and safety tips and avoid putting in materials which are unintended for these devices. Trees make for great wood chips, but wire fencing or screws don't, so be sure to check that any branches or other yard waste you put in the chipper is free of the following materials:  

Rocks, stones, and gravel:

• • Can damage blades instantly

  • May damage internal components

  • Create dangerous projectiles

  • Often hidden in root balls

Metal objects:

• • Nails and screws

  • Wire fencing

  • Metal stakes

  • Construction debris

  • Tool parts

Plastics and Rubber:

• • Garden hoses

  • Plant pots

  • Synthetic materials

  • Rubber items

  • Plastic bags

Large or knotted branches:

• • Branches with multiple offshoots

  • Twisted or interlocked limbs

  • Root balls or stumps

  • Lumber with knots

Vines and stringy materials:

• • Ivy and creeping vines

  • Rope-like vegetation

  • Long grasses

  • Fibrous plants

Wet or green materials:

• • Fresh grass clippings

  • Soggy leaves

  • Recently cut saplings

  • Rain-soaked vegetation

  • Composting material

(PRO Series Wood Chippers featuring Twin Flywheel technology are engineered to chip light, leafy, green material more consistently and efficiently than their single flywheel counterparts)

Typical safety protocols and safety gear

• • Hard hat with face shield

  • Safety glasses

  • Ear protection

  • Steel-toed boots

  • Close-fitting work gloves

  • Long-sleeved shirt

  • High-visibility vest

What happens if I insert the wrong material?

If any of the above items or any other forms of unsafe material goes into your wood chipper, stop operation immediately. Disconnect the power source by turning off the gas engine or disengaging the PTO. Allow the machine to completely stop, then remove spark plug wire on gas models.

Begin an inspection by visually checking the blade condition, looking for loose components and checking for housing damage. Be sure to inspect the discharge chute. You can then assess the various components, checking the condition of the blades, the integrity of the drive system and any other moving components.

Accidents happen though, and if one of your blades becomes chipped or damaged you can save it by resharpening it or replace it entirely.

Checking your wood for metal

While wood chippers are heavy duty machines, it's recommended to avoid putting metal through them to avoid damage to the teeth.

Many yard trees may have nails, fence or other things in them, without you even knowing, because the tree has grown around them and they are hidden inside. To avoid damaging your wood chipper, here are a few techniques some property owners use to avoid the risk of accidentally chipping metal:

• • Visually inspect your wood before putting it in a wood chipper

  • Use a magnet to detect and pull out any metal

  • Use a metal detector to check your wood pile

 The importance of following guidelines

Your wood chipper is engineered to provide you with consistent, lasting durability. By respecting these guidelines and maintaining safety awareness around your wood chipper, you'll not only extend the life of your investment, you'll also ensure that every operation is as safe and efficient as possible.

Frequently Asked Questions

Can you put wet branches through a chipper?

Twin Flywheel chippers like the TF810 PRO handle wet materials better than single-flywheel models, because their higher-velocity discharge system throws lightweight, wet, leafy, and coniferous material faster and farther. Wood chippers with a single flywheel tend to do better with dry materials.

 What are basic safety rules for wood chipper operation?

• • Always be aware of your surroundings and remove any tripping hazards

  • Maintain all safety equipment

  • Keep proper distance

  • Follow size limitations

  • Regular maintenance checks

 What should you do if something gets stuck in a wood chipper?

• • Shut down completely

  • Wait for full stop

  • Follow safety protocols

  • Use proper tools

  • Never reach into chutes