Cleaning Off Pitch & Resin From Router Bits and Saw Blades

Pitch builds up on cutting surfaces on router bits and saw blades. This may cause burning of the finished cuts or them to behave like a dull blade. Removing the buildup may restore performance and is easy to perform at home. I cleaned three saw blades and about a dozen router bits in about 30 minutes.

The local wood working store had pitch and resin remover for about $15 per quart. I looked at the MSDS sheet and found sodium metasilicate as one of the ingredients, the others were anti-foaming agents and fragrance. Powdered Brewery Wash (PWB) from Five Star is a safe cleaner used in home brewing which is 30% sodium metasilicate. A pound of the stuff costs about $10 at the brewing store and makes several gallons of cleaner which I use for other purposes around the house.

Tip: PWB works great for loosening carbonized crud and burned on grease on removable drip trays for stoves. I soak them overnight in a sink then give them a scrub. The stuff comes right off unless it was super thick which needed one more soak. As a bonus the stainless steel sink was really clean when I drained the water out.

You could also the pitch and resin remover from the store. The cleaning process is the same, only the cleaning solution changes.

Materials & Equipment

• Powdered brewery wash
• Plastic container to soak bits in
• A flat tray that can fit your saw blades
• Brass wire brush
• Paper towels
• Nitrile gloves (optional)

1. Mix about 2 tablespoons (30g) of PWB in about a pint of warm water.
2. Stir for a few minutes until it dissolves, it dissolves fairly slowly
3. Pour into a plastic container if cleaning router bits or a flat tray if cleaning saw blades.

Some router bits have a follower bearing which needs to be removed before soaking. Skip this if no bearing is present.

1. Remove the retaining screw that holds the bearing on. My router bits had a 2.5mm screw.
2. Remove the bearing. It should slide off but may require gentle prying with a small flat blade screwdriver.
3. Remove the small washer that is below the bearing if present.
4. Set aside the parts for reassembly later.

Soak for 3-5 minutes in the PWB solution. The pitch and resin should loosen up fairly quickly.

Carefully brush the router bit with a brass wire brush along the length of the cutting surfaces with light pressure. The pitch and resin should come off easily, there is no need for excessive pressure. I used only a pound or two of pressure.

You may want to consider using nitrile gloves since PWB can remove oils from your hands making them dry.

Note: Be careful when handing the tool. The carbide surfaces may be very sharp and can easily cut you. The bit may also be slippery due to the soap solution.

• Rinse the router bit in the sink then carefully dry with paper towels.

Note: Be careful since the carbide edges may be very sharp.

• Allow the bits to finish drying before storing.
• Soak the bit again if it needs a bit more cleaning.

This is step is only necessary if the router bit had a bearing attached.

• Slide the washer on with the domed surface facing toward the bearing.
• Place the bearing on top of the washer.
• Replace the screw and tighten with the hex key.

1. Pour the PWB solution into a flat tray.
2. Soak the saw blade for 3-5 minutes.

• Scrub the blade with the wire brush from the back of the saw tooth toward the front. The resin should come off quickly.
• Work your way around the saw blade working in the direction of the arrow.
• Scrub the area below the gullet of each tooth, resin builds up in that area too.
• Flip the saw blade over and repeat.
• Scrub along the edge of the blade if needed.

Note: Be careful of the carbide tips they can be rather sharp.

• Rinse the saw blade under clean tap water.
• Carefully dry the blade with a paper towel.
• Wait for the blade to be completely dry before reinstalling on the saw arbor.

The PWB solution can be disposed of in the sink since it is an environmentally friendly cleaner. The dirt is mostly pitch and resin from the wood.