When to Sharpen a Saw Blade

Saw Blade

If you’ve been cutting wood for any length of time, the question has come to your mind…. do I clean and sharpen my saw blade or should I just get rid of it and get a new one? Given that every woodworker likely has multiple blades in their shop, knowing the answer to this question could save a lot of money. Today we look at how to decide….

Background

Today’s discussion can be applied to saw blades that go in the table saw, circular saw, chop/miter saw, radial arm saw or any other saw you can think of that takes a round blade that has teeth. Actually this theory can be applied to most any blade, just the techniques will vary for band saw blades and router bits.

Step 1 – Clean the Blade

Before you even try to figure out the sharpness (or dullness) of a blade, clean it first. Cleaning is easy and fast and may just return your saw blade to it’s original condition without any sharpening.  Cleaning is pretty straightforward….

  1. Use your favorite “Blade & Bit Cleaner” (suggestions below) to soak the blade for at least 5 minutes.
  2. After soaking, take the blade out of the solution and use a cleaning pad such as a Scotch Brite Pad to manually remove as much of the dirt, pitch and general yuck as you can.  An old toothbrush works well here also.  NOTE.  Be sure to rub WITH the direction of the blade, not AGAINST the blade.  It’s still sharp and could cut you!
  3. Once the blade is clean, dry it thoroughly (clean compressed air or a hair dryer could be used here)
  4. OPTIONAL.  Use a dry lubricant like Bostik BladeCote to coat the blade to protect it from future dirt buildup.

Check out The Wood Whisperer Video (below) to see the process for cleaning a blade (or router bit)

Step 2 – Determine Whether Blade Needs Sharpening

Unfortunately you can’t look at a saw blade and tell if it’s dull. You have to go by feel…. the feel of the wood as it moves across the blade. When a blade gets dull, it becomes hard to feed material across it.  The material starts to either show signs of rough cuts or can have burns on the side of the wood when the blade gets dull.

NOTE: If your wood has burn marks on it, your blade may not be parallel to the rip fence. Check for squareness before sharpening blade.

If your blade is clean and is parallel to your rip fence and still shows signs of burning or doesn’t cut through wood cleanly and evenly, it’s probably time to sharpen or replace the blade.  So which one do you choose.. sharpen or replace?  The answer is pretty simple really… cost!

  • If your blade doesn’t have carbide tips (unusual), definitely replace the blade.  Go for one with carbide tips…. Freud or Forrest are good brands to consider (see below for options)
  • Blade sharpening costs $20-30 (and requires your blade to be gone from your saw for some time).  If your blade has carbide tips (most do), you can have your blade sharpened a couple of times before the carbide is totally worn off.  You can sharpen yourself if you are really handy, but it’s a pain and is prone to errors (broken tips or incorrect sharpening angles).  If you only paid $20-50 for your blade, it’s probably easier to just buy a new blade.  Another option could be to buy a 2nd blade, then send off the 1st for sharpening.  This could still be cheaper than buying a new blade and is more environmentally friendly.
  • If you have nice, costly ($100 or more) blades, then you’ll definitely want to get the blade sharpened.  Again, consider purchasing a 2nd blade so you are not out of commission while the blade is being sharpened.

Sharpening Options

If you’ve decided to have your blade sharpened, you have several options.  

Conclusion

If you use your blades regularly, you’ll notice when they start to get dull.  Keep the blades clean regularly and then sharpen as needed.  Remember, a sharp blade is much safer than a dull one.

We’d love to hear your experience with saw blade sharpening.  Chime in below and let us know how you tackle this task in your shop.

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