How to change planer blades?

To sharpen or not to sharpen?

Planer blades, as with all other blades, will eventually dull over time with continued use. Installing planer blades will solve this once this happens because a dull blade will definitely impact your productivity, put extra work on the tool, and decrease both completion rate and cut quality.

While hand planer blades can simply be sharpened, we find that it can be better to replace the blades if there are large chips.

When jobs need automating electric planers need to be sharp and dent free, if there are large chips, scratches, or dents that need removing from the blade now is better than later.

However, sharpening and recycling your old planer blades can sometimes work if they are just blunt without any large chips, read more below.

How do planers become dull?

If you have been using power hand planers on wider board sizes, whether you’re using an electric handheld planer or fully automated thickness planers, the conditions that cause blade-dulling are roughly the same – frequency of use and the material worked on. 

Planer blades, on average, take about 50hrs of total use for wear to appear. Working with extremely hardwood or composite material such as plywood quickens this deterioration. Because of knots and glue, contained in the wood.

Of course, if you hit metal such as a screw or nail you can cause the blade to chip as well. 

When should you change planer blades?

How often should you replace planer blades? This depends on the frequency and the stress your planer takes. Signs of too much dulling will include visible decreases in speed as well as certain audible differences in sound – well-sharpened blades are smooth sounding and cut cleanly through, whereas duller blades can generate light screeches and often produce more grain tear-out.

Once this begins appearing consistently with every use, then you know the time to get a new pair of blades has arrived.

What happens if you continue using blunt planer blades?

If you’ve ever tried to carve wood or even soap with a dull knife, then continuing to use dull planer blades is no different.

Continuous planing won’t even help [1].The result would either be an injury or an extremely crude and janky project.

Since thickness planers, like this one from DeWalt, are “corrective” tools, they have to be able to accurately shave off excess material to make workpieces meet strict specifications – something you can’t achieve with dull blades. 

Expect your tools motor to be overworked under the conditions caused by a dull blade and expect chipping and ruffler cuts.

Changing handheld electric planer blades

1. Safety precautions before changing planer blades

• Wear protective gloves when changing planer knives (Unless you’re already highly experienced in handling without one).
• Make sure the planer is switched and that the battery is removed or an electric planer is unplugged.
• Make sure you’re working on a clean, flat, and leveled surface (prevents components from sliding).

2. Tools to prepare:

• Wrench or compatible fastening tool
• Flathead screwdriver
• Knife
• Tweezers

3. . Step by step on how to change planer blades?

1. Flip the planer over sideways to access the bolts holding the cutter head.
2. Loosen the bolts using the corresponding wrench.
3. With a screwdriver or knife, carefully slide the blade out of the cutter’s head.
4. If your planer has 2 blades, simply rotate the cutter head and repeat steps 2 & 3. Once the blades become loose, we recommend using a pair of tweezers to safely handle the blades since they are razor-sharp or by holding the blades from only the two ends.
5. Planer blades are usually sharpened on both sides, so if only one side has dulled, simply flip them over and re-slide them back in place. If both sides have dulled, it’s time to buy a replacement pair. Do this beforehand.
6. To reinstall, position the grooves on the top of the blade to align with the notches on the cutter head.
7. Carefully hold the blade steady in place and tighten the bolts. Repeat for the other blade and you’re all set.

Changing / sharpening handheld planer blades

Tools needed: Screwdriver, whetstone (glass or water), lubricant, ruler

Optional: honing jig & leather strop

1. Blade installation and removal

1. Loosen the cap screw with the corresponding screwdriver and remove the cap cover (if included).
2. Take the planing iron (blade) and loosen the fastener behind it to release the chip breaker.
3. To reinstall, simply reverse the previous steps, making sure that everything is properly aligned.  When reinstalling the chip breaker, make sure that there is a spacing at least 1/16” from the tip of the blade it should fit into a groove on the tool.

2 . Blade sharpening

1. Make sure that your sharpening surface is flat and fully leveled.
2. Place and secure your sharpening stone. Adequately lube the surface to keep the blade gliding smoothly and effectively throughout the process of sharpening.
3. Begin by flattening the back of the planing iron. Carefully run them against the whetstone repeatedly in one-directional strokes. Inspect that the back has been fully flattened out.
4. Use the honing jig to establish the correct bevel angle.
5. Follow this trick to create micro bevels with a ruler.
6. Do the last finish on the iron rubbing the blade backward on a leather strap. This removes the bur created from sharpening the new edge of the blade, giving incredible sharpness.

Can you sharpen electric planer blades as well?

Yes, you can. It’s not completely different from sharpening a planing iron or even a regular knife except it’s a little smaller to hold and position. You’ll need most of the same tools for sharpening a hand planer blade.

What makes this tricky is the fact that the blades are angled and are rather small so find a way to hold and position the blade securely using a jig. Or, create your own sharpening jig with your excess hardwood [2].

How do you sharpen planer blades?

When the time comes to sharpen any flat, linear metal edge. The essential tools to use are whetstones, at an optional bevel angle by using honing tools/ jigs.

Not only will they help restore sharpness, but certain refinements made with these tools can also retain and even enhance it if executed perfectly.

Ideally, what you’d want to do is first work on the back-end of the blade.

Run the blade against a sharpening stone, or even a wheel grinder, to make the point sharp again with no chips or dents.

After, you’ll want to start working on the bevels. With either a honing tool or sanding file, to begin with, run the tip across the length of the bevel to finish up with a razor-sharp cutting surface.

Don’t forget to adequately lubricate to help quicken the process and reduce the chances of heat damage. 

Here’s a more detailed guide for sharpening tool blades.

Dos and don’ts when sharpening planer blades

Dos

• Always clean your blades and tools whenever you’re doing maintenance. 
• Do try and keep a consistent angle when sharpening and check the specs of the tool. 
• Unless you do only a touch-up, always begin with coarse to medium grits and only finish up with fine grits for a sharper final result. 
• Do polish frequently.

Don’ts

• Don’t use a belt sander or a machine sharpening tool just to hasten the process, if you are sharpening precision blades that are small we find it safer and far better to do the job by hand. 
• Don’t move the edge or blade around with your hands instead work by shifting your body weight in regard to your positioning as this will give you better control. 
• Don’t skip out on polishing and honing.
• Do routine sharpening, not only when your blades begin to dull. Doing this helps better retain sharpness and lengthen overall blade life and reduces sharpening time.

When is sharpening not enough for planer blades?

This is more of an obvious sign than anything else.

Though regular sharpening can help prolong the life of your blades, there will come a time when they simply won’t perform as they used to.

Tell-tale signs include chips that are too large to remove from sharpening.

Or blades that are outrightly just breaking!

Extremely corroded blades must be replaced unless you know how to fully restore them using acid and wet and dry sandpaper. And make sure to own a reputable planer brand.

Use only sharp planer blades!

Anyone who owns any type of blade definitely knows the value of sharpening and keeping blades sharp before a new job.

Sharpening can be a tedious process without the right tools or guide, but now you have some great tips to put you ahead.

But those who really love keeping their edges pristine treat the process with as much importance and enjoyment as grade-schoolers do when sharpening their pencils to a crisp point.

If you’re willing to put in a little extra effort, then you just might save yourself a couple of bucks worth of replacements.

Besides, knowing a thing or two about sharpening can even net you with better blades than even those fresh from the factory. As we say in our lingo, stay sharp!