how to tell if planer blades are dull / need sharpened

[cody michael]

I just got a new to me grizzly 20 inch planer, how do I tell if the planer blades need sharpened? I have been doing research but alot of what people said was it sounds different or different finish, I don't have anything to go off of. as I have not used this machine with sharp blades. it is expensive enough that I would prefer not to get them sharpened until it is necessary. any ideas? can you tell by eye, by feel?

[ernest dubois]

At a certain point you'll get a feel for how keen your blades are depending on your own tolerance for ease of planing and the surface quality resulting on the woods you use. Also, one wood species, even more, wood within a species, calls for sharper edges than another. In other words the question leads to a world of subjectivity. Starting out with the knowledge that you have the sharpest possible blades will establish a standard to use from which you can then be the judge. Otherwise at some point you will want a sharper edge and from there on out you can begin your own assessment.

[Myk Rian]

They get noisy.
Shine a light on the edges. You can tell if they need sharpening by reflected light on the edge.

[David Masters]

It's a great question and I wondered the same as I started using my 15" Grizzly planer. What I notice using oak, is that I started to see minor tear out when the blades needed attention. I did not notice a change in the sound of the planer, but then it's an older planer and the noise level when operating is already pretty loud. I found a small sharpening shop in the area that sharpened the set of knives for around $25. The guy I bought the planer from gave me an extra set of knives, so I have a spare set I can swap out.

[Ethan Melad]

I'd suggest getting them sharpened now regardless - then you know how the machine performs with sharp blades and you'll have better reference for when they get dull. Sharpening should not be expensive at all.

[Ed McEowen]

I have a 15" Grizzly planer also. I've found that, when the blades are in need sharpening (at least on oak), there's an increased tendency to see the board being pulled off to one side as it goes through the planer instead of the normal straight-thru.

[Tom M King]

IF YOU ARE GUESSING, THEY NEED IT. should CUT CLEAN AND QUIET

[Dan Hahr]

Cut a nice clean piece of maple and take a thin pass from it. Look at the surface in raking light. Unless it is smooth and glassy, it is unlikely that the blades are sharp as new. However, sharp as new is for a short, sweet time. They will slowly dull as you use them until they simply chop the wood out instead of slicing it. In my experience, you will see planer tracks from tiny nicks in the blade long before you get to this point. When these become closely spaced (several per inch) or seemingly one after another, its time for sharp blades. By this time there should be noticeable decrease in feed rate and surface quality.

I recently started using a jig to sharpen my own blades and have found it to produce excellent results. I've also found the Freud knives out there are cheaper than any sharpener I can find (50 cents/inch plus shipping.) But I would base my choice on what I want to accomplish. I have a Delta 15" planer I picked up cheap over 7 years ago. I use it anytime I get really rough wood that needs a lot of planing, but not to finished sizes. The wood comes out pretty smooth despite the rough stuff that went through it. I bought a new set of knives years ago, but it is still outperforming my expectations, so I haven't put them in yet. However, I use my Dewalt 735 for everyday use.

Dan

[Kevin Jenness]

Unplug the machine and expose the knives. Drag the back of your fingernail across one. If it digs into the nail, it is sharp, if the nail skates over the knife it is dull. If you can tell whether your chisel is dull, you can do the same with a planer knife. Sharpening should cost around $.50-.60 per inch, so it's not worth working with dull knives. If the knives are basically sharp but have a nick or two, you can move one or two to the side and retighten at the same height to eliminate or reduce the resulting ridges in the work.

[cody michael]

Unplug the machine and expose the knives. Drag the back of your fingernail across one. If it digs into the nail, it is sharp, if the nail skates over the knife it is dull. If you can tell whether your chisel is dull, you can do the same with a planer knife. Sharpening should cost around $.50-.60 per inch, so it's not worth working with dull knives. If the knives are basically sharp but have a nick or two, you can move one or two to the side and retighten at the same height to eliminate or reduce the resulting ridges in the work.

thanks the finger nail trick is a great idea.

[cody michael]

where did you see freud blades for that cheap? I just looked and I see them for about 100$ so over 1$ an inch, are the 50 cent an inch blades as good or better then the original grizzly ones? can you post a link?

[Kevin Jenness]

The last time I sent blades out for sharpening to Connecticut Saw they charged $.50/inch as I recall. Buying new blades is a different matter.

[cody michael]

The last time I sent blades out for sharpening to Connecticut Saw they charged $.50/inch as I recall. Buying new blades is a different matter.

I drive by a place on my way to work, they charge .4/inch I am going to try them

[Dan Hahr]

The Freud ones were about $64. These are probably just as good and at least as good as Grizzly.

CMT 794.381 HS Planer and Jointer Knives, 15-Inch Length - 3-Pack by CMT

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