Planer blade sharpness

[Carl Beckett]

A question:

How do you know when your planer blades are dull?

(of course a very subjective question, expecting very subjective answers...)

:)

[Kevin Jenness]

1. Drag your fingernail across the edge. If the knife digs in it's sharp.
2. Take a close look at the edge, just as you would with a chisel or plane blade. Is there a clear fine line at the edge or is it rounded over?
3. What results are you getting? Rougher surface, more noise, less depth of cut posssible than normal?

[Robert Engel]

The planer get noisier and there is more tear out.

I view the planer as a thicknesser and use a drum sander for surfacing, so I'm not interested in a pristine surface coming out of the planer.

So I use them WAY past their due date.....

[Thomas Wilson]

The sound is the first indicator. On my old lunchbox planer, it was easy to take the cover off. Dull blades look blunt. Also, the feed rollers may slip. Then, when you change the blades, the sound will be so much nicer.

[Bill Dufour]

The noise slowly increases and you do not really notice until you switch them out and realize how loud it had gotten. I can hear it better with ear protection.
Never seen a planer with a amp gauge but that would tell you just like on a belt sander. Simply note the amps for a certain width and depth of cut in hardwood or softwood with new blades and compare that to the used blades amp load fora the same cut.
Bill D.

[Frank Pratt]

The fingernail trick works well. Just as soon as they get to the point where the edge doesn't grab the fingernail, it's time for sharpening.

[Tom M King]

There is no in-between. They're either sharp, or not. If you think they may need sharpening, they have needed it for a while.

[Bruce Wrenn]

Before sharpening, check with Global Tooling on the price of a new set. Buy the new ones, install them, then send the old out to be sharpened

[Mel Fulks]

Unless there have been big changes since I retired , most of the knives that come with the planers are the cheapest low grade stuff. Don’t
buy more of that! Demand M2 or T1 ,they give much less tear-out. Don’t fall for rubbish that has “same hardness as as M2 “ New knives
that leave striations are NOT good quality.

[Thomas Wilson]

I am obsessed with having sharp, accurately adjusted tools. I have a Makita wet sharpener 9820-2 for straight jointer and planer blades. There is a bit of a learning curve, but it works very well once you get your routine down. Even “disposable” planer blades can be re-sharpened on it. I bought mine 35-40 years ago. It was cheaper then. Used ones are generally available.

[Frank Pratt]

Unless there have been big changes since I retired , most of the knives that come with the planers are the cheapest low grade stuff. Don’t
buy more of that! Demand M2 or T1 ,they give much less tear-out. Don’t fall for rubbish that has “same hardness as as M2 “ New knives
that leave striations are NOT good quality.

That's a pretty general statement. I have a Delta 22-580 lunchbox planer that I've had for ages that is still on the second side of the first set of knives. Granted, I don't do a ton of milling, but over the years that planer has done a lot. But then my General Int. jointer knives have been sharpened several times in that period of time & have removed a lot less wood than the planer.

I went to buy a second set of jointer knives and a new gib & some gib screws because they were stripped. The new knives were $36 but the gib & screws would have to come from Taiwan & take ??? weeks/months to get here. I didn't even ask the price. Then the guy offered to sell me a brand new cutter head c/w knives, gibs & bearings from the same model (but different brand) jointer that he just installed a helical head on for $40. Sold.

[Mel Fulks]

“That’s a pretty general statement “
Thanks ,Frank . The last person to call my writing “pretty” was my maternal grandmother .