dulling planer knives

[MichaelMouse]

40 grit belt sander would be a good first step.  You'll be surprised at how fast it can strip the finish which would also take off the worst of the grit, etc. that's killing your planer blades.

After a little sanding the boards will be ready for the planer

And the difference between wind-driven grit embedded in the wood and the 40 grit would be?   Wire brush is my choice for cleaning up surfaces.  If you sand, make sure to use some sort of stiff-bristle brush, and maybe even a wet set aterward to clean up any grit you may have embedded with your efforts.

All I've read about carbide blades is that they do not take as acute an edge as steel.

[Timberwolf]

And the difference between wind-driven grit embedded in the wood and the 40 grit would be?   Wire brush is my choice for cleaning up surfaces.  If you sand, make sure to use some sort of stiff-bristle brush, and maybe even a wet set aterward to clean up any grit you may have embedded with your efforts.

All I've read about carbide blades is that they do not take as acute an edge as steel.

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"All I've read about carbide blades is that they do not take as acute an edge as steel."

That is true..If sharpened to the same angle as HSS, they would chip and/or fracture because carbide is more brittle...But when sharpened to their optimum angle, they will keep that edge ten times longer.

[MichaelMouse]

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"All I've read about carbide blades is that they do not take as acute an edge as steel."

That is true..If sharpened to the same angle as HSS, they would chip and/or fracture because carbide is more brittle...But when sharpened to their optimum angle, they will keep that edge ten times longer.

You have to adjust the exposure so they don't whack the wood with the different bevel?

[GlenS]

I use a wire brush attachment on the angle grinder 1st. It gets down into the grain pockets really well. Then I'll use an 80 grit belt sander. I use a hand wire brush for the stubborn areas & to brush away the stuff left behind by the belt sander.

I do all this AND I have access to free saw blade & knife sharpening from a local professional saw sharpening service.

And pine knots can really dull the knives quick. Especially those long oval ones.

[Timberwolf]

You have to adjust the exposure so they don't whack the wood with the different bevel?

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I have never used the carbides in a planer.. but you have a point with regards to the attack angle...whether carbide would work as a HSS replacement would depend on that angle..There may not be enough clearance for the chips to escape properly.

[rwe2156]

Sorry to disagree, but there won't be enough grit in a board to dull the blades that much.  That being said, always brush off an old board like this with a stiff bristle brush before planing.

Odds are they weren't sharp to begin with.  Side note: a newly sharpened edge is subject to micro-corrosion that results from sitting around idle.  So, yes an edge can get dull just sitting around.  Believe it.

Pick up a fresh set of blades and get the old ones sharpened.



BUT, that being said, knots are very hard on planer knives

[Bill Holt]

Knots are blade killers!  Using reclaimed pine from an 1886 factory I built a trestle dinning table.  There were not a lot of knots fortunately, band saw was a huge help, but I still went through two sets of knives on my DW735.

[KingwoodFan1989]

Knots are blade killers!  Using reclaimed pine from an 1886 factory I built a trestle dinning table.  There were not a lot of knots fortunately, band saw was a huge help, but I still went through two sets of knives on my DW735.

Wait, are the knives for the 735 double edged like the ones on the 734!?

[Bill Holt]

Wait, are the knives for the 735 double edged like the ones on the 734!?

Yes, and I used both sides of two sets.

[kurt18947]

Wait, are the knives for the 735 double edged like the ones on the 734!?

For a while DW 735 knives had a reputation for not being durable. I don't know if that's still the case or not.