# Is it possible to sharpen planer blades for a 12.5 inch delta?



## Jerry66 (Jan 11, 2022)

The blades for a 12.5 inch delta planner are two sided and are designed to be disposable. Is it possible to buy blades that can be sharpened but are still "easy" to install?


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## woodnthings (Jan 24, 2009)

Disposable blade are not meant to be "sharpened" because there's not enough width to clamp the blades in the machine and not enough width to remove much if any material.
You can attempt to "hone" them if you make a jig to hold them. Honing is not technically sharpening, but it will make them sharper!
Plenty of methods on You Tube:


https://www.youtube.com/results?search_query=honong+planer+blades


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## Rebelwork (Jan 15, 2012)

If you have a shaper , they can sharpen the blades..


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## woodnthings (Jan 24, 2009)

Rebelwork said:


> If you have a shaper , they can sharpen the blades..


You can't sharpen "disposable" blades. Not wide enough, too thin. Grinding doesn't work. Only "honing" works with a stone, by hand.


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## Jim Frye (Aug 24, 2016)

Been there, done that, didn't like the results with another brand using disposable blades. Well worth the cost of replacements compared with the time spent trying to sharpen the originals straight. Might be able to be done, but I don't think it's worth the effort to do so and get them aligned.


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## BigCountry79 (Jun 2, 2021)

If their dull but not chipped, lap the backs on a 1000 grit diamond stone, and they will work once or twice more.

If they're chipped, do the same thing, but flip one blade so the chips don't line up.

If you worked a lot of softwood, cleaning them works about as well as sharpening them.

Mine are usually chipped.

I don't think there is much standardization between what "sharpening" means. Different authors use that term differently. The words GRINDING, and POLISHING are generally understood.


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## Rebelwork (Jan 15, 2012)

woodnthings said:


> You can't sharpen "disposable" blades. Not wide enough, too thin. Grinding doesn't work. Only "honing" works with a stone, by hand.


Are you saying a sharpener won't sharpen the disposable blade?


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## dbhost (Jan 28, 2008)

How expensive are replacement disposable blades?


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## BigCountry79 (Jun 2, 2021)

dbhost said:


> How expensive are replacemen disposable blades>


Most are pretty cheap...I pay like 15 per set fir my ridgid 2 blade planer


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## woodnthings (Jan 24, 2009)

Jerry66 said:


> The blades for a 12.5 inch delta planner are two sided and are designed to be disposable. Is it possible to buy blades that can be sharpened but are still "easy" to install?


The disposable blades have slots in the center which locate the blade the correct distance away from the cutterhead. You would need blades with those same slots to fit over the tabs on the cutterheads.



woodnthings said:


> You can't sharpen "disposable" blades. Not wide enough, too thin. Grinding doesn't work. Only "honing" works with a stone, by hand.


Grinding on those thin blades may cause them to lose their hardness and a sharpening service may not warranty them. They would also have some difficulty registering a two blade knife because the reference edge may be worn unevenly and that would be time consuming to set up. They would need the adapters for slotted blades to get the edges even and parallel. It's most likely not worth the time and trouble to grind them commercially. They are meant to be disposed of when dull.



Rebelwork said:


> Are you saying a sharpener won't sharpen the disposable blade?


You may find a sharpener willing to do it, I donno? Ask around and see what they say.

I own this very type of sharpener and I've used it for 13" long jointer and planer blades. It's not commercial grade, but close. It works OK, just a bit tedious to set up:











You can get commercial grade sharpening jigs and systems but they are so expensive, it's out of reach for a home shop:








20" Planer Knife Grinding Fixture - Thorvie International LLC


Quick set up with no guesswork and no chatter. Flat grind or hollow grind carbide and steel jointer, planer and chipper knives to 20" in length.




www.thorvie.com


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## woodnthings (Jan 24, 2009)

BigCountry79 said:


> *I don't think there is much standardization between what "sharpening" means. Different authors use that term differently. The words GRINDING, and POLISHING are generally understood.*


I think the term sharpening is more generic and covers all the methods. But, I use "sharpening" when a high speed wheel is used for grinding like on a table saw blade.
I use "honing" when a stone is used by hand. Honing refreshes an edge and doesn't remove any appreciable amount of metal. Polishing is a refinement of honing.
But, that's just my preferred nomenclature, others use it as well, and he even describes the "technical" difference:


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## DrRobert (Apr 27, 2015)

I think sharpening is a general term for removing metal to form an edge.

Honing = polishing, which is refining the edge to remove scratch marked and jagged edges produced by coarser stones.

Wait - did someone already say this. Ha ha.


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## Kudzu (Dec 23, 2008)

Possible? Yes. 
Smart? Probably not.

Elaborating on what was said, there is the holes that locate the blades in the proper location. Most people don't realize there is a relationship in the cutting edge location and the rest of the mechanisms in the planer. Such as feed rollers and outfeed roller positions. 

So if you grind the blades shorter this relationship changes. Not sure the tolerances but you may need to adjust the planner to work right then, maybe not. 

There is also the issue of gringding the edges in relation to the register holes. If the grinder doesn't have a way to line up on those it is likely the blade will get ground out of square and cut at an angle.

I have a makita sharpner and do my own blades but I wouldn't try these.


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## woodnthings (Jan 24, 2009)

Kudzu said:


> Possible? Yes.
> Smart? Probably not.
> 
> Elaborating on what was said, there is the holes that locate the blades in the proper location. Most people don't realize there is a relationship in the cutting edge location and the rest of the mechanisms in the planer. Such as feed rollers and outfeed roller positions.
> ...


Exactly! Well said, at least someone understands the whys and wherefores involved.
I would also worry about blade temper because of the thin metal which won't absorb as much heat and dissipate it as fast as thicker blades. 
Grinding always leaves a small burr that needs to be removed so the blades are flat again. That's more work and more time involved for the sharpening service.
All the more reason for them to turn down the job. Probably OK for a DIY'r who has lots of time to experiment I suppose.


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## Rebelwork (Jan 15, 2012)

I'm still trying to understand post #4...


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## Rebelwork (Jan 15, 2012)

I contacted Superior Grinding LLC here in KC. They do my sharpening. The answer is "yes"


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## Rebelwork (Jan 15, 2012)

Home depo cost on the two blades was $54. My sharpener charges $7 each side. If there double sided it would be $28 +$5 delivery. If there ready to sharpen I would buy a second set so I could send one off and have good blades already on tge planer while you wait...


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## FrankC (Aug 24, 2012)

Even a smart monkey can do it:


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## TimPa (Jan 27, 2010)

i think the planer model may have an impact on this. i have an early 12.5" model, and i have had the blades sharpened. i also do my own honing when that is all they need. my blades don't have holes in them. 

so i think we have a model change where disposable blades came into the picture.


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## swp (Dec 17, 2021)

I do not attempt to sharpen my throw-away planer blades, but they do not go to waste. They get cut up and reground into carving knife blades, blades for cutting gauges, shims, and anything else where I need a thin piece of metal that will hold an edge. No clue what steel they are, probably a tool steel like O1. I don't anneal and reharden, just grind away slowly and keep dunking in water. They make decent carving knives and work well for the local Cub and Boy Scouts doing woodcarving.


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## Kudzu (Dec 23, 2008)

woodnthings said:


> Exactly! Well said, at least someone understands the whys and wherefores involved.


Restored my PM-100, had it down to the bare castings. Put it back together following some good advice from Bob Vaughn and it performed near perfect first time.


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## Ac7ss (Jan 3, 2022)

Mine were double edged. Take them out and flip them over.


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## woodnthings (Jan 24, 2009)

Ac7ss said:


> Mine were double edged. Take them out and flip them over.


The question was "is it possible to sharpen blades for ...."
The OP is probably smart enough to have flipped them over already ...... you think?


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## Ac7ss (Jan 3, 2022)

woodnthings said:


> The question was "is it possible to sharpen blades for ...."
> The OP is probably smart enough to have flipped them over already ...... you think?


Anything is possible. It was never stated that they flipped them.


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