How straight should jointer knives be?

Dan Gonzales

Member
Messages
511
Location
Whittier, CA, USA
Hello All,

I took two sets of jointer knives in for sharpening, an 8" and 6". When I took them out of the wrapper to mount them they didn't look quite right.

The edges are sharp, but more like a micro serrated edge. I put them against my Starrett square blade and they aren't really a perfectly straight edge either.

Here are some pics of a knife from each set. See the light shining between the edges? They are all about the same level of wonky.

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So is this typical/acceptable? I've never seen new knives so I don't know what to expect.

Thanks.
 
That's not gonna work for you. Does the shop do jointer knives as a normal thing or were they doing you a "favor"? Let's look at it this way; you are normally trying to set your knives parallel to the table top to within .001" or so.

Quote from a "How To":

"Going through all the trouble to set the knives to +/-0.001" or so pays off, the knives stay sharp longer and the finish is noticeably better."

I'm not feeling that the knife you show will ever give you +/- .001" across it's length ;-(
 
Quick responses! Thanks.

The blades were sharpened at an established saw and grinding business. They pick up and deliver from my local tool emporium (a highly regarded establishment).

I will be taking the knives back because I know they will make it right.

Cheers.
 
I agree with the others...that sure doesn't look right to me. If the emporium you mentioned is the one I'm thinking of, I'm pretty sure you're correct about them making things right. ;)
 
Stuff happens. As long as they make it right in a prompt manner I don't know that I'd let a one-off issue determine future business decisions, but I'm an individual - woodworking is not even a self-sufficient hobby for me, much less a livelihood.
 
Joiner and planner blades are one of the few places that machinist precision is need in my opinion. People setting their fences with dial indicator is so overkill! But when I set up my joiner or planer I do use a dial indicator to set roller hieghts, pressure bar, etc. I set the blade heights within +/-.001", No way would I accept those blades, there is at least that much variation to start with. Your will have a hard time ever setting those right.

As for the shop, I would give them a second chance if they have a good reputation. Lots of things could have happened. The machine may have a problem and no had noticed yet. New employee that doesn't know how to set it up right. Lots of possibilities.

If they came back that way again, I would be looking for someone new.
 
Quick responses! Thanks.

The blades were sharpened at an established saw and grinding business. They pick up and deliver from my local tool emporium (a highly regarded establishment).

I will be taking the knives back because I know they will make it right.

Cheers.

Since you're in Whittier, I'm guessing you mean Battels. If so, I can't imagine them not making it right. Thay're a great place to deal with. I was there often when I lived in SoCal.

My guess is that the sharpening service had a new, inexperienced operator on the grinder that day. Hopefully, by now he's seen the error of his ways...
 
If they look that bad with the naked eye I can imaging what they'd look like what they would look like magnified. Take them back and explain why your not satisfied, if they say that's the best they can do, I'd tell them they need to farm them out to somewhere else that can straighten them out. If they won't I'd ask for my money back.

Bill
 
The best you can hope for (on a good day) is the surface of the work to duplicate the sdge if the blades (just like a router or shaper) so, NO, that is not a good grind. Novice work at best.
 
Hello All,

It took me a while to get knives back to my local tool store. They were very surprised at the poor workmanship and immediately took them back for resharpening. I will pick them up next week when I have a chance.

Have a good 3 day weekend to the USA part of the family!

Cheers.
 
If you think about what you want them to do, PERFECTLY flat, no knicks and square is necessary! Anything else will NOT give you the knid of surface you want.

Just my opinion for what it's worth!

Bruce
 
I received a call Friday morning that my jointer knives had come back to the store. The tool guy apologized for the sharpening service, said they forgot to place them on the honing machine after sharpening them. I am still leery of their condition so I ask him to unwrap them and take a look before I go pick them up. Five minutes later he calls back and is spitting nails he's so PO'd with the sharpening service - they came back the same as they left.

So back to the sharpening service for a third time. This is one of the best woodworking machine stores in the LA area and I know they'll make it right, but I don't think I'll be giving them any more of my sharpening business. I'll also ask for a partial refund of the fee for my own time wasted.

Wait and see what appears next week.

Cheers.
 
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Those blades should be straight even before they are honed. Honing should only remove the burr left from proper sharpening and not to straighten the edge from improper setup and grinding. I realy doubt they even touched the blades when he sent them out again ( makes you wonder how I know that ). It also sounds like they have a new person doing these blades that doesn't have a clue as to what they are doing.
 
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