Jointer/Planer knives - How sharp should I expect

[Dave Rowell]

I recently bought a second sets of knifes for my planer (Jet 13" planer/molder) and Jointer (Powermatic 54A) and sent the originals out for sharpening. I was really unimpressed with both the new knives and the "sharpened" knives. Both new knife sets were labeled as being from Jet/Powermatic and were purchased at the same local distributor. The jointer knives had really large nicks in them. The planer knifes looked better (I had to get a light out to see faults) but neither were very sharp. For what I do they are pretty much useless and perhaps worse than what I sent back to be sharpened. What I got back as sharpened was pretty much the same quality as what I sent out.

My question is am I expecting too much. I sharpen my own bench plane blades and chisels and am used to really sharp tools that work wood easily and cleanly. Is the current blade market so bad that people are using kinda sharp, but not really sharp blades or did I get taken by my local tool store and sharpener?

The results I get with either the new blades or the sharpened ones are bad: lots of tearout, lots and lots of noise and surfaces that look like junk by my standards (but I'm pretty good with the #4).

Dave R.

[Bridger]

sounds like you either need a new sharpening shop or a setup for sharpening your own....

[Kelly Shamash]

Even a honed and polished planer blade would probably never feel as keen as a properly sharpened chisel due to its much higher angle. I wondered the same thing myself, if a planer blade were to be polished to a razor edge, how much better would it perform, and for how long? Personally I think it would be a waste of time to go beyond a certain level as the pounding the blades are subjected to would probably crumble keen edges fairly quickly. As for your Jet blades, you may have gotten a defective set. You could try to return them and try another brand?

[WORSS]

I am certainly no expert in this area, but if you are getting blades back with nicks in them that is completely unacceptable. I sharpen my own planer and jointer blades on the Makita sharpener and get good results. I can get minor nicks out pretty easily. The last time I sharpened the jointer blades (6"), I actually tried to flatten the backs. Took forever and I never did get them completely flat. I have a feeling this is a waste of time.

Bill

[Mike at American Sycamore]

Dear Dave:

I have always had great luck with knives ordered from Freud. You will find them better quality from the replacement blades most companies sell and they are priced very competive. I would also suggest that you talk with the sharpening service and explain to them that you are not satified and perhaps they could do a better job for you. If they are unwilling to co-operate....find a new service.

Good luck, Mike From American Sycamore

[Bob S.]

They should be sharpening them with 600 grit which leaves a striated surface on the bevel. Any nicks viewed with a 4x loupe should be no deeper than a grit scratch. If you're seeing nicks with the naked eye - they're doing a lousy job.

Get yourself the Makita or the Delta sharpener with the planer blade attachment and you will be set up to sharpen just about anything in your shop except sawblades. I have both the 600 and 1000 grit wheels, made a leather hone wheel out of MDF plus some Scary Sharp wheels again with MDF and various grits of wet/dry paper. My chisels, turning tools, plane blades, jointer and planer blades and even drill bits can be sharpened and honed quickly.

I've seen several shop made jigs (see magazine sites) that will hold both jointer and planer blades and use Scary Sharp techniques that can be built inexpensively. In our area, getting a set of DeWalt 12" planer blades sharpened cost nearly $20. The Makita or Delta sharpener can be had for under $200 with a 600 grit wheel on the Makita and I don't recall what the Delta comes with. Some MDF and a chunk of leather from a hobby shop plus some green honing compound will add $10 plus your time to make the honing wheels if you need them (and you don't for just jointer and planer blades).

A sharpening system - shop built or purchased is a good investment. Lots of "How To" articles out there and mentors here that can explain the fine points of shapening just about anything. You'll get lots of opinions and ideas and you can pick and choose what suits you.

Bob S.

(I see I'm gonna have to trademark my sig since there's another Bob S (doesn't use a period) out there....;0

[Dave Rowell]

I use Freud for the occasional bit and saw blade, but I never thought to check there for knives. Thanks a lot for the pointer. One set of the "new" knives came so badly dinged that it maybe be cost affective to toss them and buy a set of freuds.

As far as going back to the same sharpening service, I don't think that will be a win. The service was through the store that sold me the "new" blades that I'm now convinced were someones returns. It took weeks to get a set sharpened and I'm stuck with two sets of basically unusable blades and I don't want to eat anymore downtime (before was okish because of the holidays and the kid's vacation schedule). I may try to get them to take back their POS blades they sold as new, but it's a tough fight since they could always claim I dinged them. (I used to have a regular tool salesguy that always handled my business and I really miss that now.)

I'm probably going to send the planer knives out to a sharpen by mail service. Where I live nothing is cheap (~30 bucks for sharpening 3 13" planer blades) and it's really hard to find competent services in anything (Don't even start me on the painters who just secured their tarp by nailing through my roof). If they come back reasonable I send the other sets to the same place.

Dave R.

[Bob S.]

Well let's see now.... my day job may be short-lived, I have the Makita sharpener, I know how to sharpen planer and joiner blades and he sounds like he's willing to pay the price for quality work... Yooo...... Dave

;-)

Bob S.

[Dave Rowell]

Well I just fired my painter and it looks like all my woodworking projects are pushed out until after I finish stripping and painting this puppy myself. So basically maybe I'm not in as big a rush on the jointer and I might have time to get into sharpening them myself.

I've read good opinions on the Makita setup and maybe I'll go that route. One concern I have is whether or not you have problems with blades flexing, resulting in cupped or crowned blades. I'm still a little bit worried about the balancing issues, but I see most people don't seem to have problems. Do you do anything special to make sure blades in a set all have roughly equal mass? How much time does it take to do a set of 3 13" knives?

Thanks for the info.

Dave R.

[Bob S.]

Dave,

With the Makita, the blade holder is rock solid and the blade itself rides against adjustable stops. So while it's a bit of a pain to initially set up, once it's done, lock it down and forget it. The holder is cast and steel - it will not flex. Follow the sharpening procedures in the Makita book and unless you have nicked blades, one or two light passes and you have a sharpened blade. If you have nicks, then it will take however many passes it takes.

I wouldn't worry about blades being out of balance - you're only taking off a few microns of steel. And you take the same number of passes on each blade. To check the blades, place then on a flat surface and place the sharp edges together. Use a magnifier and see if there is any gap between any two sharpened edges. If there is, double check your setup or perhaps better yet, do this before you grind them so you'll have a reference point. Then you can count the number of passes it takes to get any cupping out. As for crowning, that should come out when the blade is installed flat but unless those blades are real thin, I doubt they have any crown to them (or maybe I'm not understanding what you mean by that...)

To do a set of knives for my planer takes about 15 min. That's get the sharpener out, set it up, align the blade holder to the correct angle (since I may have used it for a different blade angle previously), add some water, insert blade, make minor adjustment so blade only contacts grinding wheel at one spot (per instructions) then make one pass, inspect, and repeat as needed. Blade is sharp when it slices your finger and you didn't even realize that you touched the blade.... Did I mention that you should wear some protective gloves while handling those blades? The garden gloves with the latex covering the woven fabric (borg - $3.98pr) type gloves work well.

Actual sharpening time - about 10 seconds per pass - slow and easy with consistent speed and pressure pushing the blade holder from left to right. Takes longer to mount the blade and remove it than it takes to sharpen it.

Bob S.

[Bob S.]

Forgot to mention - in my remark of "lock it down and forget it", I failed to mention that you need to purchase some metric lock nuts (7mm I think) that go on the adjusters on the blade holder. Your initial (PIA) alignment is where these get adjusted, then use lock nuts or double nuts (back to back) to set these adjusters so they do not move. Some Lock-Tite (blue stuff - not red) will help too.

Bob S.

[Montyhp]

[snip]

When I jointed a bunch of green oak (I know, it was pretty abusive on the equipment) with my Grizz 0500 I ended up having to clean off a significant amount of pitch from the knives. There is no way that the same amount of pitch lodged on each knife. If the amount of pitch as compared to the mass of the cutterhead was significant, I would have had a real problem. I don't think that a small amount of difference in the blades is significant (the cutterhead is only going 7000 rpm or so, we're not talking about a jet engine here).

No problem

Montyhp [snip]