Sharpening jointer blades and setup
brianmexico | Posted in Power Tools and Machinery on
Hi Everyone,
I have the delta sharpening station jor jointer and planer blades. I bought this unit for the sole purpose of sharpening the blades on my six inch jointer. Ater the first few go rounds I didn’t find that I could achieve a good edge. Am I using this thing wrong or does it just not work that great??
It seems to me that on the whetwheel the part that spins into the blade as you’re sharpening would actually tend to dull rather than sharpen the edge of the knife. I really need to sharpen the old fella up and there’s nowhere around here that does any sharpening. If anyone has some tips to help out I would appreciate the advice. Maybe there’s some other method I could use to sharpen these blades??
Thanks,
Brian
Replies
Brian, I'm not familiar with the sharpening jig but I sharpen my own 6" jointer blades on my stones. Grinding with a wheel always seems to result in a slight crown or belly in the blades. I put my 8" diamond stone in a vice and hold the knife on its bevel. I move the knives back and forth the long way. You can go through the normal progression of grits as you would a chisel or plane blade. Unless you have some large nicks, it's very easy and doesn't remove as much metal as a wheel would. The knives come out nice and straight so setting back up is easy. The cut far surpasses any ground knives I've ever used. I'm sure you could use sandpaper instead of stones if that's what you prefer.
Beat it to fit / Paint it to match
Numerous people have discovered that the type of grinder you are using doesn't do a very good job of sharpening jointer knives, but perhaps someone has some tricks to offer that can make them work better.
DMT, a maker of diamond sharpening stones makes a simple jig for holding jointer knives that allows you to hand sharpen the knives on either their diamond stones or on sandpaper on a glass plate.
I've had good success with the DMT jig and it is easy to use. As you sharpen you need to check your progress with a dial caliper or a micrometer to make sure you are keeping the knives even in width from one end to the other and fairly closely matched in width from knife to knife to keep the set in balance, but other than that, the procedure is quite simple.
John W.
Postscript: I went to the DMT website, dmtsharp.com, and I couldn't find their planer knife jig, they may not make it currently.
Edited 8/4/2005 9:26 pm ET by JohnW
Lee Valley sells a jointer knife sharpening jig (P/N 05M25.01). It works kind of like their jig for sharpening plane irons and chisels. I'm pretty happy with it. I wouldn't try to use it to grind out a major nick, but it does the trick for normal sharpening.
Hello Everybody,
First off thanks to all for the great advice. Here's what I did:
First I took out all the knives (hope I didn't warp anything by doing that) and upon inspection saw that the last time around when I sharpened these knives on the mickey mouse delta unit it actually left them concave and not truely straight.
I used the scary sharp method on the tablesaw top and started with 320 working my way all the way through to 1500 (The tips of my fingers are still numb from holding the blade accurately with no jig)
I then went to my 6000 wetstone and gave them a final dressing.
They came out really sharp and virtually flat.
Now I'm hearing some excess bearing noise.............wooonderful.
Brian
Brian, next time you need to grind those knives, I would suggest getting one of the white Alundum wheels and mount it on your table -saw with a fence across the table like for making cove. You can find you angle with blade height and backset of the fence. I use a little strip of plex to bridge the gap
Brian -
I just go up to 600 grit on my 6" jointer knives. Seems that they get dull a lot faster with any higher numbered grit. Of course, I'm running lots of Cocobolo, which makes a difference.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
Thanks for the tip, the blades are reeeally sharp and I can imagine that this could create a weaker edge, on the next go round I'll stick to a lower grit.
Brian
Brian,
I am not familiar with the machine you mention, so this may not be helpful: what type of stone is on there, maybe it could benefit from a dressing with a diamond dresser? Some stones , combined with certain steels , just don't work properly unless dressed frequently to remove glazing etc.
The stone on this unit looked to be about a 1000 grit whetstone (brown color). The problem with it is that even with a little shaprpening done the stone goes out of trueness and wears quickly. I think I'll try the other method's mentioned above and use this machine for chisels and plane blades before I go to the hand stones. O well, $140 not well spent, doh.
Brian
Brian,
Invest in a flat faced diamond wheel dresser. Even if you now only use that brown wheel for narrow stuff like chisels etc it must at least be true and not loaded with metal or be glazed. No grinder should be without this essential tool. They don't cost too much and last for years.
I used a Tormex sharpener and found out that my best efforts with the system resulted in blades failed to last 1/2 as long as those same blades sharpened by pros who sharpen the cutting edge for printers (try printers service in your phone book)
Naw, the only reason for a 2nd bevel is just to faciliate re-sharpening. But, if you have a nick in the blade (99% of the time) you have to start over and grind it out.
Plus, I just don't have time now to futz with trying to sharpen my own blades. I take everything out to MVP Sharpeners here in Houston (well, actually Cypress TX). With half the cost it would take me (considering time cost) I get twice as good a job.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
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