I've been trying to sharpen my 6" jointer blades with the the
sandpaper/scary sharp method as described here:
but for the life of me I cannot get them sharp. If anything they are duller
than they were when I started. I have a set of Hirsch chisels that I use
the same technique on and they will get sharp - very sharp. But after going
through the grits 80, 120, 220, 320, 400 the jointer blade are just plane
dull, heck the factory square edges are sharper than what I did.
I hold one blade flat along the glass with the front bevelled edge acting as
a guide for the one I am trying to sharpen. As near as I can tell the blade
stays in this position - I don't let it rotate on edge. In the article they
don't even use a guide, they just "feel the beveled surface on the paper".
I even mark the edges with a marker to make sure surface wears evenly. How
long am I supposed to stay on each grit - seconds? minutes? hours? Is it
even possible to sharpen jointer knives this way? I'm doing something wrong
I know but can't tell what.
I suppose it's possible. How would I tell?
They are factory blades from a Ridgid 610 jointer. The manual (page 23 of
http://www.ridgid.com/CatalogDocs/jp0610_6442_eng.pdf states that they can
be honed on an oilstone and reground.
If they are the original blades, they are not carbide. I'd have to say
the problem is just technique. I spent a lot of time getting a couple
of jointer blades sharp because I found holding them at the correct
angle was problematic. I have no trouble with my chisels and plane
blades because I've got a honing guide.
It should only take a few minutes per grit.
I just got an old jointer from my father in law; never used
one before. But I do know what the terms mean. Honing and
regrinding are entirely different. Regrinding means you
take the knives to a sharpening place where they "grind" the
cutting edge. Honing, means you leave the knives in the
arbor, wrap paper around most of the the stone so that it
won't ruin the table, raise the table and move the arbor so
that the stone fits flat on the knife bevel, and slide the
stone sideway across the knife.
I suggest you go talk to a saw and knife sharpener (a real
one that uses expensive tools). It cost me $6.60 to grind
my three 4-3/8" blades which were in terrible shape. I
don't see how you could grind the cutting edge parallel with
the back unless you have a highly accurate jig.
Tough to hold the blades at the proper angle without some form of a jig. If
you roll them a bit, they'll end up dull. Before I got the Makita, I cut a
saw kerf in a board at the proper angle to make the bevel on my blades
parallel to the bottom of the board, then mounted a cone stone in my
drillpress, sliding the blades back and forth, then adding a piece of paper
underneath as a shim did them very well. I believe I picked the idea out of
FWW tips section. Lapping the wire edge off completed the job nicely.
A local sharpening shop does a really nice job on mine for $0.90 an
inch. I have two sets, when the new set goes in, the other goes to the
I've gotten good at chisels of all types, plane irons, etc... but find
the cost of a pro doing my jointer and thickness planer blades well
worth it. They usually return better than any new set I've ever purchased.
Think about something here. You have a jointer to give you accurite edges
in a timely fashion. The wetstone or other hand grinding operations are
always going to be a problem in attempting to sharpen jointer knives as all
three edges need to be hitting the wood flat and square as well as sharp If
one blade is a little longer you are not going to get a good edge.
The solution is easy send them to be sharpened. This is an easy proposition
to a tool and die maker with a surface grinder, so the charge is nominal and
the job is perfect. The tool maker will set the blades on a fixture that
will hold them precisely and he just grinds them untill they all match with
a machine that can move the grinding wheel down in increments of 1/10,000 of
an inch at a time. You can never come close to that kind of precision by
The wheels are also not the kind of wheel that you find on a bench grinder.
They are designed to be dressed with a diamond to flatten the face of the
stone leaving extremely sharp edges. The surface grinder also grinds under
a flood of coolant so that all of the heat generated in the grinding process
is removed. (This is a really cool machine.)
Do your self a favor and don't waste your time dinking with the jointer
About the time I had mastered getting the toothpaste back in the tube, then
Yeah, buy yourself one of those precision grinding gizmos! That sounds like
a machine no good dorker should have to do without. :)
(Put it right next to your 16" TS and 12" jointer. :) )
Cool description. I love a good tale of a ridiculously expensive machine
I'll never be able to even dream about owning in my wildest fantasies.
Michael McIntyre ---- Silvan < email@example.com>
Linux fanatic, and certified Geek; registered Linux user #243621
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