Sharpening Jointer Knives?

[tkarlmann]

I am interested in finding out what everyone is doing when their jointer knives get dull.

I have a 6" Ridgid jointer, and I just bought a set of knives for about $21. There was a thread recently that quoted a source for knives that was about $15/set, on sale, I think.

I just got quotes on sharpening from Woodcraft and Rockler a few stores in Chicago & Milwaukee. Pricing varied and included $0.62, $0.70, and $0.85 per inch. For a three-knife, 6 1/8" blade jointer this works out to $11.39, $12.87, and $14.70.

Wow! Sharpening costs are expensive. I did a search, and it seems that it has been a while since this forum has done this topic.

Tools: Has anyone used the Vertias Jig? Costs $60, holds the knife so you can use abrasive paper over glass. It appears that payback on this jig would be rather fast. http://www.leevalley.com/wood/page.a...072,43078&ap=1

There was a Rockler jig mentioned in an earleir thread, ~2006 -- I cannot find this on Rockler's site.

Also, cgallery has created what looks like a shop-made jig for jointer knives:

http://www.bt3central.com/showthread.php?t=21253&highlight=sharpening+jointer+blades

Any thoughts? Has anyone tried this?

The issue I do not yet understand is how to hone the flat part of the blade. Clues anyone?

I would like to know what everyone is doing.

[jabe]

I used to sharpen my own with a sharpening jig made for the Rockwell 6" & 8" jointers I had at the high school shop that I taught at. Also sharpend the 24" & 12" planer knives too. It was time consuming and I ended up doing it on weekends or holidays with no pay. So it was cheaper to send it out for sharpening than doing it on my own time. But it was good that I knew how to do it and still can do it if I had too.

[tkarlmann]

I used to sharpen my own with a sharpening jig made for the Rockwell 6" & 8" jointers I had at the high school shop that I taught at. Also sharpened the 24" & 12" planer knives too. It was time consuming and I ended up doing it on weekends or holidays with no pay. So it was cheaper to send it out for sharpening than doing it on my own time. But it was good that I knew how to do it and still can do it if I had too.

From what you describe, the jointer knife sharpening requires a lot of time? What abrasives did you use? What grits? How long did it take? Was you knife-holding fixture similar to the one I referenced?

And a question I didn't ask earlier: What type fixture did you use to hone the backs of the blades?

[LCHIEN]

new blades from infinity, around $30-32 for a three blade set. Check with www.holbren.com and use his discount code for BT3central members (BT310 I think). You'll need the measurements or go to the infinity site (www.infinitytools.com ) for sizes.

[cgallery]

If I hadn't had a weird size of knife (220-MM by 1" by 2.5-MM, I think), I wouldn't have embarked on sharpening them myself.

The sandpaper worked okay for knives that were only a little dull. Not the greatest for knifes that were nicked or extremely dull.

I purchased the Woodcraft wet wheel sharpener w/ the knife jig and now use that.

[jabe]

I used the knife sharpening kit that Rockwell sold specifically for their jointers and 24" planer, it had a motor much like a dremel tool to grind the knives while it still was on the jointer & planer. It had several different grit grinding wheels. What took long was to set it up on the jointer & Planer. I also used the Tormak to sharpen the 12" planer knives, that was really slow. Results were great but not worth the your time. I found that paying to have it sharpened was what worked best for me time wise. It also formed a good working relationship with the sharpening service that I still use today for all my sharpening needs. My sharpeing service usually give me a break in the price of my personal knives or saw blades. I keep 2 sets of knives so I won't have any down time with my machines while the other set is being sharpened.
That tool you're looking to purchase would take a lot of time to sharpen if your knives are knicked. I would use it only to touch up the knives if it were not nicked. In my opinion, that tool is not worth the money.

[pacwind3]

I sharpened mine about a month ago and here is what I did.
The angle on my blades happened to be 45 degrees. I cut three slots in a scrap board at 45 degrees about 3/4" apart. The only real trick here is that my table saw blade kerf was skinnier then the thickness of the jointer blades; so I had to make a few passes to get the kerf thickness the same as the jointer blade. I then inserted my three jointer blades into the slots and ran a sharpening stone over each of the blades.

It worked pretty well and only took a few minutes. I think I'll purchase some of those stones that have the diamonds impregnated in them for the futures. Also you could wrap sandpaper around an MDF block and achieve the same results.

[cgallery]

If I had to do it over, I'd make a jig like Pacwind's and then I'd use a small wheel in the drill press and pass the knives under the wheel. I'd set the height of the press so it just kisses the knives, and then use some typing paper as a shim under the jig and take another few passes.

If you're going to do this, it is important to have a balance to make sure the knives are all the same weight when you're done.

[tkarlmann]

Common Theme: Time required sharpening Jointer

This makes sense -- as the blade edge is a lot longer than a chisel or plane.

My blades are a little nicked up -- not sure how -- but nicked on the end nearest the fence.

No one is talking about how to hone the backs (referred to as the face, not the bevel) of the knives. I spoke to 'someone' at Veritas, and they agreed that their jig did not address that. They suggested just holding it with fingers on the abrasive. (!)

Also there is no benefit achieved by only honing the two edges of the bevel as there would be with a chisel ground on a grinding wheel.

Does anyone know if griding a bevel (from a 6"-8" grinder -- presuming some attachment/jig could be found{?}) into the jointer knives would weaken them?

It's starting to sink in that hand work for a maintaining a flat bevel onto three 6" long steel blades is going to be a loooooong process.

I'm not sure that I have seen any powered sharpening system that could take the entire 6" blade and grind it evenly. I wonder how the sharpening pros are doing this job?

[tkarlmann]

The Faces?

I sharpened mine about a month ago and here is what I did.
The angle on my blades happened to be 45 degrees. I cut three slots in a scrap board at 45 degrees about 3/4" apart. The only real trick here is that my table saw blade kerf was skinnier then the thickness of the jointer blades; so I had to make a few passes to get the kerf thickness the same as the jointer blade. I then inserted my three jointer blades into the slots and ran a sharpening stone over each of the blades.

It worked pretty well and only took a few minutes. I think I'll purchase some of those stones that have the diamonds impregnated in them for the futures. Also you could wrap sandpaper around an MDF block and achieve the same results.

How are you planning on honing the faces?

[tkarlmann]

Thanks for the link at Holbren!!!

new blades from infinity, around $30-32 for a three blade set. Check with www.holbren.com and use his discount code for BT3central members (BT310 I think). You'll need the measurements or go to the infinity site (www.infinitytools.com ) for sizes.

For my Ridgid Jointer:
Holbren --> YES -- $15.99 w BT3 discount (!), not including shipping;
Infinity --> Does not have the correct size: 6 1/8" x 11/16" x 1/8"

Thanks ever so much for the BT310 Discount code at Holbren -- it WORKS!

[tkarlmann]

If I hadn't had a weird size of knife (220-MM by 1" by 2.5-MM, I think), I wouldn't have embarked on sharpening them myself.

The sandpaper worked okay for knives that were only a little dull. Not the greatest for knifes that were nicked or extremely dull.

I purchased the Woodcraft wet wheel sharpener w/ the knife jig and now use that.

What "Woodcraft" sharpening system did you get? They show 10 pages of sharpening stuff.

Are you talking about the Tormek, Jet, Worksharp, Delta?

Is this Woodcraft thing better or faster than the jig you made to use with sandpaper?

[cgallery]

What "Woodcraft" sharpening system did you get? They show 10 pages of sharpening stuff.

This one:

http://www.cgallery.com/jpthien/ws.htm

I don't think they sell it any more, but other sellers do.

It is certainly faster than sandpaper. And it also does a great job. Very happy with it.

But again, if I had a standard knife size, I wouldn't bother. I'd send 'em out. I'm just unwilling to take a chance with knives that are very difficult to replace.

[tkarlmann]

This one:

http://www.cgallery.com/jpthien/ws.htm

I don't think they sell it any more, but other sellers do.

It is certainly faster than sandpaper. And it also does a great job. Very happy with it.

But again, if I had a standard knife size, I wouldn't bother. I'd send 'em out. I'm just unwilling to take a chance with knives that are very difficult to replace.

Woodcraft does not sell this anymore, but following your links I came up with what looks like a similar item: the Makita Blade Sharpener Model 9820-2. Says it will sharpen planer blades up to 15 3/4 long. Problem: Cost is $325 on Amazon!!

Did you pay that much for your Woodcraft version?

I'm getting lost in this issue. There must be a better answer for jointer knife sharpening out there!

Can you go into some more detail as to how well or how poorly your hand-made jig worked for you? I cannot spend $325 on something to sharpen jointer blades! Thanks.

[cgallery]

Woodcraft does not sell this anymore, but following your links I came up with what looks like a similar item: the Makita Blade Sharpener Model 9820-2. Says it will sharpen planer blades up to 15 3/4 long. Problem: Cost is $325 on Amazon!!

The Woodcraft unit is really a low-cost knock-off of the Makita. I think I spent about $100 for the Woodcraft sharpener + the knife jig. Still kinda spendy unless you're paranoid (like me) about some sharpening service hosting-up your nearly impossible to replace Inca knives.

The sandpaper method was slow but gave me Popeye like biceps. Like I said above, not great for knives with nicks. But it did produce incredibly sharp knives.

The local (to Milwaukee) sharpening rates I've seen advertised for knives is about $.50/inch. So if you have a 6-inch three-knife unit, you'd be looking at $9 for each sharpening. I'd seriously consider that.

If I was starting over and insistent on doing it myself, I'd be inclined to make a jig that would work in conjunction w/ my Worksharp 3000.