Official Luthiers Forum!

I've managed to make my original jointer knives (Jet 6" jointer) last a long time without a sharpening, just touching them up without taking them out of the cutter head, but it's time to do an all-out sharpening. My tentative plan is to buy a Makita horizontal wet wheel sharpener and do it myself -

http://www.makita.com/en-us/Modules/Too ... spx?ID=170
http://www.highlandwoodworking.com/maki ... ner-1.aspx

I've found two of these used in my area, so this is looking like a very economical option. In the meantime, I've ordered a set of replacement knives (Freud HSS), so I can change them out and keep using the jointer while I learn to sharpen the first set, and so that I'll have two sets from now on.

Before I jump on the Makita sharpener, I thought I'd consult with you folks. How do you get your jointer knives sharp? Do any of you use this Makita machine? Love it? Hate it? Do you use carbide jointer knives? Would you recommend switching to carbide knives and forgetting about sharpening my knives myself? Any other thoughts?

One more thing... one reason it has become necessary to take these knives out and sharpen them is this: a few months ago I started getting rows of evenly spaced, very small nicks in the knife edges. The nicks are less than .010" deep, spaced about .040" apart, and kind of hook shaped, rather than "V" shaped. This had never happened before, and I haven't been running anything over the jointer that should have caused the nicks that I know of. The uniformity of the nicks and their even spacing suggests some interesting phenomenon going on here... Has anyone seen this before and know what causes it, and how to avoid it? Is it something that happened because of stress the knife edges were under due to being overdue for a good sharpening? BTW, I always take very light cuts on my jointer.

Thanks in advance for any help you can offer.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

I have mine done at the saw shop. Cost is around $5 per blade (8") if memory serves. If I spent even 10 minutes per blade (my jointer has 4) doing it myself the economy evaporates, and the saw shop has a machine that's dedicated to it, so they're straight, parallel and razor sharp. As the saying goes, you can't beat a man at his own trade.
-C

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Freeborn Guitars
and home of BeauGuard©

Todd,

I have an 8" General Jointer. I bought a machine from Busy Bee (here is the Grizzly equivelent):

http://www.grizzly.com/products/Universal-Knife-Grinder/G2790.

I bought this mostly because I didn't like how the local guy sharpened the knives for my 20" planer. But if I had a good guy around that could sharpen them (at $20 to $30 per set) I would do that. Less work, less learning curve on a new tool, more time woodworking! Even with the sharpening system I am going to buy carbide knives for the jointer and I may replace the head in the planer to a spiral one. A luthier friend of mine (builds 80 to 100 guitars a year) has the same jointer and has carbide knives in them and says he hasn't had to change or sharpen them in 10 years and they still cut great.

Shane

(EDIT) Chas beat me to it! But the message is the same...send 'em out if you can, if not then I guess you need to learn to do it yer self!

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Canada

Machine shops that have a surface grinder will do an excellent job on jointer blades. Todd if you only have a small nick or two you may be able to slip a blade or two sideways a bit to eliminate the raised line on your wood. Hope that makes sense .
Tom

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A person who has never made a mistake has never made anything!!!

Anyone know if you can get carbide blades for a Craftsman 5"er??

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Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

Yup, what Shane said (and Chas before him), and I have the exact same grinder from BusyBee, and it's great, but if I didn't have time to burn,(sort'a retired here) I'd send them out - it's way cheaper to send them out when you make your money doing woodworking.

cheers

John

Todd,
I have a friend who does his (on the Makita ) and he still needs to send them out after every 3 or 4 resharpenings. It takes a bit of finesse and there is a learning curve to using the Makita. My advise is, now that you have two sets you should just send them out. I would continue to touch them up as you have and you could, with a jig do a bit more than touch up with basically sandpaper on glass method, ( I refuse to refer to it as "scary sharp" bugs me as we have been doing this for many, many years before "scary sharp" became the rage , but I digress
So you would really extend the time between sending them out and as you said you are doing that already.
So yes the Makita does work but it is very cheap to send them out and you already have two sets. You will have to fuss around with the Makita (put a crown in the wheel to sharpen the jointer knives which makes it not the greatest for flattening backs of chisels and plane iron) and learn its nuances so in the end I don't think it is worth it even with the short 6" blades. With 12" I wouldn't even consider it. (The point being that 6" is a fairly short blade and easier to deal with)
Also since you have two sets why buy carbide. Pricey and you are not in a industrial setting where you are running miles of wood through your jointer. Changing jointer knives is pretty quick and easy especially on a 6". Plus the HSS can be made to be much sharper which really helps if you are a off the jointer type of guy for edge gluing. You can also have a set with a back bevel for tear out prone woods. Easy to do on the HSS.
Ask the woodworkers, cabinet shops etc. where you live who they use. There is a wide range of quality with folks who sharpen. Find someone who does a good job and send them out. IMO.
Good luck,
Link

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Cut to size.....Beat to fit.....Paint to match.

I should add also Todd, I bought my grinder mostly for the planer knives. I have typically sharpened my jointer (and portable power plane knives) on the belt sander. I just made a stepped jig to clamp all three in a block of plywood and slowly (using light pressure) 'ground' them on the belt sander. That works slick and quick (holding the knives a bias to the running belt) but the 20" knives were just too much to handle for the sander.

Shane

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Canada

There is a manual jig from Veritas also. Anyone use one of them?

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Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

I also send mine out so I can't comment on the machines you're looking at. I think my local sharpening shop charged me around $30 to sharpen my jointer knives. I won't hesitate to go that route again when the time comes.

Darrin

Thanks a lot for all the input, everyone. Very helpful and much appreciated. I'll make some calls and find out who's recommended in my area to send them out to, and how much it would cost.

Link, thanks for your input regarding carbide vs HSS.

Frei, I just might give that Veritas jig a try at some point (this is the one we're talking about: http://www.leevalley.com/wood/page.aspx ... 43078&ap=1). I was thinking that the Makita machine would be easier and more accurate, but perhaps I'm wrong.

Thanks again to everyone -

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Here, here, Link i too have been using sheet glass and abrasive paper for many years, no one taught me that method, i just came up with the system myself long before the internet was heard of. I wanted to be able to sharpen good quality bench chisels removing as little steel as possible. My oil stones were fine for site work framing and butt chisels etc to be done by hand, but would need dressing each time if i wanted to hone my bench chisels and use a jig to conserve steel. It just seemed an obvious solution to use fresh sheets of wet & dry on glass so i did. It's my bet that very many wood workers have come up with the same idea over the years out of convenience and common sense and to see anyone put their hand up to claim the method as their own is a bit rich in my view.

Cheers

Kim

I would not recommend carbide blades for guitar making: high speed steel sharpens sharper and you need all the sharpness you can get for figured woods.

Your evenly spaced nicks sound to me like they were caused by plywood.

I'd recommend you send your blades out if you have 2 sets. It'll be a long time to recoup your investment in a sharpener and the time you'll spend setting it up accurately when all you're sharpening is 6" blades. If you also have longer planer blades, well maybe it would make sense to have a sharpener.

You can shift your blades left and right to eliminate the ridges you're getting.

I have the Veritas jig .. it works great. I discovered that the knife sharpener I was using to do the jointer blade scraper I have wasnt working all that well, so I tried the veritas jig adn 600 wet dry on granite - in about 2 minutes the scraper was working better than ever ..

Anything bigger I send out thru the local wood shop - they have a guy who does their stuff every couple weeks.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I'm a little reluctant to post this, since it could be dangerous if not done right.

I touch up my jointer knives on the machine by "jointing" them with a stone. Read about it in a book once (don't remember where), gave it a try, found that it worked.

You lower your outfeed table a tiny bit, like a thousandth or two. Take off the blade guard. Place a perfectly flat stone (I use the fine side of an old "India" synthetic combination stone) on the outfeed table (machine running), advance it until it contacts the blades, pass it across the blades a few times. Put a light oil on the outfeed table and the stone first (WD-40 works). Yes, this is scary. I wear a full face shield, just in case for some reason the stone might shatter. And needless to say, you are looking at the unshielded blades spinning. If you try to take too big a cut, it will chatter.

The good thing about this is its ease and speed. It also puts a tiny back bevel on the blades which makes the edge less fragile and gives a better cutting angle for very hard woods.

Don't do this unless you agree not to hold me responsible for any bad stuff happening. Please.

Oh, I agree with Link about "scary sharp." I started sharpening with sandpaper on glass about 1972 or so. And it wasn't shown to me as if it were some new invention. Now I do it on a granite surface plate.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Actually, the serrations I'm talking about first appeared when I was jointing some ash. The boards were 3/4" wide and these serrations spanned the 3/4" width of the knives being used for those cuts. More have appeared since then on other parts of the knives. On Sawmill Creek, I read about a couple people having this happen, but nobody seemed to be able to explain it. One person suggested that it could have been caused by some abrasive grit on the wood, but that doesn't seem to explain the precise uniformity of the tiny "nicks" and their precisely even spacing (as I said, about .040" apart).

I probably could shift the knives slightly left and right to eliminate the tiny ridges, but it would be nice to know what causes these, and how to avoid it.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Thanks for your input, Todd. Your point is well taken about certain woods pretty much requiring the use of carbide. I'll bear that in mind. I might eventually invest in one of these:

http://www.sunhillmachinery.com/en/home ... gory_id=12

Another thread got me thinking about investing in an edge sander. Among the many ways that machine would be useful, it seems like it would provide an alternative to using a jointer for certain applications, such as truing up edges on woods that would wreak havoc on jointer knives.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Thanks for your input, Tony, but I confess I'm confused by your terminology. What "scraper" are you talking about?

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Thanks for posting this, Howard. I have a book that recommends this method, although they describe it slightly differently. I've been reluctant to try it, but I just might give it a go. One of the things this book recommends is clamping a board to the infeed table to act as a stop block, or, you might say, a kind of fence. The end of the stone butts against this as you do the "jointing".

Another thing they recommend is wrapping paper around the part of the stone that sits on the outfeed table as you do this, to prevent scratching the table. It sounds like you've found that putting oil on the table serves this purpose. Am I understanding you correctly?

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Todd .. in another post on scrapers I posted my version ...its a wooden handle with a 6 inch jointer blade in it ... it is simply amazing at flattening sides, levelling binding etc .... I had been sharpening it in a LV orange knife sharpener ... but the bevel is now too thick to get deep enough into the sharpener to do a good job .. hence using the LV jointer blade jig with 600 grit

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Cool, Tony. Thanks -

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

I haven't felt that the blades were trying to pull the stone on to the infeed table so as to require a stop block there. I guess it wouldn't hurt to do that, though.

Yes, you have it correct re the oil. The stone is fine enough that it wouldn't be scratching any coarser than the grind on the table, but the oil floats it, and also lubricates the sharpening cut on the blades. Other than a diamond hone, I don't know of any stone that should be used dry. I like the India stone because it is hard enough not to be gouged by the planer blades (like I think a water stone would be), and fine enough to leave a good edge. This method also can be used to bring the blades even in height with the outfeed table and parallel to it, assuming they are not off by more than a couple of thousandths of an inch to start.

And to clarify, where I said above to pass the stone across the blades, I meant side to side; not to pass it on to the infeed table and back. The stone never touches the infeed table, which is lower than the outfeed table.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Sounds good, Howard. Thanks.



I understood this, but it's good that you clarified it for anyone else who might be reading this. Thanks again -

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Hi Folks, I sharpen mine by hand. I made a blade holder from scrap wood and beveled the leading edge to match the angle the knife should be. I have a 6" diamond impregnated plastic el-cheapo sharpening stone and a larger block routed to hold it. I usually resharpen when they start to get dull, but I have been known to run over some glue that wasn't scraped off. It don't take very long to do a set, although its not quite as accurate as blade grinder it works for me.

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Mike

May be too late for this, but I have the Makita and use it to sharpen jointer and planer knives.

Yes, it is very fiddly and takes time to get the right bevel on the wheel and jig setup. There is also some technique involved in getting a straight and consistent bevel. -not too difficult with 6" knives, but it gets harder as the cutters get longer

It can also be quite messy since the splash shield always seems to be either too high or too low.

And despite having the wet wheel, I also keep a few spare sets knives on hand. When I knick a blade is start getting tear-out, I want to change the knives and keep working -not tear everything down and setup the sharpening equipment. (Of course, that means that usually my spares are also dull and knicked)

-jd