Making Jointer knives from Planer knives
Getch
| Posted in Power Tools and Machinery on
Hi all,
Having a heck of a time finding 6 inch jointer knife set locally and I need new blades fast. I need them yesterday!
I can easily pick up a set of 13 inch planer knives for a Ridgid planer.
They are just a bit wider due to thier double cutting edge.
My question, Has anyone cut down planer blades to use in their jointer?
The thickness is the same (1/8″) but like I said they are 3/4″ wide vs the 5/8″ of my original set.
If it works, I’d actually have 2+ sets of blades for $30 since they are double edged….
Replies
An intriguing idea.
For safety, and clearance with the edges of the tables, the blades are only supposed to extend a few hundreths of an inch beyond the outer diameter of the cutter head. Your machine's manual will tell you what the setting should be, and how to get your outfeed table positioned at the proper height, to then use the outfeed table to set your blade height. If you follow that procedure, and the blades will still set in the heads properly, at the proper height setting, which is possible, then it is safe to use them.
The bigger trick will be cutting the hardened steel blades and getting them to be a very close match in length to keep them in balance. The best way to cut them will be with an abrasive wheel followed by a clean up on grinder. You won't be able to saw the blades they are way to hard.
John White
To cut them I'd use my makita grinder with a cutting wheel. That will cut thru anything!
Yeah I was curious if the extra width would fit the slot...my first inclination it yes because when I removed the blades the first time to hone them a bit...it seemed like there was alot of inward adjustability.
High speed steel obviously can take a lot more heat before it loses its temper, but you could still burn them easily with an abrasive wheel which makes a lot of heat.
If you decide to do this, I'd go really slowly while cutting and dunk them in water often.
http://www.ithacawoodworker.com/
It's also my impression that there may be enough depth in the slots of many jointers to take a slightly wider knife. To cut the blade accurately with a hand held grinder, clamp a block of wood onto the blade where you want the cut and then lightly hold the cutoff wheel against the block to keep the cut square and accurate. As already mentioned, keeping the blade cool will preserve the temper but at the very end of the blade it won't matter all that much.John W.
Thanks guys!
Rick, yeah, understood. At this point anything is better that the blades on there right now. I just have a deadline approching fast and wasnt prepared for the blades being in such poor shape.
John, good tip. I will likely cut them a bit strong and then sneak up on the line via low speed grinder or file. My idea was to wrap the blade tightly in a wet rag to the cut line.
I don't know where you are but any sharpening shop should have spare blades.John W.
Why don't you just pull the dull blades and sharpen them. It's pretty easy to do 6" blades on a stone. Hold them on the bevel and move them on the stone the long way. You'll have a much nicer edge than with a grinder. The first time takes a little work to remove all the scalloping of the grinder. Probably a lot less time that going to get blades and hacking them up.If you fill in your location in your profile, a neighbor may be able to direct you to a local source you don't know about. Many mail orders have next day service for a fee.Beat it to fit / Paint it to match
Should be no problem as long as you can get them low enough in the head. That curve on the knife holding gib is actually the chip breaker. Not the edge of the table as some think.
The only real problem is the knife quality won't be as good as it could be. Buying good tool steel from Wosconsin Knife Works, Schmidt, and many others will give a longer lasting edge. Buying original equipment replacemnt blades is typcally a substandard product. You could have the bevel ground both edges on other blades.
If the blades that you have on the tool now aren't totally bunged up, you could hone them and maybe get a few more days out of them while you're waiting for replacements. Personally, I don't think cutting down planer blades would be worth the time & effort to save a few bucks. YMMV.
Mike Hennessy
Pittsburgh, PA
Hello,
I have used the jig pictured here with great success.
http://www.superwoodworks.com/Projects/JKnifeJig.htm
Probably the same amount of works as cutting planer knives and figuring out a way to install them.
Good luck,
Adam
This forum post is now archived. Commenting has been disabled