Hi Guys
A few years back I saw an article in FH re backbeveling jointer knives. It involved setting your knives then running a sharpening stone over them ( while the machine is running) to back bevel them. I have actually done this and It makes sense from the standpoint that once done all the knives should be at exactly the same height. It does seem however that the wood doesn’t feel “right” going over the jointer. Am I dulling the blades?? I would love to access that article again and maybe get some feedback
Louie
Replies
I have seen comments on that before, but have not idea when or where.
However I suspect that it was in FWW and not FHB.
But both mags have online indexes. Have you tried those.
No I haven't but I will now. Thanks a lot
So, you have enough nerve to place a stone in position against a running jointer head, so as to "back bevel" the blades?
Wow! Scares me just to think about it.
Anything the blades contact when the head is running in its forward rotation will tend to dull the knife edges. Wood does this just a little, but your stone is doing it in spades on steroids.
Just so you guys don't think I'm a total nutcase I found the issue. It is in FWW october 1993. In it the man says that when backbeveling the knives should show no more that 1/32" or it will start to "heel". I think thats what's happening. It is really meant to do when stock is tearing out or it is a particularly curly grain. Belive me that I was very nervous the first time I did it and, quite frankly I don't think the results are worth the effort. I don't think the blades are dull, but I do think they are heeling. Guess I'll change them tomorrow... a task I am not real fond of. Thanks for all the replies.
Lou
Louie, What you described is called jointing the knives. I used to do that about 20 years ago before I realized it was causing me more work than it was solving. Besides my nerves got too frazzled. I have heard back bevel as another term for a face bevel, which I do on my jointer and planer. In both the knives are set with about 30 degrees hook in saw-blade terms, which is fine for softwoods, except this will causes a lot of chip-out on figured hardwoods, and almost all of my work is with hardwoods, so I grind a 20 degree bevel on the face which reduces the hook, or actually cutting angle to 10 degrees. Whenever my knives start to dull a little, i can slide my outfeed bed back out of the way, and I use a medium then fine diamond hones 2 X 6" that I have glued wooden handles onto to sharpen 4 -5 times between taking out and grinding. It only takes about 15 minutes for four 12" knives. Much faster than taking out and replacing and $0 cost.
Problem with that trick ,besides being dangerous, is that it leaves a heal on the back side of the knives. This means that shortly after the knives start to get dull the heal starts banging into the stock instead of the leading cutting edge.
lou- the back bevel is around 10ยบ give or take a degree ,i have had a difficult time finding a place after the last place i used closed up shop. ....when i did have it done it was done correctly and there was not any noticable transistion in the function..... except when they got dull and then it was like you have posted. i 'm curious to know if you did them why they where in ( mounted ) in the joiner. i've done this while there the joiner and found it somewhat difficult, and can be alittle dangerous if you arent not that acquainted with the process. the best way find a sharpner that does the back bevel and it isnt cheap and try this once . if that doesnt suit you an initial investment of a sharpening system( i have the tormek) $ 400 for the basic set up. and do you r chisels ,plane , knives, ax , scissors. i got in the winter and EVERYTHING was sharp within a 500 foot radius of me . i'd bet you a buffalo nickel up there vermont there a guy real good at it ...