Do you sharpen (grind) your planer and jointer knives yourself? I hone my knives before installing, but now I would like to do my own grinding also. Do you use a shop-made jig on a narrow belt sander or grinder ect?
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For small blades like 6" or 8" that aren't nicked, I use my bench stones only. Many stationary planers have knife grinding jigs that attach to the planer and grind the knives in place. You don't want any irregularities in your planer blades, so, it's best to send them to a sharpening service that has the proper equipment to do a good job. It's a good idea to have an extra set or two of knives to put in rotation. If you work with figured wood, you may want a set with a different cutting angle. Good quality grinding equipment is expensive. Planer blades are not the best candidates for hand held grinding.
Planers blades can last through a lot of wood but there are some ordinary precautions that will help extend their life. Always make sure to dust or blow off the rough stock. Never lay a board on the floor, it will pick up any sand or grit and quickly ruin blades. Try to avoid knots and always check for imbedded debris.
Beat it to fit / Paint it to match
Oldgeezer,
I use a planer-thicknesser having a pair of 10 inch HSS blades. I used to get these reground when honing was no longer sufficient or they became badly nicked. This cost £7 (about $11?) and they came back sharp, flat and only in need of a basic hone to polish them to perfection.
Other sharpening needs saw the purchase of a Tormek wet grinder, which has an (expensive) option of a planer blade-holding jig. I indulged in the purchase of this jig, at 12 X the cost of sending the blades away to be sharpened. (I said it was an indulgence). :-)
Come knife-sharpening time, off I go to the Tormek. Set up was no problem and I made very sharp edges. However, there is more to it than that.
My error was to allow the 2 blades involved to end up with slightly different weights - I ground more off one than the other. This caused the planer to vibrate - not a huge amount but it didn't feel good. So I eventually understood the cause and reground the heavier blade till it weighed the same (within a gram). Problem solved.
The whole process took a significant amount of time. I reckon about 40-60 minutes grinding and honing - especially if you have to keep weighing the blades.
If you have a good sharpening service, this is the way to go. If you like to play and money burns a hole in your apron, try the Tormek or similar machine.
NB I once also tried to hand-sharpen these blades with a Veritas jig and a large diamond plate. The Veritas jig is really meant for 6 inch blades but it seemed to keep my 10 inchers flat, straight and square. However, it took ages to take off sufficient metal, even on the 10 X 4 diamond plate. In fact, I gave up after 2 hours and sent them off to the sharpening shop. Perhaps a coarse, in addition to fine, diamond plate would help.
Of course, Veritas jigs and diamond plates are also rather expensive.....
How large is your joiner or planer? The Tormek, with the special jig, works great on a twelve inch or smaller blade, sort of works on a fifteen inch blade, but on the twenty inch blade I won't even try it.
Planer is 12" . Lee Valley sells a 1" x 42" belt sander with an optional attachment for grinding smaller ( 6" ) knives. I am in the process of building a similar machine, and wondered if anyone has done something similar. I think I can build a jig that will allow me to accurately grind longer knives. However I would welcome any ideas or comments.
You may find like I did sending the planer knives out is the best way to sharpen them.It is extremely difficult to get an even grind across the knives. If you have three knives they have to be the same weight too,otherwise the cutterhead will be unbalanced.I have done it, but not worth the time.
mike
I have dreamed of a machine, as you are building, for years. Seems like there should be on and I suppose the professional shops do use them. I think I'll try to learn the woodworking trade in my few remaining days.
I send mine out for sharpening. Cost is very reasonable, they are returned the next day, and the grind is good because they are done in a 24" grinder (so no low spots).
Find someone local to do it; my local guy is Ridge Carbide in New Jersey.
I have been sharpening my own for over 30 years. When I take them out of the head, I use a jig which mounts on my smallest table-saw.
It is a simple set-up that consist of a piece of plexiglas to bridge across the insert with a piece of aluminum channel across the back for a fence. I like to use a 1/4 1-/2" white wheel, and I use a Kool-Mist system which uses compressed air and water with a rust-inhibitor to keep the blade cool.
You set the sharpness angle with blade height, and the back-set of the fence, Then just slide the blade back and forth across the jig. Once I have them all ground, I balance them by grinding a little off of the back edge before honing.
In between grinding, on both my 24" planer, and my 12" jointer, I will hone the tops of the knives with a diamond hone. I have forgotten which supplier I got them from, but I have glued the 2: X 6" 3/16" thick plate hones to handles. Then with a little wooden wedge between the face of the blade and the infeed table, to index the cutting edge plumb over the center of the arbor, I hone a secondary top bevel. This only takes about 15 minutes for four 12" knives, and I usually do this at least four times between removing and grinding.
Recently though, I used a little right angle die-grinder with a little diamond disk about the size of a nickel to remove most of the heel of the secondary bevel. This enables me to hone a few more times before removing and grinding the knives. I got the grinder from Harbor-Freight for under $20 and a box of about 30 - 40 diamond disk and burrs that I got from the same source for about the same price.
When I was in another location, sending off blades for sharpening oftentimes meant a two to three week delay before they came back, so I sharpened the 16" planer and jointer blades myself with a shop-made jig. That was 10 years ago, and out of desparation.
Most urban centres have sharpening shops which are not only capable of quick turn around times, but also capable of provision of accuracy or fineness of grind any home system ain't likley to provide, So that's what I use now for machine tool blades.
OTOH, these high tech quick turn-around places ain't likley gonna lavish the same care and attention to yer handsaws which are, from what I hear, and have experienced, more of a PITA for them.
There's lots more what could be said on achieving the balance between "Sharpen it yerself" and "send it out" and it has to do with type/cost of blade, time, quality, cost, risk of damage, turn-around time, and other considerations. But I'll not venture further into that morasse.
Eric
in Cowtown
Geezer,
I have posted pics of this before, but thought it may be of use to you, especially if you have a machine with a sliding table. I used that feature of my spindle moulder to build my knife grinder-in the long run it will save me money , also I prefer to do these things myself-any bevel angle , back bevel etc.All made from existing machines or bits salavaged here and there, with some tweaking.
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