The best tool/place to flatten chisels

Somehow the previous owners of a few of my (potentially) finer chisels didn't own:
a) a mallet
b) a hammer
c) a sharpenning stone (but did have a bench grinder handy)
d) any variety of oil

There's some fine steel there, but without some real effort, not up to snuff.

Ideally I'd like to send my chisels to someone who has some fine equipment and a real touch. Otherwise it's up to me and maybe I need to tool up beyond my Makita wetstone and diamond stones.

Any wisdom out there?

Thanks in advance,

Zach

Not sure if this will help, but I recently bought some antique framing chisels. One was bowed like a bananna, the other has a slight twist. I sent them off to Tom Perkins (Jim Rogers partner/buddy). He is going to straighten them by heating them in a forge etc etc...He apparently has experience doing these framing chisels. He will straighten them for me and I will do the lapping and sharpeing. He can do that too, but I only wanted to pay for what I couldn't do. What I've learned is that flattening and sharpening are no as precise and particular as some might make out. There is no magical angle. As long as your are between about 25 and 33 degrees, it will work just fine. Closer to 25 degrees for soft wood, and 33 for hardwood, though you can use either for either if you want. You can use a bench mounted belt sander to flatten the backside of the chisel(hopefully you only have to do this once to a used chisel and it will stay flat if you use it correctly. You can also use the bench mounted belt sander to get your bevel angle. Cut a block of wood to the correct angle to use as a guide on the tool rest of the belt sander. Grind a little and dip in water so you don't build up heat. Check your edge for square and get it square if it's not. Now you can use sandpaper of various grits on flat glass to lap the back side and bevel face to a mirror finish. Last step is to create a micro edge about 2-3 degrees off your bevel face angle. After you establish that with the sandpaper, you can then use your wetstones and finally a stop if desired. Now, I am not an expert sharpener, so you can take this as you will. This is just what I was recently taught by head woodshop guy at Vermont American, who has been a wood worker all his live, taught by his father and grandfather. I have been learning myself and am in the process of getting 5 antique chisels into shape. What he told me sounded right. Praphrasing... A lot of people will pontificate about the angle and precise sharpeing. He said those guys spend too much time sharpeing and talking about sharpening and not enought time woodworking. You can't spend all day sharpening. You have to be able to get a good edge within 5 minutes, not an hour. As long as you take car of your tools and never let them get dull, sharpeing should only take a minute or two. (touching up the micro edge on chisel). He also told me that you don't need any fancy gadgets. You can make simple wooden guides for the belt sander, and for honing your microedge, you shouldn't need anyting. You should be able to learn to tip your edge that extra couple degrees from the bevel edge by feel. I've tried to summarize what he taught me. I'm sure some will disagree, but I will work with this method while getting these chisels into shape and see how closely I agree.

If there is a machine shop in town or neighboring town bring the chisel/slick in there. The scariest sharp edge I've seen on a slick was put there by a surface grinder and a talented tool maker.

I'd devote an evening or three and do it by hand but thats a lot of time.

I use 60 grit(emery is best) glued to plate glass and an angle grinder for shaping.
For the back, I'll start lapping on the plate glass for maybe 30 seconds, till I can see what is going on. Then I clamp the chisel in a vise and use the angle grinder to remove the obvious, being aware of overheating the chisel. I'll bounce back and forth between the plate glass and the angle grinder until back is flat. Often there is a low spot just behind the edge of the chisel that can be tapped down with a hammer and anvil(cold).
For the bevel, I use the Lee Valley guide

http://www.leevalley.com/wood/page.aspx?c=1&p=33001&cat=1,43072,43078&ap=1

I had one years ago and wore it out, then went free hand, then recently bought the guide again and am loving it. I use the same process, set the chisel to 25deg, work on the plate glass for 30 seconds till I can see what is going on, then move to the angle grinder to remove the obvious, have to be a lot more careful about overheating when grinding the bevel. I like the angle grinder because I can see what I'm doing at all times, as opposed to a bench stone where you can't see until you take it off the stone.
Once the shape is there, I move to waterstones and finish up. The Lee Valley guide does a good job on the microbevel.

I use a retired machinest as well. He get all the old tools I buy up to snuff, and then I can take it from there. He also likes to find timber framing and woodworking tools to restore and sell. I'd be there more often if I had the money.

Raycon, your toolmaker isn't in Hartsville MA is he?


Dave

Good advice. I'll try a machinist first. I wish the abuse had been such that I could take care of it myself.

Otherwise, anyone had experience with one of the fancier sharpeners for flattening the back of chisels?

Best,

Zach

You see...that's where I started out, I wanted to use a surface grinder to fix a chisel - to get the bevel angle and grind it back past a chip in the edge. The head of the wood working shop set me up to do it but told me that I was spending more time and effort than was needed to fix it. I am hard headed and spent two hours with the surface grinder getting the bevel where I wanted. Shortly after I started using it, I dropped the chisel on concrete and chipped the edge. That's when he explained to me how he'd fix it..first on the belt sander with a cup of water for cooling and a wood block set to about 25 degrees. It took about 5 minutes and it was as square as you can get. He had wanted to let me do the the long tedious way first on the surface grinder so I'd understand better. Doing it his way, we had it fixed and sharp in short order. You should spend more time working wood than sharpeing tools. His method is not a hack job at all, but practical and effecient. Note: after fixing the chisel on the belt sander, you can then (as I did) use wet/dry or emory paper on glass to lap and product your microedge. Actually PSA paper may be best. It comes in rolls with an adhesive back so no messing with spray glue.

I've used just wet/dry sandpaper and water to adhere it to the plate glass, seemed to work as I remember it, but it has been a while....

the makita wetstone is a good tool but if there needs to be a good amount of material removal then i use a benchtop belt sander and zirconia belts. I was amazed at what a great job that it did. and then of course run it through your stones.
the zirconia belts cut the metal really fast without heating up to bad but keep a glass of water handy anyhow.


bloveland

Thanks everyone. I'll give it a try on my own with the belt sander and follow it with the Makita. I was concerned that was too barbaric for a good old tool.
I'll try with my most beat up one first.

I have a 2" bevelled-back with a heck of bite out of the edge. I figured to use a beveled block of wood as a rest and grind with the cutting edge trailing.

For what it's worth, I'm sure happy I switched from water stones to diamond stones a couple years ago.

Happy Solstice.

Zach

What about the diamond stones do you like? I find that the edge that they produce is not as fine and precise. However I know that people love them. Any thoughts?
bloveland

I picked up the big DMT diamond stones and have been happy with them, after making the big investment.
No truing. Cut faster than anything stationary, and wonderful for cleaning up edges on the job in a hurry.
I haven't experienced the less than fine or precise edges, although I have to confess I really like sandpaper on glass.
All this said, I haven't been in the need of scary scary sharp and haven't pushed it that far, as I encounter grit regularly. If it'll shave the hair on the back of my hand easily, I call it good.

Best,

Zach