Tool Sharpening ?'s/recommendations

[Traveler]

I'm looking for recommendations on a good system for sharpening my various chisel and planer blades....any help on specific products would be a big help as I have almost no exp. in this area. A friend who worked in a door shop talked about creating a hollow grind with a grinder and advised not to get tools too sharp as the fine edge wears quickly. I generally find his advice sound but at times he talks above his level of knowledge and as luthiers you know what and how the tools will be used and on common build materials used in luthiery. thanks.

[ToneMonkey]

and advised not to get tools too sharp as the fine edge wears quickly.

Well it's the first time I've heard that, but that doesn't mean to say it's untrue.

However, I take mine to the local harware shop where he does an excellent job for very little money. I don't really use my woodworking tools often enough to warrent buying a wheel. I've got an oil stone, but to be honest, it's one of those jobs where I prefer to pay to get it done propperly.

[Mattia]

Google 'Scary Sharp', and/or look at Ron Hock's website (makes great replacement irons for planes) for information on sharpening. Machine tools are NOT required to keep a tool in tip-top condition, although they can make it an easier job in some cases, and serious regrinding is more fun with something other than your arm doing all the hard work.

Assuming your tool is in good shape (ie, the back is perfectly FLAT and polished, the bevel is accurate, and for my money, flat, with a microbevel at the end), 'sharpening' it isn't difficult. I use a combination of diamond stones (flattening), sandpaper and japanese waterstones (honing, depends what I'm in the mood for really/what's around), and a scrap of 1200 grit paper stuck to a scrap of glass on the bench for touch-ups. Because if you want a seriously sharp edge, particularly on a chisel, you need to occasionall (during use) hone the edge just a touch. Makes all the difference in the world. Total investment? Cost of a few sheets of sandpaper you may already have lying around anyway, and some scrap glass from your local glazer/window company if you want a flat bottom. You only need to really flatten the back of your blades (chisel, plane) once, and then 'merely' keep them maintained and flatten them as part of working on the edge.

Re: hollow grind, I wouldn't bother, but I don't to machine tools. What the hollow grind does is give you a thinner edge and shallower angle, both of which make the edge MORE vulnerable/prone to dulling/chipping. A microbevel does the opposite, giving you a slightly higher cutting angle and more metal behind the sharp edge - if you can't cut arm hair with it, it could be sharper. Remember - lutherie is different from regular cabinetmaking. It's even more nitpicky than most fine cabinetmaking, and shares a number of characteristics with machining (ie, what other woodworker uses calipers quite so regularly).

[ToddW]

I use the scary sharp method. Glass plate and sandpaper. It's pretty easy. I didn't see that Mattia mentioned a honing guide. I just got the cheap Grizzly sells, but Lee Valley has nicer ones to hold the blade at the correct angle. You can also make your own.

Todd

http://www.grizzly.com/products/Honing-Guide/G1482

[John Abbett]

1. Flatten and polish the back of the blade at least the edge.

2. Use a sharpening guide to put an edge on the blade with a stone.

3. Occasionaly take the burr off the edge by stoning the back edge.

4. Once you have a nice back and edge, adjust your guide a degree or two, to put a micro bevel on the blade. This is so you can touch up the blade without having to resharpen the entire edge.

Once in a while, put the blade back in the guide at the angle of the micro bevel and touch it up. Two or three passes of the stone.

You only have to prep the blade once, then just hit the micro bevel occasionally. I ususally touch it up if I'm going to do a lot of work with it. I think the last time I touched it up was a few months ago.

Oh, my stone is a water stone, very very fine. 8000 grit if I remember, I use that for the micro bevel, 1200 for the edge.

Taking off the burr will allow you to get the blade sharper. I take the burr off, then one final pass on sharpening as the last step. Otherwise you are continually rolling a burr and not really getting a fine edge.

Look at the edge with a magnifying glass. You can tell a sharp edge by the fact that it's stright across and not very jagged. A big burr leaves a jagged edge when it breaks of.

Oh, for a very quick hone, you can always take the iron and polish the back of the blade on your fine stone, it will touch up the amost sharp iron withouth guides. It's just touching up from the other side. It won't take off enough to thin your blade if you stone is fine enough to polish instead of cut.

There are a lot of ways to do it, some use fancy sharpening set ups, they probaby work great for initial sharpining. I've found a good stone and 5 minutes per blade will get it sharp enough to take thin shavings off of oak without effort.

-J

[Traveler]

as always, great advice from great people. most of my blades are in good condition ie no nicks to really have to grind back down to, just needing a nice sharp edge put back in to do the job. so one of the 8000G water stones maybe a honing guide?? any other basics I should be looking at??

[ToddW]

I'd probably get something in addition to the 8000G stone. That's really just for the final polishing of the edge. Even a sharp blade will benefit from a few passes over something in the 1200-2000g range, and a pack of wet dry sandpaper is only $2.47 at WallyWorld. Course they only had up to 800g last time I was there, so had to head to the auto parts store for the 2000g and spend $3.50

Todd

[Guest RavenT]

Here is what you well need mineral spirit some wet/dry sand paper 1000G to 3000G a plate glass the size of the sanding paper and a sharpening jig and a grinder and as to the brand you get it is up to you. Now if you take your chisels and planes like the guy to your local hardware shop it is going to be hard when you decide to chisel a board of ebony, when you have to sharpen again after a few cuts. The harder the wood the more often you are going to sharpen your tools. First form on the grinder your squared edge of 90°. Then proceed to the sand paper put some mineral sprit on the paper place chisel or blade on the jig as indicated 2 1/3” depending on the model you have. Now just wheel the jig back and fort on the 1000G, test from time to time the sharpness of the blade by shaving a little hair from your arm. If the hair comes off clean then just polish on the 3000G and your done. Remember the harder the wood the more often you need to sharpen the blade.