Thread: The vexed question of sharpening tooling

Hi Michael,
I have tried similar but not the same.

HSS lapped on a manual stone-well not stone -the diamond dust is stuck on a metal bar. I had some lapping soap=the sort of green soap stick used with buff.

Polished on a leather strop(on a stick) that I made for knife sharpening.

Result?- maybe a bit better- it was turning CRS bar. I should do some comparison tests and make it a bit scientific.

I will get back to you on that one.

Grahame

Hi Michael,

If you arent aware, google "ornamental lathe tool sharpening"
Now those guys the excited about sharpening. For good reason, though I don't really think it applies to "us".

http://conradhoffman.com/advancedsharp.htm

Not overly keen on the mop idea....mops are great for taking corners off things..... but if it does the job.

Stuart

Originally Posted by Stustoys

If you arent aware, google "ornamental lathe tool sharpening"
Now those guys the excited about sharpening. For good reason, though I don't really think it applies to "us"

Agreed. I'm just interested to get a good edge with minimum fuss - I wondered whether a wet stone combo may do it (although a leather strop rather than mop may be preferable). I do need to get the diamond rig together though.

Michael

I just use a file to sharpen all my wood working tools..... Works well on a chainsaw....

Originally Posted by .RC.

I just use a file to sharpen all my wood working tools..... Works well on a chainsaw....

Ah - I see that you are also a 'fine woodworker' like me....

PDW

All you need to hone/polish the cutting edge of HSS lathe tools is a smallish fine hard Arkansas stone. About 20mm wide and 50-100mm long and 6mm thick will do. There is nothing better than an Arkansas stone for this. Second choice for me would be a man made fine Norton India stone. A diamond lap would only be my third choice, but it has to be very fine grain and preferably already well used - the problem with cheap diamond laps is there are always a few oversize grains that spoil the overall finish, these oversize grains break down as the lap wears, and IMO only at this stage it gets usable to hone HSS tools. Remember, you cannot cut a finer chip than the radius on your cutting edge (the cutting edge is not to be confused with the tip radius). Try to take off a finer chip than your cutting edge width and the tool rubs instead of cutting.

The leather strap method and polishing paste etc do work well on knife edges (cutting edges with very small angles of 5-10 degrees), but are completely useless on the wide angled cutting edges on lathe tools (>45 degrees).

Originally Posted by Michael G

At the last scrapefest, Phil introduced us to diamond wheels for putting edges on scrapers and I use a diamond hone on lathe tools once they have been free hand ground.
For Christmas my family gave me a wood carving course (which I'm quite enjoying in a hand powered sort of way) Sharpening of wood tools is very contentious so I won't ask this question of the wooded brethren, but one set up they typically use is a wet stone coupled with a leather wheel and a lapping/ honing compound. The carving instructor's sharpening method is a mop with green polishing compound on it
Has anyone tried this on say a HSS lathe tool?
Just curious if there is a better or even another way to get an edge on a tool.

Michael

Hi Michael,

Final honing on a polishing mop was how I always used to sharpen woodworking tools, chisels plane blades etc.. you have to be carefull to keep the angle right to avoid dubbing the edge.... these days I have a tormek with leather wheel and diamond paste, takes just a few seconds and you've got a razor sharp edge... Josh has a totally different method, he uses waterstones and goes down through the grits.

He was turning some pulleys out of UHMW with profiled HSS tooling and you need a really sharp edge for that stuff.. HSS honed on water stones... razor sharp.

Sharpening carving chisels is a different procedure again, I use the tormek, but with the chisel on top of the wheel handle facing away from me, and wheel turning towards me, and a strong light on the edge. You shape the inside with stones or slips and then sharpen the outside by watching the light reflected off the edge, just as the light disappears.. there's your edge.. follow up with a light stop on the profiled leather wheel with diamond paste.

Ray

I know the woodies get right into the sharpening thing but if a cutting edge is sharp enough to shave with does it need to be any sharper?

Bob.

Originally Posted by Anorak Bob

I know the woodies get right into the sharpening thing but if a cutting edge is sharp enough to shave with does it need to be any sharper?

Bob.

You can still shave with a blunt razor.....but a sharp razor is sharper right? As someone who owns and sometimes uses a cutthroat there is a big difference between sharp enough to shave with and sharp enough to shave with properly.....

Coming from a tradesmans view i have to laugh at the guys going through their waterstone grits to get the perfect edge. Not that i think there is a problem if thats what you want to do, but i just want to know when you get the time to actually do some work. Any more than a few minutes on a stone is time wasted in a commercial sense.

Ew

Sharpening becomes an obsession for some... I think taking nice end-grain shavings is a good sign you don't need any sharper. The straight razor people take sharp to a whole other level of obsession.

The other aspects of sharpening, bring in issues like edge durability, micro-bevels, back bevels, different steels.. advantages and disadvantages of different stones for different alloys..

If you want to travel that path, I can recommend the work of Brent Beach http://www3.telus.net/BrentBeach/Sharpen/

But be carefull, before you know it you'll be buying micron diamond lapping sheets and Naniwa 8000 grit diamond stones... it's a slippery path.

But there's always another group to take it to crazy extremes, for different exotic blade materials, you can't beat the knifemakers.. titanium damascus, mammoth ivory scales, muonionilista meteorite iron...


Ray

Originally Posted by cba_melbourne

The leather strap method and polishing paste etc do work well on knife edges (cutting edges with very small angles of 5-10 degrees), but are completely useless on the wide angled cutting edges on lathe tools (>45 degrees).

Probably true, but with my growing collection of (yet to be applied) microscopes I suspect that if I looked at the tool edge I'd be horrified at how round it is. Once the garden tools are moved out of the shed proper there may be room for me to finally set up a T&C grinder that I have but at the moment it is all free hand.

Originally Posted by Ueee

Any more than a few minutes on a stone is time wasted in a commercial sense.

Agreed. I don't need perfect edges down to atomic level but would like to be able to get a good edge consistently with minimum quantities of goat's blood, sacrifices under a full moon and complex Harold Hall devices. Holding my tongue the right way is acceptable.

However, not having that trade background or enough opportunity to get really good with a bench grinder, I'm after any edge I can get on this issue.

Michael