Honing a skew

[rsser]

A skew has been described as a finishing tool.

The more refined the edge the cleaner and easier the cut so honing isn't a bad idea and you don't need a Tormek to do it.

This is what works for me and in very little time I have an edge polished to 8000 grit.

1. Hollow grind on a dry grinder.

Here I'm using a cheap platform with a mitre gauge. I've used a square to draw a line on the wheel face at 90* to the side. I line up the skew edge with this and set the mitre angle.

Normally I ink both bevels but this skew's been through the process.

This kind of platform is a little prone to flexing so modest consistent pressure will give a consistent bevel.

You can of course do this with your choice of jig.

2. Hone.

This is easier than it looks and quicker than it takes to describe.

You press the bevel down on a waterstone with one finger and cradle the shaft with the other hand. You can feel it register properly after you lower the handle a little so the tool pivots on the bevel bottom and then raise the handle til the edge contacts the stone. Draw it down the stone. Skewing the edge on this stone produces a smooth glide.

This stone is 15 micron, about 700 ANSI or 1000 JIS rating.

The object is to hone out the scratches left by the wheel in order to produce a refined, ie. less jagged, edge**. That was 80 grit or about 300 micron so it's quite a jump. But about 10 strokes on each bevel does it. You're only taking a small amount of steel off at the cutting edge and the bevel bottom and creating two new co-planar micro bevels.

I repeat this on 4 micron and 1 micron stones for a polished cutting edge. These stones were laid in for another purpose but perform well for this. The first honing after hollow grinding only needs about 4 strokes of each side on the 4 and 1 micron stones. Inking the bevels at the cutting edge helps you see if it's working. All you're doing is polishing out the scratches from the previous grit.

When next you have to sharpen, ink the micro-bevels and just hone instead.

Over time the bevels get wider and honing takes more strokes. When you run out of patience, hollow-grind again.

If I was starting over I'd just settle for a 15 micron and a 2 micron (6000 JIS) stone and then go for a coarser stone as a refinement to speed up the first honing step and remove minor edge damage.

(4 micron is about 4000 grit JIS, and 1 micron 8000 JIS)

Another option to refresh the cutting edge is to hone with an extra-fine diamond paddle; but I find it a little harder to use than the bench stones.

....

As posted elsewhere, I have a concern about cash-strapped woodies shelling out over a grand for a Tormek and jigs when there may be alternatives. I don't believe that you need a wet grinder for HSS tools, but jigs and a honing system are close to essential. I'm working on two options for putting jigs in front of powered honing discs.

** Up close the edge off a dry grinder looks like a badly abused wood saw.

[wood hacker]

Hi Rsser

Speaking as a relative newby on a tight budget who is still struggling to master the art of sharpening that sounds very good advice. Very similar approach to what is shown near the end of this demonstration (http://www.woodworkingonline.com/2008/09/23/podcast-37-turning-tools-sharpen-your-skills-with-sharp-tools/). It's a pretty big file (259MB) but lots of stuff I've found helpful.

cheers
WH

[hughie]

As posted elsewhere, I have a concern about cash-strapped woodies shelling out over a grand for a Tormek and jigs when there may be alternatives. I don't believe that you need a wet grinder for HSS tools, but jigs and a honing system are close to essential. I'm working on two options for putting jigs in front of powered honing discs.

I agree Ern, with some lateral thinking the whole process should well inside the budget of nearly all woodies.

Most jigs and hones can be DIY made with a little help from knowledgeable others. In days gone by honing was achieved with leather wrapped around a mandrel and coated or impregnated with a fine compound.
As for jigs, well we have some of the hardest wood around and it will do just fine for jig making.

*

[Tiger]

Would agree with a lot of what Ern has said. The skew chisel is probably the easiest woodturning tool to hone and hardly justifies buying a Tormek for it although a Tormek would make honing gouges easier than honing them freehand.

I would also say that I have not seen any jig that does a good job of grinding the skew with consistent bevels on each side or even aligned with the skew's edge. The method outline by Ern is the method that I have returned to after trying various jigs. It is economical and gives consistent results.

[rsser]

When the snow melts I'll tackle the power honing array on the lathe arbour. Three leather clad MDF wheel rims with 3 grades of diamond paste; Tormek BGM mounted on a tool post; lathe running in reverse.

The hand honing method has been something of proof of concept: that you can get from 80g scratches off the grind wheel to something like a 6000-8000g polish in three steps.

[Durdge39]

I've been reading through a lot of the sharpening threads that you have been contributing to in recent time Ern and I think something to note may be the use of good waterstones like the ones you have that will cut effectively and leave a good finish, although the cost of said stones is a pebble in a desert in comparison to a Tormek (and you don't have to pay for electricity to run a waterstone :D).

Very sound advice Ern, thanks for sharing (and adding to the sharpening threads I might add). All helping to make me decide which stones etc I hope to purchase one day in the not too distant future.

[rsser]

Thanks.

Yes, which waterstone is a perennial :rolleyes:

I was wondering whether this issue would arise here.

The value of a honed edge has been advocated only fairly recently among woodturners on a wide scale (though if you go back through the decades you find the occasional argument for it in a book or mag) with the modern means being a wetgrinder and leather honing wheel.

Anyway for the benefit of those interested, the two stones on the pic are Shapton Glass stones (1k & 4k). I wouldn't buy these again.

I've had better results with a Bester (http://www.toolsfromjapan.com/store/index.php?main_page=index&cPath=335_404_468)1k and Sigma (http://www.toolsfromjapan.com/store/index.php?main_page=index&cPath=335_404_403)8k (all ratings are JIS).

At 8k you're getting a polish that will reflect your face. Just as well the bevels are narrow ;-}

[Christopha]

Honing is for hobby turners.....

[rsser]

Don't overlook the fact that Tormek added a honing wheel to their design for a reason. But getting from 200g (c. 70 micron) scratches off the whetstone down to the 1-3 microns of their honing paste is optimistic. Fine for taking the wire edge off.

Yes, you can regrade the wheel for every sharpening - but the time and expense ... ?

[Chief Tiff]

My "power hone" is a 10" dia MDF disc 19mm thick mounted on my lathe. I dress it with buffing compund and it gives me a razor sharp edge on any tool in seconds. I now need to build a jig to accurately position things like skew chisels so only the very edge is bieng honed at the correct angle, but even doing it roughly by hand gives noticable results.

[rsser]

Sounds good CT. Post a pic?

[derekcohen]

Hi Ern

I've been posting this for years and years .... No one appears to notice. I wonder why? Anyway ...

I freehand hone skews (and other lathe chisels) on the disk sander of my beltsander combo machine...

http://i13.photobucket.com/albums/a262/Derek50/Sharpening/Honinglathechisel.jpg

Since the chisels are HSS and are not affected by the level of heat produced by this process, you can use highish grits without fear of affecting the temper of the steel.

At 1400 rpm, a disk of 240 grit will leave a very fine finish. Generally this is sharp enough for most shaping work. I use an 80 grit for very rough grinding.

If you want the finest finish, one that you can shave with, then I use a leather disk as a powered strop. Ths is a strop with a different as it is flat, not round. To make this I contact glued chamois leather (from an auto shop) to a velcro-backed sanding disk. To this I add green rouge (.5 micron). In about 3 seconds you will have a mirror shine. Just hold the face of the chisel flat on the disk. It is easier than you think - just make sure that you are holding the edge away from the spinning disk!

Regards from Perth

Derek

[John Lucas]

I do mostly the same thing. Grind to produce a bevel then I use the EZ-Lap diamond hones to get the edge. I take the medium hone and lay it on the bevel. Then work it back and forth until there is a full burr on the other side. Then I go to the other bevel. It goes really fast after you establish the first burr. Once the edge is established it's pretty easy to keep it there using the fine or ultra fine hone. In a worse case I go back to the medium. I rarely have to go back to the grinder.

[JDarvall]

I like the idea of honing for details...but I'd go the quickest way....I just buff the tip, with honing compound on buffing wheel. Something of late that I find works well too, is to have a little bottle of oil at the lathe (something cheap like sunflower oil thinned with turps is what I use), that you dip the very tip of the tool into just before use occationally.....and the oil frees up the chips further (more control) and runs down onto the tool rest freeing up movement of the tool on the rest.....also, stops me having to bother remembering to oil those tools that I don't use much and tend to rust.

[rsser]

Lot of good tips; thanks guys.

There's an earlier thread on power honing here (http://www.woodworkforums.com/f127/power-honing-114122/)

Derek, why alternatives to dry and wet grind wheels haven't taken on is an interesting question of info dissemination and opinion leadership in Australian woodturning. Certainly Darlow has been an advocate of sanding discs and belts for bevel shaping and of honing with a stone. But I think the real barrier is the lack of ready jigging systems for anything other than wheels. Not many turners can do a swept back grind on a gouge freehand.

Another barrier is the divisions in the forum structure here, with relevant material appearing in sub-forums that turners may see little reason to browse (eg. carving, sharpening, handtools, woodwork).

As always there's an important distinction to be made between shaping the bevel and refining (honing) the edge. I confess to fudging that in this thread, as the first stone after hollow dry grinding is actually forming two new co-planar bevels. It also starts refining the edge.

[NeilS]

Your long term contributions on this topic are acknowledged, Derek...:2tsup:

The following are a few links on using grinding belts for sharpening woodturning tools:

Jon Siegel (http://www.bigtreetools.com/articles/sharpening2.html) - A belt advocate

Dale Nish (http://www.woodturningdesign.com/askdale/16/16.shtml) - Pros & Cons - 3rd Q&A

Brent Beach (http://www3.telus.net/BrentBeach/Sharpen/beltsander.html) - some more arguments for belts

Herman de Vries (http://www.hdv.net/tips/tips.htm) - his belt setup

Laymar Craft (http://www.laymar-crafts.co.uk/tip45.htm) - adapting tool rest/platform

Derek's Mk II (http://www.inthewoodshop.com/WoodworkTechniques/BeltSanderBladeGrinderMK%20II.html)- his adaptation

Sorby ProEdge (http://www.robert-sorby.co.uk/proedge.htm) - a commercial belt grinder system, with jigs, etc. Almost as expensive as the Tormek, but might give anyone thinking of adapting their own sander a few ideas.

For me the wheel vs belt decision has more to do with concave vs flat bevels. Not made up my mind about that yet.

One thing that belts do is blur the boundary between grinding and honing... with their quick grit changes and extensive range of grit sizes. There is merit in that if you like to hone after grinding. The running cost are a bit higher than wheels, but on the other hand the start-up costs of wet grinders are a bit steep for most turners.

....and back to the topic - a bit from Alan Lacer (http://www.alanlacer.com/articles/honingturningtools.htm) on honing turning tools.

.....

[Farnk]

Whilst not having anywhere near the experience of others on this forum, I've used a white stone fitted to a cheapy bunnings combination grinder / belt linisher for ages and have been happy sharpening freehand with that. The oval skew gets the belt treatment and I seem to get pretty consistent results.

However, having had a chance to try my spindle and bowl gouge after re-shaping and sharpening them using the Tormek at 's, I'm very pleased with the difference. this I put down to having a more suitable profile on the tool, as well as the finish from the finer stone / slower grind speed. Clearly my freehand sharpening skills need to be improved!

The issue for me now, however is that while I like the ease of use and consistent results that the tormek would provide, there's no getting away from the price. Turning is just a hobby for me and between work and family commitments I get to the lathe once or twice a month. I don't try and sell my work so any expenditure for turning is a sunk cost.

I'm not against buying a tormek system as such, It would just take a bit of convincing to get agreement from the domestic financial controller:D. I'm thinking about alternative approaches as well that could possibly deliver some of the benefits at a reduced outlay.

There are a number of cheapy wet/dry grinders out there like this GMC — Global Machinery Company (http://www.gmcompany.com/index.cfm?module=products&pid=28)
Would it be worth while to setup some form of jig arrangement on a grinder like these? What do you all think?

[Grumpy John]

Frank, don't know if you're aware but GMC went belly up quite a while ago. Ozito has an equivalent, personally I'd give it a big miss. Jet (http://165.228.72.165/webshop/EWWItem.csp?ID=ECM%7C%7C153464%7C%7C3) and Scheppach (https://www.machineryhouse.com.au/Wet-Stone-Grinder) have more cost friendly wet grinders,

[Chief Tiff]

Just for you Ern,

as I mentioned earlier in this thread this is just a 10" dia MDF disc mounted on my lathe. I only use the edge for honing but there's no reason why the face coudn't be used also. I use a polishing compound on the edge just before I apply the tool edge. Penknife blades take about 3 seconds per side!

I've also added a picture of my 1" skew; this item is literally straight out of the box. I gave it a minute or so of honing by hand on a 1000 grit diamond plate then put it on the wheel. The photo is a bit pants I know but the edge is sharp enough to shave my arm with.

What would be better for me personally is a reverse switch on my lathe! As the wheel is running in the normal direction I have to gauge the honing by hand with the blade under the wheel. Having the wheel running the other way would mean that the blade could be placed on top of the wheel and the edge actually seen. That or build another jig to add to my collection.....

[Farnk]

Frank, don't know if you're aware but GMC went belly up quite a while ago. Ozito has an equivalent, personally I'd give it a big miss. Jet (http://165.228.72.165/webshop/EWWItem.csp?ID=ECM%7C%7C153464%7C%7C3) and Scheppach (https://www.machineryhouse.com.au/Wet-Stone-Grinder) have more cost friendly wet grinders,

Thanks GJ! I hadn't heard that they were no more..
Strange that their website is still up.

Having had a few Ozito tools die very quickly I hear what you say about their grinder.
I'll look into the Jet and Scheppach units as well as the Tormek.

[Grumpy John]

Thanks GJ! I hadn't heard that they were no more..
Strange that their website is still up.

Having had a few Ozito tools die very quickly I hear what you say about their grinder.
I'll look into the Jet and Scheppach units as well as the Tormek.

You might be able to prise my Scheppach out of my hands if Ern wants to sell me his Tormek :p.

[rsser]

Re chief tiff's setup, I'm assuming there's no space to work behind the lathe?

Either the wheel edge or face should lend itself to mounting a 12mm diam rod on a tool post in order to use Scheppach or Tormek jigs. Or to mounting a Tormek BGM on a bit of RHS welded to a tool post. Providing you can work behind or reverse the lathe of course.

(Sorry GJ; you got the better deal by far anyway!).

[NeilS]

Would it be worth while to setup some form of jig arrangement on a grinder like these? What do you all think?

A jig arrangement on any type of grinder is better than freehand, well at least for your first 1,000 regrinds. After that you will have the hang of it and will know if your freehand efforts are working any better than jigging.

Perhaps the exception to this is if you are apprenticed to a master turner, in which case you will be doing whatever they do but under their guidance, and endlessly until you get it right...:D

.....

[Chief Tiff]

Re chief tiff's setup, I'm assuming there's no space to work behind the lathe?

Either the wheel edge or face should lend itself to mounting a 12mm diam rod on a tool post in order to use Scheppach or Tormek jigs. Or to mounting a Tormek BGM on a bit of RHS welded to a tool post. Providing you can work behind or reverse the lathe of course.


The current way I have my lathe set up means that working from the rear isn't particularly practical; which probably goes some way to justify to myself why I never thought about working from the back! :rolleyes: At the moment nothing is bolted down properly as I'm still fine tuning my set up and want to install dust collection, ready use tool storage and the grinder on the bench too.

I might have to look at building a jig at the rear, it's going to be much easier than honing from the front. Cheers for the mental nudge Ern.

[Rifleman1776]

I view a skew as an almost 'everything' tool, not just finishing.
That debate aside, until about a year ago I sharpened all my tools on a low speed (1750 rpm) grinder hand held. Once you get a feel for it, you can be very consistent with this method. I like a 120 grit.
However, I acquired, in a trade a Wolverine rig and like it very much. Consistent and perfect edges can be sharpened on all your tools with this.
But, your skew can be sharpened in any of a half dozen ways.
I don't see honing as necessary at all for turning.

[rsser]

There's an increasing amount of good evidence from tests that a honed or refined edge cuts cleaner, easier and longer than an edge off a dry grinder.

Anyone can PM me their email address if they'd like to read some of it.

Here's some online articles:

Read Scraper Sharpness at http://www.alanlacer.com/
Gouge test, wet vs dry: click (www.tormek.com/en/leaflet/pdf/wet_or_dry_en.pdf)

[NeilS]

The Farrance article would be more convincing if it had compared apples with apples.

Comparing the finish from an #80 dry wheel honed with a medium Arkansas stone at 17 micron grit with the finish from a #220 wet wheel then honed with Tormek's 3 micron polishing compound may prove that a finer grind/hone performs better but not that "a universally far better performance could be obtained by adopting a wet grinding method, in conjunction with honing".

A dry 220 grit diamond wheel followed by 3 micron paste power honing would have been a better comparison to prove his wet is better thesis.

I'm following Brendan Stemp's trial of his #120 diamond grinding wheel with interest, here (http://www.woodworkforums.com/f8/diamond-grinding-wheel-113355/). There may be a more economical third way to get a finer edge.

.....

[rsser]

LOL. I advanced a similar argument some years ago on the forum, and it's really only the two articles by Lacer et al. in American Woodturner that persuaded me. One of them is on his website as per my last post.

The full Farrance article (The Tormek site has an abridged version) is also unclear about a key measure of edge life.

's test protocol is a better real life test (but didn't control for the skew's included bevel angle - then again you can't control for everything).

[RETIRED]

After a few test runs yesterday the protocols may be altered a bit.