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RETIRED
6th October 2010, 05:06 PM
After weeks of playing, getting all the necessary gear together in one place, numerous photographs, a stack of timber, burnt hands and sore muscles here are the results of the different sharpening practices using grinders and honing.

RETIRED
6th October 2010, 05:08 PM
These tests were carried out by a production turner the same as a production run would be done. The chisels were pushed to the limit in both speed and cut depth until they would not reasonably cut any more.

The sharpening devices used for this test were:

8” Abbot and Ashby fitted with an 8” Norton Blue max and a 6” 80# Aluminium Oxide wheels. I don't have a 8” 80# wheel.
A Tormek wet grinder fitted with a 4000# Japanese water stone. SJ250.
A Tormek wet grinder fitted with a 220# Blackstone Silicon stone. SB250
A Tormek wet grinder fitted with a 220# Original stone SG 250.
A Norton combination India oil stone approx 600# I have been told.
The Tormek leather honing wheel with Tormek honing paste.
Tormek jigs.
Tru-grind jig on the Blue max.
A Unijig on the 80# wheel.

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Each edge was photographed with a 50x microscope.

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The chisels:

1” Marples Carbon Steel.
1” Henry Taylor High Speed Steel.
1” Bohler S7 tool steel.

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The three chisels were used as these are indicative of most chisels on the market today. It was not a test of steels but of “sharpness” and for comparison of edge holding using the most common grinders, tools and wheels in use by woodturners.

The “needed sharpening” in the tables refer to when I would resharpen the tool under normal usage but they would be sharpened before that for a final cut.

To go beyond this point can result in disaster because you are forcing the tool which generally results in a catch and ruined work.

The chisel was honed on the Fine India stone after being sharpened on the Tormek SB250. It was not sharpened on a grinder but honed for all 3 cuts.

The timber used was Red Gum stumps. They were machined to 70mm x 70mm and cut to 250mm long blanks. These were lettered so that we did not use 3 consecutive pieces and to get an average “hardness” across the test. The “blank” in the table refers to these letters.

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They were then roughed down to a cylinder with a roughing gouge.

Three runs were done on the separate blanks and the times averaged. The runs consisted of a planing cut, V cuts approx. every 20mm for the beads, a peeling cut 20mm wide to about 25mm diameter and then as many beads until the chisel could be used no more.


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We did not do 3 runs on the Tormek4000# as the time taken to sharpen the tool (up to an hour) did not warrant it being considered as suitable for a woodturners grinder unless you are a complete masochist. The polish and edge that it put on the tools was something to behold though and the finish off the tool very superior. However it is interesting to note that the the tool went blunt because the edge was “mushroomed” rather than worn out.

The timing was started when the chisel first touched the timber and stopped when it could cut no further or was unsafe to carry on.

All jigs were set at the correct angles and sharpening times were taken with the jig on the bench, picked up, chisel set in jig, sharpened, the jig removed and placed back on the bench.

All skews were sharpened at the same angle. 25 Degree skew angle and the bevels at an included angle of 50 degrees. I run slightly shorter bevels than some because I find the longer bevels harder to control in the sort of work I do. It works out to be about 1.5 times longer than the thickness, e.g. 6mm thick has a bevel length of 9mm.

As they are both 220# there was no test done on the Tormek SG250 as the finish off the wheel would be the same as the Tormek SB 250 and magnification showed that to be the case.

The penultimate test was to sharpen with the Tormek SB250 and then hone using the Tormek leather wheel and honing compound. This was carried out on 1 Redgum blank for each chisel.

The final test was done on pine using just the HSS as it was the best performer across all other tests to give a comparison between softwood and hardwood.

I was surprised at the lack of performance by the S7 steel until it was honed on the Tormek hone. Whether this is because it is a new chisel and still a little “soft” at the ends or not I do not know. Time will tell.

The 80# and the TormekSG does not sharpen the S7 chisel well.

Honing the chisels makes only a tiny difference in performance (length of cutting time) however on finishing cuts it leaves a superior finish, but bear in mind that all things get sanded anyway and one wonders whether the extra time is worth it. The best finish on the timber was from chisels done on The Tormek SJ4000 but at nearly an hour to regrind the edge it is out of the question.

The Carbon Steel chisel seems to cut better in a planing cut and leaves a superior finish than the others.

The following are snapshots of the edges. As stated earlier I have used only the shots taken off the Tormek SB wheel as it gave the same results as the SG wheel.

80# wheel
Carbon Steel High Speed Steel S7 Bohlerit steel.
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Blue Max wheel.
Carbon Steel High Speed Steel S7 Bohlerit steel.
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Honed on Fine India stone
Carbon Steel High Speed Steel S7 Bohlerit steel.
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Tormek SB250 wet grinder.
Carbon Steel High Speed Steel S7 Bohlerit steel.
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Honed on the Tormek leather wheel using honing paste.
Carbon Steel High Speed Steel S7 Bohlerit steel.
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Conclusions.

If money were tight and I was just starting I would buy an 80# Aluminium Oxide wheel and a Norton Combination stone and use those. This assumes that you know how to sharpen and hone by hand. It is an acquired knack. If not, then a jig would also be very handy.

Use straight off the grinder and only hone for finishing cuts.

If money was not an issue then the Tormek is the way to go. It leaves a better edge straight off the wheel and the hone is always there.

The times are in the spreadsheet below.

Nomex and fire retardent on.

Cliff Rogers
8th October 2010, 09:03 PM
Confusing spreadsheet. :?

Pat
8th October 2010, 09:43 PM
, the spreadsheet is not the clearest. I had a look at it and I could not really make heads or tails of what information you were trying to impart.

Cliff Rogers
8th October 2010, 09:50 PM
Isn't that what I just tried to tell him? :D

Pat
8th October 2010, 09:52 PM
Isn't that what I just tried to tell him? :D

Cliff, we might have to be a bit careful, 's Axe may have received a sharpening as well:;

TTIT
8th October 2010, 10:41 PM
Good onya for putting it all together :2tsup: Would have been even better if Brendan had lent you that diamond wheel - would love to see the results from that in the comparison :shrug:

Paulphot
8th October 2010, 11:08 PM
Very thorough test, thank you for taking the time to do that, I don't feel that bad now not having a tormek, but I need a blue max :)

RETIRED
8th October 2010, 11:11 PM
I will see if I can make it better. I am a woodturner not an accountant.:D

govarney
8th October 2010, 11:46 PM
,

I'm happy to help re-jig the spreadsheet. I'm no accountant but I am a computer nerd.

PM me if you want and I can give you a tingle.

RETIRED
9th October 2010, 08:04 AM
Good onya for putting it all together :2tsup: Would have been even better if Brendan had lent you that diamond wheel - would love to see the results from that in the comparison :shrug:Maybe next time. It would have been interesting.

Ozkaban
9th October 2010, 09:00 AM
Thanks for going to the effort to put this together . Very interesting.

Interesting points raised about honing.

Cheers,
Dave

Paul39
9th October 2010, 11:41 AM
Thank You ,

For the time and effort for the sharpening test and trial of the FETool.

Ed Reiss
9th October 2010, 12:28 PM
The Carbon Steel chisel seems to cut better in a planing cut and leaves a superior finish than the others.


Very telling statement . A few decades ago when a carver friend, Bill, was giving me lessons in carving all the tools used were CS. He explained that a far keener edge could be achieved on the CS as opposed to HSS. Of course the trade off was that CS lost it's edge quicker than HSS.

Good workup, ...very informative.:2tsup:

Tim the Timber Turner
9th October 2010, 02:02 PM
, the spreadsheet is not the clearest. I had a look at it and I could not really make heads or tails of what information you were trying to impart.

What!!! only 7 decimal places in the spreadsheet?:oo:

How about a bit more accuracy please ?:rolleyes:

Cheers
Tim:)

NeilS
10th October 2010, 02:42 PM
After spending some time reading and re-reading the spreadsheet and your writeup I think I've got it sorted out now, .

Looks like a very thorough exercise that has yielded some very useful results. I'll take on board the take home message.

If the spreadsheet could be tidied up I reckon it's a publishable article. As I see it, the main issues with the spreadsheet are mixed data (not immediately clear if the times are referring to grind/hone times or cutting times, eg there appears to be only two sharpening times) and more descriptive labels. Rather than one spreadsheet, perhaps several tables in something like MS Word might work better.

Publish or not, good stuff .

.

RETIRED
10th October 2010, 03:14 PM
After spending some time reading and re-reading the spreadsheet and your writeup I think I've got it sorted out now, .

Looks like a very thorough exercise that has yielded some very useful results. I'll take on board the take home message.

If the spreadsheet could be tidied up I reckon it's a publishable article. As I see it, the main issues with the spreadsheet are mixed data (not immediately clear if the times are referring to grind/hone times or cutting times, eg there appears to be only two sharpening times) and more descriptive labels. Rather than one spreadsheet, perhaps several tables in something like MS Word might work better.

Publish or not, good stuff .

.Thanks Neil for the info on the spreadsheet. It works for me but I wrote it.:D

Cliff Rogers
10th October 2010, 08:34 PM
Means nothing to me but I can't read music either. :rolleyes:

RETIRED
10th October 2010, 09:19 PM
It is being fixed.

powderpost
10th October 2010, 09:29 PM
Very informative , but far to technical for this old chippie. I will stick to my spark producer and #800 grit Japanese water stone. But then I have trouble tying shoe laces.. :D
Jim

Howard Van Huis
10th October 2010, 10:49 PM
I guess that says a lot about You, Your like Einstein. Much to intelligent to remember the small things :2tsup:

Tiger
11th October 2010, 02:40 PM
Thanks for doing this , I'm always more convinced when claims can be backed up by real data. You've had some offers for help on your spreadsheet and I can also help if you wish. Hoping to see you at the Woodworking show this weekend.