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Thread: D-way vs Thompson gouge
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21st January 2012, 02:45 PM #1
D-way vs Thompson gouge
Prompted by Bellyup's thread CBN wheel - first impressions I gave in and got myself one from D-waytools. Couldn't wait any longer for the A$ to reach my target exchange rate...
I'll do a comparison between the Diamond and CBN wheels when I've spent a bit more time with the two.
As I had some spare capacity in the parcel I decided to add one of Dave's bowl gouges to the order. His gouges are made of high Cobalt M42 HSS. They are slightly more expensive than the Thompson gouges but one of his selling points is that his gouges come with the flutes hand polished to remove all grinding marks.
As claimed, the gouge arrived with a high polish. The highest polish of seen on any gouge as received.
Attachment 195379 Attachment 195380
I opted for the V fingernail profile. As can be seen from the following pic, Dave uses quite an acute nose bevel angle that approaches what I would normally use on a detail gouge. So, the chances are that you will need to regrind. The top gouge is my standard bowl gouge angle. The bottom is Dave's.
Attachment 195381
To compare the 5/8" D-way with my 5/8" Thompson 10% Vanadium gouge, which are similar priced gouges, I used the same protocol that I used to compare the Thompson 10% and 15% Vanadium gouges reported here. Basically, as follows:
- 100 year old red gum fence posts. Hard and brittle with the usual quota of included dirt (sand).
- Starting with a fresh grind on each gouge, turned in 1 minute relays between the two gouges. This way each steel encountered equal levels of hardness (and silica).
- Kept a stop watch tally of 1 min cuts and turned until each gouge had to be pressed firmly to keep 'cutting', a point well beyond where I would normally go before resharpening. This way I had a distinct exhaustion point against which to measure the performance of each gouge.
The result, the Thompson V10 cut just over three times as long as the D-way.
This significant difference would be produced by the difference in the metallurgy and the heat treatments to optimise the performance of each steel.
The quality of the cut from each steel is a different aspect of a gouge's performance. For example, the steel in my Ellsworth Sig gouge produces a much cleaner cut than the Thompsons. I will look at that next, probably comparing the Ellsworth, D-way and Thompson, and report my impressions.
I'll also do a comparison with the Vicmarc vanadium gouges when they produce one in V flute profile.
Last edited by NeilS; 21st January 2012 at 02:55 PM. Reason: note re Vicmarc vanadium gouges
Stay sharp and stay safe!
Neil
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21st January 2012 02:45 PM # ADSGoogle Adsense Advertisement
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21st January 2012, 05:04 PM #2
Neil interesting comparo.
It will be good to do the same test once you reduce the lenght by about 6-8mm.
I tend to find some tools are not hardened right to the tip and generally after a few sharpens the tool behaves as you would expect and start getting a better life between sharpens.Jim Carroll
One Good Turn Deserves Another. CWS, Vicmarc, Robert Sorby, Woodcut, Tormek, Woodfast
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21st January 2012, 05:13 PM #3
very curious
.
It will be good to do the same test once you reduce the lenght by about 6-8mm.
I would find it remarkable if they held it by the other end. But it would explain the variance in hardness.Inspiration exists, but it has to find you working. — Pablo Picasso
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21st January 2012, 06:35 PM #4Retired
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I have been saying the same thing for the last 30 odd years.
I asked a metallurgist I used to know about this and his reply (and his mate concurred) that in the hardening or tempering process the ends can sometimes cool quicker thereby not receiving the same treatment as the main body of the tool.
He said that the result can go one or two different ways depending on the steel: 1: A "softer" steel, i.e. not as hard as the rest therefore bluntens(?) quicker or 2: An extremely brittle edge which can crack. I have experienced this on an Ashley Isles spindle gouge many years ago when HSS was in its infancy for turning tools. It was a bloody good tool after the missing bit was gone.
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21st January 2012, 07:30 PM #5SENIOR MEMBER
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:I found P&N tools to be like this.
They needed 20 or so sharpenings before they would produce an edge that would hold up.
They defiantly got better after that.
Cheers
TimSome days I turns thisaway, somedays I turns thataway and other days I don't give a stuff so I don't turn at all.
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21st January 2012, 07:48 PM #6
It might also go a long way to explain why 2" of bowl gouge decided to detach itself from one of my 1/2" Henry Taylors but after a regrind became the best bowl gouge I possess.
Maybe I'll saw a bit off some of the others that are not preforming quite as well!
Interesting, thanks for the detail in this post.Dragonfly
No-one suspects the dragonfly!
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22nd January 2012, 10:48 AM #7
Thanks Jim, and Tim for the expert input on the tip tempering. An important caveat if that is the case.
Can't say I have experienced that effect myself, except maybe for P&N, but have definitely noticed marked differences between tools from the same manufacturers (not just McJing). Or, perhaps I'm starting to forget what my tools were like 8mm ago...
Certainly won't take long to remove 8mm of tool with the new CBN wheel. It eats HSS...Stay sharp and stay safe!
Neil
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22nd January 2012, 01:20 PM #8Hewer of wood
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Watching with interest. Thanks for the post Neil.
In terms of tip hardness, maybe some of the variation depends on whether the treatment process precedes or follows the flute milling and bevel shaping. And how much of the tip is removed in bevel shaping if it happens after that process.
Re wheels, as posted, the Norton #46 3X gobbles up the Thompson V10s. The diamond wheel from your group buy (#120) leaves a nice polish on the bevel but produces quite a wire edge.
In terms of flute shape and how friendly that is, the Thompson 5/8 U is OK for freehand touch ups at 45º but reground at about 70º for transition ease, it's hard to get an even curve even with a jig.
As an aside, I've been spending some more time on methods of taking out the milling marks on gouges.
The only gouges I've used that appear to have been polished at the factory were Sorby. The two Thompson detail gouges had distinct milling marks and involved some effort to fix. His bowl gouges were clearly better; odd.
My Ellsworth Sig gouge is pretty clean (made by Crown). Henry Taylor all need(ed) work. P&N is usually p*ss poor.Cheers, Ern
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23rd January 2012, 02:58 PM #9Senior Member
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A timely post for me, just got a 1/2 in. P&N from an online supplier here .
I wanted to compare it to the Thompson tools I use regularly .
It came with a lopsided asymmetrical bevel and needed regrinding .
I ground a Thompson first and immediately noticed the P&N metal
grinding away at a more rapid rate.
Was playing on some local unknown species of gum so the P&N dulled fast.
I put it away and went back to the stalwart Thompson .
I think now I'll regrind a few times and consider the other variables before judging the P&N.
Thanks to the above contributors.
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24th January 2012, 01:35 AM #10
OK, done that now. Didn't want to wait until I'd sacrificed 8mm off the D-way...
Put the Crown Ellsworth, D-way and Thompson head to head on a finishing cut.
Selected some red gum with the crankiest grain I could put my hands on. A good test for a finishing cut. Each tool was resharpened before each test.
First The D-way up against the Crown Ellsworth. I did alternating 1" bands.
Attachment 195810
Here are close-ups of the finish cut on the side grain, D-way on the left and the Crown Ellsworth on the right.
Attachment 195811 Attachment 195812 Attachment 195813
And on the endgrain.
Attachment 195814 Attachment 195815
I couldn't detect any difference in the quality of the finishing cut from these two gouges.
Then the D-way and the Thompson. Same procedure.
Attachment 195816
D-way finish on the left and the Thompson on the right.
Attachment 195817 Attachment 195818
The D-way definitely produced more tear-out (on the left) than the Thompson (on the right).
Having added the Crown Ellsworth to the finishing test, I then decided to do a comparative endurance test on that as well.
Again a blank from an ancient red gum fencepost.... as hard as nails and abrasive as beach sand!
The Crown Ellsworth lasted 30% longer than the D-way. Not a significant difference. The Thompson over three times longer than the D-way, again.
However, the 5/8" Crown Ellsworth now costs about twice the D-way and the Thompson. I like to do my finishing cuts with the Ellsworth, it keeps its keen edge long enough for that purpose. But I don't think I would buy one again. It cost about the same as the Thompson and D-way back when I bough it, but now that the others are available at half its price it is no longer value for money.
Unless the D-way improves after it has lost some length (I'll report back if that happens), I would put the Thompson comfortably ahead of the D-way. Freshly sharpened the Thompson gives a very good finishing cut and then keeps cutting, but progressively less crisply, for longer than any other gouge I've used in the same price bracket.
The Glaser may do a better job but I haven't got my hands on one of those yet and I'm unlikely to do so at those prices, well not while there is so much HSS remaining in my tool rack...
PS - the flute profiles on these three gouges vary. The Ellsworth has the widest 'valley floor' at the bottom of the V, the Thompsons are narrower, and the D-way narrower yet again. Chip ejection varies accordingly and the wider V floor works well across the inside bottom on a finishing cut. So, personal flute profile preferences will be a factor in deciding on tool selection.Last edited by NeilS; 24th January 2012 at 12:25 PM. Reason: PS re flute profiles
Stay sharp and stay safe!
Neil
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24th January 2012, 04:25 AM #11GOLD MEMBER
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Thank you Neil,
I have a just plain Crown 5/8 bowl gouge and a Thompson 5/8 bowl gouge I traded from another turner.
I also find the Thompson cuts longer and cleaner than the Crown. Seat of the pants impression.
Freshly sharpened the Thompson gives a very good finishing cut and then keeps cutting, but progressively less crisply, for longer than any other gouge I've used in the same price bracket.So much timber, so little time.
Paul
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24th January 2012, 05:22 AM #12Senior Member
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Hmm, I don't have the hard gum that you have, but I have played extensively with the Thompson gouges, and a bit with the D Way gouges. I do prefer a more open flute design to the V shape which is the D Way flute. I was not able to notice any cutting differences between the two. I have a friend who has done Myrtle wood trays to the tune of 700 or so a year for 20 years. He could not detect any significant difference.
That being said, I know there are differences in the individual pieces in each batch of tools being made. With a cutting edge performance difference of 3 to 1, it sounds like you may have gotten a bad tool. Do contact Dave about that.
robo hippy
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24th January 2012, 12:40 PM #13
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29th January 2012, 12:10 PM #14
OK, done that now.
Removed 8mm off the tip.
Repeated the above test run with the same wood.
The D-way improved slightly. This time the Thompson 10V outperformed it by only twice the cutting time.
I had expected the D-way to perform better than that based on a number of reliable sources.
- Bill Neddow, who I always find is worth listening to, uses both Thompson (10V) and D-way (M42) says, "from my experience, you get a minimum of five times more 'sharp edge time' with the 10V and M42 compared to high speed steel -- maybe slightly more with the 10V". Slightly more, not twice to three times more.
- Jimmy Clewes uses both D-way and Thompson (even has a line of Thompson sig gouges) says of the D-way, "these tools hold an edge longer than any other tool currently on the market."
- And, Robo Hippy and his production turner colleague have also said that the D-ways hold up against the Thompsons.
So, why was I getting very different results?
As described above, my durability test were with roughing cuts to the point of exhaustion (ie. until the tool would no longer cut wood). That is not the way I or most others turn. But it was a way of getting an objective measure of durability, as distinct from a subjective measure of that point at which the edge had stopped cutting sweetly, which varies from turner to turner.
Maybe the results would be different if I could accurately measure Bill Neddow's 'sharp edge time', as distinct from 'still cutting, albeit roughly', which may be more measurable and applicable to roughing cuts, but a less useful measure of how long a tool will hold an keen edge that will take a sweet cut.
Is there a way of objectively measuring 'sharp edge time'?
See next post for an attempt at this and the surprising results.Stay sharp and stay safe!
Neil
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29th January 2012, 01:13 PM #15Hewer of wood
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Nice work Neil.
Following Leonard Lee, sharpness involves the keenness of the edge, the bevel shape, the application and the tool metal.
So that makes for a lot of variables.
Application involves the interaction of the wood specimen, the type of shaping of it and the bevel geometry of the tool. You've mentioned the the fact that the last is an issue in this test, the control of which is nigh impossible for end users including as it must the flute shape of gouges.
The other variable of course is that tools are made in runs and the steel composition and hardening treatment may vary within a brand according to metallurgists.Cheers, Ern
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