# LV steel lapping plate too hard?



## ali27 (27 Mar 2012)

Hi guys, a while ago I bought a LV steel lapping plate. I sprinkle some
loose grit on it and flatten waterstones, backs of plane blades and the sole
of small planes. What I have noticed though is that the grit does not embed
in the steel, rather it rolls on the plate, no matter how hard I press. I was under the 
impression that the grit would embed itself in the plate because the steel had a certain 
softness.

Not sure how I should proceed now. Is there an easy way to soften the steel? I have
read a bit about this. One needs to heat up the iron to a very high temperature and then cool 
it immediately and then warm it up again to soften it. Could I put the plate in boiling
water or very warm vegetable oil to soften it without the need of first having to heat
it up? I don't want a torch or something like that in my house.

Ali


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## Jacob (27 Mar 2012)

If it was soft it would wear hollow with use and you'd have to flatten it. But you seem to like flattening so why not just stick the plate in the fire or something?
How's the woodwork? :lol:


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## ali27 (27 Mar 2012)

Jacob":2pn48wxg said:


> If it was soft it would wear hollow with use and you'd have to flatten it. But you seem to like flattening so why not just stick the plate in the fire or something?
> How's the woodwork? :lol:



Jacob I thought that if the metal has a certain softness, then the grit embeds in the steel
which actually prevents it from wearing hollow. If the steel is harder than this, then the
grit rolls around, which actually causes scratches and wearing hollow.

I do very little woodworking, I am trying to learn all skills so I can build a musical instrument.
It's a hobby thing.

Ali


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## GazPal (27 Mar 2012)

ali27":1a9vupdq said:


> Jacob":1a9vupdq said:
> 
> 
> > If it was soft it would wear hollow with use and you'd have to flatten it. But you seem to like flattening so why not just stick the plate in the fire or something?
> ...




Sincerely and from a luthier's standpoint, if you wish to craft musical instruments your best bet is to focus upon skills that will benefit such builds. Namely choosing stock, materials manipulation, applying finish and each of the intermediate steps, rather than metalworking unless your intention is to craft woodwind, percussion or brass instruments, or make your own parts i.e. tuners.


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## Racers (27 Mar 2012)

Hi, Ali

Is it this one http://www.leevalley.com/US/wood/page.a ... 3072,59752
If the grits did embed you would need on for each grit as they would contaminate the plate.
Are you using the grits with oil? it is only for final flattening not taking a lot of material off.

Don't heat it you will only warp it and render it unusable, well a paper weight.

Pete


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## JohnCee (27 Mar 2012)

Using one of these to flatten waterstones doesn't seem like a terribly good idea to me. Surely you'll end up with coarser grit embedded in your stones?


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## Richard T (27 Mar 2012)

I haven't used a lapping plate Ali but I'm sure yours is as hard as it is supposed to be. If it works precision flattening irons and soles - great. Not so sure about their use with flattening waterstones ... I wouldn't risk it. 

NB; the way to soften hardened steel is to heat it thoroughly red (non magnetic) and let it cool slowly. Please don't!


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## Tony Spear (27 Mar 2012)

LV say that their Lapping Plate is soft iron, and should not be used for flattening stones.

Dry abrasive is no good, you need an abrasive slurry basically oil/abrasive powder.

I've still got a tin of the old fashioned Grinding Paste from my messing about with old Motorbikes. It's got a lid each end, coarse in one and fine in the other.

If it's good enough for valve seating, it should be good enough for flattening blades and plane soles!  

Further info here: http://www.timbecon.com.au/assets/files/05-M-2020.pdf


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## bugbear (27 Mar 2012)

Jacob":ikhxcypw said:


> If it was soft it would wear hollow with use and you'd have to flatten it.



You might want to look up any convenient reference on "lapping" as used by engineers.

You will (apparently) be surprised to find that it is a process where the softer of the two metals is worn away.

It's counterintuitive, which makes it interesting.

BugBear


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## ali27 (27 Mar 2012)

Guys you all make good points. Wiki gave me this info:

''Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.
This can take two forms. The first type of lapping (traditionally called grinding), typically involves rubbing a brittle material such as glass against a surface such as iron or glass itself (also known as the "lap" or grinding tool) with an abrasive such as aluminum oxide, jeweller's rouge, optician's rouge, emery, silicon carbide, diamond, etc., in between them. This produces microscopic conchoidal fractures as the abrasive rolls about between the two surfaces and removes material from both.
*The other form of lapping involves a softer material such as pitch or a ceramic for the lap, which is "charged" with the abrasive. The lap is then used to cut a harder material—the workpiece. The abrasive embeds within the softer material which holds it and permits it to score across and cut the harder material. Taken to a finer limit, this will produce a polished surface such as with a polishing cloth on an automobile, or a polishing cloth or polishing pitch upon glass or steel.''*

_http://en.wikipedia.org/wiki/Lapping_ 

This following information comesin from LV instructions of this product:



> Conditioning the Lap
> 
> As received, the lapping plate will need to be conditioned prior to first use. Conditioning coats the lap with a uniform film of oil and abrasive and* beds some of the abrasive into the surface of the lap. This optimizes the time spent lapping and ensures uniform results. Conditioning is needed only when the lap surface is free of abrasive. The residual abrasive left on the lap from a previous session eliminates the need to recondition the lap (unless you are switching to a finer grit).*



Is it possible LV made this plate accidentely too hard ? Cause I can't get the grit to embed
in the plate in a noticeable way. After having used the plate, I clean it with water and if I then feel the
surface of the plate, it feels almost completely smooth. So I tried the back of a plane blade
to see if there was indeed any grit embedded. Very fine lines were created which suggests 
that there is some embedding, but way too little. 

I knew that the plate was not designed to be used with water. I even contacted LV
and they told me the plate would rust and might change flattness. I don't mind that,
my problem is that the plate does not do what it's supposed to do. The grit doesn't
embed in the steel plate. When I first bought the plate, I used it with oil and silicone
carbide powder. I tried flattening the backs of plane irons and flattening a block 
plane sole. The grit never really embedded in the steel plate and was moving around
like when one uses loose grit on a glass plate.

Ali


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## Racers (27 Mar 2012)

Hi, Ali

Get in touch with LV see what they say
They say "Conditioning coats the lap with a uniform film of oil and abrasive and beds some of the abrasive into the surface of the lap"
So in normal use its coated with oil and abrasive, and after you clean it there is only some left, that sounds about right. 
I think you are asking to much of it its for the final finishing not bulk metal removal try some wet and dry on glass. Its the way I flatten planes.

Pete


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## jimi43 (27 Mar 2012)

Derek Cohen's excellent article on lapping with diamond paste might assist you.

I think that I might try the diamond paste soon.

I believe this will be the right compound to condition and then act as the ideal cutting medium on your LV plate.

Cheers

Jim


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## Jacob (27 Mar 2012)

Thing is though nobody needed this stuff in the past but woodwork didn't seem to be diminished in any way. Why is this?


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## yetloh (27 Mar 2012)

I too can confirm the efficacy of diamond paste, but Icertainly would not use it for flattening water stones. For that, you need something where the abrasive is captive and cannot contaminate the water stone. I my opinion, by far the best tool for that is the DMT 120grit continuous diamond plate. It is quick and highly effective.

As an alternative to water stones Derek Cohen's idea of making lapping plates for use with diamond paste from the soles of old broken Bailey planes is excellent, particularly for very hard modrn steels. The paste will embed well with limited wear to the plate but you do need one for each grade of paste. On the other hand, you could just use a filthy old dished oil stone like Jacob!  

Jim


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## Jacob (27 Mar 2012)

yetloh":amed14rs said:


> ... On the other hand, you could just use a filthy old dished oil stone like Jacob!
> 
> Jim


You may well larf - but it works! And fast and cheap. It's not that filthy. Grubby yes, but not filthy.


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## Phil Pascoe (27 Mar 2012)

I always flatten my waterstones on the concrete coping on the wall outside the workshop (1200 finest)--plenty of water-- works perfectly well!


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## Derek Cohen (Perth Oz) (29 Mar 2012)

Hi Ali

I've not used your lapping plate - too expensive to ship to Oz - so my thoughts are the result of reasoning , not direct experience with this tool.

Simply, the lapping plate you have is designed for loose diamond grit, not paste. In other words, the diamond is not meant to embed in the steel. It rolls loose and laps the cast iron or steel that runs over it.

That is likely why the steel is so hard - to actually prevent diamond embedding.

Now LV have just brought out mild steel plates specifically for diamond paste. They are an alternative to cast iron. I was involved with the pre-production testing, and I can confirm that these are excellent for diamond paste. These are intended for sharpening blades, not lapping the soles of planes, as is the plate you have.

http://www.leevalley.com/US/wood/page.a ... 72&p=69438

Regards from Perth

Derek


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## Tony Spear (29 Mar 2012)

Derek Cohen (Perth said:


> Hi Ali
> 
> Simply, the lapping plate you have is designed for loose diamond grit, not paste. In other words, the diamond is not meant to embed in the steel. It rolls loose and laps the cast iron or steel that runs over it.
> 
> ...



That's not what Lee Valley have been saying!

http://www.timbecon.com.au/assets/files/05-M-2020.pdf


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## tim burr (29 Mar 2012)

I agree with Jacob on this, surely the money that has been spent on all these lapping plates, diamond powders, pastes etc etc could have gone towards a plane that was flat enough to be fit for purpose in the first place and the obsessive amount of time spent flattening could actually go into making something. Without wanting to sound too harsh this instrument is going to be an heirloom by the time you get round to finishing it ! :shock:


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## ali27 (29 Mar 2012)

Derek Cohen (Perth said:


> Hi Ali
> 
> I've not used your lapping plate - too expensive to ship to Oz - so my thoughts are the result of reasoning , not direct experience with this tool.
> 
> ...



Derek, I did not use diamond paste or powder, but silicone carbide powder. The 
information given and in the instructions say that grit will embed and that one
doesn't need to put grit on the plate the next time one uses it. The problem is that
there is hardly any embedding at all.

If the steel plate is actually harder than the object being lapped, than what happens
is that the loose abrasive will actually embed in the softer object and lap the harder
object, which in this case would be the LV lapping plate.

Diamond paste, powder will actually embed in practically everything Derek. It will
even embed in glass which I know from experience. Glass is quite a bit harder than a soft steel. ''The lapping plate is made of soft iron and will wear over time''. That's what the LV instructions say.

Unfortunately I think LV had made this plate a bit too hard for it to be used 
correctly with silicone carbide. The SiC doesn't embed very well. Diamond paste
/dust powder is probably the best thing I can use as diamond is much harder than
silicone carbide and will embed without any issues. Perhaps this could make a cheap
diamond lapping plate. Using 100 grit diamond paste or powder and pressing it in
the plate so it embeds in it.

Ali


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## yetloh (29 Mar 2012)

Jacob":pify0wcn said:


> yetloh":pify0wcn said:
> 
> 
> > ... On the other hand, you could just use a filthy old dished oil stone like Jacob!
> ...


 
A joke, but I do have the greatest respect for the very fine work that you do. However there is a serious point here. In my opinion it is unquestionably the case that, historically, master crafstmen produced wonderful work often with what would today be regarded as inferior tools and certainly, edges which are inferior to those possible today both in terms of longevity and ultimate sharpness. That is of course just as capable of being true now as it was 100 or 200 years ago. Having used both oil and the best modern water stones I am of the firm opinion that the latter are capable of producing a superior edge. 

It is often said that bad workmen blame their tools but amateur woodworkers like me need all the help we can get and there is no doubt in my mind that top quality tools make it easier for the amateur to get good results. But let us not pretend that there is not also an element of tech addiction at work here and of course, there is real pleasure to be obtained from owning and using top qulaity tools, even if some of the refinements are not strictly necessary. If you can afford it and it gives you pleasure and helps make satisfying results easier to obtain, then why not? 

Jim


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## jimi43 (29 Mar 2012)

I think the point has to be made Jim that it is not the medium of lubrication, rather the type and quality of the stone that does a specific job. That the stone in question works better with one type of lubricant than another is a function of the stone in many cases.

For instance...a hard resilient stone which does not shed particles relies on the movement of the steel across it to wear down the metal. I prefer a coarse hard natural stone with oil for hand grinding primary bevels and reshaping.

For honing however, I change between Scary sharp, diamond hones and my coticule...the latter as you know prefers water to make a slurry which has released particles of garnet carried in it as the fine abrasive for polishing.

So there is really no "correct" stone..rather stones which are more suited to one job than another.

Modern steels tend towards needing special hones such as ceramic to even touch them...and I think this is why some are disappointed with the results they get from previously excellent and successful methods.

My latest success has been using a Tormek stone to create a shallow concave bevel and then keeping both sides of the bevel level with a diamond hone...creating a polished edge. These two edges are automatically aligned and eventually meet in the middle to form one primary bevel. This of course only works with smoother, shoulder and other straight edged irons configurations and not rounded edges.

I must have picked this up reading somewhere but it does not require any jig or trained arms as each side of the bevel supports the edge while the honing is done. Has anyone else tried this?

Jim


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## No skills (29 Mar 2012)

Jim

I have read this but not tried (or maybe seen on youtube), considering some of the complex routines people are using it seems nice and quick. Tell me you not adding a secondary bevel afterwards


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## jimi43 (29 Mar 2012)

No skills":bh2v45gu said:


> ................Tell me you not adding a secondary bevel afterwards



No mate...no secondary bevel seems necessary. I guess the only drawback is if you want to use a secondary bevel to adjust for more difficult woods...a steeper angle...but I don't see why you can't then hone a steeper secondary. For everyday use it simply isn't necessary and a lot of people who are constantly swapping tend to have a second prepped iron anyay.

Jim


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## Aled Dafis (29 Mar 2012)

jimi43":3dxb8frt said:


> .
> 
> My latest success has been using a Tormek stone to create a shallow concave bevel and then keeping both sides of the bevel level with a diamond hone...creating a polished edge. These two edges are automatically aligned and eventually meet in the middle to form one primary bevel. This of course only works with smoother, shoulder and other straight edged irons configurations and not rounded edges.
> 
> ...



I use a similar method, but only hone the front edge of the iron, it's the quickest and easiest method I've come across by a long way. I'd post a link to my youtube vid, but I'm on the ipad at the moment and not quite sure how I'd go about it.

Cheers
Aled

Edit: just worked it out, here you go

http://www.youtube.com/watch?v=wFRJIAOGSJI


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## David C (30 Mar 2012)

Jim,

I think the method you describe is the one used by James Krenov, see his first book.

The only difference being that he hollow ground on a six inch hand grinder!

It's a very good method, but one ends up working on and polishing, a larger and larger area of bevel with each subsequent sharpening.

best wishes,
David Charlesworth


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## Jacob (30 Mar 2012)

yetloh":3myme5hv said:


> > ...arf - but it works! And fast and cheap. It's not that filthy. Grubby yes, but not filthy.
> 
> 
> 
> A joke, but I do have the greatest respect for the very fine work that you do. However there is a serious point here. In my opinion it is unquestionably the case that, historically, master crafstmen produced wonderful work often with what would today be regarded as inferior tools and certainly, edges which are inferior to those possible today both in terms of longevity and ultimate sharpness. That is of course just as capable of being true now as it was 100 or 200 years ago. Having used both oil and the best modern water stones I am of the firm opinion that the latter are capable of producing a superior edge. .........


Not a joke - and the work not that fine! 
It wasn't just master craftsmen using grubby oil stones - everybody did, including amateurs and schoolkids. Sharpening was never a problem, as it certainly is now. This started changing about 40 years ago when the amateur woodwork trade started picking up.
I don't think you are right about waterstones; natural stones even come in "surgical" grades for those who want ultimate sharpness. 
But in any case what we all want is practical working systems - optimum, not ultimate.
I've taken to using the Paul Sellers system - freehand, three diamond plates, rounded bevels. This is very fast and very effective. For a finer finish I go to a fine oil stone and then a strop on leather, if I feel the need. Never go anywhere near a grindstone; the system means you replicate the edge every time you hone and there is no need ever to fuss about with multiple bevels, re-grinding etc.


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## David C (30 Mar 2012)

The finest waterstones are much finer i.e. smaller grit particles, than any western, natural stone, including surgical grade Arkansas.

This is not thought, it is fact.

D


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## jimi43 (30 Mar 2012)

Aled, David....thanks for confirming that I am not going bonkers (yet!) :mrgreen: 

I discovered this by accident when using a diamond hone on a turning skew...not taking any notice when touching up the bevel and realising I was rubbing across both points. I didn't have time to regrind and just went for it on some lignum and was astonished to find the edge was keener than before! 

Clearly the bevel was conducive to doing this as it was substantial and the chisel was slightly butch to say the least! :mrgreen: Later on I tried it on a very fine thin chisel and discovered it was far easier to control on such a tiny surface. This weekend I deliberately used this technique on the WARD cutter I had to restore on the gunmetal shoulder I acquired at a bootfair on Sunday and the results were impressive. 

Whilst being pleased with the technique...I had a feeling I hadn't discovered something new...so it is probably subliminal and I became convinced I would have seen/read it somewhere...probably your superb video Aled! 8) 



Jacob":3s7dfmv6 said:


> ...........But in any case what we all want is practical working systems - optimum, not ultimate



No we don't "all" want what you want Jacob...and the sooner you realise that the more harmonious this forum will be. :wink: 

I have no doubt that you are happy with whatever process you use and are happy making fine furniture. I like the _process_ of sharpening as a subject...I use the things I learn to make tools and I get pleasure from doing this and, as with religion....I ain't about to allow anyone else to say their way is the "right" way! :mrgreen: 

Jim


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## Jacob (30 Mar 2012)

David C":16ni5auy said:


> The finest waterstones are much finer i.e. smaller grit particles, than any western, natural stone, including surgical grade Arkansas.
> 
> This is not thought, it is fact.
> 
> D


Yebbut so what? Surgeons may need this but woodworkers certainly don't.


jimi43":16ni5auy said:


> .....
> 
> 
> Jacob":16ni5auy said:
> ...


That's interesting. By "all" I meant those whose priority is woodwork. A clear admission that sharpening has become a separate hobby in it's own right! 
No wonder there are crossed lines!
Presumably there is a fuzzy border line between the interests of hobby sharpeners on the one hand, and woodworkers on the other. Many people wouldn't know this. I wasn't sure myself until relatively recently. I think the honing jig puts you firmly into the hobby sharpener camp. If woodwork is your thing, throw it away!


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## David C (30 Mar 2012)

It's such a pity that so many of your posts have such a rude tone. "Hobby sharpeners" is a good example.

What on earth is your concept of a woodworker? The ones I know hardly ever touch a hand tool, even though they know how to use one if necessary. CNC and large thickness sanders have become common in medium sized workshops.

The majority of members of this forum will probably be amateurs who work wood for a pleasureable hobby at home. They are likely to get a far more satisfactory and repeatable result with a honing guide.

David Charlesworth


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## Racers (30 Mar 2012)

Leave him David 'es not worth it :wink: 

I have pointed this out to him several times (we do woodwork as a hobby) but he still dosn't get it.

Pete


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## Jacob (30 Mar 2012)

David C":2ti87115 said:


> ...
> What on earth is your concept of a woodworker? The ones I know hardly ever touch a hand tool,


Really? You need to get out a bit more Dave. There are hundreds of small workshops not unlike mine, using a mixture of machines and hand tools as necessary.


> ....... They are likely to get a far more satisfactory and repeatable result with a honing guide.
> 
> David Charlesworth


Some maybe. Some are obviously spending a huge amount of time and money with not a lot to show for it.
All I know is that as soon as I stopped using a honing guide sharpening became a whole lot easier and hand tools became much more viable for many operations.
Easy sharpening means you can do more or spend longer actually using the tools, which in turn are sharper for more of the time.


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## Paul Chapman (30 Mar 2012)

Blimey, Jacob, do you sit in front of your computer all day waiting to pounce on any hand tool thread :? You ought to do a bit more woodwork.........

Cheers :wink: 

Paul


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## Alf (30 Mar 2012)

David C":21gejh0w said:


> I think the method you describe is the one used by James Krenov, see his first book.
> 
> The only difference being that he hollow ground on a six inch hand grinder!
> 
> It's a very good method, but one ends up working on and polishing, a larger and larger area of bevel with each subsequent sharpening.


More to the point from my perspective, you end up working on and polishing an area of the bevel that's not going to be doing any work anyway. But then I like my secondary bevels and heartily dislike metalworking of any kind, but particularly the unnecessary sort.


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## deserter (30 Mar 2012)

Sorry was tired last night and jumped in both feet, apologies.


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## Jacob (30 Mar 2012)

deserter":3jvm658v said:


> Jacob":3jvm658v said:
> 
> 
> > David C":3jvm658v said:
> ...


Very interesting, but you seem to have missed the point. I didn't set any criteria for cabinet maker. In fact you are the first to raise the topic in this thread.


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## No skills (30 Mar 2012)

jimi43":n91k19xc said:


> No skills":n91k19xc said:
> 
> 
> > ................Tell me you not adding a secondary bevel afterwards
> ...




Good... what I mean (sorry) is I thought it was a great simple solution to a sharp cutting edge so why complicate it. It must of been Aled's video I saw! #-o And really, thinking about it - should you want a steeper angle as you mentioned, its not really an extra step at all, just lifting the chisel on honing. So to re-cap, I'm talking myself round in circles    what a wally.


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## Derek Cohen (Perth Oz) (31 Mar 2012)

> My latest success has been using a Tormek stone to create a shallow concave bevel and then keeping both sides of the bevel level with a diamond hone...creating a polished edge. These two edges are automatically aligned and eventually meet in the middle to form one primary bevel. This of course only works with smoother, shoulder and other straight edged irons configurations and not rounded edges.



Jim my friend, I hate to break this to you, but many of us have been freehanding blades like this for yonks. 

A primary bevel that is hollowed at the desired angle is self-jigging when freehand sharpening. In plane blades this is easy enough to camber. In a chisel the coplanar bevel face makes it more user friendly against a guiding surface, such as when used bevel down.

The only time I do not do this is when using blades for BU planes, since a secondary bevel is required to create the desired cutting angle.

As always ..

Regards from Perth

Derek


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## ali27 (1 Apr 2012)

Derek, I know you have used diamond paste on a steel plate
for sharpening, but what about using the plate as a lapping plate
for waterstones? 

I was thinking of buying coarse diamond paste(100-200 grit or so) and 
smearing some of it on the steel plate, then use something to press it in the 
plate. Would that not give me a diamond flattening lapping plate like DMT or
Eze lap? Seems like a very cheap way to get a diamond lapping plate to dress
waterstones. I know there is a risk of the diamonds ending up in the waterstones,
but I am thinking if the diamonds are embedded well with high pressure, they will
probably stay in their places. What do you think?

Ali


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## CHJ (1 Apr 2012)

There is no way you are going to get diamond 'grit' to embed in a hard steel plate and stay there, at best you will just achieve a frosted surface on the steel, the diamond particles will just drop or wash off as soon as any disturbance is presented.

At best they will be sat in a depression about 100th of their 'diameter', manufactures of diamond plates have considerable difficulty in forming a plated layer (nickel ?) with enough depth to retain the 'shoulder' of the particles.

Think in terms of how a stone is retained in jewelry such as a broach or a ring with claws, something achieving similar is required, failure to achieve this successfully is the reason cheap diamond plates 'wear out' rapidly.


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## ali27 (1 Apr 2012)

CHJ":2sbkq8oz said:


> There is no way you are going to get diamond 'grit' to embed in a hard steel plate and stay there, at best you will just achieve a frosted surface on the steel, the diamond particles will just drop or wash off as soon as any disturbance is presented.
> 
> At best they will be sat in a depression about 100th of their 'diameter', manufactures of diamond plates have considerable difficulty in forming a plated layer (nickel ?) with enough depth to retain the 'shoulder' of the particles.
> 
> Think in terms of how a stone is retained in jewelry such as a broach or a ring with claws, something achieving similar is required, failure to achieve this successfully is the reason cheap diamond plates 'wear out' rapidly.



I have seen diamond lapping plates which have the diamonds sintered in them. Obviously I
would not be able to do that as well, but from my experience silicone carbide embeds quite
easy in soft steel. Diamond is much harder than SiC and should embed even easier.

This gives some more info:
http://www.ehow.com/how_11401951_charge ... spray.html

Ali


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## GazPal (3 Apr 2012)

ali27":1prbaunb said:


> from my experience silicone carbide embeds quite easy in soft steel. Diamond is much harder than SiC and should embed even easier. Ali



Perhaps the above answers the original question by recognising a softer plate is best suited to embedding grits of various grades. Depending on your regime, why not invest in some mild steel plate, have it milled true and use a section slab for each grit being used? The hardened plate you've bought doesn't seem to match your chosen mode of lapping.


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## Harbo (3 Apr 2012)

I've used a sheet of Acrylic - it holds the grit very well.
And much cheaper too?

Rod


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## James C (3 Apr 2012)

Harbo":2hfw47xh said:


> I've used a sheet of Acrylic - it holds the grit very well.
> And much cheaper too?
> 
> Rod



Garrett Hack makes the same point about using hard level plastic in his Handplane book. I was suspect but glad to hear it works as I have a couple of sheets of spare acrylic. What thickness do you use and what is it mounted on?


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## Harbo (3 Apr 2012)

I think my stuff is about 5mm.
I just place it on a piece of old kitchen worktop.

Rod


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## James C (3 Apr 2012)

Sounds good I might have to check with management to see if we have funding for some SiC powder.


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## ali27 (5 Apr 2012)

GazPal":3ov8hor9 said:


> ali27":3ov8hor9 said:
> 
> 
> > from my experience silicone carbide embeds quite easy in soft steel. Diamond is much harder than SiC and should embed even easier. Ali
> ...



Gazpal, your response makes sense. I am a bit confused because supposedly the 
LV plate is soft steel. So lets say I buy mild steel and it turns out too hard again!
What hardness do I need? What specifically should I ask for?

Are mild steel and cast iron the same? Cause I think I need cast iron.

Anybody knows where I can get soft steel ground flat for a nice price? I think
buying a bigger plate might be a good idea. I could use it for flattening my no6
and perhaps a no7 in the future. 

Is it possible to get a lapping plate that does not corrode?

Thanks again guys.


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## GazPal (6 Apr 2012)

ali27":3rol981u said:


> GazPal":3rol981u said:
> 
> 
> > ali27":3rol981u said:
> ...



From my basic understanding, mild steel (Low - Medium carbon content) tends to be softer than cast iron (Very high carbon content) and tool steel (High carbon content) but each can be in an annealed state when supplied or (if hardened) tempered to draw/reduce it's hardness. The hardening and tempering process and characteristics of a metal are key to how well suited it is to the task in hand.

The engineers and metalworkers here are - by far - the best sources of advice on this topic, but I think supply and machining would be best handled via a local small engineering company with suitable milling facilities. Most carry suitable metal, whilst pre and post machining heat treatment can also be handled locally and sourced once in-roads have been made with the engineering element.


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