flattening chisel backs with lapping film

[bugbear]

Level of finish/polish depends upon end use and resulting improvements in edge retention and sharpness, but returns can diminish by quite a degree when taken beyond 3,000 grit. Especially so if one considers the fact some timbers are far more abrasive than others and a razor-like chisel/plane iron edge can be lost during the first contact between tool and working medium.

Especially for our Australian brethren.

It is interesting (for some...) that there is research showing that a polished
edge degrade more slowly (last longer) than a crude edge.

http://www.amgron.clara.net/page72.html

BugBear

 

[GazPal]

Level of finish/polish depends upon end use and resulting improvements in edge retention and sharpness, but returns can diminish by quite a degree when taken beyond 3,000 grit. Especially so if one considers the fact some timbers are far more abrasive than others and a razor-like chisel/plane iron edge can be lost during the first contact between tool and working medium.

Especially for our Australian brethren.

It is interesting (for some...) that there is research showing that a polished
edge degrade more slowly (last longer) than a crude edge.

http://www.amgron.clara.net/page72.html

BugBear

I'd agree wholeheartedly, but for the fact some timbers can crucify an edge regardless of it's level of finesse. Especially if there's a mismatch between honing angle and duties the blade is being put to. Many sharpeners also don't realise the need to vary direction of blade travel with each consecutive grit (e.g. straight, diagonal left, diagonal right, straight, etc.), otherwise progressively smaller grits are simply tracking in previously made scratch marks.

Ideally we'd run through each progressive grit involving much closer sequences/shorter leaps between grits, but this seldom happens or proves practical if the priority is to work using a blade/iron instead of spending a great deal of time honing/whetting edges.

Quite often it's simply a case of matching edge finesse to the work at hand.

 

[wem]

I have never been able to get a mirror polish on the back of my blades?

 

[Phil Pascoe]

Just as well you don't need to, then.

 

[Fromey]

I'm wondering if this - sometimes - excessive amount of time spent flattening is due to newcomers not realising there's protective lacquer on most new chisel/plane blades which needs stripping before they begin. The presence of lacquer could also account for false readings when initial checks are made.

Interesting. What's the best way to remove it and does anyone know if Narex chisels come with lacquer. I suspect they do as it would account for what I see around the business end of them when I first use them. Is it just the tips that are lacquered or the whole ironworks?

 

[Phil Pascoe]

Paint stripper usually works.

 

[GazPal]

I'm wondering if this - sometimes - excessive amount of time spent flattening is due to newcomers not realising there's protective lacquer on most new chisel/plane blades which needs stripping before they begin. The presence of lacquer could also account for false readings when initial checks are made.

Interesting. What's the best way to remove it and does anyone know if Narex chisels come with lacquer. I suspect they do as it would account for what I see around the business end of them when I first use them. Is it just the tips that are lacquered or the whole ironworks?

Some makers only coat the blade tips, but most I've seen have a fully coated blade/iron for the sake of pre-sales storage and shipping. I normally give them a wipe over with lacquer thinner or paint stripper, but acetone will work too and - if you think you can get away with it - you could always raid SWMBO's supply.

 

[Jacob]

I've actual flattened one today. It's a very nice old 1/2" stanley 5001 from ebay which unfortunately had been "flattened" by the previous owner leaving the face dubbed over at the edge corners and down both sides, so the round-over would never go away without flattening, or applying a permanent back bevel. NB if this was a new one I'd have sent it back as faulty goods.
I don't normally do this but I thought of this thread!
Didn't take long on Tilgear Ezelap diamond plates (coarse, medium fine).
Film and/or paper is not a good idea IMHO as it's fragile and tends to dub the edges over unless you are very careful. Not to mention slow and expensive.
With a solid plate or stone you can use maximum force and pressure and get the job done in a few minutes. Not water stones obviously (too soft) so has to be diamond plate or oil stone in good condition.

 

[carlb40]

I'm wondering if this - sometimes - excessive amount of time spent flattening is due to newcomers not realising there's protective lacquer on most new chisel/plane blades which needs stripping before they begin. The presence of lacquer could also account for false readings when initial checks are made.

Interesting. What's the best way to remove it and does anyone know if Narex chisels come with lacquer. I suspect they do as it would account for what I see around the business end of them when I first use them. Is it just the tips that are lacquered or the whole ironworks?

My Narex chisel that i purchased last week has a lacquer coating on the whole blade. To be reviewed soon

 

[GazPal]

I'm wondering if this - sometimes - excessive amount of time spent flattening is due to newcomers not realising there's protective lacquer on most new chisel/plane blades which needs stripping before they begin. The presence of lacquer could also account for false readings when initial checks are made.

Interesting. What's the best way to remove it and does anyone know if Narex chisels come with lacquer. I suspect they do as it would account for what I see around the business end of them when I first use them. Is it just the tips that are lacquered or the whole ironworks?

My Narex chisel that i purchased last week has a lacquer coating on the whole blade. To be reviewed soon

I've every confidence your Narex chisel purchase will prove a positive experience. Regarding lacquer removal, I often haunt Lidl when they have tool offers on and find their lacquer thinner is pretty good for stripping back protective coatings on new blades. :wink: It will strip screen printed lettering from chisel backs, but you can always work around that area, as the only parts in need of stripping are areas likely to come in contact with sharpening stones/plates.

 

[GazPal]

I've actual flattened one today. It's a very nice old 1/2" stanley 5001 from ebay which unfortunately had been "flattened" by the previous owner leaving the face dubbed over at the edge corners and down both sides, so the round-over would never go away without flattening, or applying a permanent back bevel. NB if this was a new one I'd have sent it back as faulty goods.
I don't normally do this but I thought of this thread!
Didn't take long on Tilgear Ezelap diamond plates (coarse, medium fine).
Film and/or paper is not a good idea IMHO as it's fragile and tends to dub the edges over unless you are very careful. Not to mention slow and expensive.
With a solid plate or stone you can use maximum force and pressure and get the job done in a few minutes. Not water stones obviously (too soft) so has to be diamond plate or oil stone in good condition.

It has to be one of the worst things, when you find someone has misunderstood what's involved in the tool prep process and you find yourself needing to remedy mistakes before you're able to put a tool to good use. Quite often a little prep goes a very long way in helping you gain the most from a piece of equipment, whereas an overzealous approach can virtually kill anyone's chances of obtaining the same end results. Little is very often more and certainly far better than overkill.

I've just picked up one of Tilgear's black Arkansas 8" x 2" stones for my son and it's not bad at all in comparison to the one I've been using since Moses was a lad.

 

[bugbear]

It has to be one of the worst things, when you find someone has misunderstood what's involved in the tool prep process and you find yourself needing to remedy mistakes before you're able to put a tool to good use.

Agreed - although ignorant long term use can have similar consequences.

One particular nightmare is back beveled garden shears - this can be done in around 30-60 second to a degree which is (AFAIK) irrecoverable :-(

BugBear

 

[GazPal]

It has to be one of the worst things, when you find someone has misunderstood what's involved in the tool prep process and you find yourself needing to remedy mistakes before you're able to put a tool to good use.

Agreed - although ignorant long term use can have similar consequences.

One particular nightmare is back beveled garden shears - this can be done in around 30-60 second to a degree which is (AFAIK) irrecoverable :-(

BugBear

Possibly even less time. I once had a 2nd year college trainee on short term placement in my workshop and - after asking to check the toolkit he had when he arrived - was astounded to discover he'd double bevelled several new chisels the college had provided. I honestly don't know where he'd learnt that trick, but he didn't last beyond a few days with me and definitely confirmed the reasons why I don't loan or share tools.

 

[Jacob]

I've got a really nice oval bolster 1/8" mortice chisel which has been polished . The trapezoid section has been rounded slightly so that it's now slightly fatter in the middle which means it sticks tight instead of slipping out when you lever it back and forwards to loosen it.
Still usable but with unnecessary difficulty. I'm wondering about flattening the sides to get the shape and the nice sharp edges back. A lot of work and it'd end up thinner but they go down to 1/16" I believe. I've got a project involving slots.

So polishers and flatteners out there - do yourselves (and us) a favour and stop it immediately!

 

[Corneel]

I've actual flattened one today. It's a very nice old 1/2" stanley 5001 from ebay which unfortunately had been "flattened" by the previous owner leaving the face dubbed over at the edge corners and down both sides, so the round-over would never go away without flattening, or applying a permanent back bevel. NB if this was a new one I'd have sent it back as faulty goods.
I don't normally do this but I thought of this thread!
Didn't take long on Tilgear Ezelap diamond plates (coarse, medium fine).
Film and/or paper is not a good idea IMHO as it's fragile and tends to dub the edges over unless you are very careful. Not to mention slow and expensive.
With a solid plate or stone you can use maximum force and pressure and get the job done in a few minutes. Not water stones obviously (too soft) so has to be diamond plate or oil stone in good condition.

That's how most of mine arrive in my shop. It's what turned me into an obsessive back flattener.
Indeed sandpaper doesn't work as good as it should. Dubbing the edges is very easy.
I wonder about the diamond stone. Can you press down hard without damaging the plate? I always thought you shouldn't press down hard on these, otherwise the bond between plate and diamonds could break loose.
At the moment I do the heavy lifting with a Sigma 120 stone. That's a waterstone, but it's very hard. I also think about getting some coarse diamondpaste and a flat plate, to see if that is quicker.

 

[Jacob]

[....
I wonder about the diamond stone. Can you press down hard without damaging the plate? I always thought you shouldn't press down hard on these, otherwise the bond between plate and diamonds could break loose.....

Seems OK so far. I've had them about a year and have done a lot of sharpening.
The diamonds shouldn't detach - not the same but I've had the same 3M diapads for many years and they seem to last forever even with a lot of rough work (nb not sharpening), so firmly attached diamonds apparently are possible.

 

[bugbear]

I wonder about the diamond stone. Can you press down hard without damaging the plate? I always thought you shouldn't press down hard on these, otherwise the bond between plate and diamonds could break loose.

I recall (but can't place) a thread about diamond plate longevity, with some people saying they lasted for ever, and others saying they wore out in 6 months.

After some useful information exchange, it emerged that pressing too hard was the obvious cause of wear.

BugBear

 

[Corneel]

Thanks for your opinions, Jacob and Bugbear

 

[bobbybirds]

I have been using DMT diamond plates (along with water stones at higher grits) since 2010, and on them I have flattened (or better said, confirmed flatness and/or flattened) and sharpened from new a set of 8 and a set of 9 bench chisels, set of 4 paring chisels, a few skews and fishtails, as well as many multiple plane irons, kitchen knives, pockets knives and other tools etc, as well as day to day sharpening duties, and using the plates to flatten my water stones. The DMT diamond plates are still very fast cutting and reliably flat to this day. I would not hesitate to buy them again if/when they wear out...

 

[GazPal]

While initial "bite" can drift off as a new diamond stone settles into use, the norm is to use light pressure - as you would with oil and water stones - and allow the diamond's texture to do it's work. If the cut isn't sufficiently aggressive, simply switch to a coarser grit.