Need Advise, Flattening a Plane Iron or Chisel Back

[Wayne Hendrix]

I got great results using sandpaper, but found it did wear quickly, although I was using really cheap sandpaper.

I used 3M Super 77 spray adhesive to stick it to my plate, it should be available at any hobby store, hardware store and most likely Walmart. Spray the back of the sandpaper and allow it tack up then stick it to your flat surface. I would use WD40 as a lubricant while sharpening which would allow me to simply pull the sandpaper up without problem yet I never had problem with it sticking down or causing any rounding over of the edges.

Some adhesive residue will usually remain so I rotated to a new spot on the plate each time I changed out the sandpaper and cleaned the plate quickly with 409 and a paper towel when all the spots were used up. When the paper is first pulled up the adhesive is pretty soft and could easily be removed quickly with a putty knife. I bought a roll of 12" masking paper found in the painting section of hardware store to use a backer when spraying the adhesive, its super cheap and keeps from making a mess where you are working.

[David Ragan]

Yes, I often wonder about the quality of the tools that folks had 2 or 3 or 7 hundred years ago (and the monumental artistry), and then look at my tools and think how far metallurgy and sharpening has come.

Certainly, very fine work is possible without a pristine edge.

That said, I too like razor quality edges.

For a flat surface, my understanding is that any glass you get from a store for a regular picture, etc is 'float glass' ie-pretty flat indeed. Did not use to be so.

When i need to hog off a lot, I have set up melamine shelving board with self adhesive SiC rolls I got from Klingspoor. Is it perfect? probably not. Is it something I can take to refine on Shaptons? For sure.

The board has grits from 60 to 400, is maybe 3' long. Hangs on the wall. The paper is really easy to change out.

[ian maybury]

I'm a relatively recent recruit to more serious hand tool preparation, but won't necessarily offer a simple one size fits all answer to the question.

I seem to find that what works best for back flattening depends quite a lot on how out of flat the blade back is, what volume of metal is to be removed, what the steel is, and how large an area is involved.

Derek Cohen has a nice write up on flattening the backs of plane irons using Al Ox paper on his website: http://www.inthewoodshop.com/Woodwor...%20Blades.html Jim K (i think) wrote of using a long strip of sandpaper glued down on a long piece of granite to speed up the lapping/slow wear to the paper.

Most of my sharpening so far has been Japanese chisels and Lee Valley BU plane blades - there's been several threads. I had good luck flattening the backs of not very flat white steel Japanese chisels on the top surface of a WorkSharp running 120 grit AlOx or a similar grit diamond lapidary disc - albeit that it requires considerable care in presenting the tool to the disc to avoid dubbing/rounding or overheating.

It got slow on some wide Western chrome van or similar chisels that needed a fair amount of metal removed to get them flat. Against that a series of very well made mixed O1 and A2 Lee Valley BU plane irons were without exception each capable of being flattened all over in a few minutes on a 1,000 grit waterstone.

This was very much the result of their having been very well lapped by the factory, an older/less than flat plane iron would prove impossibly slow this way and Derek C's method would likely be called for on these, or on less than flat wide Western chisels.

One key issue is that quite apart from how flat a back it's felt is required to get a blade handling properly, it's very clear that the lapping/grinding of the back has to be very accurately flat if the subsequent honing and polishing on e.g. waterstones is not to become a huge (and unpredictable since problems may result in the wear bevels not being fully removed) task. i.e. the waterstones don't remove a lot of material/cut all that quickly. They do a good job of progressively removing the scratch marks from the preceding coarser steps, but are not necessarily the plan if the surface is not yet flat.

The same applies in respect of grinding primary bevels. Even a single flat bevel as on a Japanese chisel doesn't require a hugely aggressive technique (the WorkSharp on 120 grit works well for me - or even a waterstone) if the task is only to cut it back enough to remove a honing bevel. Against that if the task is large scale adjustment of the bevel angle on something like a thick (4mm or so) BU plane blade from say 50 deg to 25 deg then something of an altogether more aggressive nature is required - and a lot of care is needed to avoid the risk of overheating the edge and drawing the temper.

Against that if hollow grinding is acceptable then lots would say that an appropriate bench dry grinding set up with a soft/low heat wheel becomes possibly the most universal option...

Sandpaper of an appropriate grit bonded to a long flat surface comes fairly close it seems to a universal technique capable of handling most jobs when a flat bevel or back is required, but there are other possibilities too....

[Stewie Simpson]

Sean, you just can't imagine the low quality of work that was done 40 and 50 years ago. Even the old men who thought they were preserving traditional work were at a low level. I remember seeing an old man about 1976 working at a historic site and there was a trying plane on his bench. I asked him if he knew how to use the plane, "I've used it all my life". "What do you do to adjust the iron in and out?" "You can't adjust it, you have to take out the wedge and start over". In many cases there was a disdain for fineness and skill.

You can still see this kind of craftsmanship on videos. A guy will sharpen a chisel on a grey wheel, then hold the back against the side of the wheel. Then it is "razor sharp". Or sharpen the chisel on a combination SiC stone, sharpening the back on the medium side. Just really sloppy> Even tool collectors and dealers often sharpen tools this way. And because carpenters continued to use hand methods long past the furniture makers, most chisels you find were used by carpenter, handyman, home owner. This is especially true of socket chisels.

So probably some chisels you have seen were flattened on the back, just not to the fineness a craftsman would expect today.

Hi Warren. The primary concerns you raised are more likely an indicator to the poor standards that have been in place in the USA for many years relating the level training and overall competency required before you are licenced to work within any of these trades. Self taught seems to be the general criteria from what I have read in the past. Look further afield to Europe and Australia and you will find and abundance of much more talented and highly skilled tradesmen who have all worked their way through a traditional trade apprenticeship.

Stewie;

[Warren Mickley]

Hi Warren. The primary concerns you raised are more likely an indicator to the poor standards that have been in place in the USA for many years relating the level training and overall competency required before you are licenced to work within any of these trades. Self taught seems to be the general criteria from what I have read in the past. Look further afield to Europe and Australia and you will find and abundance of much more talented and highly skilled tradesmen who have all worked their way through a traditional trade apprenticeship.

Stewie;

I think if you were talking about 1960 I would agree. However from what I have read about trade in Australia today, I don't get the idea they are operating on a high level. Guys brag about their training, but their technique does not impress me the way 18th century craftsmanship does.

[Steve Voigt]

Look further afield to Europe and Australia and you will find and abundance of much more talented and highly skilled tradesmen.

Stewie;

What utter nonsense. No country has a monopoly on talent.

[Stewie Simpson]

Hi Warren. Unfortunately those days have long gone by. For modern day Cabinetmakers, its more about remaining competitive when pricing a job. Getting the job done in the quickest time possible to lower your overall costs. As a result the use of more modern tooling has now overtaken what was primary done with traditional hand tools. What's driven this change. The customer. Flat pack Ikea furniture is viewed as a far better option over traditional craftsmanship primarily because of the cost difference. A sad fact.

[Kees Heiden]

I seem to find that what works best for back flattening depends quite a lot on how out of flat the blade back is, what volume of metal is to be removed, what the steel is, and how large an area is involved.

That's very true! Vintage tools is my way of having fun, so I am usually confronted with pitting (which always goes much deeper then expected) and blades that are way out of flat. I don't buy into the flat chisel theory too much, but I like the area just behind the edge to be flat across the width. It's hard to get the corners of a chisel sharp when the back doesn't touch the stone in these corners. And pits in the edge are a good start for creating a nick in that same edge.

So I have quite a bit of experience with heavy metal removal, and must say, in my experience, sandpaper just doesn't cut it. I even tried these expensive 3M PSA sheets. They do help with the dubbing issue, but they wear out just as fast as other types of sandpaper.

Diamond plates are nice when they are new, but soon settle onto their normal mediocre performance level. Good as an intermediate step, but not so good for gross steel removal. Like I said, loose 80G silicon grit is the best I tried so far because they are so easy to replenish. I'll have to try loose diamonds too and see if they don't break down so quickly as the silicon grit.

[Stewie Simpson]

I agree with Ian. There can not be 1 single approach to how much surface area should be flattened on the back of plane irons and chisels. Early vintage tools as Kees rightly points out is a classic case where you are not only having to deal with potential of surface pitting but also the fact that the surface of the back may be convex, concave, or have a slight twist to it.

I personally am not keen on the concept of applying a back bevel as perscribed by Brent Beach. If you scroll down to the bottom of the attached page of Brents article you will note the shortfall of his back bevel approach when its principle is applied to a pitted surface along the cutting edge. He then makes the astonishing claim that "this blade worked very well, cut cleanly and lasted well, in spite of the small pitted area". The photo's would deem a totally different outcome.

http://www3.telus.net/BrentBeach/Sharpen/bevels.html

[ian maybury]

The need for a back (clearance side) bevel on plane irons will in many respects diminish in direct proportion to how good a job we do on our back flattening (and honing) I suspect Stewie...

I guess once our set of tools is more or less complete and has been set up that the task of back flattening (actually just the odd re-hone and polish) and cutting back bevels must become pretty much routine - in that case a single (likely hand) technique may well cover most of the bases. It's only us newcomers that are still clearing brushwood from the garden, and zeroing in on a routine that will suit us.

Apprenticeships to my mind are a very good idea - because most skills (not just the craft variety) can only really properly be taught and learned hands on. My feeling is that as societies we badly need to get serious about the 'learning by doing' principle again, and to value creative and craft skills as well as the magic (but practically not hugely useful) bit of paper. I just recently while beating myself up on how long it's taken me to get going on some commercial work realised that I'm on a one man apprenticeship. Which with the web and enough space with minimal commercial pressures may not be the worst route these days. Against that (ref. the mention of poor workmanship in years gone by) - it was tough luck then if you ended up with a guy that wasn't a good mentor.

Over here (Ireland) we've seen craft apprenticeships dwindle to a very low level. Companies and businessses seem simply unwilling to spend the money/make that sort of longer term investment in employees in a situation where once trained they will likely be gone to the highest bidder next week. Lack of political will and a pretty disastrous state vocational training set up have probably not helped. Perhaps the fundamental problem is the mentality that has presided over the shipping of the greater part of manufacturing jobs overseas....

As usual they still seem to be able to do it pretty well in Germany where by creative use of technology and other business improvements etc they seem to have managed to stay competitive in many industries regarded in most Western countries as being financially non viable - there's really no alternative to people buying into constructive/societally useful principles, and applying the grey matter.

It's a sort of a chicken and egg deal. Skills when valued become worth training in, and worth investing in the development of. It likewise becomes worth the trainees while to make the commitment...

[Kees Heiden]

Brent Beach is indeed quite optimistic about that pitting! Also about thinking it will be gone after the next sharpening. Personally I would have opted to grind back the edge.

He also didn't know how a plane blade wears in a 3 dimensional way at the time he wrote that webpage. Steve Elliott got a much better understanding.
http://bladetest.infillplane.com/htm..._profiles.html

It means that Brent put way too much emphasis on the back of the blade in a bevel down plane. Important is the wear bevel on the bevel side, because that one kills the clearance angle. When you hone the bevel, that wears is removed. When you manage to remove the burr from that honing operation and leave the back further alone, you will see under a microscope that the wear bevel on the backside of the blade is still there, but also that it is polished. This polish comes from the wood shavings flowing over the blade during planing. You can even see that polish with the naked eye as a gleaming line just behind the edge.

So how do you remove the burr? When you hone the bevel with a very fine stone, you will see that most of the burr is allready gone. With a bit of stropping you can remove the last bits. Or you put the back on the finest stone and put pressure with your fingers as close to the edge as possible. Just a quick action on the stone will remove the burr without entirely removing the wear bevel.

I won't say that this produces a super duper edge, but it'll be a workable edge for woodworking nonetheless. That might explain why you won't see much back flattening going on on vintage irons.

[Stewie Simpson]

Thanks Kees. Appreciate your thoughts.

Stewie;

[Sean Hughto]

So how do you remove the burr? When you hone the bevel with a very fine stone, you will see that most of the burr is allready gone. With a bit of stropping you can remove the last bits. Or you put the back on the finest stone and put pressure with your fingers as close to the edge as possible. Just a quick action on the stone will remove the burr without entirely removing the wear bevel.

I won't say that this produces a super duper edge, but it'll be a workable edge for woodworking nonetheless. That might explain why you won't see much back flattening going on on vintage irons.

I think your speculation makes a ton of sense here.

[Stew Denton]

Hi All,

I have been reading the threads and thoughts with a great deal of interest.

The thoughts on the old world apprenticeship system have certainly struck a note. The fact is that the loss of truly skilled craftsman is not a new thing, it has been going on for around two centuries, and the movement to factory production of wooden furniture has been driven by lower cost, although at the cost, often, of fine craftsmanship. My wife and I have been there, in that for a long time we could not afford much except "Early American Walmart" for some of our furniture, for example TV stands and bookcases, etc. I suspect many others are in the same boat. Now I hope to replace some of these items by building replacements myself.

My son in law pointed out to me that it is primarily the hobby fine woodworkers that are the driving force for keeping the old high level of skills alive. Certainly there are some of you professionals that are highly skilled, but because of the cost of buying such items that you produce, there can't be the number of such highly skilled professionals as there used to be.

Bob, yes I am looking for the holy grail of a wickedly sharp cutting edge, but do have some experience getting there, and have some tools that I have taken pretty much to that point. That said, I have been replacing and purchasing planes and chisels to either replace ones that are none too good, or to fill in holes in the tools that I have. As such, I have several vintage Stanley plane irons and several moderately priced chisels that now need to be sharpened. Because of that I have been looking for a faster way to get there. As pointed out, it seems that at least some of these early 1900s to 1930s plane irons are none too flat.

I did read the linked articles on sharpening, but have a few to read yet, and have been thinking on such. I think that there is some great insight there, but also think that there is more than one side to some of the statements.

My main concern is what will best work in my case, given the sharpening tools I have, etc.

Thank you all for your comments, and I will continue to read the further comments that are being added with great interest.

Thanks and regards,

Stew

[Jim Koepke]

My main concern is what will best work in my case, given the sharpening tools I have, etc.

That is the important part of the sharpening equation. Whether it be some super duper honing guide or symbols made of chicken bones, if it works it doesn't matter one bit what others may say.

Evangelists for all the different ways to get to a useable edge are everywhere.

For me keeping it simple and getting back to making shavings is what works.

The hardest part may be to stop and hone a blade before it gets overly worn.

jtk