Flattening, polishing and friction.

[bobbybirds]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

This applies to end grain, and cross grain. Long grain will depend on fibre orientation,

Simple eh? I have been doing this for 40 years, though it might not always have gone quite right in the beginning!.....

David Charlesworth

If I didn't know better, I would think you were Canadian eh! :lol:

 

[GazPal]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

This applies to end grain, and cross grain. Long grain will depend on fibre orientation,

Simple eh? I have been doing this for 40 years, though it might not always have gone quite right in the beginning!.....

David Charlesworth

Hence my emphasis upon good technique and it is as simple as that. A flat back and poor technique........ well.......

------------

An example of how an edge can dive/drift into a workpiece can be found when paring mortise end grain to a line. The blade can drift if one is not careful, or technique is lacking. Regardless of flat or sharpness.

 

[David C]

Bobbybirds,

Are you refering to my friend Mr Cosman?

David

 

[G S Haydon]

Wow!

David C, nice to see you sharing you knowledge here!

 

[Jacob]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

That's what is known as a self evident truth - a lot of "ifs". But we all know that in reality it's easy to over do it paring along or across the grain with a chisel. Flatness has only little to do with it, nothing at all if convex - it's about technique more than anything.
Cosman burbles on about flattening here http://www.youtube.com/watch?v=cOvkNuwO_YM but when it comes to the paring demo his chisel dives and he cuts a deep notch!! What lot of tosh!
PS expanding on that - he says all chisels need "preparing" This isn't true, they are "prepared" by the maker (if not, send them back) they just need sharpening. He doesn't explain why they need "preparing" and finally fails to demonstrate any point in "preparing". In spite of this many people spend many hours "preparing" (and sometimes spoiling) chisels, even old ones which may have been well used for many years without ever having needed "preparing". Madness! :lol:

 

[G S Haydon]

After making a return to woodworking for pleasure as well as doing it for a living I am in the throws of putting together a second set of tools that will only be used for my pleasure http://gshaydon.co.uk/blog/tool-chest-done/. Life is tough for my job tools, I could be out repairing or installing or at the bench making. Before returning to the craft for enjoyment all my cutting tools were hollow ground on a tormek and finished up on the polishing wheel attached to the machine. I never even thought about flatness or the ideal angles for my cutting tools, I just clamped the chisel in and set it using the plastic jig provided sharpened away. I never had a problem and my tools were sharp.

Now looking into the finer details of sharpening I have started to examine my cutting tools more closely. I have a set of budget faithful blue handled chisels for my second set of tools and some vintage Record bench planes which are all being prepared at the moment. All of these tools will be freehand sharpened on diamond plates.

All the chisels are slightly concave on the back and I have tried to flatten them a little. But it's hard going, so much so I am resigned to just leveling them off a touch. In the ideal world I would like them to be flat on the back just like David mentions (I would also like a nice set of LN socket chisels so I wouldn't have to bother flattening at all ) . But I figure that over time the chisels will become flatter and flatter as I sharpen them and remove the burr.

On the plane blades I tried to lap the whole of the blade and quickly decided that Davids ruler method would be the best approach. Sure beats lapping!

Like anything though, it's all about finding something that works for you and the type of work you do. I will most likely stay with the tormek for job tools and spend the extra time on my personal tools as they will have to work on finer and more intricate work.

 

[bugbear]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

This applies to end grain, and cross grain. Long grain will depend on fibre orientation,

Simple eh? I have been doing this for 40 years, though it might not always have gone quite right in the beginning!.....

David Charlesworth

Indeed, it's rather difficult to visualise how it could.

Like a fluking whale?

BugBear

 

[Jacob]

......
All the chisels are slightly concave on the back and I have tried to flatten them a little.

That's how the are supposed to be. They make them like that. It makes sharpening easier. If you flatten them it makes subsequent sharpening more difficult
You really do not need to polish the whole of the face. It doesn't even need to be perfectly flat. There's a thread here which covers it pretty well flattening-chisel-backs-with-lapping-film-t68506-225.html
This is as much flattening and polishing you need on a typical chisel face:

.

 

[Jacob]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

This applies to end grain, and cross grain. Long grain will depend on fibre orientation,

Simple eh? I have been doing this for 40 years, though it might not always have gone quite right in the beginning!.....

David Charlesworth

Indeed, it's rather difficult to visualise how it could.



Like a fluking whale?

BugBear

Why don't you try it BB instead of theorising about it? Try and remove a long chisel-width paring from a long grain surface, keeping it uniformly 1/16" thick. Let us know how you get on.

 

[GazPal]

Sharpening methods. technique and end results should always suit the end user's needs. So much depends on how often you're likely to use the full chisel length to pare instead of a plane. From personal experience I tend to find paring is more typically used as an intermediate step - e.g. housing joints - in the overall process and often followed up by planing or using abrasive papers.

One factor regarding the current flatness fad is the fact that chisel and plane iron backs virtually flatten by themselves through repeated honing as the burr is wiped from the refreshed edge on the stone. Common sense tends to dictate the need to remove residual manufacturer's machine marks, but it's seldom necessary to treat the entire blade length.

If a new blade is warped or bent, return it for exchange or refund, but by all means bring an old chisel of plane iron back into use using whichever method and style you see fit.

 

[G S Haydon]

I totally accept the ideal should be flat on the back or very slightly concave. Over time my chisels will get flatter and flatter with sharpening and burr removal. When I was college the old boy said you should never BB a chisel "It is a chisel, not a screwdriver" he would say. He pointed out the difficulty in paring with this type of detail. But like anything, if it works for you, great. I don't see myself applying a BB to a chisel any time soon.

On plane blades Davids ruler method seems perfect, much more fun than all that lapping!

 

[David C]

I do find Jacob's breathtaking miss information quite extraordinary.

He needs to watch that Cosman video again.

The long paring cuts are straight. (He even states they are "downhill").

The information imparted is sound. whatever Jacob may think.

David

 

[GazPal]

I don't know what I'm missing here, but if a fine enough cut, is taken with a sharp enough chisel, with good technique and a nice flat back, it will not dive.

This applies to end grain, and cross grain. Long grain will depend on fibre orientation,

Simple eh? I have been doing this for 40 years, though it might not always have gone quite right in the beginning!.....

David Charlesworth

I'd have replied with more detail in my previous reply but was short on available time. I've been doing this for a wee bit longer than you David and most probably made the same initial mistakes as yourself, but seldom find myself needing to pare end or long grain to a finish using the full reach of a paring chisel.

Indeed, it's rather difficult to visualise how it could.



Like a fluking whale?

BugBear

You must be taking the water.

If your diagram doesn't confirm the presence of factors that make setting a blade within a solid frame to maintain depth of cut and prevent it from nose-diving (Didn't they invent the hand plane for this precise purpose? :roll: ), you lack experience and need to attend a woodworking course or get on with some practical fidgeting about with paring chisels and timber in your shed/garage.

Per your drawing:
You need to counter balance the leading edge by adding weight to the trailing end of the blade. This in turn applies downward force and prevents the wedge from digging itself deeper than necessary as the edge bites. If the blade were bevel up you'd need the apply upward pressure on the trailing edge in order to keep the edge aligned and prevent it from scooping the cut.

Enter a chisel edge horizontally into end, cross, or long grain timber and drive it forward without downward pressure on blade or handle. With bevel up you'll find the blade has a tendency to nose dive into the cut and your 1/64" soon becomes 1/8" in depth, while bevel down will have the chisel rise out of the cut and your original 1/64" depth tapers to 0.

 

[Jacob]

:shock: What's this whale stuff about?

 

[Jacob]

I do find Jacob's breathtaking miss information quite extraordinary.

Don't hold your breath too long!

...
The information imparted is sound....

Very misleading IMHO. Resulting in lots of people wasting lots of time doing silly unnecessary things. It comes up all the time; "I'm struggling to flatten my new LN chisel backs, I've worked through 25 grit grades and 2 water-stones..... etc etc". Very silly.

This is as much flattening and polishing you need on a typical chisel face:

 

[Racers]

.
The information imparted is sound....[/quote]Very misleading IMHO. Resulting in lots of people wasting lots of time doing silly unnecessary things. It comes up all the time; "I'm struggling to flatten my new LN chisel backs, I've worked through 25 grit grades and 2 water-stones..... etc etc". Very silly.





Can you link to any examples of this Jacob?

Pete

 

[G S Haydon]

I must admit as a new member to UKWorkshop this thread does not encourage me too much. I'm finding some of the posting her a little aggressive and confrontational over something than can be treated, as most things in life, something to take or leave.
I'm all for various approaches and sharing what works well for each of us, perhaps that should be as far as it goes?

 

[bugbear]

:shock: What's this whale stuff about?

Google fluking and learn, if you want to. I thought the metaphor rather apt.

BugBear

 

[Jacob]

.
The information imparted is sound....Very misleading IMHO. Resulting in lots of people wasting lots of time doing silly unnecessary things. It comes up all the time; "I'm struggling to flatten my new LN chisel backs, I've worked through 25 grit grades and 2 water-stones..... etc etc". Very silly.





Can you link to any examples of this Jacob?

Pete

Nearest one (typical, but not word for word) is in this thread above flattening-polishing-and-friction-t68962.html (Gary Morris). Often repeated with variations - whole threads devoted to the problem of flattening.

 

[Racers]

.
The information imparted is sound....Very misleading IMHO. Resulting in lots of people wasting lots of time doing silly unnecessary things. It comes up all the time; "I'm struggling to flatten my new LN chisel backs, I've worked through 25 grit grades and 2 water-stones..... etc etc". Very silly.





Can you link to any examples of this Jacob?

Pete

Nearest one (typical, but not word for word) is in this thread above flattening-polishing-and-friction-t68962.html (Gary Morris). Often repeated with variations - whole threads devoted to the problem of flattening.

So most are just your impression from one or two posts you have misinterpreted in your usual way, or am I misinterpreting.


Pete