Bench Plane - Sharpening/Tuning question

[Dissolve]

Hello,

I sharpened all of my hand tools today, and I'm confident in creating an edge that can shave hairs! But my bench planes seem to lose their razor sharp edge quite quickly.

I was wondering how close to the blade edge should the cap iron/chipbreaker be set? I usually have it clamping just a fraction below the edge on the back of a newly sharpened blade.. But what effect does the distance between the cap iron and the blade have?

I usually grind my bevels then create a micro bevel a few degrees higher than the large bevel to polish on my fine stones which creates a razor edge.. Any thoughts on whether a micro bevel is better/longer lasting than just sticking with the polishing the ground bevel?

Thanks

 

[dunbarhamlin]

On a finishing plane, a very (very) closely set cap iron can help reduce tear out. On other planes its setting helps shaving ejection, and depends on how rank a cut you're taking.
As with other edge tools, what constitutes working sharp depends on the application, so you just have to get used to feeling when an iron needs touching up for the job at hand.
Using multiple or just a single bevel has no bearing on edge longevity. It just dictates/is a result of your sharpening/honing strategy. Single bevel keeps on top of sharpening/shaping, whilst multiple bevels saves up sharpening/reshaping for later.

 

[Dissolve]

On a finishing plane, a very (very) closely set cap iron can help reduce tear out. On other planes its setting helps shaving ejection, and depends on how rank a cut you're taking.
As with other edge tools, what constitutes working sharp depends on the application, so you just have to get used to feeling when an iron needs touching up for the job at hand.
Using multiple or just a single bevel has no bearing on edge longevity. It just dictates/is a result of your sharpening/honing strategy. Single bevel keeps on top of sharpening/shaping, whilst multiple bevels saves up sharpening/reshaping for later.

Hello,

Thanks for the tips! When you say a single bevel keep on top of sharpening/shaping and multiple bevels saves up sharpening/reshaping for later do you just mean you will need to re-grind the single bevel sooner as once the edge is dull the entire bevel needs grinding flat/honing?

Will increasing the distance between the cap iron and the blade produce a thicker cut? or is that solely down to the amount of blade protruding from the sole?

If I were to be using a standard no 4 say for thicknessing a board.. How would the plane benefit most from being set up?.. I'm not sure what would achieve best shaving ejection in this case?

 

[Cheshirechappie]

On the subject of edge life before resharpening, I find that about half an hour is the most I get in mild timbers such as Redwood, and rather less in harder timbers. That's working steadily but continuously, and with irons of 'normal' steel rather than expensive exotics. A re-hone will bring sharpness back, and I manage about eight to ten re-hones before the secondary bevel has become wide enough to justify a quick regrind.

Cap iron setting depends on what you want the plane to do. For heavy stock removal with thick shavings, about 1 mm is usually satisfactory, and for fine smoothing with very fine shavings, as close to the edge as you can get it - literally a hair's breadth. A try plane set up for final dimensioning of stock may take a slightly thicker shaving than a smoother, so the capiron should be just a shade further back, say about 1/4 mm or so. However, these are just a general guide - the type of wood you're working may demand slightly different set-ups. A few experiments on scraps, or the first few components of a project usually leads to the right sort of compromise between fastest stock removal and quality of finish. Like a lot of things in woodwork, judging what's best in a particular circumstance is something you get better at with experience, so the best thing to do is pile in and experiment a bit. The more shavings you make, the better you'll be able to judge a set-up that suits your planes, your wood, and your way of working.

 

[dunbarhamlin]

Using a single bevel strategy means that every time you hone the iron, you must remove metal from the full width of the bevel. For speed's sake this means always working the bevel on both medium and fine stones, whereas using a micro bevel, a number of honings can be undertaken using your fine stone only, until the micro bevel becomes too large to efficiently rework with a fine stone after which a longer session on your coarser stone (or grinder) will be required to reestablish the primary bevel. So with a single bevel strategy, grinding is only required when an edge is damaged, not as a part of routine maintenance.

Moving the cap iron further back from the edge will not produce a heavier cut, but it will allow you to take a heavier cut. Consider the shape of the cap iron... It forms a wedge on top of the iron, which you are advancing into the slot of the mouth. The farther back, the thicker the shaving that can squeeze through the slot (but vide infra...the mouth can be widened.)

To efficiently thickness a board, you want to get within a whisker of final dimension as quickly as possible with a rank set plane, preferably with a cambered iron, and then sneak up on the last few thousandths of an inch with a finer set plane with little (or no) camber.
To set the plane up for the first operation, I would open the mouth wider (with a normal Bailey type plane, this involves removing the blade assembly, loosening the two screws thereby exposed and sliding the frog backwards) and set the cap iron 1/16" back from the edge (or more, in an amenable wood.) This both allows more room for shavings to pass and stops thick shavings curling too tightly next to the mouth, potentially leading to clogging.

 

[bugbear]

Hello,

I sharpened all of my hand tools today, and I'm confident in creating an edge that can shave hairs! But my bench planes seem to lose their razor sharp edge quite quickly.

Several factors effect edge retention in plane blades - including effective pitch, included angle, steel quality type, and abrasiveness of the wood.

BugBear

 

[Dissolve]

I'm currently using a no. 5 plane for everything at the moment, due to lack of funds! But I hope to get a few more in my collection before long!

Why would a cambered blade be better for fast stock removal and a straight edge blade better for finishing?

I find the no 5 very comfortable as I have large hands, is a no 4 smoothing plane any better for the purpose of thicknessing boards?

I can see why a lighter plane might be preferable when removing stock quickly and possibly the larger sole of a no 5 might be better for achieving a final flat surface?

Can anyone recommend some good reading material regarding bevel angles? Have no idea yet what angle to grind my blades at for different purposes!

Many thanks

 

[Jacob]

Hmm, is this a "baited swim"?

......
Why would a cambered blade be better for fast stock removal and a straight edge blade better for finishing?

Interesting question.
The force needed to push a sharp edge through wood is roughly proportional to the length of edge, so e.g. a narrow chisel will go deeper than one with a longer (wider) edge, given the same amount of force.
A cambered plane blade is a bit like a gouge. For the same amount of force a shallow gouge will remove less material than a deep gouge with the same edge length (hence narrower). The optimum shape of edge of given length for maximum material removal would be a semi circle (like a deep gouge ), but obviously this is not flat. The flattest surface is produced by the shallowest gouge shape, which also removes least material.

So it's down to striking a happy medium between deep (narrow) semicircular cut and rapid removal, or near flat (wide) cut and minimal removal.

Unless used only for edge planing all plane blades need a bit of camber.
NB this oversimplified (there are other factors) but basically gives the picture

I find the no 5 very comfortable as I have large hands, is a no 4 smoothing plane any better for the purpose of thicknessing boards?

Not much in it. Anyway they have the same size handles.

...
Can anyone recommend some good reading material regarding bevel angles? Have no idea yet what angle to grind my blades at for different purposes!

30º for everything, until you are more into it. There is too much information out there!

 

[Sawyer]

In planing, the edge has to work hard, very hard and will not usually stay sharp for long, even with good quality steel. If you are doing any heavy duty work, eg. thicknessing a board of hardwood, expect to be re-sharpening every few minutes. Finer planing, eg. dressing joints, is easier on the steel, but sharpness becomes more critical, so you'll probably be re-sharpening just as often.

I find it good practice to avoid letting wood touch the floor, to avoid picking up grit - one of your plane's worst enemies. Also, as much as possible, try to avoid using abrasives until you have finished planing. Abrasive residue left in the grain will drastically reduce the edge life of your plane iron.

 

[dm65]

I'm currently using a no. 5 plane for everything at the moment, due to lack of funds! But I hope to get a few more in my collection before long!

Why would a cambered blade be better for fast stock removal and a straight edge blade better for finishing?

I find the no 5 very comfortable as I have large hands, is a no 4 smoothing plane any better for the purpose of thicknessing boards?

I can see why a lighter plane might be preferable when removing stock quickly and possibly the larger sole of a no 5 might be better for achieving a final flat surface?

Can anyone recommend some good reading material regarding bevel angles? Have no idea yet what angle to grind my blades at for different purposes!

Many thanks

Try watching this series of video's http://www.finewoodworking.com/how-to/v ... lanes.aspx - I did and they explained a lot to this old knownowt

 

[bugbear]

The force needed to push a sharp edge through wood is roughly proportional to the length of edge.

if that were even roughly true, a straight blade would require the same force, regardless of depth of cut, which is clearly nonsense.

There are more factors involved.

BugBear

 

[Jacob]

The force needed to push a sharp edge through wood is roughly proportional to the length of edge.

if that were even roughly true, a straight blade would require the same force, regardless of depth of cut, which is clearly nonsense.

There are more factors involved.

BugBear

You haven't understood the point. Never mind. It would be more civilised to ask another question rather than shrieking nonsense!

 

[Cheshirechappie]

I'm currently using a no. 5 plane for everything at the moment, due to lack of funds! But I hope to get a few more in my collection before long!

Why would a cambered blade be better for fast stock removal and a straight edge blade better for finishing?

I find the no 5 very comfortable as I have large hands, is a no 4 smoothing plane any better for the purpose of thicknessing boards?

I can see why a lighter plane might be preferable when removing stock quickly and possibly the larger sole of a no 5 might be better for achieving a final flat surface?

Can anyone recommend some good reading material regarding bevel angles? Have no idea yet what angle to grind my blades at for different purposes!

Many thanks

If I had to rely on only one plane, it would be a number 5. However, I'd be tempted to cheat, by obtaining at least one extra iron and cap-iron, and having it set up differently to the one already in the plane. I'd have one with a distinct camber ground and sharpened on it, at about 8" radius, and with the cap-iron set about 1/16" behind the edge. The other, I'd grind and hone straight across but with the extreme corners rounded off a touch, and the cap-iron set close to the edge. The reason for this is that you can swap the two irons and cap-irons over, the cambered one being used with a fairly deep cut (say 1/32" or even a bit more) and used predominantly across the grain for heavy stock removal and flattening warped boards, and the straight one set much finer for truing-up after the 'jack-iron' and for smoothing duties.

With this strategy, you may have to fiddle with frog setting when swapping blades, or if you use generally mild timbers, you may by experiment find a 'compromise' frog setting that does for both. Ideally, the 'jack-iron' would have a wide mouth to clear thicker shavings, and the 'try/smoother-iron' would have a much tighter mouth for a finer finish - that's how planes dedicated to duty would be set up. However, sometimes in woodwork, things that may not be ideal in adverse circumstances (wild-grained wood) can work tolerably well in easier conditions (mild wood) - hence the 'compromise' frog setting might work. Worth a bit of experimenting, anyway!

Once you're in a position to expand the plane collection, I'd go for a number 4 first, and set it up for fine smoothing (cap-irin very close to blade edge, tight mouth, very shallow depth of cut). Later, get a number 7 for try and jointer duties. The 7 will cost a lot, unless you drop on a good one at a boot sale; 4s can be found almost everywhere, so it's worth being picky and waiting for a really good one. With a jack, a try and a smoother, you'll have all the bases covered (though like most of us, you'll probably end up with a few more - for example, woodies don't cost much, and are fun to use....)

On bevel angles, about 95% of woodworking can be accomplished perfecly adequately with a 25 degree grind and 30 degree hone angles. Those angles are 'about', by the way - a couple of degrees either way won't cause any real problems.

 

[bugbear]

It would be more civilised to ask another question

Let's try that.

The optimum shape of edge of given length for maximum material removal would be a semi circle (like a deep gouge ).

it's down to striking a happy medium between deep (narrow) semicircular cut and rapid removal, or near flat (wide) cut and minimal removal.

If you believe that to be the case, why don't scrub planes, made for the fastest possible stock removal, take semi--circular cuts? The camber of a real life scrub is far below your posited optimum.

BugBear

 

[Jacob]

It would be more civilised to ask another question

Let's try that.

The optimum shape of edge of given length for maximum material removal would be a semi circle (like a deep gouge ).

it's down to striking a happy medium between deep (narrow) semicircular cut and rapid removal, or near flat (wide) cut and minimal removal.

If you believe that to be the case, why don't scrub planes, made for the fastest possible stock removal, take semi--circular cuts? The camber of a real life scrub is far below your posited optimum.

BugBear

Fair question. The answer is that yes for any given material and strength of operative an appropriately sized semi-circular gouge would remove most material. But you have to allow for diversity - or have a range of planes to cover varieties of wood
This is why scrubs are narrow and deep cutting - i.e. on the way to a semi circular cut

 

[bugbear]

The answer is that yes for any given material and strength of operative an appropriately sized semi-circular gouge would remove most material. But you have to allow for diversity - or have a range of planes to cover varieties of wood
This is why scrubs are narrow and deep cutting - i.e. on the way to a semi circular cut

I don't think the notion that cutting edge length is the main determinant stands any careful thought. It is obvious when using a plane that cutting depth, and the action on the shaving after it's been cut (e.g. effective pitch and cap iron distance) are also large factors.

With a curved edge, things become even more complex, since the cutting depth isn't even constant.

In the case of a scrub, used 45 degrees across the grain, many factors converge to give excellent efficiency - the shaving turns easily in the throat, since it is "short grain", but further, the curved blade completely frees the shaving at both ends.

In short - as with so many real life situation - the practice is often more complex than a simple theory.

BugBear

 

[Jacob]

....
In short - as with so many real life situation - the practice is often more complex than a simple theory.

BugBear

Well yes, as I said earlier.

 

[Duncumb.fc]

Chipbreaker [should be] set close to the edge. Very close, more then 0.3mm from the edge renders the chipbreaker mostly ineffective.

I've rather forgotten, in the heat of the moment finding the quote, what I was going to say about the above quote, but it's there for reference!

Regarding sharpening, we're stumbling into a minefield very quickly, but I would also say my planes get about 30 minutes of use before a honing is need. Personally I never got on with the micro bevel theory, the idea of regrinding the blade so often didn't appeal, so I switched to a technique I can only describe as a nano bevel! I make a bevel so small that the next time I sharpen I hone that bevel completely off (which is very quick because the bevel is so small), and then start again. This way I can sharpen very quickly, no rounding happens, and I don't need to bother with a pesky honing guide! :mrgreen:

Fraser

 

[lwilliams]

...Regarding sharpening, we're stumbling into a minefield very quickly, but I would also say my planes get about 30 minutes of use before a honing is need. Personally I never got on with the micro bevel theory, the idea of regrinding the blade so often didn't appeal, so I switched to a technique I can only describe as a nano bevel! I make a bevel so small that the next time I sharpen I hone that bevel completely off (which is very quick because the bevel is so small), and then start again. This way I can sharpen very quickly, no rounding happens, and I don't need to bother with a pesky honing guide! :mrgreen:

Fraser

Sounds like traditional honing to me, Fraser. Just like Nicholson described in the 1830's:
http://books.google.com/books?id=_XYOAA ... 22&f=false

But then we had a bunch of people who couldn't figure it out reinvent the wheel and we got a lot of gimmicks like honing guides that just slow down the process and get in your way.

With my tremors, if I can quickly hone a good sharp edge anyone can:

http://www.youtube.com/watch?v=Z0ClNp_Eknw

But it is important to hone both surfaces that make up an edge because both suffer wear.

 

[Duncumb.fc]

...Regarding sharpening, we're stumbling into a minefield very quickly, but I would also say my planes get about 30 minutes of use before a honing is need. Personally I never got on with the micro bevel theory, the idea of regrinding the blade so often didn't appeal, so I switched to a technique I can only describe as a nano bevel! I make a bevel so small that the next time I sharpen I hone that bevel completely off (which is very quick because the bevel is so small), and then start again. This way I can sharpen very quickly, no rounding happens, and I don't need to bother with a pesky honing guide! :mrgreen:

Fraser

Sounds like traditional honing to me, Fraser. Just like Nicholson described in the 1830's:
http://books.google.com/books?id=_XYOAA ... 22&f=false

But then we had a bunch of people who couldn't figure it out reinvent the wheel and we got a lot of gimmicks like honing guides that just slow down the process and get in your way.

With my tremors, if I can quickly hone a good sharp edge anyone can:

http://www.youtube.com/watch?v=Z0ClNp_Eknw

But it is important to hone both surfaces that make up an edge because both suffer wear.

Thanks! I picked it up from my tutor, and didn't realise there was a historical basis for it! In my humble opinion I think it makes much more sense, but I'm sure there's an argument to be had there!
I would also always advocate flattening the back of the blade, more than anything to remove any burr (I don't bother with stropping, other than a quick brush on my hand), but it's much easier to do when there isn't any wear there!

Fraser