In this months F&C there is an article on Clifton shoulder planes. It says that one problem is the tight mouth that is so necessary for cross grain work on shoulders, but which jams up when used on long grain. Now as I have always understood you do not need a tight mouth for end grain (as you are not splitting long grain fibres) but you may need a tight mouth on some long grain. :? :? :?
Confused
- Thread starter newt
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Chris Knight
Established Member
Pete,
The ultimate open mouth is a chisel and you might recall seeing tearout when chiselling endgrain if you take too big a bite and the chisel was not as sharp as it could be. I guess the wood fibres are simple broken in tension as they are dragged by the passing blade. Presumably the same thing can happen with a plane although I haven't experienced it personally.
The ultimate open mouth is a chisel and you might recall seeing tearout when chiselling endgrain if you take too big a bite and the chisel was not as sharp as it could be. I guess the wood fibres are simple broken in tension as they are dragged by the passing blade. Presumably the same thing can happen with a plane although I haven't experienced it personally.
Chris I take your point. However my veritas apron plane which is stated as very good for end grain work has a mouth opening of nearly 2mm. I am sure I have read in books somewhere that end grain work does not require a tight mouth.
matthewwh
Established Member
I'm inclined to agree with you Newt, a tight mouth is beneficial where the fibres run along the shaving but in crossgrain or endgrain applications it isn't.
It's easy to confuse the reasons for different design elements - a low effective angle (which is purported to be beneficial for endgrain) is more prone to lift fibres from the surface when working along the grain, a tight mouth alleviates this problem.
Personally I can't find any tangible benefit from a low angle that is specific to endgrain. It does however improve control by reducing the pressure needed to push the tool through the work, which is always a good thing.
As Waterhead says, the ultimate open mouth is a chisel and you'd have to be completely out of other options before you would attempt to pare along the grain.
It's easy to confuse the reasons for different design elements - a low effective angle (which is purported to be beneficial for endgrain) is more prone to lift fibres from the surface when working along the grain, a tight mouth alleviates this problem.
Personally I can't find any tangible benefit from a low angle that is specific to endgrain. It does however improve control by reducing the pressure needed to push the tool through the work, which is always a good thing.
As Waterhead says, the ultimate open mouth is a chisel and you'd have to be completely out of other options before you would attempt to pare along the grain.
Paul Chapman
Established Member
I have the Clifton 3110 shoulder/bullnose/chisel plane which has shims to vary the size of the mouth. Whatever the theory, I find it works best with no shims and a very tight mouth and that's how I use it. For most shoulder plane work I would have thought you would be taking quite fine shavings, so there shouldn't be too much of a problem with the shavings clogging the plane.
When I bought the plane, I discusssed with Mike Hudson from Clifton what he recommended as a honing angle and he always hones the shoulder planes at 25 degrees. I took his advice and have found that it works fine like that on end grain.
Cheers :wink:
Paul
When I bought the plane, I discusssed with Mike Hudson from Clifton what he recommended as a honing angle and he always hones the shoulder planes at 25 degrees. I took his advice and have found that it works fine like that on end grain.
Cheers :wink:
Paul
woodbloke
Established Member
matthewwh":154a1af0 said:
I use a skew chisel to pare end grain when I make exposed and wedged m/t joints. A squarly ground chisel would tear, but the skew works fine - Rob
bugbear
Established Member
newt":8jtpp93t said:
Given the long standing tendancy (150 years at least) of shoulder plane to have very tight mouths, I suspect there's a good reason behind it.
I know that planes where the blade is the full width of the body require more care at the start of the stroke - it's actually possible to end up with the leading corner of the workpiece crammed into the shaving aperture of the plane, if the heel of the plane is too low. A tight mouth would reduce this difficulty.
BugBear
During the last hour I have performed the following tests using my veritas medium shoulder plane which has an adjustable mouth. Varitas suggest that it can be used for end grain or for long grain rebates, hence the adjustable mouth. ( lovely plane by the way)
I planed end grain on some greenheart, lemonwood, and pine with a tight mouth. There were no major problems however the greenheart shavings were not continuous but the planed surface was smooth. The shavings were 2 thou measured with a micrometer.
The mouth was opened up to 1.5mm (60thou) the lemonwood was easier to plane in terms of effort however the shavings and finish were the same. Both the greenheart and pine remained the same as with the tight mouth. There was certainly no tearout ( I cant see how you can have tearout as such in end grain like you do in long grain).
The blade was honed at 28 degrees, the bed angle is 15 degrees giving a effective cutting angle of 43 degrees. All I can learn from the above is with these 3 species of wood and with this plane , the mouth size makes no real difference.
I planed end grain on some greenheart, lemonwood, and pine with a tight mouth. There were no major problems however the greenheart shavings were not continuous but the planed surface was smooth. The shavings were 2 thou measured with a micrometer.
The mouth was opened up to 1.5mm (60thou) the lemonwood was easier to plane in terms of effort however the shavings and finish were the same. Both the greenheart and pine remained the same as with the tight mouth. There was certainly no tearout ( I cant see how you can have tearout as such in end grain like you do in long grain).
The blade was honed at 28 degrees, the bed angle is 15 degrees giving a effective cutting angle of 43 degrees. All I can learn from the above is with these 3 species of wood and with this plane , the mouth size makes no real difference.
Modernist
Established Member
I don't think a tight mouth is any benefit at all on end grain. A low angle and sharp blade are however.
Where the tight mouth will help is awkward grain on a long grain rebate or possibly having to plane against the grain on a rebate or fielding.
Where the tight mouth will help is awkward grain on a long grain rebate or possibly having to plane against the grain on a rebate or fielding.
Modernist":2mf5ytab said:
Gareth Hacks book on bench planes confirms what you say Brian.
I am not suggesting that a tight mouth will not work on end grain, all I am saying is that the editor of F&C states under the Pro & cons that "the fine mouth necessary for cross grain work limits their use for other applications"
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