any tips on sharpening shoulder plane blades?

[G S Haydon]

Hi Steve

Personally I would freehand it and it's no different to honing any any other plane iron. Aim for 30ish degrees. Even if you hone the iron dead square sometime the shoulder plane itself is not totally accurate and will require you to bias the side that is cutting deeper. Only sharpen the cutting edge.

 

[David C]

Karl Holtey calls that Azimuth error.

It can be caused by the bed being twisted relative to the sole.

David

 

[G S Haydon]

Very cultured David . Round these parts we call it fuc£ed :lol:

 

[bugbear]

Karl Holtey calls that Azimuth error.

It can be caused by the bed being twisted relative to the sole.

David

I had (have, in fact) a Record #4 1/2 with a bad case of that. The blade was very jagged and chipped,
so I reground it neatly - and needed full lateral adjust to make it work...

it's more noticeable in low bedding angle planes, where the geometry massively
exaggerates any bed error.

BugBear

 

[David C]

I have a 1970 Stanley 60 1/2 with a bad case.

However once the blade was prepared out of square, the front edge of throat plate filed to match, and the sole flattened it did work fairly well.

Forgot to mention blade seating adjustment, short lever cap and front plate seating where the cost cutters had removed the center support.

This meant the knob had to be done up to a constant torque each time.

A Hock blade improved it no end, but it now languishes all lonely and little used. It is no match for a L-N or a QS for that matter.

David

 

[David C]

I think that Karl also told me that azimuth error was not uncommon in old infill shoulder planes.

The peining of the dovetails (with a big hammer) having introduced a certain amount of twist !

The important thing is that if you know what is happening, it is easy enough to work with, and not completely fuc£ed.

David

 

[Sam R]

Interesting stuff all, thanks. Yesterday I spent an hour or so fettling a Preston bullnose plane that had a bad case of iron skew - somthing like a 10 thou cut on the right and zero on the left. Honed the blade square with a Eclipse guide: still there. Filed the bed a touch: still there. Ground the lever cap in case it was putting uneven pressure on the sole: still there. A >1mm difference in lever cap pivot height from sole corrected with tape: it's still bloody there. Damn it! So I assembled the plane, advanced the iron to where the left side was *just* proud & flattened the whole thing on a diamond stone. Then honed the resultant bevel away freehand. It now cuts equally on both sides but is nothing like square. I think it is possibly to get a bit hung up on squareness and lose sight of the fact that the plane can be any shape, what matters is the cut & a 1930s tool is now back in action

 

[David C]

A perfect example.

David

 

[D_W]

Interesting stuff all, thanks. Yesterday I spent an hour or so fettling a Preston bullnose plane that had a bad case of iron skew - somthing like a 10 thou cut on the right and zero on the left. Honed the blade square with a Eclipse guide: still there. Filed the bed a touch: still there. Ground the lever cap in case it was putting uneven pressure on the sole: still there. A >1mm difference in lever cap pivot height from sole corrected with tape: it's still bloody there. Damn it! So I assembled the plane, advanced the iron to where the left side was *just* proud & flattened the whole thing on a diamond stone. Then honed the resultant bevel away freehand. It now cuts equally on both sides but is nothing like square. I think it is possibly to get a bit hung up on squareness and lose sight of the fact that the plane can be any shape, what matters is the cut & a 1930s tool is now back in action

Bingo on the last part. It doesn't matter that much if the blade is perfectly square. If the bed of it is coplanar (without twist anywhere), mating the iron to the bed and honing the iron so that the depth is even left to right is all that needs to be done.

Significant fettling of iron, wedge (or lever), bed, etc can create bigger problems.

 

[bugbear]

If the bed of it is a coplanar (without twist anywhere), mating the iron to the bed and honing the iron so that the depth is even left to right is all that needs to be done.

I think you mean simply "planar".

"Coplanar" would apply to two flat surfaces, and describes the relationship between them, "planar" describes a single surface as
what we can simply call "flat".

You cold stretch language to breaking point and describe a surface where all the points are coplanar, but that would just be weird.

BugBear

 

[D_W]

Yes, planar...in a single plane.

 

[Paddy Roxburgh]

You cold stretch language to breaking point and describe a surface where all the points are coplanar, but that would just be weird.

BugBear

Would it be less likely to break if you warmed it first?

 

[David C]

I will attempt to be clear,

Azimuth error occurs when the plane of the bed, is twisted laterally, to the plane of the sole.

David

 

[bridger]

I will attempt to be clear,

Azimuth error occurs when the plane of the bed, is twisted laterally, to the plane of the sole.

David

That says it pretty well.

No way for those two to be coplanar, though.

 

[D_W]

I will attempt to be clear,

Azimuth error occurs when the plane of the bed, is twisted laterally, to the plane of the sole.

David

I gather then that the bed itself may be a perfect plane, resulting in a good bedding of the iron, but the inability to cut even depth with a square iron?

If so, this is common and easily remedied with freehand sharpening. Not as easily remedied without it in every case.

An extreme angle being an intentional skew bedding (another thing where if one has more than one, it's very easy to maintain freehand - both grinding and honing, but it becomes very complicated and equipment intensive to do a "perfect" job with guides.

I haven't yet made a wooden plane with a perfectly perpendicular edge, but introduce camber and it becomes harder to detect the problem (and the wooden plane bed is biased, as are the old tapered irons, so having everything lying in a plane prior to machine made planes is just a concept, anyway).

 

[David C]

David

"I gather then that the bed itself may be a perfect plane, resulting in a good bedding of the iron, but the inability to cut even depth with a square iron?"

Yes that's it.

Many shoulder planes have very little lateral adjust.

Hence the need to prepare blade out of square.

Easily done with narrow roller or ball Guide.

Less easy with wide straight roller, or training wheel types.

Skilled operators will find it easy to do by hand.

David

 

[Derek Cohen (Perth Oz)]

I wonder how common this is ? I have not experienced it in any of the several shoulder planes I have owned over the years. I have found the error in one BU plane (and I have had quite a number pass through my hands). In the case of the BU plane, I chose to file the bed until it was correct.

In my experience, this is a situation where one returns a new plane for replacement, or correct the bed if it is an older plane. If the body is square, then the bed is out of alignment. Alternately, the body may be in need of adjustment - I recall stories of poorly aligned UK-made Stanley shoulder planes from the 80s or 90s. I have a UK-made #93, which is perfect in body (just that the blade does not hold an edge very long).

Adjust the bed before the blade. This is a one-time operation. It is easier to maintain a square blade than fiddle and adjust the angle of the edge each time it is ground/honed.

Regards from Perth

Derek

 

[D_W]

David

"I gather then that the bed itself may be a perfect plane, resulting in a good bedding of the iron, but the inability to cut even depth with a square iron?"

Yes that's it.

Many shoulder planes have very little lateral adjust.

Hence the need to prepare blade out of square.

Easily done with narrow roller or ball Guide.

Less easy with wide straight roller, or training wheel types.

Skilled operators will find it easy to do by hand.

David

I agree...difficult with a straight wide wheel guide.

 

[David C]

Derek,

Agreed generally, but I don't think adjusting the bed of an old infill Norris shoulder plane is very practicable.

Much easier to work with an out of square blade.

David

 

[bugbear]

I have found the error [Azimuth]in one BU plane (and I have had quite a number pass through my hands). In the case of the BU plane, I chose to file the bed until it was correct.

That sounds ... difficult. Well done!

In the case of a shoulder plane, the bed is often very inaccessible, making such a remedy nigh impossible.

I think a skewed blade edge is the most practical solution in this case.

BugBear