Scratches in my planed work

[Aaron Rosenthal]

I'm scratching my head on this one, and I can't quite understand how to fix it.
I have a slight edge relief on both my Veritas 5, and my Veritas # 5 1/4 planes. I use the MkII honing guide and DMT diamond plates for my final bevels. Primary @ 25 deg., secondary @ 27.5 deg. I hesitate to call them cambered, I've just relieved the 2 corners.
I'm planing some Red Alder, and the #4 in particular, leaves a scratched surface. The # 5 1/4 less so.
Yet, when I plane with an old Stanley #5 with the original blade, no camber, I get no scratching.
I have not yet planed any of my Oak, or Maple, so I can't comment on that yet, but it sure seems strange to me.
Any ideas?

[Brian Hale]

There could be many reasons you're getting a scratch but I suggest finding where it is in relation to the plane. Clamp a board/fence to a smooth piece of wood, run your plane along this fence and you should be able to narrow down what area of the plane is causing the scratch.

[Nicholas Lawrence]

I have seen two types of “scratches.”

First where the iron is not properly aligned, and there is a heavier set on one side than the other. The shaving will be thicker on one side than the other. Correct with the lateral adjustment until the shavings are the same thickness all the way across.

The other is where there is pitting on the back side of the iron near the edge. You get little nicks almost near the edge that can leaves tracks in the surface. With LV stuff, I assume that is not your problem.

Photos might help those with more expertise identify your issue for you.

[Jason Martin Winnipeg]

There could also be a burr on the heel of the sole of your plane.

[Robert Hazelwood]

Pretty sure you're getting micro-chipping on your edges. I had this issue with a LN A2 iron, and it left little scratches in the surface, just as you describe. The edge itself didn't seem damaged until you looked at it extremely closely. Raising the sharpening angle is the main thing to try- 27.5 degrees is a very low angle for a bevel down plane. Try raising it to 30. You can go as high as 35, hopefully by that point the chipping stops.

For a given angle, plain carbon steel is less prone to this sort of micro chipping. So that explains why your vintage plane doesn't do this. I eventually replaced my A2 LN blade with an O1 so I could sharpen it at 30 degrees like my other tools.

[Graham Haydon]

A few things to try and think about. What steel do you have? It seems many who choose to use modern steel work with steeper levels, something between 30 to 35 could be worth trying.
Diamond stones can leave quite a harsh edge, a good strop or a finer sharpening medium could help.
If the scratches are tracks the blade is going to need more camber.
As mentioned by others, proper removal of the burr is essential.

[Aaron Rosenthal]

A great thank you to all who responded.
I went back and looked at the iron (PMV 11) which I sharpened last night, and it looked good, although I do often see the scratches on the micro bevel if I don’t strop it.
The scratches showed no matter how I adjusted the blade orientation.
I pit on a set of magnifying lenses and discovered a slight nick in the toe of the plane, so slight I had to feel the plane with the back of my hand.
Sandpaper and we were good again.
Mom the 5 1/4, a piece of dirt under the opening mouth that pushed that assembly ever so slightly out. Now cleaned and working.
Thand for the great replies.

[Warren Mickley]

Aaron, you are using a very harsh sharpening system. Diamonds leave deep scratches in the iron which makes it prone to damage. Your are also using a very low honing angle, which also makes for a fragile edge. And you are using a steel that has poor texture, also prone to damage.

It could be that you have so much chipping that you are not getting past the damaged areas when you hone. If there are chips you will be able feel a burr (from the undamaged areas) long before you hone enough to get to solid steel. This is one thing that takes some judgement: the worse shape the edge is in, the more of a burr is needed. Honing past the damage might make some real improvement, as would a higher bevel angle.

For a nice planed surface, I recommend vintage steel finished with Arkansas stones and a strop, a thirty degree bevel with a nice gentle rounded camber. I have never seen a nice surface from A2 steel.

Alternatively you could use a Japanese plane finished with fine water stones.

[Brian Hale]

Aaron, you are using a very harsh sharpening system. Diamonds leave deep scratches in the iron which makes it prone to damage.

This is Not true. It's the grit size, not the sharpening medium, that controls the depth of the scratches in the cutting edge.

[Warren Mickley]

For the same grit size, a hard grit tends to have sharper edges which cut deeply while softer grit tends to get rounded over and makes a smoother edge. And with good water stones the grit tends to break down in the slurry so that in practice it can act like a finer grit. "Grit size" is a very primitive model for sharpening.

[Steve Voigt]

For the same grit size, a hard grit tends to have sharper edges which cut deeply while softer grit tends to get rounded over and makes a smoother edge. And with good water stones the grit tends to break down in the slurry so that in practice it can act like a finer grit. "Grit size" is a very primitive model for sharpening.

I hate commenting on sharpening topics, but Warren is right. Different sharpening media, even when they are the same micron or "grit" size, will give very different results due to differences in shape, hardness, and fracturing characteristics. Diamonds leave much harsher, deeper scratches than waterstones do, and waterstones leave deeper scratches than Arkansas stones do. Grit comparisons are only meaningful when comparing stones within the same type.

[Philippe Grant]

A great thank you to all who responded.
I went back and looked at the iron (PMV 11) which I sharpened last night, and it looked good, although I do often see the scratches on the micro bevel if I don’t strop it.
The scratches showed no matter how I adjusted the blade orientation.
I pit on a set of magnifying lenses and discovered a slight nick in the toe of the plane, so slight I had to feel the plane with the back of my hand.
Sandpaper and we were good again.

Been there, done that.
I was just thinking of posting my "lesson learned" on the matter.

I dinged my plane on my steel vice while planing with clutter on the bench. It took me a while to link the scratches to the dent in my plane, but the fix was very easy (sand-paper).

I still plane with clutter on the bench, but at least I'm more careful to to hit anything with my plane...

[Jim Chan]

I hate commenting on sharpening topics, but Warren is right. Different sharpening media, even when they are the same micron or "grit" size, will give very different results due to differences in shape, hardness, and fracturing characteristics. Diamonds leave much harsher, deeper scratches than waterstones do, and waterstones leave deeper scratches than Arkansas stones do. Grit comparisons are only meaningful when comparing stones within the same type.

Search on google for "sharpening grit chart" -- there are charts out there that try to normalize grit sizes across media and manufacturers. Even among ceramic stones, grit sizes claimed by different manufacturers have some variance.

FWIW, I bought a Veritas Shooting plane w/ PM-V11 blade in January, which comes with a 25 degree primary bevel. I was seeing streaking in the end grain after just a few strokes (<5) in Spanish Cedar. The edge was exhibiting microchipping almost immediately after I started using it. I swapped it with an A2 blade, and had no problems. I contacted Lee Valley a few weeks ago asking them whether I might have had a sample with a bad heat treatment, and they agreed something was wrong with it. They sent me a replacement PMV11 blade and this one has much better edge retention, and the finish looks much better. Just one data point, but you might want to ask Lee Valley about it. They were very helpful and made the replacement easy.