Thread: Smoothing plane blade question.

Depending on the exact purpose of the blade you need to apply different techniques. For a jack you really need to apply a radius to the iron, but a smoother taking very fine shavings you need only round over the corners a little. I prefer to apply a large radius rather than nick off the corners.

Anyway, I usually apply a radius using a pivot action in the wrist on the grinder. As you move your forearm across the face of the grinder, slightly pivot your wrist at the same time. During honing you then find you need to roll the blade over to it's edges in order to apply an even micro bevel.

If you really just want to remove the corners, I usually do this at the honing stage after grinding a straight edge. Using your coarser stone (I use a 300 grit straight from the grinder) lift one corner a few millimeters off the stone a hone away. Check the edge against a square to verify you have 0.2mm+ clearance at the corners, then hone the micro bevel ensuring it is even across the edge.

The ultimate test is to set the iron in your plane and site the edge to ensure that it no longer protrudes at the very end of the mouth, but a couple of millimeters away.

Basically it takes practice. There's no fool-proof way to do this to the best of my knowledge.

Hi Sean

My preference is an even camber across the bevel face rather than cklipping off corners. You still run the risk of track lines with the latter.

The method I use was influenced by David Charlesworth (he has a DVD on this that is worth viewing). This may be done either freehand of with a guide. My preference is freehand on bevel down (BD) blades and a honing guide for bevel up (BU) blades.

I call it "Cambering by the Numbers". It is simple, and repeatable.

Use whatever media you wish. I use waterstones - 1000, 5000 and 12000.

1. Create a straight bevel on the 1000 (blade straightening stone). Remove the wire edge on the 12000.

2. Return to the 1000 and hone again, this time concentrating all you force on one corner. Count the number of strokes it takes to raise a small wire edge at that corner.



3. Now work on the other corner, using the same number of strokes to create the wire edge at that corner. Remove the wire edge on the 12000

4. Move to the 5000 stone (intermediate stone). Ditto right and left corners , counting the number of stroke you use on each to polish the bevel (you will again feel a wire edge developing). Use the same number of strokes to polish the centre of the bevel. Now remove the wire edge on the 12000

5. Repeat step #4 on the 12000 stone (final polishing stone). Remove the wire edge.

You are ready to go.

Note: this process is quicker for hollow ground blades (that receive a microbevel) or for flat primary bevels (that receive micro secondary bevels). These have less area of steel to remove than trying to shape a flat bevel. In addition, BU and BD plane blades are treated slightly differently. See my article at: The secret to cambering Bevel Up plane blades

Regards from Perth

Derek

Thanks for the replies, I was having a 'dumb bunnie' moment. A slight lift of the edge on the coarser stone first was all it needed. Good results on two out of four blades so still some practice needed.

Gee, lucky I didn't nick the edges off one on the grinder while I was waiting for a reply because that probably wouldn't work very well at all as the transition from straight bevel to angle is too abrupt and gives the exact same grooved finish to the timber as a jointer blade would.......or so I've heard.

I realise this post is old, but I thought it might be worth resurrecting.

I've been using the LV Mk II honing guide a great deal (it's brilliant).

As far as smoother blades are concerned, even using the cambered roller assembly, I can only produce a sort of wavy edge rather than a nice, smoothly radiused one. But I imagine that's just a matter of practice, so no worries there.

However, I've finally come to trying to get a radiused edge on my jack. I find that it's difficult to achieve a sufficiently curved blade just using waterstones (including the 120 grit ceramic grindstone). From what I can tell, most people do this bit on a powered grinder; but I don't own one, and haven't needed one for anything else.

No matter how much pressure I apply to one side, I can't seem to get more than 1/64" off...

Does anyone else camber their blades using stones alone?

EDIT

Answering my own question again..,

The answer is yes, it can be done, but it's easiest if a mild camber from the stones is accompanied by filing off the edges.

I've only ever sharpened with stones without guides so YMMV, but I just put pressure on the left corner for 8-10 strokes than the same on the right, continue this a few times then softly in the middle. Wipe the blade off and see how much more this needs to be repeated. When finished you should see a soft curve around the corners.