Micro Bevel 30˚ versus 33-35˚

[Mark R Webster]

I have always used a 25˚ primary with a 30˚ micro bevel on my bevel down planes. I am aware that with the A2 and PMV-11 steels, it is often recommended to use a 33-35˚ micro bevel for durability. Has anyone compared the feel of the cut between the two micro bevel angles. Can one feel a difference? Again on a typical bevel down bench plane. Thanks

[Derek Cohen]

Mark, somewhere between 30-33 degrees is the hotspot. No doubt that 33 is a little more enduring than 30, but it will really be determined by the wood you plane. I just use 30 degrees for everything (including bench chisels). Life is simpler.

I very much doubt that there will be a difference in feel when planing these angles - the cutting angle comes from the bed and not the bevel.

Regards from Perth

Derek

[Michael Bulatowicz]

I’ve experimented in the past with a number of different bevel angles on my PM-V11 blades for my bevel-down planes. I can’t say the feel changes based on bevel angles unless you violate the clearance angle requirement (I made that mistake once when I was first starting out with planes).

I freehand sharpen, and I go by the rule of “if the edge life isn’t satisfactory, raise the angle until it is.” Having measured the angle at which I sharpen a number of times (out of curiosity), I seem to settle in the range of 30 degrees or just a few degrees greater in general on my bevel-down plane blades, regardless of the steel (PM-V11, stock Stanley for a type 11 or type 15). I can’t say that I notice a difference in edge life for anything above 30-33 degrees for figured hard maple, red oak, hickory, purpleheart, or softwoods such as pine, spruce, fir, and cedar.

Best regards,
Michael Bulatowicz

[Mark R Webster]

Mark, somewhere between 30-33 degrees is the hotspot. No doubt that 33 is a little more enduring than 30, but it will really be determined by the wood you plane. I just use 30 degrees for everything (including bench chisels). Life is simpler.
I very much doubt that there will be a difference in feel when planing these angles - the cutting angle comes from the bed and not the bevel.
Regards from Perth
Derek

I too have historically used the 25-30 combination. I just recently had problems with crumbling on a PMV-11 iron and an A2 and was trying the 33-35ish micro-bevel to see if it helped. It seemed to help with the durability, but the cut also felt a little different. (using a lighter vintage Stanley not a heavier LV and at very light cuts) I was trying to determine if it was me or the change in angle. Just wondering what others had found. Thanks

[Mark R Webster]

Thank you Michael for sharing your experience with this. It is nice to hear your perspective and Derek's. I recently was working with a PMV-11 iron, it was for a friend. When I received the plane, the edge was almost saw toothed and the edge rolled over. I cleaned it all up and put a 25,30 edge on it and did some testing on fairly soft wood. I almost immediately started getting some tiny chips here and there. I adjusted the micro bevel to a 33-35 which seemed to improve things. I have read that sometimes the first 1/16" of a new PMV-11 iron can be abnormally brittle. (I think Derek has noted that in the past) If that was the case I may have just ground past the problem. Anyway I started playing with the higher angles after that which brought me to my current question.

[Charles Guest]

An average steel of not much import works pretty well at 35* If you have to go that high, save your money.

[Mark R Webster]

Thanks Charles!

[Charles Guest]

Just one man's opinion Mark.

[lowell holmes]

Am I the only that will put 2 or 3 swipes on the back of the iron to to strengthen the bevel? It eliminates any back curl.

[Mark R Webster]

Hi Lowell if you are talking about a back bevel, I don't personally. I do put a couple last swiped to remove the burr but keep the iron flat on my finest stone.

[Mark R Webster]

Thanks Charles

[Michael Bulatowicz]

Hi Mark,

You may indeed have simply ground past some kind of degraded part near the original edge. A couple of years ago I received a couple of PM-V11 Stanley replacement plane blades as a gift. At first, of the two one would always chip in the same place. The rest of the edge stayed sharp longer than the stock iron it replaced, so I used that one only before final smoothing. Each time I sharpened, I’d sharpen out the chip and it would come right back in a few plane strokes. The other didn’t have any such issue and was used for smoothing. Two years later, I no longer know which of the two blades is which—I seem to have sharpened past the “crumbly” speck at the edge. Both PM-V11 blades are excellent: they take a very sharp edge and hold it quite a bit longer than the stock iron.

[Mark R Webster]

Thanks Michael. It is nice to know others have observed this. It would be nice if Veritas or Lee Valley customer service would acknowlege the possibility and suggest grinding past the problem. I called them when I was trying to figure out what was going on, and the answer was that they had never heard of the problem. I suppose it is easier to just replace an iron for them. Don't get me wrong. I am a strong supporter of Lee Valley and Veritas. They have wonderful customer service. I am sure if I had asked for a replacement they would have sent me one. Anyway sometimes understanding how things work or why they don't just helps me deal with what is in front of me.

[Winston Chang]

I also have a PM-V11 blade which seems to have an area in the middle about 3-4mm wide, which tends to chip much, much earlier than I would expect. It's on a smoothing plane, so it's really annoying when it happens and I start getting big tracks in the workpiece. The blade chipping out and leaving tracks is almost always the thing that drives me to re-sharpen the blade, whereas with most of my other blades, I resharpen when I notice that they're getting dull.

I had been thinking that maybe the problem was that I wasn't properly deburring the blade, but I don't seem to have the same problem on any other blades, which I sharpen with essentially the same routine. I don't know exactly how many times I've sharpened the blade -- probably somewhere between 10 and 20 times. I hope that the problem will go away on its own soon.

[Mark R Webster]

Hmmmm. Maybe we are seeing a pattern here. Anyone else experiencing this? Thanks. I imagine Winston, Lee Valley will let you return the iron and will send out a new one... maybe it is just an occasionaly iron that has the problem. I didn't ask to return the iron I was working on for the friend because I didn't buy it originally. The adjustments I had made seemed to fix the abnormal chipping. If the problem reoccurs for him he may just ask to exchange it.