Plane Sharpening Issues

[Nick Roznak]

I've read numerous threads on this forum but this is my first post!

I am sharpening the irons for three planes which I recently acquired. These are all Stanley Type 13 with Sweetheart irons. Right now I am working at getting a primary bevel using a diamond plate and a honing guide. All of the irons have issues:

Iron for my No. 6 - The primary bevel is about 15 degrees. I've changed about half of the bevel to 25 degrees, but would have to shorten the iron about 1/8" to get the entire primary bevel to 25 degrees. I have a similar problem with a No. 5 iron that must have been sharpened by hand on a bench grinder and has a "primary radius" in lieu of a bevel. Should I leave it where it is now, or correct the entire primary bevel? (This photo may be from the No. 5)

483100

Iron for my No. 7 - This one was looking really good. It didn't take a lot of work to get a 25 degree primary bevel and the cutting edge is square to the long edge. But when I was comparing it against the iron from the No. 6 I found that the iron is bent. It has a bend about 4-1/2" from the cutting edge and is bent at about a 3 degree angle. I put the iron back in the plane and now I see that the iron does not fully contact the frog. Can this iron be straightened?

[Prashun Patel]

If it were me: No.6: No need to get the whole bevel to 25. Use 25 as the micro bevel. Over months/years, you'll grind it back completely as you resharpen.

For the No. 7, I'd buy a new blade. It should contact the frog and chipbreaker cleanly.

[Scott Clausen]

This makes me wonder, how do you bend a plane iron?

[Nick Roznak]

If it were me: No.6: No need to get the whole bevel to 25. Use 25 as the micro bevel. Over months/years, you'll grind it back completely as you resharpen.

For the No. 7, I'd buy a new blade. It should contact the frog and chipbreaker cleanly.

Thanks. I suspected I'd need a new iron for the No. 7. I've been looking at the Veritas, but I don't want to modify the mouth.

[Nick Roznak]

This makes me wonder, how do you bend a plane iron?

Looking at the way it is bent (more on one side than the other side) I'm guessing someone dropped the plane and it landed on the upper corner of the iron.

[Stephen Rosenthal]

If you have a metal working/machinist’s vise, you can try straightening the blade in it by gradually putting pressure on one side, turning it around and doing the same thing on the other side, repeating until straight. I did that with a slightly bent blade (can’t remember if I heated it with a propane torch) and got it to rest flat on the frog of an old #4 Stanley. Otherwise a new blade is in order (Veritas PMV-11 or Hock) and I don’t think you’ll have to mess with the mouth.

[Jim Koepke]

Iron for my No. 7 - This one was looking really good. It didn't take a lot of work to get a 25 degree primary bevel and the cutting edge is square to the long edge. But when I was comparing it against the iron from the No. 6 I found that the iron is bent. It has a bend about 4-1/2" from the cutting edge and is bent at about a 3 degree angle. I put the iron back in the plane and now I see that the iron does not fully contact the frog. Can this iron be straightened?

Hi Nick and welcome to the Creek.

Stanley blades are usually laminated. The hard steel only runs to the area with the slot for the chip breaker screw. The area beyond that is softer steel and should be easy to "adjust" as needed to seat well on the frog.

jtk

[Rafael Herrera]

As long as the bevel at the cutting edge is 25 degrees, it should be fine.

The iron is hardened only below the slot, the upper part can easily bend. Don't fret too much about it since the only points of contact that matter between the iron and frog are the top and bottom, where the lever cap exerts pressure, contact in the center is inconsequential. Besides, if you think about it, the cap iron creates a slight flex on the iron when installed.

[Jim Koepke]

Don't fret too much about it since the only points of contact that matter between the iron and frog are the top and bottom, where the lever cap exerts pressure, contact in the center is inconsequential.

This point is debatable. Full contact of the blade against the frog dampens vibration. Even with the lever cap pressing on points near the top and bottom of the blade the unsupported center can begin to resonate creating other problems.

Simple physics enters the act.

jtk

[steven c newman]

Depends on the chipbreaker....and how tight one cranks it down onto the iron...Have seen a few irons "bowed" by too tight of a chipbreaker....

EARLY Stanley irons were laminates....but that soon changed...

[Jim Koepke]

Depends on the chipbreaker....and how tight one cranks it down onto the iron...Have seen a few irons "bowed" by too tight of a chipbreaker....

EARLY Stanley irons were laminates....but that soon changed...

Part of "tuning up a plane" involves the chip breaker.
Chip breaker tuning is covered a little here > https://sawmillcreek.org/showthread.php?114373 < scroll down to the 27th post if you are viewing in linear mode. (Chips Ahoy or is that a Cap Iron?) A chip breaker can be "tuned" to divert chips and not bow the blade.

Some of the links in that thread may have broken since it was posted. Some have been archived.

If a blade is bowed (or bent) one way, it can likely be move in the other direction to remove the bow (or bend).

jtk

[Rafael Herrera]

This point is debatable. Full contact of the blade against the frog dampens vibration. Even with the lever cap pressing on points near the top and bottom of the blade the unsupported center can begin to resonate creating other problems.

Simple physics enters the act.


Several of my smoothers have a gap of at least 2 thousands between the iron and frog around the lever cap screw, it does not affect their performance. Any vibration started at the edge while cutting will be dampened/cut off when it hits the area where the cap iron is pressing the cutting iron against the frog.

The plane on the left is an old Bedrock. The chip breaker indeed flexes the cutting iron, and not just the thin ones. The picture on the right, that's a PM-V11 iron, that's a 0.1" thick piece of steel.

All irons will flex when you attach the cap iron/chip breaker, just take a straight ruler to it when you assemble it, wanting to somehow tune the assembly so it tightens flat is counter productive since the plane does not need that to work.

One can certainly fettle and adjust things so there's no gap, there's no rule against it.

483123483124

[Charles Guest]

Plane irons are meant to be used up and replaced and are part of the ongoing cost of the hobby/profession. That said, they last a good long time and if you sharpen one down to nothing you will have done a whole lot of woodworking. If you lose some length learning how to hone, no big deal, it's a pretty cheap way to learn compared to the alternatives.

You're basically hand grinding it sounds to me. I'd grind away however much is needed to get a nice, clean and even bevel that you can work with. If that means taking off an eighth then so be it. You might later want to hollow grind and then tip up for a secondary bevel, but what you're doing now by using a jig is producing a flat bevel and that's fine too. You might find in the fullness of time that it's hard to elegantly impart curvature to the iron that goes in your No. 5, but some jig makers have figured that problem out as well. You can of course freehand that shape onto the iron at a point when you feel up to it.

If the iron for the No. 7 is visibly bent (i.e. you can see the bend without putting a straightedge on it), I'd simply replace it. Find something else to beat, bang, and squeeze on.

Some planes and their irons make a more or less airtight fit between the iron and the frog. Some don't. A tiny bit of light usually isn't a problem, but the ones that show no light not surprisingly end up being the ones that plane the best in my experience. Don't let any of this stuff send you into a tailspin of plane fettling, or worry. At this stage you may do more harm than good. Get the irons sharp, replace the bent iron, and see how the planes work. If you take a detour into extreme plane rehab, you run the risk of never returning to the actual craft itself in any meaningful way. Woodworking tools are made to remove material down to a mark you've made on the wood. A plane is no different. Don't overcomplicate things.

[Rob Luter]

I've refurbed a dozen or so Stanleys of various sizes and ages. Occasionally I've run across an iron that's seen hard duty like the one the OP features in his post. If I plan on keeping the plane as a user I just order up a blade and matching chipbreaker from Ron Hock, and save the originals in the old blade archive. The new iron gets you started off right. If you ever sell the plane you have the historically accurate cutter for those that like that sort of thing, and a cutter you can sell with the plane or separately for nearly what you paid for it.

[Rob Luter]

Several of my smoothers have a gap of at least 2 thousands between the iron and frog around the lever cap screw, it does not affect their performance. Any vibration started at the edge while cutting will be dampened/cut off when it hits the area where the cap iron is pressing the cutting iron against the frog.

The plane on the left is an old Bedrock. The chip breaker indeed flexes the cutting iron, and not just the thin ones. The picture on the right, that's a PM-V11 iron, that's a 0.1" thick piece of steel.

All irons will flex when you attach the cap iron/chip breaker, just take a straight ruler to it when you assemble it, wanting to somehow tune the assembly so it tightens flat is counter productive since the plane does not need that to work.

One can certainly fettle and adjust things so there's no gap, there's no rule against it.

483123483124

I think the photo on the right illustrates why the blade flexes. The frog is adjusted back too far and the blade is riding on the body casting that is protruding under the frog. This causes it to deflect when clamped down by the lever cap. I never adjust frogs that far back for just that reason. At the rearmost position, the frog surface should be coplanar with the angled portion of the body casting below. If this position doesn't offer enough clearance between the cutting edge and the front of the mouth, address this with a file. I've only had to do this once.

483125

[Nick Roznak]

Thanks for everyone's responses. I bought a new iron for the No. 7 and have a new 2" iron that I can use in the No. 5. I do like the idea of keeping all the Sweetheart irons for "historical value" as they are close to full length.

[Rafael Herrera]

The frog is back because the iron is 0.1" thick, if not, the shavings will choke at the mouth. As it is, the plane works w/o modification. Even if the iron bevel were to touch the bottom casting, the deflection would be in the direction of closing the gap around the middle. It doesn't in this case.

[Rob Luter]

The frog is back because the iron is 0.1" thick, if not, the shavings will choke at the mouth. As it is, the plane works w/o modification. Even if the iron bevel were to touch the bottom casting, the deflection would be in the direction of closing the gap around the middle. It doesn't in this case.

That's why I mentioned the file. Dressing the leading edge of the mouth in order to compensate for thicker blades is pretty common.

[Andrew Pitonyak]

That's why I mentioned the file. Dressing the leading edge of the mouth in order to compensate for thicker blades is pretty common.

I had a really good friend so I gave him my old trusty No. 8 that worked great. That one was easy to get so I figured a replacement would be easy as well. I obtained a replacement that came with a Lie Nielsen blade, which is thicker than the original. The replacement No. 8 easily chokes so I think that I need to widen the mouth, I just need to get around to doing it. Honestly, I will probably make a trip out to see Stephen since he seems to be able to make anything work. Last unusable plane I brought him he had working (not fabulously, but working) in very short order.

Always hesitant to widen the mouth, however, because then I have committed to it and it is easier to take stuff away than to add it back.

[Rafael Herrera]

Always hesitant to widen the mouth, however, because then I have committed to it and it is easier to take stuff away than to add it back.

I don't know if this is what you already intended to do, but I would start by filing the front of the mouth so that you remove the metal indicated in red in the sketch below. This has to be combined with moving the frog back.

483696

Widen the mouth as a last resort.

Raf

[Andrew Pitonyak]

I don't know if this is what you already intended to do, but I would start by filing the front of the mouth so that you remove the metal indicated in red in the sketch below. This has to be combined with moving the frog back.

483696

Widen the mouth as a last resort.

Raf

That is useful, I would have tried filing in exactly the other direction. Your drawing makes it wider at the "top" and I would have angled it the other way or simply gone directly up and down.

And yes, take off as little as possible. I am a bit apprehensive about this, which is why I have not done it yet. Well, that and because I have two No. 7 planes that I usually use instead.

[Rafael Herrera]

The shavings will choke at the mouth, the chipbreaker will deflect them and hit the wall of the front of the mouth, crumpling them. One needs just enough clearance for the shavings to pass. If you want very thick shavings, you may have to actually file the mouth wider.

If only removing the red, the mouth is not made wider.

[Richard Coers]

Late to the show, but you wouldn't believe how easy sharpening can be if you use a good holder on a bench grinder. Honing is incredibly easy with a good bevel already there.

[steven c newman]

Have yet to file a plane's mouth....not a fan of the newer, thicker irons, anyway....a choked mouth is usually the least of the problems....

483705

[Jack Dover]

I am sharpening the irons for three planes which I recently acquired. These are all Stanley Type 13 with Sweetheart irons. Right now I am working at getting a primary bevel using a diamond plate and a honing guide.

This is going to take you ages. Try 80 grit sanding papers, there's packs that are for sanding drywall, they're cheap and they have flaps long enough to be wrapped over a diamond plate. This way it will take you just a couple of minutes to shape a bevel to a desired angle.


Should I leave it where it is now, or correct the entire primary bevel? (This photo may be from the No. 5)

This is not really necessary, it will be there in just a few sharpening sessions. Keep in mind that actual cutting is done by the very first few µm of the blade and that bevel is mostly for clearance (it affects the thickness of the cutting edge, but let's not go there just yet). Also, just so you know, many people do this to their irons on purpose, it's called "hollow grinding" and it's a tremendous help if you hone freehand (not so much with a guide).


I put the iron back in the plane and now I see that the iron does not fully contact the frog. Can this iron be straightened?

You should check the whole assembly: the iron, the chip breaker and clamped under a cap iron. You could do it with automotive filler gauges. Basically you're looking for contact tight enough that the iron assembly doesn't vibrate but at the same time you can adjust depth and lateral position. You can adjust the right amount of tension by turning the cap iron screw 1/4 of a turn - the cam should give you a good solid "click", not too hard, not too loose, kinda like a good handshake from a decent man, if you know what I mean.

I don't think that any of my planes there's a full tight contact over the whole bed. Even wooden planes have a U shaped contact area, the middle part is usually ever so slightly hollowed. So I wouldn't worry. If you want to do something - put it on a piece of wood (2x scrap works fine) and whack it a few times in different spots. This usually remedies a bellied iron, so I'm sure it will straighten your iron somewhat too.

Also, congrats on the first post, welcome to the forum!

[Jack Dover]

This makes me wonder, how do you bend a plane iron?

Technically one needs two points of contact from one side and one point in between these from the opposite side. I've straightened plough irons from Stanley combo plane. The iron will spring back though, there's also a risk of breaking it. But I did it a few times, so it's definitely possible. My approach was to nail two 1/2" square blocks of hardwood to some base (mine saw plywood off-cut), attach it to a moving vice jaw with some tape, then place an iron over this such that both ends rest on the blocks, put a hardwood dowel somewhere in the middle and in between the iron and the stationary jaw. Cinch the vise such that the iron is bent in the opposite direction and leave it overnight. How much to bend and how long to keep is something to figure yourself, you might have to do it a couple of times. Mine wasn't straight after that, but it straightened just enough.

Another way is cold forging, basically you whack an iron with a blacksmith hammer on an anvil until it gets flat. This requires a blacksmith, an anvil and a hammer, probably some skill too. A woodworker could try it on a stump or something rigid with just a little bit of give, idk, maybe this is a good use for all these endgrain cutting boards.

But I don't think it's a huge issue unless an iron is in twist and you can't lap its back or something. But then I'd juust buy a new one, 20$ on ebay can go a long way. Or our Chinese comrades offer very serviceable HSS and high carbon irons and assemblies for a reasonable price.

[Jack Dover]

The iron is hardened only below the slot, the upper part can easily bend.

This might actually depend on an iron type, most of mine aren't laminated and they're hardened all the way: couldn't find a spot where a file would cut. I also had a couple irons worn to the last 1/16" before the slot, they were cut down lengthwise and converted into marking knifes and narrow irons for shop made planes — fully hardened too.

It's totally possible that a bent iron was hardened halfway, maybe that's why it bent in the first place: the tension from the chip breaker can totally do it to a soft steel. Just need to check before doing anything, it's actually not too hard to snap it once you start using levers of all kinds.

[Jack Dover]

This point is debatable. Full contact of the blade against the frog dampens vibration.

This is correct, but only when there's a pressure along the whole length. When holding pressure applied at a single point then full contact doesn't prevent chatter that much. Of course it's easier to fettle a plane with a flat bed and a flat iron being in full contact, but it's not a hard requirement.



Even with the lever cap pressing on points near the top and bottom of the blade the unsupported center can begin to resonate creating other problems.


Again, only if lever cap is the only point of contact, 'cos this point is a fulcrum then. Bailey planes have two points, the second is on top where a cam presses it down. Tw contact points with modest pressure will dampen vibrations enough to prevent chatter.

Also, the lever cap can exert a tremendous amount of pressure, like, it can keep a blade dead tight. On my wooden planes I can pull a wedge just wiggling it with my fingers back and forth, no chatter issues whatsoever even with Bailey type blades. So probably the amount of pressure necessary is not as high as most of us think. Otherwise a spokeshave would be a beast to use, yet they don't chatter when properly bedded close to a mouth.

[Rafael Herrera]

It's mostly hollow around the lever cap screw, at least in the frogs of this style. Good contact at the bottom and top of the frog is more important than worrying if there's contact in that central area. Even if there's contact, it's not under pressure.

483934

[Jim Koepke]

It's mostly hollow around the lever cap screw, at least in the frogs of this style. Good contact at the bottom and top of the frog is more important than worrying if there's contact in that central area. Even if there's contact, it's not under pressure.


Two things that may refute this;

First is the ogee frog design helped to lower manufacturing costs by requiring less grinding of the contact surface. If the designers/engineers at Stanley felt contact at the top and bottom were all that was required they would have likely done away with machining in all but those two areas.

Second is Millers Falls design and claim:


The other way chosen to distinguish the bench planes was the promotion of the design of their jointed lever caps. The standard lever cap used by competitors applied pressure to the chip breaker/cutter assembly at two points—one at the point of contact with the cap’s cam lever, the other along the lower edge where it made contact with the hump of the chip breaker. The hinged cap was designed to apply force to the chip breaker/cutter assembly at a third point, just above the chip breaker hump. Three points, rather than two—the company advertised the arrangement as a method for preventing chatter.

Millers Falls biggest problem is they came to the hand tool market late in the game. They introduced their new line of hand planes in 1929. Bad timing indeed when the stock market crashed later that same year.

jtk

[steven c newman]

And yet...I have never had a Millers Falls plane ( I have a bunch of them) have any sort of chatter...other than me talking about them...

Strange that Clifton also used a hinged lever cap? Maybe they were on to something?