Chip breakers and rougher planes

[Tony Wilkins]

I can’t remember if it was a blog or thread here but there was a discussion of the use of a chipbreaker on a rougher plane. I know a lot of sources say pull it back a long distance but it serves no purpose. This particular discussion was saying the chipbreaker could be more useful.

where do you put the chipbreaker on planes other than smoothers? Does it help with tear out on earlier planing steps?

[Tom M King]

I don't put a chipbreaker close unless it needs to be. For roughing planes I mostly want it back out of the way so the shavings can easily curl up and fly away. If it tears out too deep, then it would need to be closer. With a really sharp blade, I don't think there are lots of wood grains that need it close for hogging off a lot.

[Rafael Herrera]

I think I was discussed here and in other forums by Warren and David W. I discussed it with them also, so the line is blurred.

I think the bottom line is that if you want to mitigate tearout, engage the chipbreaker.

When using a cambered plane and you're hogging off quite a bit wood, there's always a risk of hitting some section of reversing grain and causing a big chip to lift leaving a gouge. It happened to me once, it was almost 1/4" deep.

[Mark Rainey]

Inexperienced hand planing can do more harm than good. And many of us just don't have a wealth of experience. I agree with Rafael.

[Jim Koepke]

The "sweet spot" of setting a chip breaker has a relationship with how thick of a shaving is to be taken.

If a smoother is being used to take gossamer, see through shavings, it can be very close to the edge. This will be helpful in the case of tricky or reversing grain.

If the plane is being used as a scrub plane to knock down twist and high spots, the chip breaker should be set to the back of the camber. The problem with this can be with a small radius on the blade's camber, the chip breaker may be back too far to properly use the blade adjuster. Some will modify the chip breaker to work with this. My solution is to use a larger radius.

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These blades, from left to right are used in a #5, a #5-1/4 & a #40. The #40 of course doesn't use a chip breaker.

For my other bench planes there is very little to no camber used on the blades. A plane taking very thin shavings, 0.0015" or less, tends to not leave noticeable tracks. it is also possible to give an extra stroke or two at the edges of a blade so the edge of the shaving tapers off to nothing.

Here is an old thread on that > https://sawmillcreek.org/showthread.php?158373


jtk

[Jim Koepke]

I think I was discussed here and in other forums by Warren and David W. I discussed it with them also, so the line is blurred.

I think the bottom line is that if you want to mitigate tearout, engage the chipbreaker.

When using a cambered plane and you're hogging off quite a bit wood, there's always a risk of hitting some section of reversing grain and causing a big chip to lift leaving a gouge. It happened to me once, it was almost 1/4" deep.

I used to lift huge hunks of wood when first starting to work wood. This was mostly in pine or firs around knots.

Different woods or different areas from the same tree might require differing approaches to get to a finished surface.

Just when you think your experience has taught you how to approach a piece, it will have a different twist in its grain structure.

One rule of thumb that works for me is, the thinner the shaving, the shallower the tear out.

jtk

[steven c newman]

Question: WHY are you trying to scrub WITH the grain, in the first place? And, then complain about getting tear-out?

BTW: Last I looked...a Stanley No. 40 does no have a chipbreaker....just a cap iron...hmmm..

I do use a #5 Jack plane with a cambered edge...however, it goes at a diagonal to the grain...as the need is to level out rough sawn lumber...quickly. The Chipbreaker on that cambered iron stops where the camber begins at the corners..There is zero need to cut a chipbreaker to conform to the camber...dumb idea, anyway.

I have 6 jack planes..the camber on each is slightly different from plane to plane,,,from NO camber up to 8" radius...each for a different task being done.

Note: I can take rather thick shavings while traveling along at a 45 degree angle to the grain..then back off the depth of cut, and come back "up" the plank going 90 degrees to the first trip...Then a No. 6 can level the Scallops...then either a #7c or the #8c can go with the grain. followed by the smoother of my choice, if needed...

Clear as mud, right? YMMV, of course..

[Charles Edward]

Hog across grain or diagonally just be careful about blowing the far edge out. If you hog down the length you can hit a spot of turbulent grain and dig a chunk out that goes deeper than planned workpiece thickness. Going straight across or diagonally lets you hog and can reduce risk of lifting chunks.

All this said, work this out in your own shop on the woods you use. You don't need to read a master's thesis on it. Figure it out with plane in hand and wood on the bench. You might like the safety of a chipbreaker setting that's closer than other people say they use for the task (or you may effectively use none at all). So what? Do what feels right for you with the wood you happen to be working on. A lot of people are invested in making stock prep high science and discuss it unceasingly. Build a couple of projects by hand and you'll figure it out.

[Jimmy Harris]

I thought the purpose of the scrub plane WAS to tear out the wood!

Besides, tear out doesn't have much to do with the chip breaker in my experience. To me, the chip breaker is mainly there to strengthen the blade and prevent blade chatter. Tear out is usually more an issue of the opening of the mouth, direction of the grain, sharpness of the blade, depth of cut, and angle of the cutting edge. So on a scrub plane, you really don't even need a chip breaker, other than most planes won't work right without one, due to their design.

Typically, the further forward a chip breaker is, the better it supports the blade against chatter. The trade off is, the further forward it is, the easier it is to clog with shavings. So with something like a scrub plane where you're taking thick (and thus stiff) chunks of wood out at a time, you want the chip breaker further back. Whereas with a smoothing plane, you want the chip breaker up close to the cutting edge, because there's less danger of the shaving getting wedged underneath it, and more work created by any blade chatter. Plus, thicker shavings, by their nature, tend to mitigate blade chatter on their own.

Really, it just comes down to experimenting and experience to set the proper distance. I usually have my scrub plane chip breaker back about 1/8" or so, so that the edge of the chip breaker lines up with the edges of the cambered blade. Whereas with a smoothing plane, my chip breaker usually sits back around 1/32-1/64" of so. With my fore plane, where I'm leveling off the humps left by the scrub plane, I usually have the chip breaker set back about 1/16" or so. But different situations can change any of that. Basically, if I get blade chatter, I push the chip breaker up further. If I get shavings lodged under my chip breaker, I'll pull it back a bit. The only hard and fast rule is: do what works best.

[Rafael Herrera]

I hope the kind of misinformation about the chip breaker that keeps being propagated falls on deaf ears.

The chip breaker was invented around 1750, they were fitted to irons as thick as 3/16" to 1/4". Like the one in the picture. That iron doesn't need strengthening and it won't chatter. The advent of metal planes with thinner irons included the chip breaker because otherwise the planes would not be very useful except on ideal wood grain conditions.

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[Jim Koepke]

Heavily edited

I thought the purpose of the scrub plane WAS to tear out the wood!

Besides, tear out doesn't have much to do with the chip breaker in my experience. To me, the chip breaker is mainly there to strengthen the blade and prevent blade chatter. Tear out is usually more an issue of the opening of the mouth, direction of the grain, sharpness of the blade, depth of cut, and angle of the cutting edge.
…

Typically, the further forward a chip breaker is, the better it supports the blade against chatter. The trade off is, the further forward it is, the easier it is to clog with shavings.

…

Basically, if I get blade chatter, I push the chip breaker up further. If I get shavings lodged under my chip breaker, I'll pull it back a bit. The only hard and fast rule is: do what works best.

Jimmy, much of what you posted is similar to my own feelings from the past.

A scrub plane's purpose is to remove excess wood such as high spots. It removes wood efficiently, not by "tearing" it out in an injudicious manner. One wants to carefully create less work for the next plane, not more. Used carefully, at an angle to the grain, a scrub plane will 'slice' out the unwanted material without leaving divots to be corrected by removing more wood than desired.

In Leonard Bailey's patent application for his "cap iron" design, he did claim the chip breaker allowed for the use of thinner blades. The purpose of controlling the force of lifting a shaving to prevent tear out appears to have been known before Bailey's design.

A well set chip breaker exerts pressure on a shaving (chip) as it is being removed. This, in effect, reduces the shaving's ability to lift wood from the surface ahead of the blade's edge.

If your chip breaker is clogging with shavings, it isn't properly seating on the back of the blade.

Here is an old post on plane restoration > https://sawmillcreek.org/showthread.php?114373 < posts #27 & 28 deal with the chip breaker. A lot has been learned in the 13 years since it was posted.

The Stanley/Bailey planes before type 9 were more likely to have chatter on thicker shavings due to the frog being able to slightly flex. The blade could dig in, pulling the frog forward, the surface would "tear out" allowing the frog to move back and start the process all over. When this happens on my older planes it sounds almost like a zipper. It leaves a very distinctive surface.

jtk

[Tony Wilkins]

Besides, tear out more than necessary isn’t beneficial. That just means more work at each step along the way. That was part of my reason for asking the question.

[Eric Brown]

Besides, tear out more than necessary isn’t beneficial. That just means more work at each step along the way. That was part of my reason for asking the question.

Not sure I agree with the amount of work required. A thick shaving might require more than twice the effort than one half as thick. Most of us can't take thick shavings for long. A table top for instance. My preference is to work easier, even if it takes longer.

[Jim Koepke]

Not sure I agree with the amount of work required. A thick shaving might require more than twice the effort than one half as thick. Most of us can't take thick shavings for long. A table top for instance. My preference is to work easier, even if it takes longer.

That would be true if a scrub plane were taking a shaving as wide as one's jointer or jack. To the best of my knowledge, for scrub plane work, one doesn't take a full width shaving.

This is a #5, jack plane, set up as a scrub:

513925

Only about 5/8" of the 2" blade is engaged in the work.

Of course this is a smaller piece than Tony is working.

jtk

[Tony Wilkins]

I was thinking more about getting to the bottom of a deep ‘scar’ of tear out with jointer and smoother.

[Jim Koepke]

I was thinking more about getting to the bottom of a deep ‘scar’ of tear out with jointer and smoother.

This is how my thought process looks at a "deep 'scar' of tear out."

How deep is it? Will that much depth have to be taken off of the full surface?

If this 'scar' has much depth, that could be a lot of planing with a jointer and smoother.

A decorative patch/inlay might be easier.

jtk

[Rob Luter]

The "sweet spot" of setting a chip breaker has a relationship with how thick of a shaving is to be taken.

If a smoother is being used to take gossamer, see through shavings, it can be very close to the edge. This will be helpful in the case of tricky or reversing grain.

If the plane is being used as a scrub plane to knock down twist and high spots, the chip breaker should be set to the back of the camber. The problem with this can be with a small radius on the blade's camber, the chip breaker may be back too far to properly use the blade adjuster. Some will modify the chip breaker to work with this. My solution is to use a larger radius.

513734

These blades, from left to right are used in a #5, a #5-1/4 & a #40. The #40 of course doesn't use a chip breaker.

For my other bench planes there is very little to no camber used on the blades. A plane taking very thin shavings, 0.0015" or less, tends to not leave noticeable tracks. it is also possible to give an extra stroke or two at the edges of a blade so the edge of the shaving tapers off to nothing.

Here is an old thread on that > https://sawmillcreek.org/showthread.php?158373


jtk


^^ This ^^

[Warren Mickley]

Besides, tear out more than necessary isn’t beneficial. That just means more work at each step along the way. That was part of my reason for asking the question.

Yes, you want less work each step, not more.

We generally don't try to "hog" material when flattening a side. We want to preserve as much material as possible and we want to make a flat surface with as little effort as possible.

I wrote a post on another forum promoting the value of double iron use for roughing planes. That was December 7, 2007.

David Weaver wrote similar posts in 2012 and 2014.

[Charles Edward]

Lordy, it would sure be wonderful if every component of a piece of furniture had a finished thickness of 7/8". Wives, daughters, sisters, and aunts could be brought to bear on that. The reality is that you sometimes have to remove a lot of material, resawing may not be an option, whatever. You need a plan and a procedure for those occasions. You need to remove the material quickly, but without making it look as if it had been carpet-bombed. You won't learn to do this reading about it, you'll only learn by doing the work at the bench.

[Ben Ellenberger]

I had to get out the calipers today and measure some shavings because this thread made me curious. I had about a 1/4” to take off this piece of hard maple. I measured the shavings at a strong 3/128”. So, I’d guess my chipbreaker is set back from the middle of the blade by a strong 1/32”. Because of the camber on the blade the corners of the chipbreaker and the blade are almost even (I haven’t bothered putting a camber on the chipbreaker). Because of reversing grain I needed to change directions in the middle of the board. I still got tear out, so switched to a finer-set plane sooner than I would have if the grain was more favorable. It all seemed to work out OK in the end. These will be octagonal legs, so more material is getting removed before everything is done.

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[Rafael Herrera]

The chipbreaker can be moved forward a bit more, still taking the same shaving thicknes. The cb corners and the iron corners don't have to be aligned, you're not taking full width shavings, aren't you?

Test to see if tear out is mitigated or eliminated.