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Forum topic by stefang posted 12-16-2013 05:32 PM 3591 views 3 times favorited 44 replies Add to Favorites Watch
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15881 posts in 3303 days

12-16-2013 05:32 PM

Topic tags/keywords: hand plane question

Most of my modest knowledge about hand planes comes from the net. The one thing I really don’t get is the correct mouth opening. The experts say that the mouth opening should be set to about the desired thickness of the shaving. I don’t dispute this, but it just doesn’t work for me.

For example, I’ve been smoothing some maple today, starting with a small mouth opening of about 1/32”, a really sharp iron with a very slight camber also about 1/32”. Didn’t get much bite with the plane set with the small opening, so I enlarged the throat opening to a little under 1/8” and got the shavings I wanted. My planes are all high quality and well tuned. I also have an inexpensive Stanley/Bailey which is about 3 years old, but which is also well tuned and performs beautifully (miraculously). My experience with the mouth openings has been the same for all of my planes.

It probably doesn’t really matter as long as the planing results are good, but it it’s irritating that my own experience doesn’t coincide with standard practice. Any idea why that might be?

-- Mike, an American living in Norway.

44 replies so far

View pintodeluxe's profile


5624 posts in 2782 days

#1 posted 12-16-2013 05:40 PM

My experience has been the same as yours. Fairly narrow throat opening, but not equal to the shaving. I still don’t trust a hand plane on quartersawn oak. The first three swipes I see smooth, delicate shavings and the fourth pass I get tearout. For this reason I trust sanders and card scrapers on figured wood.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View dbray45's profile


3320 posts in 2745 days

#2 posted 12-16-2013 05:52 PM

Hard maple can be interesting on any day. All my planes have an opening of less than 1/32” except for the scrub and that one is 1/4”. I use a scraper plane or #12 for hard maple, curly maple I take to someone that has a planer or jointer with a spiral or helical blade set – or drum sander.

-- David in Damascus, MD

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15881 posts in 3303 days

#3 posted 12-16-2013 05:59 PM

Thanks Willie, I feel better already! I bought a #80 scraper plane from Kunz which I often take a few strokes with after smoothing. It really leaves a beautiful surface. I rarely get any quarter cut or pure straight grained wood here.

My only experience with planing oak has been white oak and I machine jointed and planed quite a bit of it a couple of years ago with great results. I thought it would quickly dull my plane blades, but didn’t. I was surprised at the nice shiny surface I got.

-- Mike, an American living in Norway.

View Dallas's profile


3599 posts in 2456 days

#4 posted 12-16-2013 06:19 PM

My understanding and experience (albeit not much), leads me to believe you have the iron extended too far.
I don’t know if it’s just me, but setting the iron seems to be an almost esoteric art.
I have 8 planes, nothing fancy, just the standard Stanley/Bailey’s, 409 Sargent, 414 Sargent, #7 Stanley, 60 1/2 Stanley, and a small record block plane or two.
Each one I need to work at setting the blade depth correctly.
My Stanley #5 takes a whole different setup than my Sargent 414. My Stanley #4 is completely different from my Sargent 409.
I have a wood 24” shipwrights plane that I have still never figured out how to set up. Certified built in 1754, a nice lady at TX. A&M I know did some tests on it and is 95% sure the seller was honest.

-- Improvise.... Adapt...... Overcome!

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15881 posts in 3303 days

#5 posted 12-16-2013 06:31 PM

David To be honest I doubt this is hard maple, compared to rock maple for example, but it is pretty hard. All I could find out from my supplier is that it is European maple and that’s it.

DallasI have the iron out about 1/32” from the chip breaker. I was thinking about that myself, but it doesn’t seem excessive to me. However I’ll take your advice and try an even shorter extension just to see if it helps. Everything is working fine for me as is, but I don’t have any basis for comparison, so I guess just have to experiment a little.

-- Mike, an American living in Norway.

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7967 posts in 2767 days

#6 posted 12-16-2013 06:33 PM

Is that maple for the chevalet Mike?

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

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15881 posts in 3303 days

#7 posted 12-16-2013 06:49 PM

Yes Paul. I had a little spare time today so I wanted to see how well it would hand plane. I had already machine jointed and planed it so I just wanted to correct a very slight belly in one of the boards. I could probably glue it up with the belly which might even be an advantage as it would keep the ends very tight. I am just trying to get some more experience with my new planes.

-- Mike, an American living in Norway.

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7369 posts in 2812 days

#8 posted 12-16-2013 07:00 PM

Mike – Read and inwardly digest this article. It helped me.

-- - Andy - Old Chinese proverb says: "If you think something can't be done, don't interrupt man who is doing it."

View a1Jim's profile


117063 posts in 3546 days

#9 posted 12-16-2013 07:01 PM

Hi Mike
I’m sure just about everyone knows more about planes than I do ,I just adjust them until they do what I want.
I did find this on line from Roy Underhill who’s planes always seem to glide through wood like a hot knife in butter on TV. Some of it is pretty basic but further down the post he gets into mouth openings among other details.

-- wood crafting & woodworking classes

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15881 posts in 3303 days

#10 posted 12-16-2013 07:44 PM

Andy I read it and here is an excerpt ”You won’t need the mouth to be set tight if the cap iron is working properly” That seems to be my experience here. Although my cap iron is not set ‘super close’ it is pretty close.

-- Mike, an American living in Norway.

View stefang's profile


15881 posts in 3303 days

#11 posted 12-16-2013 07:53 PM

Jim Thanks. I had a look at it.

-- Mike, an American living in Norway.

View Smitty_Cabinetshop's profile


15283 posts in 2587 days

#12 posted 12-16-2013 09:53 PM

“It probably doesn’t really matter as long as the planing results are good…”

Mike, I think that nails it.

Mouth setting (either adjustable or tightened by moving the frog forward) is done to reduce tearout, as is setting the chipbreaker closer to the cutting edge of the iron. Without tearout, no need to tighten the mouth in my world.

I’d not heard “the mouth opening should be set to about the desired thickness of the shaving” before. I mean, it makes some amount of sense because jack planes are set more open than smoothers (for example) and the finest smoothers are even tighter. But if there were a 1:1 intended, it’s news to me.

Very interesting post, thanks for putting it out there. This is something I’ll pay closer attention to now.

-- Don't anthropomorphize your handplanes. They hate it when you do that. -- OldTools Archive --

View Dave's profile


11429 posts in 2809 days

#13 posted 12-17-2013 02:11 AM

Mike I have a small coffin with a bit of wear on the sole. When I get the iron at a razors edge and set the chip breaker to where I just see a glint of light shining off of the iron it will take wonderful shaving off of figured maple and other hardwoods with no tear-out. The shavings are under a thou.
That is a wood bodied plane. I am still learning metal bodies. I don’t have enough experience to give a good opinion.
To me proper set up and tuning is the key.
Keep in mind everything I own is 75 to 200 years old.
A mouth that is to tight just hinders the egress of the shaving leaving the plane.

-- Superdav "No matter where you go - there you are."

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5618 posts in 2636 days

#14 posted 12-17-2013 03:23 AM

Hand planes , a art and sciences .
Enjoy learning your planes and the good results you get .

-- Kiefer

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407 posts in 2043 days

#15 posted 12-17-2013 03:28 AM

The mouth is suppose to minimize tearout if the plane was push down hard on the surface. If the grain is too bad then it does not matter if the mouth is super close.

If the tearout is occurring I will adjust the blade height first then the chipbreaker. The mouth would be the last. I generally have the mouth midway unless it is heavy stock removal which I need the mouth all the way open.

In all, I still am learning about the mouth opening. It does help if I push down the plane hard with small opening on bad grain but not much. On against grain it does help well to close the mouth gap.

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