Functional Distinctions between #4, #5, and a scraper

I sure am confused! I just don't observe or comprehend what the functional difference is between a Jack Plane and a Smoother. I also don't grasp what determines when one would use a Smoother or a Scraper (plane or hand). What is the purpose of a Jack Plane?

• I am a novice - I haven't built any furniture yet or done any fine finishing. I really like the idea of preparing the final surface by planing or scraping instead of sanding.
• I read about planes here and other forums. I read the recent FWW article.
• I've watched all the David Marks shows, a big fan of scrapers.
• I experiment using some 12"x6" oak scraps held firmly on my bench, shaving the face mostly.
• I experiment using a recent non-Bailey Stanley #5, a recent Bailey #4 smoother, and a high-angle Hong Kong style smoother from Lee Valley (pretty good but I found it hard to make fine adjustments).
  • All 3 had 2" wide blades and all were somewhat sharp.

When the blades are all adjusted so they "protrude" a similar amount, I just don't notice much difference in action or result between my 3 planes. If I adjust the blade to protrude enough so I am making shavings, the finished surface doesn't feel flat enough or smooth enough for finishing.

To me, a scraper used on a flat surface does seem to produce a surface that seems ready to finish.

I KNOW THERE ARE ANSWERS, and I thank you smart people ahead of time for educating me.

A "Jack" plane is really a "multi purpose" plane. it can do the job of a smoother or a jointer. A smoother is shorter so it can conform better to small irregularities. A jointer is longer so it's better for knocking down high spots. A jack fits somewhere in between. A scraper is intended more to polish the surface before finishing in lieu of sanding.

The names and No.s go with the lenght of the planes..

Smoother, Jack, Trying or Fore and Jointer

Smoother is for per finishing
Jack is a all around good for Preping stock
Try/Fore Big Jack for larger work
Jointer is for Jointing boards together for a glue joint..

The longer the plane the straighter the board will come out after a swipe.. The longer the plane more it rides on the high spots only.. The shot planes will go up and down the highs and lows, kind of like a row boat vs a yatch..

A scraper is just for finishing and a plane can be used for finishing but most times your better doing a light scraping before finishing..

A lot of what you are talking about is merely semantics. A #5 can be set up as a smoother or a jack plane or a short jointer. As a smoother, you would set it up with a slightly cambered blade and a very tight mouth. You would then set it to take very fine shavings that should be good enough for finishing. As a jack plane, you would set up the #5 with a more cambered blade, open the mouth and take larger shavings. This would make it easier to get the wood shaped as you need it but probably it wouln't be ready for finishing. As a short jointer, you would set up the blade without any camber and a medium open mouth set to take deep or shallow shavings depending on how much wood you needed to remove.

It is often easier to have a plane set up to do one specific job than to keep adjusting that same plane again and again to perform different tasks. Thus, the name (smoother, jack, etc) referes to how it is set up.

Peter

Peter,

Just changing the blade orientation or configuration won't make the relatively short smoothing plane perform as a jointer plane; tool length is critical to function, as David and Johnny noted. If the stock is already perfectly flat or straight edged, then, yeah, you can use a smoother or a longer plane interchangeably. Sort of.

Doug, try to get the blades more than "somewhat sharp"; I think you'll notice an improvement in performance.

I recommend the DVD "Coarse, Medium and Fine" from Lie-Nielsen. As a fellow novice, it helped clear up much of my confusion.

Harry Strasil has a nice write-up here:
http://www.sawmillcreek.org/showthread.php?t=43231

I put a bit of camber on my smoother irons to eliminate plane tracks. I also radius the corners on my bevel up jack 38 degree iron for the same purpose.

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Doug, try to get the blades more than "somewhat sharp"; I think you'll notice an improvement in performance.

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There is a lot of difference between the surface created by a "somewhat sharp" blade and a blade that is very sharp.

To just knock of some wood, a blade does not have to be scary sharp.

To do some fine smoothing, a blade has to be as sharp as it can get.

When a piece of wood has changing direction, it is easier to tackle with a shorter plane. A lot less work to swing it around and change directions.

If it swirls beyond the ability to attack from all directions with a plane, then it is time for a scraper.

jim

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Originally Posted by Doug Hobkirk

I sure am confused! I just don't observe or comprehend what the functional difference is between a Jack Plane and a Smoother. I also don't grasp what determines when one would use a Smoother or a Scraper (plane or hand). What is the purpose of a Jack Plane? .... I KNOW THERE ARE ANSWERS, and I thank you smart people ahead of time for educating me.

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Doug,

Perhaps this will help:

A jack plane is for rough- to medium-level board prep; i.e., it is normally intended to remove large to medium amounts of wood quickly. It's used for quickly getting the general flatness, dimensions, and thicknesses, when initially preparing a board with hand tools. The mouth setting is usually fairly wide, and the iron is set to remove a substantial amount ("rough" -- up to about 1/16" or even 3/32"+ thick) of wood in each pass. As the board approaches its general final dimensions, the iron is gradually retracted to remove somewhat less ("medium" -- about .003"/.004" to .008"/.010" or so" thick) wood with each pass.

Once the wood is flat and mostly to final dimension (often accomplished via a jointer plane), then a smoothing plane is used for fine board prep. It is normally intended to remove very small amounts of wood. Both the mouth and the iron are generally set fine to very fine. The intension is to remove whispy shavings (.001" to .003" thick) that will leave a marble-like, glassy-smooth surface.

With some minor adjustments in the settings, both planes can be used other purposes: a jack for smoothing, and a smoother for rough removal of wood, etc. The primary adjustments involve widening/closing the mouth, and adjusting the iron's depth of cut accordingly.

The primary factor in determining the quality of your finished wood surface is the sharpness of the plane iron. All other things being equal, a sharp iron will leave a much better quality surface than a dull(er) iron. If you don't already know how to put a SHARP edge on your plane iron, I urge you to learn to do so. You will be absolutely amazed at the difference in effort, as well as result. This is also a skill that directly transfers to chisels, draw knives, and all similar edge tools, with equally impressive results.

Hand planing (like sawing, boring/drilling, carving, etc.) is a skill that requires learning proper technique and (at least) a moderate amount of practice to get good results. A decent quality plane helps, as well, but you'd be impressed at what can be done with even a piece-of-junk plane and a bit of skill.

Maybe the following article will help clarify some of the differences in functions. It takes you through the steps of dimensioning and finishing a piece of rough-sawn lumber from start to finish, and should give you a fairly good idea what each plane is primarily used for (as mentioned before, there is some overlap in function between planes). Also take a look at some of the hand plane/hand tool books and videos; they all contain a wealth of information to help you better use your tools.

STOCK DIMENSIONING USING HAND TOOLS:


Ideally, you need 5 planes: a scrub plane, a #5, a #7 or #8, a #4 or #4½, and a low angle block plane, but you can get away with a #5 and a low angle block plane -- it's just a little harder. (Or you can use wooden equivalents.)

You'll also need a good straight edge, an accurate try or combination square, a marking/panel gauge, and a pair of winding sticks (you can make these yourself). A card scraper (with holder, if desired) is also handy.

Select a board face for the reference face. Use a pair of winding sticks and a straight edge to determine the high and low spots. Mark the high spots and use the scrub plane to reduce them to the approximate level of the rest of the board. Check for twist with the winding sticks. Correct with the scrub, as necessary. By this time, you should have a roughly flat (length and width) board with no twist and with a lot of troughs in it. Use the #5 to remove the troughs made by the scrub plane. (Planing diagonally or straight across the grain in both directions with the scrub plane and the #5 to remove the scrub troughs will significantly reduce tearout in most woods. Then follow up with the #5 by planing with the grain.) Once the troughs are mostly gone, use the #7 or #8 with the grain to plane the face flat. Once you get full length and full width shavings, your board is very, very close to FLAT. Check with the straight edge and winding sticks. Correct as necessary. Finish up with the smoothing plane (#4 or # 4½). Use the scraper on gnarly grain that gives your smoother a hard time, but be careful not to scrape a dip into the wood. Part 1 of 6, complete.

Mark this face as your reference face. All other measurements of square, etc., will come from this face.

Select one long edge, and use the #5 to roughly flatten/smooth it, and then use the #7/#8 to make it straight and square to the reference face. To do this, use your straight edge to find any local high spots and trim those with the #5 first. Then use the jointer plane to flatten. Be careful to keep the edge square to the reference face. Mark this edge as your reference edge. Part 2 of 6, complete.

Use the reference edge and the try/combination square to mark one of the short edges square. Use a crosscut saw to saw (on the waste side!) almost to the marked line, if necessary. You can use the #5 to rough plane it flat and square to both the reference face and edge -- if the short edge is 4 to 6 or more inches wide; if not, then start with the LA block plane. (Chamfering the edges down to your cutting line will reduce tear out on the corner edges; alternative methods are to clamp a sacrificial piece of wood to the edge and let it tear out instead of your board, or to plane in from each outside edge.) Use the LA block plane to clean it up. Mark the other short edge to the desired length (saw it to rough length, if necessary) and do the same thing to the other short edge. Parts 3 and 4 of 6, complete.

Use your combination square or a marking/panel gauge to mark the other (unplaned) long edge to the desired finished width. Saw to rough width, if necessary. As you did for the reference long edge, use the #5 to roughly smooth it down almost to the cutting line, and then use the #7/#8 to make it straight and square to the reference face. Check for straight and square to the reference face and to the 2 short edges. All 4 edges should now be square to the reference face and square to each other. Part 5 of 6, complete.

Use your marking gauge, basing off the reference face, to mark the thickness of your board around all 4 edges. Flip the board over to the unplaned face and use the scrub plane to plane down almost to the marked reference lines (The bottoms of the troughs should be about 1/16th to 1/8th inch above the cutting line). Use the #5, and the #7 or #8, as before on the reference face, to make this face flat and square. Finish up with the smoothing plane and, as necessary, the scraper. Part 6 of 6, complete.

At this time, you should have a board with 2 flat, smooth, and parallel faces, 4 flat and square edges (long edges parallel to each other, as well as short edges parallel to each other, and all 4 edges square to the two faces and to each other), and of the required thickness, length, and width, ready for whatever needs to be done next.

The first board you do by hand will take what seems like an inordinately long time, but with just a little bit of practice, it becomes nearly as fast as -- and often faster than -- putting a board through a jointer, thickness planer, and sanding sequence.

If you have a shooting board, you can use it to assist with steps 2, 3, 4, and 5.

A couple of things to keep in mind:

Keep your plane irons SHARP!! Your iron is sharp enough if you are able to take fine shavings (not saw dust) from end grain pine – even with a jack plane or a jointer.

If you have only a couple of planes, open the mouth up for the initial rougher planing, and close the mouth for the finer, finish planing.

Let the plane do the work -- don't force it.

Skewing the plane often helps to reduce tear out and makes planing easier.

Take deliberate, slow-to-moderate speed planing strokes. This helps maintain the plane vertical to the surface/edge of the board, and gives you better control over the quality of the planing.

To help keep the edges square to the reference face, keep the tote (rear handle) vertical (you can usually do this by feel); you can also help keep the edges square by hooking your thumb around the rear of the front knob and curling your fingers under the plane sole against the face of the board, using your fingers as a kind of fence (don’t do this if you’ll end up with a finger full of splinters).

Try to keep the amount of wood removed from each face roughly equal; otherwise any internal stresses present may cause the board to warp or cup again, after you have put all that work and effort into making it flat.

Expect to get a good upper body work out!

The listed sequence is not the only sequence that this can be done in, but it works quite well. YMMV.

Good luck, and have fun! There's nothing quite like the sense of accomplishment you get when you have taken a piece of rough-sawn timber and turned it into a nicely finished, dimensioned board -- ready for the next step -- using only hand-powered tools.

James, that's not a "post", that's a book! Well at least a pamphlet....:D

Everybody - Excellent!
James - ZOWIE! Exquisite!
Thank you all.

The info that a #4 or #5 can be adjusted so they perform similarly is exactly what I observed. Adjusting them so they perform differently and use them for different functions is what I didn't grasp.

Now I just have to figure out what "camber" is!

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Originally Posted by Doug Hobkirk

Now I just have to figure out what "camber" is!

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Camber is a slight curvature to the cutting edge of the blade.
The idea is the cut will get thinner and thinner towards the edge of the blade. A square corner on the edge of the blade can lever ridges on the surface of board being planed.

jim

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Originally Posted by Doug Hobkirk

Everybody - Excellent!
James - ZOWIE! Exquisite!
Thank you all.

The info that a #4 or #5 can be adjusted so they perform similarly is exactly what I observed. Adjusting them so they perform differently and use them for different functions is what I didn't grasp.

Now I just have to figure out what "camber" is!

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For a recent birthday I got a bunch of Lie-Nielsen DVDs. David Charlesworth has an excellent one on sharpening plane blades: Hand Tool Techniques Part 1: Plane Sharpening.

I was sharpening essentially a straight edge on all my planes. The camber puts a slight curve on the edge so it doesn't make plane tracks in the wood. Also a more pronounced camber (and wide open mouth) helps the jack plane take off a lot of wood.

This is an excellent online vid by FWW:
http://www.taunton.com/finewoodworki....aspx?id=29711

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Originally Posted by David DeCristoforo

James, that's not a "post", that's a book! Well at least a pamphlet....:D

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Gosh, I'll second that!!! Very nice concise explanation.

I will agree with many of the posters here.... someone new to hand planes will never have an appreciation for how well hand tools (with blades) can perform, UNTIL, they have mastered sharpening. For me, I have defied a lot of conventional wisdom with blades so sharp, you can not gently drag your finger tip over them, - like we often do to sense their sharpness. Upon the lightest contact, they will instantly slice you open... (don't ask me how I know this :-)


It takes a lot of experimenting to get to this next level of sharp.... for me, it involved 30k water stones and 1/4 micron diamond paste. Some may consider this extreme, but using a tool this sharp is a joy. Under normal circumstances, this extra level of sharpness does not produce added benefits, but when the going gets tough, this level of sharpness adds tremendously to a tools usefulness. Sometimes though, it takes a quality piece of metal to hold an edge this sharp, and be able to hold that edge. So use this information accordingly.


Anyway, in addition to pushing a tools function much further than conventional wisdom suggests, the joy of using such sharp tools is the ultimate satisfaction, IMO.