How Flat?

[Russel Tauras]

Greetings,
Bought an old #3 plane on ebay. Trying to flatten the sole using sand paper on my table saw.

How flat must it be? I spent a long time on 100 grit and the toe is still about .004 deep (feeler gauge). Is there a point where you should give up because the plane is un-recoverable? Or do I need more elbow grease and patients.

Russ

[Johnny Kleso]

Japanese planes only touch at the Toe, Mouth and Heal

They are shaved down in between those area a tiny bit..

If you have 80% of the plane touching that would be fine, myself I am hard to please even with planes I am selling..

No one says you have to finish flatten the plane at one time..
Just don't move on to finer grit before your done with the 100

[John Dykes]

Eh, sounds fine to me....

This flattening business can get out of hand. Even Charlesworth thinks a convex sole is ok... (within reason of course).

Polish up the sole and use it!

- jbd in Denver

[Steve Hamlin]

Since you absolutely definitely want contact at the leading edge of the mouth, surely slightly convex is better than concave? Agree, too much will behave like a monster spokeshave, but if concave I don't see how to avoid crowning the work.

[Thomas Knighton]

David Charlesworth, in David Charlesworth's Furniture-making Techniques: A Guide to Hand Tools and Methods, on page 24 (at least in my copy) states "To work well, areas 1, 2, 3 and 4 must lie in a straight line or be minutely convex." (emphasis added) These areas are the toe, heal, and in front and back of the mouth.

Edited to remove parts that made me look stupid

[John Dykes]

Thomas has it -

Page 25 in my book - pictures included.

From the same reference, "...for accurate work, the sole must be flat or minutely convex in length and width. Concavity is not acceptable."

This has been a mantra of Charlesworth in any discussion he has regarding planes. Again, convexity must be within reason - in his words "minute."

Again, I follow his guidance as much as my skills allow - and the results are beyond question. I was watching his newest DVD this morning (Furniture Making Techniques: Five Topics), and I recommend it highly (as all his others). Perhaps a more formal review would be appropriate...

Respectfully,
- jbd in Denver

[Tony Zaffuto]

I'm with Alan on this. Something is not quite right. Did you check the plane sole against a known flat surface? Is the table saw top flat? You're using sandpaper to flatten the sole, what is the length of the paper? Did you afox the paper with spray adhesive to the saw top?

Take three deep breaths, step back a bit and re-think your process. Do a search on sole flattening on this forum and any other WW'ing forums you visit. A #3 is a smoothing plane and you want the sole of a smoothing plane as flat as you can get it.

T.Z.

[John Dykes]

Eh, if it's good enough for Charlesworth and Frank Klausz, I'm fully confident it's good enough for John Dykes. And I'm also betting good enough for Russel.

The tool makers in Berea seemed to indicate that the market's obsession with flattening is overkill. But since we demand it, and we'll pony up the big bucks for it, they'll continue to provide that level of perfection...

Russel - if you decide to give up on the #3 and junk it, I'll pay you postage to ship it to me vs toss it in the garbage. I've always wanted a nice little #3.

- jbd in Denver

[Thomas Knighton]

Thomas has it -

Page 25 in my book - pictures included.

It's page 25 in my book too. The section starts on page 24 and I just had a bought of cranial flatulence.

[Rod Sheridan]

If the plane cuts 0.004" from flat, exhale once on the wood and it will take care of that.

Regards, Rod.

[Mark Singer]

Flatness is often over done. It should be reasonably flat...I don't measure much

[Jim Koepke]

Have to stand with Mark on this.

The only planes that have been given the sanding treatment here are ones that had rusted soles.

One of my planes has visible gaps under a straight edge, side to side and end to end. It can still smooth and square an edge with no big problems. Maybe someday it will get full fettling. But only if there is nothing else of importance to do that day.

Me thinks the Flat Plane Bottom Society has taken things a bit far.

We need to launch a Sharper Than A Razor's Edge Society. A sharp as H E double hockey sticks blade will cure a lot of what ails many a plane.

So, the first thing that a person should do when they acquire a plane is to use it. Then, check the blade and sharpen if needed. Make any adjustments one can with the knobs, levers and screws provided. If adjustments and a sharp as can be honed blade do not produce a satisfactory result, then, maybe it is time to map out a plan of attack on getting the plane up to snuff.

jim

[John Dykes]

Deleted with apologies to those I often turn to for help.

Respectfully,

- John Dykes

[John Powers]

Where are all of these warped iron planes coming from? I got a no 5 from Ebay, a Ward Master 4 and a stanley 3 in an old rusty box from craigslist and a 7 from a guy here and laying a metal ruler on them they all look fine. Are we fairing the wing on the space shuttle or what?

[Ken Shepard]

There are many things that affect how well a plane works, and in my book the flatness of the sole is way down the list. I have found that sharpening the blade, getting a good fit on the chip breaker, and fine tuning the frog is a much more productive use of time that the mind-numbingly boring process of honing the sole. I have planes that are over a hundred years old and are not quite flat. I figure if multiple users planed miles of board with them that way, they are probably not too bad. Maybe I am just lazy, but I really cannot tell much if any difference between pre- and post-flattening. If a plane is seriously out of whack, I don't buy it. I have found myself on both sides of the argument, however. As an engineer, I would like the sole of my planes to be ground flat within tenths, but as a woodworker, I can't tell any difference.