How flat is flat enough?????

[Karl]

Hi all

I have an old (1920's) Stanley No 6c, which I love dearly - the balance and feel of the tool are superb. I have therefore decided to spend some of my precious shop time on a bit of fettling.

Having obtained a new blade and chipbreaker and a nice set of new Rosewood handles (the old ones were knackered), I decided to turn my attention to the sole.

Referencing the sole against my Veritas straight edge (accuracy one thou over 24") I have determined that the heel of the sole is very slightly convex (referenced from the mouth) - probably by no more than 2 thou. A double thickness of blue Rizzla papers is "sticking" (if you know what I mean - pulls out with a slight tug). From memory these come in at 1.5 thou thick (my digital calipers are broke so can't confirm). The toe and mouth are flat.

Do I need to spend time flattening????

All input welcome.

Cheers

Karl

 

[Racers]

Hi,

It will promote restful sleep if you flatten it but it ain't that far out do you have any problems when using it? I had to do my No7 after I noticed it wasn't giving me a straight edge and it took ages even with fileing it to take most of the metal off and laping on 60 grit.

Pete

 

[Digit]

Do they make them that accurate now-a-days Karl?
Leave it alone would be my advice.

 

[Philly]

Karl
In my opinion it depends on what purpose you are using the plane. If you are taking fine, finishing shavings then you need to give the sole a little tickle. As the plane has a corrugated sole it should be an easy job - you have a large granite surface too, if I remember??
Of course, if you are using it for roughing out then the sole is plenty flat enough.
Bottom line - if you feel the plane isn't performing as well as it should be then fettle. If it works fine for the purpose you want, leave it alone.
Hope this helps
Philly

 

[Karl]

Pete - in use, the plane is fine for shorter pieces. But longer pieces (anything over 15") there is a problem - when taking fine cuts, as one shifts weight towards the rear of the plane to avoid Crowning, the blade lifts out of the cut. Can only assume it is to do with the convex heel???

Digit - modern tolerances? I have a Clifton 7 and I think that is said to be flat within 1.5 thou, IIRC.

I don't really want to spend countless hours flattening the sole, although I appreciate that, give the age of the plane, once it is flat it is not likely to move.

Cheers

Karl

 

[Digit]

I think that is said to be flat within 1.5 thou, IIRC.

When made Karl, yep. But any engineer will tell you that metal also moves with time, and remember that a human hair is only about 3 thou thick, and a wooden plane that flat would be a miracle. But we use them successfully.

 

[MrJay]

What Philly says.

Traditionally the No.6 is for removing material quite aggressively - for that sort of thing you don't need to be super flat - just get it as close as the plane allows then move to a finer plane. I'd suggest for an easy life fine fettling be reserved for smaller planes like the #4 if possible. If you're using the #6 for shuteing then you might want to be more fussy.

 

[Karl]

Philly - I have been testing it out as use for an over sized smoother, taking fine shavings. So looks like a little ([-o<) more flattening will be required.

Digit - you've lost me now. Wooden planes????? Also, I know that metal moves with time/stress release etc. But I thought modern quality planes or older planes will have no movement due to complete stress release? At least that's what we're told by the high end manufacturers. Unless i'm missing something???

Cheers

Karl

 

[Digit]

Depends on how you wish to measure movement Karl. Take the shape of a Record No 4, even after leaving the bare casting/forging to stand for some months it will move again as soon as it is machined and in an ideal world should now be stress relieved.
After that, for perfection, it would need hand working to get it flat, and after a period of time it will move yet again. In my experience, on planes of a good age they often seem to twist ahead of the mouth.
Wooden planes effectively begin to wear the first time you use them and are rarely flat. Some of the Jap planes of course have a wavy sole. At the other end of the scale you get wooden planes of composite woods, usually hard sole softer body, they don't seem to stay anything for long unless you can keep the moisture content under control.
They all seem to work though.

 

[Wiley Horne]

Karl,

Just one thought. This sole is a bit convex, from what you've said. Not sure how extensive the convexing is behind the mouth. But, whatever the exact shape of the convexity, this will be a tough job to flatten.

It's easy to flatten concave. But when the problem is convexity, lapping can easily produce more convexity, not less. So that leaves engineer's scraping or careful filing. Bugbear's site has a good section on attacking this problem--you could take a look and see if that's the kind of thing you want to do.

Two pence.

Wiley

 

[pam niedermayer]

...Some of the Jap planes of course have a wavy sole. ...

Wavy connotes many wave shapes to me and quite a bit of imprecision, which is not the condition of Japanese planes. They have at most two hollows, usually one between toe and mouth plus, occasionally, another between mouth and heel.

Pam

 

[David C]

If you wish to do accurate preparation with this plane, will it plane a straight or minutely hollow edge?

See the 'Edge Planing Experiment' on my Blog.

This is in the Techniques section 1st October 2006 .

I like to tune large planes as super smoothers but as has been stated this is not their original function.

As Pam says, the critical surfaces of Japanese planes are tuned carefully and accurately. They just choose to create slight hollows between these areas.

David Charlesworth

 

[Digit]

Agreed Pam, but a hollow is a hollow and if the Clifton is flat to 1.5 thou Karl personally I'm damned if I can see that a further half thou is going to make a damn of difference.

 

[Karl]

David - thanks for the tip - will check it out over the next few days.

Digit - The "problem" is that the 2 thou difference is at the heel of the plane - imagine the toe and mouth are perfectly flat, then a gentle convexity until the heel is 2 thou out of line. Having said that, the accuracy of my Veritas straight edge is 1 thou, so the plane might only be 1 thou out. Or it might be 3 thou...... :lol:

Cheers

Karl

 

[Digit]

Granted Karl, and if I was still working in the aircraft industry I might be concerned, but just how far from flat is the planed timber?
It's not the tools that count is what we do with them.

 

[Karl]

Digit - that is true. But if one is trying to improve on hand tool skills, it is important to know whether the tools themselves are working as they should.

I am fairly new to hand tools - I have had no training in these matters and am feeling my way.

I'll tell you what started me thinking about it. I was watching one of David C's excellent DVD's (can't remember which one - I have three, and am expecting the others for Xmas!). In it, he refers to a review he carried out of two planes by an unspecified manufacturer (although I doubt it was LN, LV or Clifton!). The planes were 6 thou hollow and, consquently, not capable of planing a straight edge. (David C - I hope I have not misquoted you there).

Hence the reason behind my initial question. How flat is flat enough?

Cheers

Karl

 

[Digit]

6 thou hollow would inevitably mean that timber would plane high in the centre I grant you, but having had to plane by hand for a living I always keep the weight on the front of the plane, so basically anything after the mouth is then irrelevant.
I'm 67 and when I was an apprentice wooden planes were still very common and usually worn at nose and heel, 'so keep the weight on the front boy!' was the order of the day.
Old habits die hard.

 

[David C]

If working with fine shavings, a hollow plane won't plane a straight edge.

Therefore flat or minute convexity is good, hollow is not.

I'm afraid to say that the 6 thou hollow was on the first batch of Clifton Planes, a no 6 if I remember correctly, which I reviewed for F&C.

I believe they are a lot better now.

David

 

[Paul Chapman]

I'm afraid to say that the 6 thou hollow was on the first batch of Clifton Planes, a no 6 if I remember correctly, which I reviewed for F&C.

I believe they are a lot better now.

If mine are anything to go by (#3, #4.5, #6 and #7), they are superb now. All have very flat soles and are capable of the finest shavings.

Cheers :wink:

Paul

 

[bugbear]

Philly - I have been testing it out as use for an over sized smoother, taking fine shavings. So looks like a little ([-o<) more flattening will be required.

Digit - you've lost me now. Wooden planes????? Also, I know that metal moves with time/stress release etc. But I thought modern quality planes or older planes will have no movement due to complete stress release? At least that's what we're told by the high end manufacturers. Unless i'm missing something???

Cheers

Karl

Wood that doesn't move? - hah!

BugBear