Straight talking

[dddd]

Hey guys,

Once again it's stupid question time, but if you don't ask the stupid questions you just end up doing stupid things.
So my hand tool adventure continues, I'm now pretty happy with my plane blades, so I thought I'd move on and do some slightly more advanced planing, first stop I thought was to make a pair of winding sticks, so a quick trip to ebay and I am now the owner of a pretty nice No7, I've installed a nicely sharpened Hock blade and chip breaker and I'm off with a suitable piece of 1m long oak and the plane is taking a nice shaving off the full length. However here's the issue, no matter what I try I just seem to end up with a very slight hump. I've search around the archives here but can't find anything, so is there some technique I'm missing, is it just a matter of planing from one end to the other or should I be planing out the middle first.
I've checked the plane and it is slightly concave along the length but nothing huge and I really don't relish the thought of hand lapping a No7 flat (I'm still recovering from doing my No5 1/2).

I'd really like to crack this as I've promised myself a LN No8 for xmas id I do.

Cheers

Neill

 

[Scott]

Neill

Regurgitated knowledge from DC's planing DVD - Set the blade for a fine cut and plane the middle until it it no longer cuts (if the blade is set fine this will only be a hollow of a couple of thou. Then take a "through" shaving off the whole length to finish and see what you've got.

HTH

 

[deirdre]

I also recommend David Charlesworth's videos. The one mentioned is called "Hand Planing" and is the 2nd video in his series (of 3, soon to be 4).

 

[Keefaz]

As another newbie, I can say I tried this and kept taking shavings. I would've planed right through the board if I'd kept going.

 

[Paul Chapman]

Another thing you can do is to scribble along the wood with a pencil so that you can see clearly that you are planing off the right bits and check frequently with a straight edge and a square.

Paul

 

[Shady]

In addition, check your technique - this effect can be caused by not pressing down at the front of the plane as you start the cut, shifting weight to the center for the majority, and transferring to the rear as you clear the workpiece... Sounds complex, easy in practice once you've 'clicked' to it.

 

[engineer one]

reckon paul chapmans' idea has the most merit when you are
starting out, dc still uses it. a wavey line along the edge that you
are trying to plane, then start in the middle with the blade having
only a small shaving. do a couple of these, then where it has
removed the pencil lines, re-draw, and try a longer shaving
using the techique of weight at front as you start, moving to the
middle and then at the end to the back.

then the only thing to worry about is getting it square.

are you sure the surface you are planing on is flat. the wood
maybe bending under loading, and then springing back.

how are you holding the wood,, vice. end stop, or another means??
does change how the wood reacts.

paul :wink:

 

[Colin C]

Hi dddd
If you are still try to make your winding sticks, try this
First cut them to the lenth that you want and put a small dowel in one end of each ( clamp them together to do this ).
You can then plane them at the same time and this way you will have your sticks the same size at the same ends, they will also be much easier to get straight.
I hope that is clear :wink:
Ps I still have the ones I did when I was about 18, some 20 years ago and if they move, you can still plane together if it is needed

 

[Alf]

As another newbie, I can say I tried this and kept taking shavings. I would've planed right through the board if I'd kept going.

Possibly too thick a cut, or you forgot to start in from one end and plane up and off just short of the other. Do that enough times and the nose/heel of the plane running on the unplaned areas will stop the plane cutting anymore.

In addition to all the advice so far, as a general rule, it helps to try and plane the wood concave. You won't be able to, especially with a decent length of plane, but the effort of trying to do so puts the pressure on the plane in the right places at the right time as described by Shady. One of the most useful bits of planing advice I ever got when I was learning.

Cheers, Alf

 

[Paul Chapman]

And once you've cracked the business of planing straight and true in the length, and you are then struggling with getting the wood square across the width, set the blade for a fine cut, keep the mouth of the plane free of shavings, plane slowly using your fingers as a fence, and look into the mouth of the plane and you will be able to see clearly whether the blade is taking off shavings to the right, left, centre or right across. And keep using that pencil so that you can see what you have done :wink:

Paul

 

[bugbear]

In addition to all the advice so far, as a general rule, it helps to try and plane the wood concave. You won't be able to, especially with a decent length of plane, but the effort of trying to do so puts the pressure on the plane in the right places at the right time as described by Shady. One of the most useful bits of planing advice I ever got when I was learning.

Cheers, Alf

Where'd you get that tipette? I'm (at least) an independant re-discoverer. I doubt I truly invented it.

BugBear

 

[bugbear]

I've checked the plane and it is slightly concave along the length but nothing huge and I really don't relish the thought of hand lapping a No7 flat (I'm still recovering from doing my No5 1/2).

I saw some poor students at the APTC lapping a #7 on SiC. They were achieving very little.

Lapping becomes decreasingly effective as the plane widens and lengthens, since the pressure (generating the cutting action) decreases.

You also need a very large lapping surface (3 times the length of the plane is normally recommended!!).

I would recommend this technique:
http://www.geocities.com/plybench/flatten.html

(but I'd see if you can get by with the plane "as is" before doing that much work).

BugBear

 

[Paul Chapman]

Where'd you get that tipette?

Don't know where Alf got it from, but in my case my woodwork teacher at school passed on the same tip to me 50 years ago - pity they don't teach useful stuff like woodworking at school any more :wink:

Paul

 

[David C]

Here are some thoughts.

Oddly, the geometry of a bench plane does not produce a straight edge, without concentrating on hollowing first, (stop shavings) and then taking one or two through shavings. (On shorter stuff).

If you then take ten more through shavings a small bump will almost inevitably return, on stuff of about 12" to 20" long. Do try this, it is a revealing exercise. If you don't have a precision straight edge, plane two edges and offer them up together, for comparison, sliding the surfaces to detect high, pivot points..

A well set machine planer does have the correct geometry, i.e. the 'in' table is dropped by the thickness of shaving taken.

Another fundamental cause of difficulty with the planing of a straight edge, is the shape of the sole of the plane. The vast majority are slightly concave in length, a byproduct of factory machining and chucking. Minute convexity is actually more helpful.

I did try to cover all aspects of precision component planing in the dvd. There is a great deal to understand in this 'basic' process, which is not straightforward at all.

David Charlesworth www.davidcharlesworth.co.uk

 

[Alf]

Where'd you get that tipette?

Ooo, haven't the foggiest. Read it somewhere - might have been Jeff Gorman back when I only knew him from Good Woodworking.

If you then take ten more through shavings a small bump will almost inevitably return, on stuff of about 12" to 20" long. Do try this, it is a revealing exercise.

It's also depressing when you do it unintentionally.

There is a great deal to understand in this 'basic' process, which is not straightforward at all.

Ain't that the truth. Although sometimes I think there's a lot to be said for just being able to do something and not wondering how. Too often I'm rememinded of how much woodworking used to get done chez Alf before I knew enough to realise what I was doing was really, really difficult... :lol: Hopefully at some point the other side of the hill will hove into view and suddenly I'll not only know how difficult it all is, but will be able to do it too.

Still waiting. :lol:

Cheers, Alf

Cherishing ignorance as a rare and precious gift since 1996 - that's my excuse anyway...

 

[dddd]

Cheers for all the advice. Have been trying to hollow it out and the results are getting much better thanks, not perfect but heading in the right direction. Of course now it's not square, so after some wondering plane action I get it square and then it's not flat anymore etc etc etc, oh the joys of woodwork. Still DC's 2nd DVD is on order now, the workmate will soon be put into retirement and I seem to be learning something new each time I get the planes out.

Thanks for all your help.

N.