Thread: flattening a plane without reference

What could you do if they were flat? What can't you do because you believe they are not flat now?
Build an elbow adze and a D adze like the Pacific Northwest. Not impossible as I've done it.
Buy the blades and make the handles.

Kestrel Tool

Using fine sand as abrasive, I'd be scrubbing the blades against each other, back to back.
I can polish fossils in sedimentary rock that way. It is a good sharpening abrasive.

Originally Posted by Robson Valley

What could you do if they were flat? What can't you do because you believe they are not flat now?

This is actually hard to answer.
For once joining two pieces of wood might be harder if the plane was convex on the sole, near to imposible if it was concaved.
If you could make even one flat surface, you could flatten anything that should be flat on it, making your work more precise in the proces.

I was thinking more about making this first flat thing. How doest one find out that flat is flat? how does one make things flat on something that is already flat is easy.

To make one flat surface, you must make three. Have a look at the "Whitworth 3 plate method", it's generally used for metalwork, but could probably be adapted for timber
The Whitworth Three Plates Method — Eric Weinhoffer

Newton Rings provide evidence of "flat". Right down to nanometer wavelengths of light.

Rubbing one surface against another with some abrasive in between
kinda sorta works for flattening but both stones do wear at the same time and in different places.
I've done quite quite a lot of that with water & sand in the shade on hot summer afternoons!

After a while, I can see easily where the high spots are. Some are so tough, I don't think they will ever cut down
while the sand keeps grinding away at the softer surrounding stone.

That shouldn't be an issue with more homogeneous metal.

What makes you think that the work produced by an optically flat and true plane will be flat?

The reality is that it will not... A good flat plane may make it easier - but it's not the end of the world.

Flat wood requires technique...

Even edge jointing relies upon considerable technique... And a dead flat plane is not always a guaranteed success factor....

Originally Posted by kokodin

Hello, my first post here , and I admit I am a free thinker, so bare with me for minute.

This is my hipotesical and kind of practical question.
How far can you go with wood working without tools, or way to buy tools?
let's say all you have is a few plane blades, old warped wooden joiner plane, and 1 or 2 iron planes, long after their prime, worn out and out of true by miles. You also have infinite amount of pine 4x4, and sandpaper, just because.
We playing lost on a deserted island scnario

Can a person in this conditions make any of those planes true and flat? If yes , how?

I know it is a little silly asking something like that, but I always was a fan of "build your own tools" motto. Going a little bit extreme here, but first wooden hand plane had to be flattened on something. Otherwise it wouldn't work. But how to flatten something without having something flat first to reference yoursel to?

Originally Posted by kokodin

I was thinking more about making this first flat thing. How doest one find out that flat is flat? how does one make things flat on something that is already flat is easy.

when working with wood, flat is relative.
two non-flat pieces of wood can easily be joined together provided "bumps' on one correspond with "hollows" on the other. And then the wood moves with changes in humidity, so why did you bother getting it optically flat to begin with?

Hi kokodin, welcome to the Forum.

There are numerous ways to check if a surface is 'flat', some much more accurate than others, so you choose your method according to need & the gear available. As others have said 'flat' is relative. In woodwork, you need surfaces either flat enough for appearance (a table top) or for joining. In the latter case, the surfaces should meet to within fractions of a millimetre to maximise glue strength. For surfaces like table tops, the most common 'primitive' way of checking for straight & flat is to sight along the surface. You are not aiming for something with the tolerances of the Hubble telescope, just a surface with no visible dips & hills.

If two surfaces are to be joined, simply hold them together with the light behind them, & you'll soon see where the gaps & high spots are. In this case, it usually doesn't matter if the surfaces meet any definition of 'perfectly flat', it's more important that a large proportion of the surfaces meet, to maximise glue strength. We usually pay special attention to straight, visible edges because any mis-matches will be very evident even to an inexperienced eye, but it's more important they meet without gaps than be perfectly straight to within nanometres as the eye will pick up the former more easily than the latter.

The most important aspects you need to control to build anything from a desk to a house are 'plumb' & 'square'. A weight on a piece of string (plumb-bob) suffices for the former, and a square can be made from a few bits of wood using the 3:4:5 ratio for the sides of a right-angled triangle (which was worked out a very long time ago).

I've seen pretty impressive furniture & houses built in Asia, using nothing more than those two tools - not a tape-measure in sight, just a 'story-stick' or two for setting out. And the planes and saws they used would not fetch too much on Ebay. As truckjohn says, much depends on technique, for instance our woodwork teacher, a good journeyman cabinetmaker of the old school, showed us how you can shoot an end square to quite close tolerances using a very ordinary #4 bench plane in which the blade wasn't quite square to the sole. It's amazing what skilled hands can do with very ordinary tools, but the best tools in the world won't produce really high quality work in less-skilled hands. I am reminded of that every time I use my nice shiny tools and things don't turn out exactly as I wish.......

Cheers,

Thanks for your answers, they kind of work, but some of it I already know.
Laping plates are for smaller, things i belive though.

To be perfectly honest the whole idea about making flat reference surface came out of the simple thing, in my few years long engadgement with woodworking as hobby. More precisely guitar building.
For a long time now I could make flatter boards (joints) than my tools were, and for some reason I never was able to fully flatten my planes , using internet techniques. Glass pane,stone tiles, or wooden beam shaved paralel to a straight edge, nothing seems to work for me as a laping surface for my planes. IF anything I am getting worse every time. I always get convex sole, no mater what I do. It might be only a printer paper out of flat on both ends, but for no4 plane it is a lot in my head. for a jack that would be even more, because curvature seems the same.
I am mad on myself for that, and got even more bumped down when i read mr.Paul Sellers blog about import planes, part 4 i belive. Picture with filler gauges mede me scream why is it not working for me?
Plane collector videos are also very interesting, again he seems to be doing the same thing with no problems.

kokodin, you're not alone - I went the plane-lapping route 40 years ago & had the same sorts of results. It's extremely difficult to flatten a surface that way, mostly, I think, because as you push the plane back & forth, whatever the lapping medium, particles of grit & iron begin to build up ahead of the direction of travel, then get pushed under the sole, lifting it slightly and cutting more at front & back than will be abraded away from the centre. The inevitable result is a slight rounding of the sole from front to back, which will get worse the more you lap. It's also very difficult to hold the plane so that one side doesn't get cut more than the other - you have to keep reversing it to avoid that, and also try to avoid rocking it so you don't cause a slight convexity across the sole. I lap the soles of planes when I make them, but only to 180 grit (whatever the Polish equivalent of that is?). That seems to be plenty, I don't get any discernable rounding if I'm careful, and he planes work well, which is the acid test.

Perhaps the only reliable way to get a plane sole truly flat is to scrape it, but that requires some proper tools, a truly flat reference surface and a lot of tedious, exacting work. In my opinion, it's all quite unnecessary for 99.9% of everyday usage. You said yourself you were getting perfectly acceptable results from planes that were not flat to absurd tolerances. Results are what counts, in my view, so when it's not broken, why fix it??

Cheers,

Ye, that is basically what i figure out by myself. But it is still frustrating, especially when me being a kind of compulsive perfectionist from time to time. That being said, i was avoiding like a plauge to move my planes back and forth while working on them.(i have done some "rocking chairs" out of some tools in the past already) I prefere to push them away only , so the sandpaper would straighten up by itself from tension. And i mostly aply presure from the frog, or leave it to the gravity.
Maybe i have too high of expectations, but at least if i lap 2 no4 on the new sandpaper on a glass pane 4 times as long as the plane body itself, i would expect them to being flat referencing each other, and i got contact in the middle, 2-3 office paper sheets gap in front and back. I know it is 1/2 that per plane, but that just so annoying. Or when you figuring out that your jack is convex with a straight edge, but it only lap on both ends when you give it to the sandpaper. I could go on.

Scrapeing is a good idea on paper, but with no training it would probably end up as another disaster.

Are you sharpening from your elbows or sharpening from your knees?
Have you painted many stripes of black felt marker on the surface to follow your efforts?

Technique makes a huge difference when lapping.

If you are hollowing the ends - move your hand pressure to the center and vice versa....

I gave up lapping using abrasive paper a few years ago and took up scraping. If you are really going to do this properly, I recommend, getting a good scraper, a proper flat plate and some marking blue. Scraping is pretty easy if you have those three things.

If you are going to stay with an abrasive solution, I found that I reduced (but did not eliminate) the bowing of the surface, if I used a figure-of-8 motion when abrading the surface, it tended to even out the pressure points and produce a 'flatter' surface.

Do you sharpen from your elbows or from your knees? In freehand, one is a major mistake. Fight it as you will.