Thread: Flattening hand plane soles (again)

Hi Snafu might be wise to post this thread on the metal work forums where all the scraping happens.

The scrapping method sounds far more risky that using a reference surface to me.

Originally Posted by chook

The scrapping method sounds far more risky that using a reference surface to me.

Well, you still use a reference surface with scraping. I guess that the worst thing that could go wrong with scraping is getting a bit over-excited and taking a deeper shaving than intended. But, since I'll be practising on a junker first, and a scraper with a large radius only allows a very shallow bite, I can't see this as being too catastrophic.

I recently flattened the back of a chisel using a small circular grindstone mounted on a hand drill. After that, scraping doesn't seem so bad.

I've pretty much convinced myself to have a go at this now, I'll give it a crack and report back. I think that a reference surface shorter than the sole I'm flattening will be a problem for the #8, but shouldn't be too much of a biggie with the #5 and #6 provided I rely upon a straightedge too (in my case a bit of angle iron).

Eddie, you are amongst a bunch of metal workers down that way who will help you out if you get in touch with them - there have been courses run in the recent past.
I am self taught but have done a bunch of planes by scraping. Once you have experienced a super flat plane you will never want to flatten it any other way. But do not think you will be able to use thick glass, unless it is a glass surface plate. Any glass other than one made as a surface plate is a recipe for frustration when spotting for scraping, it is just not flat enough! Borrow some time on someone else's if you have to. Don't mess around with anything but tungsten scrapers, it is just not worth the time.

The problems with lapping are well known and while some have success, I'm yet to see someone spot their lapped soles to show how flat they are. Additionally if you have an old plane that has been "rehabbed" before and the sole is convex, it is practically impossible to flatten a convex sole by lapping.

There are some horror stories about machinists and handplanes - I have one. One machinist took off so much meat he went right through some of the thinner parts of the sole. The one I had done came back less flat than it began. Handplanes are notoriously hard to clamp sufficiently for machining without distorting the sole.

good luck with it.

Forgot to say McJings have reasonably priced granite surface plates

I just picked up a $55 granite surface plate from Carbatec.

I don't want to use a tungsten carbide scraper because I can't sharpen it, and they cost much more. I only have a few planes to scrape, so hardened steel would be alright, don't you think?

Originally Posted by snafuspyramid

I just picked up a $55 granite surface plate from Carbatec.

I don't want to use a tungsten carbide scraper because I can't sharpen it, and they cost much more. I only have a few planes to scrape, so hardened steel would be alright, don't you think?

That is where it'll help you to contact some of the scrapers down that way, they'll be able to show you how to sharpen so you can try both and see for yourself the difference. While I use diamond powder on a cast iron lap, I have also used a fine diamond plate. You may even have one.

Hi,
Firstly have you read my thread here: https://www.woodworkforums.com/f65/sc...-plane-153138/ i am also fairly new to scraping, and like you i do not yet have the ability to sharpen carbide, but one sharp insert should do all your planes. As it is, a cheap diamond wheel from CTC tools will go on a grinder and you can sharpen all the carbide you like. The Carbatec plates are flat to 2.2 micron (so it seems from the few reports i have seen). They are really only long enough to do a no5 properly, although you could get away with your 6 but certainly not your 7.
You will also need something to spread the blue, a brayer etc.
Watch Nick Muellers Vids, best scraping vids bar far. Kanal von MuellerNick - YouTube
Post this in the metalworking section, there will be plenty of guys that can help you in Melbourne.
You will be blown away by how much better a scraped plane feels over a lapped one, i know i was.

Scraping is really difficult, thats why milling machines and surface grinders were invented IMHO. Life is too short
I can remember our apprentices trying to fool their TAFE teachers by using machine tools and then adding some scraper marks, the teachers didn't fall for that though

I was wrong. Apparently this is a well established method of flattening soles of planes. I might have a go myself.

I have now ordered (or already own) all of the necessary bits and pieces, which are:

A flat 8" hardened steel engineer's scraper from eBay;
A tube of Prussian blue (bearing blue);
A Carbatec surface plate;
A 12" second cut flat file.

I've already got the bits and pieces for sharpening the scraper.

Aside from flattening plane soles, apparently scraping can be used to mate surfaces to an extremely high degree of accuracy (i.e. the frog).

I'll start on this project in a week or two once the bits arrive and report back.

Got a picture of the scraper?

Originally Posted by snafuspyramid

I have now ordered (or already own) all of the necessary bits and pieces, which are:

A flat 8" hardened steel engineer's scraper from eBay;
A tube of Prussian blue (bearing blue);
A Carbatec surface plate;
A 12" second cut flat file.

I've already got the bits and pieces for sharpening the scraper.

Aside from flattening plane soles, apparently scraping can be used to mate surfaces to an extremely high degree of accuracy (i.e. the frog).

I'll start on this project in a week or two once the bits arrive and report back.

Although the scraper I ordered hasn't yet arrived, I tried scraping using a Tungsten carbide paint scraper from Masters.

Although this worked quite well, removing nice even shavings of steel, it quickly became clear that I'd be at it for three or four hours. Scraping, it appears, is best for those situations where you are making a flat thing REALLY damn flat. (And besides, the carbide blade on the paint scraper was at too small an angle to hold an edge for very long working in steel). The handplane I'm working on has already been lapped "flat" on abrasive sheets, checked with a straightedge and so on. But a single round on the reference plate with the blue made it very clear that it's got no contact around the mouth, and is instead resting on a spot at the toe and a long section along the rear right of the heel (a typical wear pattern on old planes). This looked like a lot of work.

So instead of the scraper, I using a small diamond file (a few dollars from eBay). Using the very tip of the file as a scriber, it's possible with a little practice to "scribble" away the blue spots, using a cross hatch pattern. This works much more quickly and in about forty minutes I have a plane that is genuinely co-planar at the heel, toe and along the width of the front and rear of the mouth. The diamond file allows a remarkable degree of control - about the same as using a pencil. It's rather like colouring in. And I dare say I could get the surface even flatter, if I felt so inclined, without resorting to a scraper.

To give you an idea of how delicate the diamond filing marks are, it's possible to remove them in about one minute using a very fine sandpaper, say 400 grit.

The accuracy of the bearing blue depends upon how much is used. A very very thin coating - achieved by applying the blue and then rubbing it all off again with a rag - shows that there are slight variations within the surface that I've diamond-filed away. These variations are too slight to make any difference to the function of the plane, in my opinion, but I'll nevertheless attempt to remove them when I get a proper engineer's scraper.

I'll post photographs when I can.

In the meantime, I was surprised at how easy this was, and how far away from being flat the plane was after lapping. It was certainly less boring, and much quicker, than lapping. What do you guys think of this method?

I am fascinated to watch your progress on this task but as an Engineer used to dealing in minute tolerances, where appropriate, I have to ask Why?
Will your hand planing be more accurate?
How many decimal places are you using when measuring your wood?
This is not meant as a criticism and I wish you well
I have spent many years explaining to Engineering graduates that you don't have to specify 3 decimal places on absolutely everything you design as accuracy costs money and time, as you are well aware by now.

Originally Posted by ClintO

I am fascinated to watch your progress on this task but as an Engineer used to dealing in minute tolerances, where appropriate, I have to ask Why?
Will your hand planing be more accurate?
How many decimal places are you using when measuring your wood?
This is not meant as a criticism and I wish you well
I have spent many years explaining to Engineering graduates that you don't have to specify 3 decimal places on absolutely everything you design as accuracy costs money and time, as you are well aware by now.

Well, of course you're right, in the sense that this will not improve my woodworking in the slightest. It's certainly difficult to justify from a functional perspective.

However, from what I can tell (having only done one plane), this method doesn't take as long as abrasive sheet lapping, is cheaper (excluding the surface plate, which is handy to have anyway) and is almost impossible to screw up. It removes the element of trial and error. So it seems to me to be an improvement on all fronts.

At the least, it will hopefully start a useful argument.

However, at this stage, I am not even close to machinist's tolerances; as I mentioned, when I use only very light blueing, I can tell that some spots within the filed areas are slightly higher than others. The only reason why I'll be using a scraper to reduce this difference is curiosity; I'm perfectly happy with the result I've achieved scribbling away with the diamond file.

I've added a photograph, so you can get an idea of the sort of accuracy I'm talking about. It's a long way from a universally flat, shiny sole. (And again, you'll notice I've used the blue quite heavily).