Thread: Scraping tool for flattening

Originally Posted by Clinton1

I think that I’d like to scrape a surface flat.
Where do I even start?

First, by telling us whether it's wood or metal & what it is you want to flatten...

There is a wealth of info on the inter-web that explains the process, the tools & the various approaches involved. There have been several Forum threads on flattening plane soles by scraping, e.g.:

Scraping a plane sole

or

Flattening hand plane soles (again)

If you search in "Hand Tools" for "plane, sole, scraping" you'll get quite a few hits, but for some of them the pics are lost or links broken, so they aren't as helpful as they might be....
Cheers,

Thanks Ian.
yes, it’s for removing rust and flattening steel plane soles.

Hi Clinton. I have had plenty of success with coarse sandpaper and a flat platen (glass/steel/tile). Any reason you want to scrape?

Sent from my SM-G986B using Tapatalk

Hi Clinton, I use a Sandvik scraper (coromant) with carbide inserts to do my plane soles. If you Google Sandvik scraper images you'll see it is the file shaped object with a red handle, a silver bar and an insert mount at the end. Scraping is the best way to flatten plane soles. I have never seen a plane sole lapped with sandpaper that was not convex or at least rounded over a significant amount of the perimeter, both from my own practice and those people willing to let me put an actual machinists straight edge on their planes! Surface grinding also does not work because the clamping pressure required to hold the plane sole distorts it and when released from the clamp it relaxes and the ground sole is no longer flat. Indeed, as an experiment when blueing some soles as I would for scraping, I deliberately twisted knob and tote and could get different blueing patterns, indicating that with a bit of human brute force the sole will distort!

The bad news is that you MUST have a surface plate that is flat, such as a granite surface plate (Got mine from McJing I think), glass is just not flat enough.
To resharpen the cabide insert you will also need something like a cast iron lapidary lap and two different grits of diamond powder. It's a pity you're not closer or you could use my setup, it sits around doing nothing at the moment.

Cheers
Michael

Clinton,

I’ve actually though about scrapping in the soul of hand plane, I’ve done as Mountain Ash suggested few a times, an for me it seems too work,

I’ve checked on my small surface plate an could not get a feel gauge under it, sorry no pictures you just have to trust me[emoji849], but maybe it’s still dished in the centre, an only the edges are flat, as I didn’t actually blue it!!!!!.

But I’m sitting on the fence to weather what degrees we need the soul too be flat,we work with timber, made by Mother Nature, an in my humble opinion she’s a complete B…. An always win, will that piece of timber be flat, tomorrow too with in a micron ??.

How Flat Should Your Hand Plane Be - YouTube

Some interesting idea’s here [emoji115].

Cheers Matt.

Originally Posted by Simplicity

Clinton,

But I’m sitting on the fence to weather what degrees we need the soul too be flat,we work with timber, made by Mother Nature, an in my humble opinion she’s a complete B…. An always win, will that piece of timber be flat, tomorrow too with in a micron ??.

Cheers Matt.

The fact that timber moves has no bearing on why we would want to make a plane sole flat. By flat, I do not mean polished, and I do not mean necessarily the whole sole, but especially the toe up to the mouth and just behind it and around the perimeter and at the heel. The two reasons are :

1) A scraped plane is very easy to use, it registers very positively on the work at the beginning of the shaving and maintains a constant register of the blade to the work so a consistent shaving is taken off.

2) In the case of planing edges of long boards so they may be mated for glueing eg for a table, it is very difficult to plane an edge straight without a lot of practise if using a plane with a convex of concave sole. The convex sole tends to make the board overly concave, so there is a big gap in the middle of the two boards placed edge-on (more than would be considered useful if you want a sprung joint). The concave sole tends to go the opposite way and make the edge convex. These errors are cumulative so if you're used to running the boards through machinery first and then doing a final pass with the hand plane to removes cutter marks then it won't make much difference. If however you use only hand tools, All that planing is going to add up. The flat sole plane does not have an error and is a joy to use.


I did a blog on here where I showed how much error you would get with a certain amount of out of flat, but it has been deleted. If you search my name and plane maths you should find a summary I think

The argument about how flat a plane sole needs to be will go on forever, I think. My answer is "as flat as it needs to be to do the job you expect of the plane".

I'm no fan of lapping soles on sandpaper (it's hard yakka for starters), but I maintain you can get a sole flat enough for practical purpose, if you are careful. I agree with Michael that it's all too easy to make a complete mess of a sole by lapping (been there, done that!), but it is possible to get a working surface - my home-made & lapped smoother will take one thou shavings from end to end of a board, on almost any wood and that's good enough for me.

A slightly convex sole (& I mean very slightly), can work on a smoother, and can even be an advantage in certain situations, but a concave sole is definitely not wanted on anything bar a compass plane. You simply cannot plane a flat surface with it, at least I certainly can't, the plane cuts more at the start & end of a stroke and will form a hill. The more you try to correct it, the bigger the hill gets.....

Cheers,

Originally Posted by IanW

The argument about how flat a plane sole needs to be will go on forever, I think. My answer is "as flat as it needs to be to do the job you expect of the plane".

Too true. When one considers the best furniture made was done with wooden planes... They didn't worry about thousands of an inch. It was all about knowing how to use what you had and working with the results to come to a nice product.

Originally Posted by mic-d

The fact that timber moves has no bearing on why we would want to make a plane sole flat. By flat, I do not mean polished, and I do not mean necessarily the whole sole, but especially the toe up to the mouth and just behind it and around the perimeter and at the heel. The two reasons are :

1) A scraped plane is very easy to use, it registers very positively on the work at the beginning of the shaving and maintains a constant register of the blade to the work so a consistent shaving is taken off.

2) In the case of planing edges of long boards so they may be mated for glueing eg for a table, it is very difficult to plane an edge straight without a lot of practise if using a plane with a convex of concave sole. The convex sole tends to make the board overly concave, so there is a big gap in the middle of the two boards placed edge-on (more than would be considered useful if you want a sprung joint). The concave sole tends to go the opposite way and make the edge convex. These errors are cumulative so if you're used to running the boards through machinery first and then doing a final pass with the hand plane to removes cutter marks then it won't make much difference. If however you use only hand tools, All that planing is going to add up. The flat sole plane does not have an error and is a joy to use.


I did a blog on here where I showed how much error you would get with a certain amount of out of flat, but it has been deleted. If you search my name and plane maths you should find a summary I think

I agree the soul needs too be flat,an ye I’m talking flat, an not polished, as I can make a soul polished an not actually have it flat.
An please no one mention optical flat [emoji849][emoji849].
An yes agree the Toe area an behind the mouth, needs to be flat an register on the timber you are planing,which is the whole reason a plane works in the first place.

I did mention I was sitting on the fence, maybe I should have said 50/50 !.

Im starting too also question sandpaper as a tool too use for flatting souls !!.

But agree with Ian’s comments these “Discussions” pop up from time too time, but are hardly ever ended peacefully or should that be flattened out in the end[emoji849].

Cheers Matt.

Anyone who wants to argue a pragmatic stance on this is clearly not aware this is a matter of life or death!!

It'd be nice to try a number 7 or 8 jointer that was known to be as close as can be to dead flat. To see if there was a difference from off the shelf jointers.
Wouldn't an engineers surface grinder do it right?
I get my table top joints right with stock standard planes.
Not much point it doing a smoother though I wouldn't think. They have never left me wondering if the sole is true. The jointers though have had me scratching my head a few times. Its not an automatic, just push the plane through to get the joint right though is it. Some adjustments and matching joint to joint and it works out fine every time with standard condition quality Stanley 7 or 8 or Bedrock versions.

What would be nice to have a go on a plane sole with is one of these. With a tungsten blade fitted.
A metal workers plane .
A nice thing to build for a plane making project maybe Ian ? .

mp_1.jpg

Here is the link to more of it.
Metal Cutting Smith's Plane

Rob

Originally Posted by auscab

It'd be nice to try a number 7 or 8 jointer that was known to be as close as can be to dead flat. To see if there was a difference from off the shelf jointers.
Wouldn't an engineers surface grinder do it right?
I get my table top joints right with stock standard planes.
Rob

Yes it would be good to try. The reason a surface grinder is no good is the clamping pressure required to hold it distorts the plane sole, once surfacing is complete and the sole is released it relaxes and the sole is no longer flat. I did a post years ago where I showed I could distort a plane sole by twisting the tote and knob by hand and getting different blueing patterns, in the same post this was backed up by a laser interferometry experiment (!) on a number of different planes. If you had a thick casting and the sole was really out, you could have it surface ground as a start. And I've heard from two woodworkers who took their planes to an engineering shop and they ground right through the thinest part of the sole!

Originally Posted by auscab

It'd be nice to try a number 7 or 8 jointer that was known to be as close as can be to dead flat. To see if there was a difference from off the shelf jointers.
Wouldn't an engineers surface grinder do it right?
I get my table top joints right with stock standard planes.
Not much point it doing a smoother though I wouldn't think. They have never left me wondering if the sole is true. The jointers though have had me scratching my head a few times. Its not an automatic, just push the plane through to get the joint right though is it. Some adjustments and matching joint to joint and it works out fine every time with standard condition quality Stanley 7 or 8 or Bedrock versions.

What would be nice to have a go on a plane sole with is one of these. With a tungsten blade fitted.
A metal workers plane .
A nice thing to build for a plane making project maybe Ian ? .

mp_1.jpg

Here is the link to more of it.
Metal Cutting Smith's Plane

Rob

Rob,
That’s extremely cruel, you an many of us hear, have heard Ian say many many many times, this is the last plane I’m ever making.[emoji849]

Cheers Matt.

Originally Posted by Simplicity

Rob,
That’s extremely cruel, you an many of us hear, have heard Ian say many many many times, this is the last plane I’m ever making.[emoji849]

Cheers Matt.

That's right Matt. LOL.

Rob