Sole Flattening Report to the Teachers

[Dan T Jones]

336575

Further progress towards actually using these planes.

This is my attempt at flattening this Stanley Bailey No 4 sole. Flattened on a piece of glass with 150 grit cloth belt. I marked out the problem areas. Am I finished? More to do? BTW the sides are nice and square. This may be my shooting board plane.

I really appreciate the opportunity to ask experienced craftsman.

Thanks for the help.

Dan

[Derek Cohen]

Hi Dan

The section to the side of the toe is OK to leave. However the section at the heel needs ideally to be coplanar with the mouth and toe (- otherwise you have effectively a shorter plane). Of course, you could try it as is and see how it works as a smoother - the important area around the mouth and toe is done. As a shooter, you have done enough.

Regards from Perth

Derek

[george wilson]

It appears that you have actually flattened the outside edges of the rear end of the plane,leaving a dip in the center. If this is true,I don't see why the plane would not function as a full length plane. If you are planing the EDGES of a board,of course,then you would really need to keep working on the sole until all the low areas are sanded away.

The closer you get to 100%,the harder the going is,because you are having to remove so much more metal.

[Dan T Jones]

Yes, the heel outside edges are ok. I'm also working on a No 5 so that may be my go to for edges.

[bridger berdel]

Dont put too much trust in the pattern of shiny metal left behind by the sandpaper. Use a straight edge to check it against a bright light, lengthwise, across and diagonals. That said, the actual flatness required for a plane to work is not too extreme, just that it not be concave.

[Ethan L D Cook]

Could you post a picture of your flat glass setup?

Your posting this thread motivates me to work on converting my antique shop Corsair #4 into a scrub plain. The sole of it needs flatening like your doing now.

THanks!

[Mike Cherry]

Ethan, I thought I'd offer you a little advice about your #4 that you plan to convert to a scrub. If thicknessing is all you have planed for it, it need only look flat. I wouldn't even put it to sandpaper. If you have other planes that you might want to rehab, I recommend calling a local glass shop and asking for a piece of float glass. I paid 15 bucks or so.

[Patrick Chase]

Dont put too much trust in the pattern of shiny metal left behind by the sandpaper. Use a straight edge to check it against a bright light, lengthwise, across and diagonals. That said, the actual flatness required for a plane to work is not too extreme, just that it not be concave.

Putting numbers to this: #150 corresponds to a nominal abrasive particle size of 100 microns, with a fair number up to 200 microns or so depending on the grading system (FEPA, CAMI, and "micron" all have different tolerances). 200 microns is about 5/1000", so you could have pretty significant flatness variation and still "see scratches" even if the paper is perfectly flat.

As Bridger says, don't trust the scratch pattern. Use a good straightedge.

With experience you can learn to tell when one area is being abraded less than others from the scratch pattern alone, for example by periodically changing lapping direction and seeing how long it takes to work out the scratches from the previous direction.

[steven c newman]

Another, easier way....take a black sharpie, make a series of lines across the sole. Sand until they are gone.

As long as the plane is assembled, with the iron retracted back up out of the way. You want the body of the plane to be in the same tension as it will be in use.

IF the vise allows you to hold a fully assembled plane, with the sole uppermost, you can use the longest, widest, straightest mill file to "sand" the entire sole.

[Patrick Chase]

Another, easier way....take a black sharpie, make a series of lines across the sole. Sand until they are gone.

As Warren pointed out in another thread a week or so back, the "Sharpie method" is fallible. Grain variation can cause most of the sharpie to be abraded away before the surface is fully true, and of course it doesn't work at all if your sandpaper isn't completely flat.

If you want to know if something is flat then directly measure its flatness, period. Indirect measures such as scratch patterns and sharpies all have edge cases where they fail.

[Dan T Jones]

Ethan, here you go. Cost $15, 12 X 19 X 3/8 glass. Cloth backed sanding belt.
Dan336588

[Lenore Epstein]

If you have other planes that you might want to rehab, I recommend calling a local glass shop and asking for a piece of float glass. I paid 15 bucks or so.
I suggest bringing a straight edge. I got a 1/4 inch thick piece of what was said to be "float glass" from a local shop, and it was only after struggling with a few chisel backs that I figured out that neither side was anywhere near flat. My wild guess is that the woman I dealt with had no idea what float glass was.

[Patrick Chase]

I suggest bringing a straight edge. I got a 1/4 inch thick piece of what was said to be "float glass" from a local shop, and it was only after struggling with a few chisel backs that I figured out that neither side was anywhere near flat. My wild guess is that the woman I dealt with had no idea what float glass was.

Most likely they sold you *tempered* float glass. If you don't specify a lot of places will assume you want it tempered, and that tends to warp it a bit esp in thinner pieces.

My understanding is that most sheet glass on the market these days is in fact float glass.

[Bob Glenn]

Most likely they sold you *tempered* float glass. If you don't specify a lot of places will assume you want it tempered, and that tends to warp it a bit esp in thinner pieces.

My understanding is that most sheet glass on the market these days is in fact float glass.

Patrick, You are correct. I was in the glass tempering industry for over 30 years.
During the tempering process, the glass is heated to 1200 to 1400 degrees, which is visually red hot. In this state it is quite flexible and bendable, but not yet liquid, so it can deform during the rapid cooling process, especially if the cooling air is not distributed on both sides of the glass equally. So it can deform during tempering. Untempered float glass is your best bet, since it is drawn out of the tank onto a bath of molten tin. Tin is heavier than glass, so the glass literally floats on top of the tin creating a very even, flat and smooth sheet of glass.

Sheet glass however, is vertically drawn out of a tank and usually has visual inclusions and is not nearly as flat as float glass. I don't think sheet glass is made anymore, with the last plant, PPG, in Mt. Zion, Illinois, closing their sheet glass tanks a decade or so ago.

Probably more than you wanted or needed to know, but I thought I would chime in. Bob

[Lenore Epstein]

Thanks, Patrick & Bob, my mystery is finally solved. Timely, too, as I need another piece of something to play with flattening methods (the approx. 6x22 stone I have is going to be servicing plane soles for a while yet), and it'll be easier to go to a glass shop knowing exactly what I'm looking for than to spend an hour digging through scraps of counter and tile.

[John Burrows]

Patrick, You are correct. I was in the glass tempering industry for over 30 years.
During the tempering process, the glass is heated to 1200 to 1400 degrees, which is visually red hot. In this state it is quite flexible and bendable, but not yet liquid, so it can deform during the rapid cooling process, especially if the cooling air is not distributed on both sides of the glass equally. So it can deform during tempering. Untempered float glass is your best bet, since it is drawn out of the tank onto a bath of molten tin. Tin is heavier than glass, so the glass literally floats on top of the tin creating a very even, flat and smooth sheet of glass.

Sheet glass however, is vertically drawn out of a tank and usually has visual inclusions and is not nearly as flat as float glass. I don't think sheet glass is made anymore, with the last plant, PPG, in Mt. Zion, Illinois, closing their sheet glass tanks a decade or so ago.

Probably more than you wanted or needed to know, but I thought I would chime in. Bob

Bob,

Float glass is not all that flat either. Is plate glass, which is ground and polished on both faces, even made today?

John

[Patrick McCarthy]

Bob Glenn, thank you for the insight. I am frequently amazed about the wealth of information available thru the creek. I have long heard the term "float glass" but had no idea what or how it came to be. Don't know if I will ever need it, but I do feel a little bit smarter today . . . and that has to be a good thing.

Best regards, Patrick

[Jim Koepke]

If finding flat glass is a problem, another source for a lapping surface might be a local monument maker. (often called tombstone carvers)

http://www.sawmillcreek.org/showthread.php?134511

My lapping station doesn't get as much use as it used to, but it is still a good thing to have.

Just like shopping for glass, take a straight edge.

jtk

[Chris Fournier]

An A Grade granite inspection plate is not expensive, it is durable and it is very flat. Buy one and it will pay for itself over the years.

The sharpie hash marks are just fine for this task, fallible at what increment I wonder? .001", .003"? Either way plenty reliable for the surface that you are trueing. The straight edge that you buy will have a similar tolerance...

As a woodworker and metalworker I can say that your efforts are just fine as long as your technique keeps the sole on the paper and not rocking. Personally I true soles on 320 grit but your piece may be pretty out of whack and be a slow process at that grit.

You could use your plane with a shooting board as you have it in the photograph and obtain good results.

[Pat Barry]

It sure looks like you have gotten it to the point that it's mostly flat with a bit of pitting. If you have scratch marks from the sanding spanning the area, even if not totally continuous you are done enough for the intended function. You can always go further if it makes you feel better