Adding Fleam to Backsaws

[Stewie Simpson]

I have always found it difficult & tedious when having to add fleam to a crosscut backsaw using the traditional method. Recently I tried a different method of fleaming, with pleasing results. I would appreciate feedback from those members who already resharpen their own handsaws.

This is the method I used;

Joint teeth.
Shape teeth.

Adding Fleam -
Set file handle to 15* down, and entry angle at 90* to the saw plate.
Commence by adding fleam to the 1st 2 teeth, leaving a fine flat spot.
Skip 1 tooth, then repeat on the next 2 teeth.
Turn saw around when last 2 teeth have been fleamed on the 1st side.
Add fleam to every missed tooth, making sure all flat spots are removed.

Saw set tooth pattern.
Test cut & finished.

[David Weaver]

Sloped gullet method.

I think if you do both methods, you'll find after a while you can basically do both to the same extent (i.e, until you've just cut away everything but the outside point of the tooth and without threatening to create varying height).

I filed a few saws with sloped gullets on my first crosscut saws, but from a practical standpoint, I haven't noticed any effect and I can sharpen a lot faster if I don't have to take the saw out of the vise.

But, whatever works to get the right geometry and have consistent tooth height, it certainly will make a sharp saw as well as any other.

[Stewie Simpson]

Sloped gullet method.

I think if you do both methods, you'll find after a while you can basically do both to the same extent (i.e, until you've just cut away everything but the outside point of the tooth and without threatening to create varying height).

I filed a few saws with sloped gullets on my first crosscut saws, but from a practical standpoint, I haven't noticed any effect and I can sharpen a lot faster if I don't have to take the saw out of the vise.

But, whatever works to get the right geometry and have consistent tooth height, it certainly will make a sharp saw as well as any other.

Thanks David. Appreciate your feedback. I found I achieve a sharper & more consistant tooth height with this method. Especially when working on high tpi saws. As you rightly mention,"whatever works to get the right geometry and have consistent tooth height, it certainly will make a sharp saw as well as any other."

Stewie.

[Marv Werner]

Stewie,

If I'm reading you correctly, you have 2/3 of the teeth with the fleam on one side of the blade and 1/3 with fleam on the other side?

That seems to me that the saw will tend to cut more on one side than on the other, causing it to cut more toward the side with more fleamed teeth.

Everyone I know and including myself, the fleam is 50/50. I always start on the handle end of the blade to my right and file every other tooth with the file handle angled to my right. When I get to the toe end, I angle my file handle to the left and file all the other teeth. For crosscut teeth, I use a 15* rake angle and a 25* fleam angle.These two angles work well for general purposes. I do not bother with lowering the handle for sloped gullets.

[Pedro Reyes]

Adding Fleam -
Set file handle to 15* down, and entry angle at 90* to the saw plate...

Stewie,

In addition to the questions by Marv. I'm no expert but is seems (by the way you describe it) that you are adding slope, not fleam. Am I reading this wrong?

peace

/p

[Chris Friesen]

Adding Fleam -
Set file handle to 15* down, and entry angle at 90* to the saw plate.


As long as the file is at 90 degrees to the saw plate you cannot be adding any fleam. You're sloping the gullets, but you can't create fleam by filing straight across the saw.

You've just filed it rip.

[Stewie Simpson]

Stewie,

If I'm reading you correctly, you have 2/3 of the teeth with the fleam on one side of the blade and 1/3 with fleam on the other side?

That seems to me that the saw will tend to cut more on one side than on the other, causing it to cut more toward the side with more fleamed teeth.

Everyone I know and including myself, the fleam is 50/50. I always start on the handle end of the blade to my right and file every other tooth with the file handle angled to my right. When I get to the toe end, I angle my file handle to the left and file all the other teeth. For crosscut teeth, I use a 15* rake angle and a 25* fleam angle.These two angles work well for general purposes. I do not bother with lowering the handle for sloped gullets.

Thanks for the feedback Marv. I will keep in mind the importance of balancing out the fleam each side. Stewie

[Stewie Simpson]

Stewie,

In addition to the questions by Marv. I'm no expert but is seems (by the way you describe it) that you are adding slope, not fleam. Am I reading this wrong?

peace

/p

Hi Pedro. Thanks for the feedback. The method I use is adding fleam to each crosscut tooth. Not by the traditional method, but the end result is the same but includes fleaming the gullet. The outside edge of each tooth are left with a bevelled edge, with each tip ending in a sharp point. Instead of the file coming across the teeth at an angle to add fleam, this method sets the file entry at 90* to the blade, but sharpens in an upward direction of 15* into the tooth to add the fleam.

Stewie

[Stewie Simpson]

As long as the file is at 90 degrees to the saw plate you cannot be adding any fleam. You're sloping the gullets, but you can't create fleam by filing straight across the saw.

You've just filed it rip.

Hi Chris. Thanks for the feedback. Can you read the feedback to Pedro.
Stewie.

[Ray Gardiner]

I have always found it difficult & tedious when having to add fleam to a crosscut backsaw using the traditional method. Recently I tried a different method of fleaming, with pleasing results. I would appreciate feedback from those members who already resharpen their own handsaws.

This is the method I used;

Joint teeth.
Shape teeth.

Adding Fleam -
Set file handle to 15* down, and entry angle at 90* to the saw plate.
Commence by adding fleam to the 1st 2 teeth, leaving a fine flat spot.
Skip 1 tooth, then repeat on the next 2 teeth.
Turn saw around when last 2 teeth have been fleamed on the 1st side.
Add fleam to every missed tooth, making sure all flat spots are removed.

Saw set tooth pattern.
Test cut & finished.

Hi Stewie,

Welcome to the forum, I see this is your first post, so welcome.

Sloped gullets is a well known technique and works fine, but what you are describing above doesn't quite make sense (to me at least), why are you doing two teeth and skipping one, I would have thought, file one skip one would make more sense.

Or if you are doing it all from one side, file one with the file 15 degrees down, and the next tooth with the file 15 degrees up..

Maybe you can post a picture or a drawing to explain the technique. I'm confused.

Regards
Ray

[Marv Werner]

I'm just a bit confused also...:confused:

I don't understand the two and one tooth profile. And I don't quite understand how fleam can be filed with the file not angled either right or left. However, I know an experienced saw filer who says that he depends on filing sloped gullets to get the fleam. Without actually doing it, I'm picturing it in my mind and I can see that a bevel would be filed on the side of the teeth that the file is angled downward. Stewie does not mention anything about rake angle though. I'll guess that he did his rake angle when he shaped the teeth.

[David Weaver]

If you are filing with rake and with the file handle tipped toward the floor, you will end up with fleam somewhere between 0 degrees and the amount of rake.

Put 20 degrees of rake on a file and hold it straight up and down next to a saw plate.

[Chris Friesen]

However, I know an experienced saw filer who says that he depends on filing sloped gullets to get the fleam.

Visualize the geometry in your head. You've got the saw clamped in front of you, with the toe of the saw to your right. Find a tooth that is set away from you, and set the file to the right of that tooth. The left side of the file will be rubbing on the cutting edge (the "front") of the tooth.

1) The rake is controlled by rotating the file along its own long axis. Basically twisting your wrist. Twisting clockwise increases the rake, counterclockwise decreases it.

2) Sloped gullets are created by dropping the handle of the file.

3) Finally, fleam is created by moving the handle of the file to the left. The more you move the the left, the more fleam the tooth will have.

As you can see, sloped gullets are not technically necessary for fleam. However, they do have an impact in tooth geometry and can be useful to get specific shapes. If you're interested in the details, there is a lot of information at:

http://www3.telus.net/BrentBeach/sawjig/sloping%20gullets.html

[Chris Friesen]

If you are filing with rake and with the file handle tipped toward the floor, you will end up with fleam somewhere between 0 degrees and the amount of rake.

Put 20 degrees of rake on a file and hold it straight up and down next to a saw plate.

Hmm...you may be right, but I think that you would need to have very sloped gullets to get an appreciable amount of fleam. Also, as you increase the gullet slope the rake angle of the file is no longer the rake angle of the resulting tooth.

I should sit down and work out the math...

[Marv Werner]

Chris,

I have read Brent's informational instructions on sloped gullets. Been there several times. He has lots of good information there on that site. All beginners would be wise to read through it.

I file the fleam with the file perpendicular with the side of the blade and with the file to the left or right. I don't do sloped gullets. Don't see much advantage to it. However, if one were to drop the file handle down far enough, fleam can be filed with using only that angle and at the same time maintain the rake that was filed when reshaping the teeth, and the gullets would be sloped. Focus should be on the cutting edge of the tooth. I would not recommend this style of filing for western style saws. Japanese pull saws however, are filed in a similar way but they use a different type file.

[Stewie Simpson]

Hi Stewie,

Welcome to the forum, I see this is your first post, so welcome.

Sloped gullets is a well known technique and works fine, but what you are describing above doesn't quite make sense (to me at least), why are you doing two teeth and skipping one, I would have thought, file one skip one would make more sense.

Or if you are doing it all from one side, file one with the file 15 degrees down, and the next tooth with the file 15 degrees up..

Maybe you can post a picture or a drawing to explain the technique. I'm confused.

Regards
Ray

Hi Ray. Thanks for the welcome. I have visited your site many times. My apologies if I gave the wrong impression with the description on the method I trialed. When I stated doing 2 teeth then skip 1. I am placing the file between 2 teeth, filing fleam each side of the file, then skip 1 tooth, and file the next 2 in the same manner. I turn the saw around after doing the 1st side , so fleam can be added to the skipped teeth.

Stewie.

[Stewie Simpson]

I'm just a bit confused also...:confused:

I don't understand the two and one tooth profile. And I don't quite understand how fleam can be filed with the file not angled either right or left. However, I know an experienced saw filer who says that he depends on filing sloped gullets to get the fleam. Without actually doing it, I'm picturing it in my mind and I can see that a bevel would be filed on the side of the teeth that the file is angled downward. Stewie does not mention anything about rake angle though. I'll guess that he did his rake angle when he shaped the teeth.


Hi Marv. As you rightly guessed. The rake angle was done during shaping.

Stewie.