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Dead file vs. stone?

homebrewed

Active Member
Active Member
#1
I've seen much in the forum regarding the use of a stone to de-burr work that has been scraped. Nothing on using a burr file, at least in recent history. I've been using a burr file but have a soft Arkansas stone if I need it. I could be opening a can of worms here (or starting a religious discussion), but I'm curious about opinions of stone vs burr file. Or when one would use one as opposed to the other. A burr file shouldn't affect the surface much while a stone could (would?) remove some material; but maybe that's not all bad.

I got a CD "how to scrape" from LMS & that's where my main source of knowledge about scraping has originated. The home shop machinist series on the subject seems pretty good too. Wish they would turn that into a book.

Mark
 

benmychree

John York
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#2
I use an India stone to deburr, and so does Rich King. I ground a bevel on one side so as to fit into dovetails, it is about 3" square and 1/2" thick and was part of a Noeton three stone knife sharpening stone.
 

brino

Active User
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#3
Hi Mark,

I have nothing to add in answering your question, but just stopped in to say:

Welcome to the the Hobby-Machinist!
-brino
 

terrywerm

New Member Liaison
Staff member
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#4
The retired machine rebuilder that I learned from also uses a stone, as do all of the folks that I know. You have to remember that when you are only taking off a few ten thousandths per pass, the burrs are quite small but must be removed just the same. The stone is also used lightly on the work, and the amount of material removed with a fine stone would be miniscule at best, even compared to the amounts that we are talking about with scraping. All the stone has to do is lightly hit the surface to break off and remove those tiny burrs.

Now, a burr file may work just fine, and if it works for you, I would continue with it. Burr files are something of a rare item but stones are easy to come by.

What if you were scraping a dovetail on a mill knee or table, for example? Finding and using a very thin wedge shaped stone might be far easier than coming up with a burr file that will fit into those tight areas.
 

mark_f

Global Moderator
Staff member
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#6
Back when I worked for a major machine tool manufacturer, the scrapers used both. The files they used would be hard pressed to remove metal. They were not ordinary files. They scraped large cast iron ways up to 10 inches wide and as much as 40 feet long. They used a file when rough scraping but always went to a stone to finish. I learned to scrape at the factory but never enjoyed it. It also seemed every one of those guys had different options on how to do it. It is a lost art.
 

homebrewed

Active Member
Active Member
#9
Okay, I have to ask ... what is a burr file?
A burr file starts out as a regular flat file. It is placed flat on a stone then run back & forth to remove the sharp edges that would normally cut metal. The result is a file that will only catch small burrs that are on the surface of your work. To answer dlane's request for a photo, these things look exactly like a regular file. You'd have to know what it was, or figure it out when you notice it is a pretty crappy file :)
 

homebrewed

Active Member
Active Member
#10
The retired machine rebuilder that I learned from also uses a stone, as do all of the folks that I know. You have to remember that when you are only taking off a few ten thousandths per pass, the burrs are quite small but must be removed just the same. The stone is also used lightly on the work, and the amount of material removed with a fine stone would be miniscule at best, even compared to the amounts that we are talking about with scraping. All the stone has to do is lightly hit the surface to break off and remove those tiny burrs.

Now, a burr file may work just fine, and if it works for you, I would continue with it. Burr files are something of a rare item but stones are easy to come by.

What if you were scraping a dovetail on a mill knee or table, for example? Finding and using a very thin wedge shaped stone might be far easier than coming up with a burr file that will fit into those tight areas.
Thanks for your comments. It sounds like I should keep my eyes peeled for some wedge shaped stones.

BTW burr files don't appear to be difficult to make (I made one myself). Start with a regular file and knock the cutting edges off with a stone. So a triangular file with the right profile _might_ work for dovetails, but holding it flat AND getting into the corners could be a pain in the butt.
 

mikey

Active User
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#11
A burr file starts out as a regular flat file. It is placed flat on a stone then run back & forth to remove the sharp edges that would normally cut metal. The result is a file that will only catch small burrs that are on the surface of your work. To answer dlane's request for a photo, these things look exactly like a regular file. You'd have to know what it was, or figure it out when you notice it is a pretty crappy file :)
Never heard of a file being used this way. Draw filing, yes, stones to remove burrs, yes, but nothing like this. So, if you grind the teeth off then I assume the idea is that the sharp edges of the flats you create do the cutting instead of the original crests of the teeth, correct? Hunh, learn something new every day.
 

Bob Korves

H-M Supporter - Premium Content
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#12
Never heard of a file being used this way. Draw filing, yes, stones to remove burrs, yes, but nothing like this. So, if you grind the teeth off then I assume the idea is that the sharp edges of the flats you create do the cutting instead of the original crests of the teeth, correct? Hunh, learn something new every day.
It sounds like a similar idea to the flat ground precision stones that Robin Renzetti has got us all psyched up about...
 

mikey

Active User
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#13
Well, there's flat and then there's flat like you guys are doing. I have always used a translucent Arkansas that was trued on sandpaper on a tempered glass plate and that has served me so far. Nothing like you're doing, though, Bob.
 

homebrewed

Active Member
Active Member
#14
One advantage of a burr file is that it can be used dry, no need to lubricate it like a stone. Of course, you still have to clean your work before marking it again.

Still, it sounds like I need to get out my tempered glass plate to flatten/refresh my Arkansas stone. Hopefully I will get to a point on my surface gauge where I can switch to the stone.

Mark