Thread: Scraper edge pictures

1095 scraper - hock burnisher (supposedly O1 at 64 and I have no reason to believe that's inaccurate).

First step, making sure both the base and the edge are honed well and clean. A washita stone is convenient for this. I file the bevel side of a scraper about 20 degrees off square and just give up one of the faces. It makes this process easier. Then, hone the edge on the bevel side about 10 degrees off square. More or less a micro scraper bevel. Quality of this edge is important - more important than saving $2 a year or a scraper.

The washita is nice because it will do a very good job quickly -oilstones might be a little slow, but they aren't when the subject steel is not very hard. they're only slower on chisels and such because the hardness of the abrasive and the tool can be close together.

Capture - honed.jpg


The pictures for all of these are the flat face and not the bevel side. 150x optical, with the height of the picture about .019" or just under half a millimeter for people who don't like inches.

the next is after drawing out the face. I don't know what people do here typically, I lean the burnishing rod a little and don't spare the pressure too much. About 10 fairly heavy strokes? i don't know- five seconds or so. You can see that it rounds the edge over a little , face toward bevel, and there is some burr forming at the edge. point here is that turning this burr shouldn't be that hard and it should leave a neat little line where it leaves on the last picture. you can see the effect of the burnisher on the steel. If a scraper is too hard, this doesn't occur and you end up not getting any better edge life as a trade off for the hardness. BTDT after making stainless scrapers in the mid to upper 50s hardness and using carbide. I could not move the steel and the life at the edge wasn't really that much better.

Capture - scraper front drawn.jpg

Now, for the next picture, I apologize for the light levels, but a metallurgical scope is made to feed light down and see it coming straight back up. Angles going other directions just spray the light off to some area where the top tube doesn't see it and you see black.

If you look very closely at the edge of this picture - this is AFTER the burr roll from the bevel side. One light pass across to feel it and to turn it, to make sure it's uniform, especially if you might finish right off of a scraper. if you feel little nits, they will show up on the surface. very smooth means very smooth surface.

After that, then it's just a matter with angle and pressure, how much burr you roll. I remember one of the things that dave barnett said long ago was make sure not to roll a gigantic burr over so that you have to lean the scraper a lot - not on the first burr in a filed edge cycle. if you do that, you're sort of stuck. the next time you roll a burr, you're kind of out of angle and space. Or as he put it "where are you going to go with the next burr" if you don't have some additional angle to roll into. Doesn't mean you have to roll a tiny burr, but don't chase bad prep into bad use by trying to go ever harder and steeper to get a burr.

Capture - scraper burr rolled.jpg

How do you see the actual burr? Look at the very very edge - there's a tiny black area (curved metal) and then what looks like a tiny wire edge. it's not a wire edge, though, that is the part of the burr that is looking toward us. it's washed out in the middle due to the light level, but it's there.

If that edge is tiny like it's shown here and very straight and even as it is - even though it doesn't show up that well - everything will work neatly.


I think this is a great territory for oilstones, but it takes about a washita, or soft or cheap hard arkansas to do it.

The bonus is you do all of your post file prep quickly (30 seconds?) when establishing the first edge and then even after you wipe off the edge, you still have enough oil to roll the burr and not tear it.

if there is any dirt on the edge or any poor conditioned areas on the burnisher, they will tear this edge up, and it's critical.

total time to file and hone set an edge and burnish is probably 2 minutes, and you'll be able to refresh the burr four or so times before it starts to get ratty. Ratty meaning it ran into something and got damaged and didn't reroll well. It's false economy to keep trying to roll it when it's probably starting to look like a serrated knife from being beaten up - it doesn't last.