Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 1:10:06 GMT
I decided to try the sharpening method given in the forum (filing with metal file followed by multiple grades of sand paper). I started with a junkie bolo that could cut a pool noodle if hit right. It was ugly and not well taken care of, bent and twisted with undulations down the blade- good practice piece. I had previously put a rough edge on it with a file and 400 grit and could snip little branchs witha flick, could cut through newspaper rolls, etc.... I figured that I could clean it up well and get a better (professionalesque) edge. Oops.
I started out with a file and tried to keep 30 degree angle off the sword. I went through (220, 400, 600, 800, 1000 and 2000, followed by a metal polish) I was doing okay through 600 grit or so. I would reach over and run it down some cardboard that the sandpaper came in and I think it was getting sharper; it appeared to be anyway. Somewhere along the way, the bolo became dull. I think I started losing the edge around the 800 or 1000 grit.
In the end, it wouldn't cut the carboard and would only dent the pool noodle. It would cut through a branch that was a little over an inch.
So, understanding that you can't see my bolo, any idea where I might have went wrong? Does it suggest an error at the filing stage that just came out in the end or did I round off the edge as I progressed throught the sandpaper? Should I start over with the file? 400? Your wisdom is appreciated.
May it be blessed, Todd
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 1:46:56 GMT
If I had to guess, I think there is too much haniku. The edge, even if it has a rounded slope, could be too thick.
Like the difference between a V and a U. Each is just as thick as the other, but the V is a sharper angle.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 1:51:25 GMT
Almost throughout the process, I would feel a burr. It would move from side to side as I polished. I was gone at the end of the process. FWIW.
If what you say is true, too much haniku, I should go back to the file. I probably should refrain from any rocking while polishing or I'll end up in the same position. Just guessing because I have no idea what I'm doing!
Todd
|
|
|
Post by randomnobody on May 17, 2010 3:19:00 GMT
It does sound as though Hyoujin may be right in that your edge is simply to fat. Pool noodles, especially, require a near-razor-edge. Cardboard, well, that depends on the thickness...but tree branches etc. are better off with a fat blade. What you want is probably a compromise; if you did 30 degrees, go back and try maybe 25? Just a thought, I'll shut up now.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 3:54:01 GMT
I doubt you need to go all the way back to file working.
I would say you could probably jump in at the 400, unless really feels dull, then go with the 220. You might even be able to start with the 800. I would suggest get a good close look. Well lit if needed get a magnifying glass and look at that blade edge. Did you give it more U than V, how much do you need to do to fix that little bit? Probably not much really to fix. One thought if it dulled so much would be did the bur fold over rather than break off?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 4:28:46 GMT
Hmm...Good ideas all. I'm going to get out the magnifying glass and see what's going on. Maybe I didn't do so bad after all. I'll update later. Thanks.
Todd
|
|
|
Post by Dan Davis on May 17, 2010 12:19:57 GMT
I suppose that the blade never got sharp at all and the reason was as Kevin said: ha-niku ( literally "edge meat", too much thickness). If you started at a 30o angle and rolled the blade up on the edge then you polished the edge blunt.
The burr you were feeling was "flash" or a sharpening burr and the fact that you could feel it tells me it was substantial. I see this a lot with home-sharpened blades; the blade cuts really well until the fine grits where that burr is removed, then it "gets dull". Reason: on the previous sharpening tests it was the burr that was starting the cut, not the edge. That burr is only 1-2 molecules thick and cuts like a razor. Remove it and the edge turns blunt.
How to get rid of the burr: in between grits run the blade over a buffing wheel with white rouge on it, or strop it with an old-fashioned razor strop. Then clean it and check the edge. Get a magnifying glass.
edit: Sorry, this took a bit long to post and I see others had already posted much the same information.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2010 17:24:43 GMT
Dan,
I think you got it exactly right. I was suspicious that this is what was going on. I looked at the blade this morning and ran my finger down the blade- dull, no feeling of sharpness at all. Didn't get to use the magnifying glass but I couldn't feel any remnants of a burr. It seems that I polished the edge dull. I was wondering if the burr could have been the cutting "edge" and you're thinking the same thing.
I'll try it again at 25 degrees and really watch any rocking. I was lifting the blade up slightly as I drew it back over the sandpaper.
The blade isn't all that thick so I have to be careful once I establish the edge. I am also wondering just how hard this steel is. It's a cheapo agricultural bolo given to me by a friend; they picked it up in the Philipines. Prior use caused chips in the edge. Is it possible that I used too much pressure when sharpening? Could this combined with the rocking have done in the edge? Thanks.
Todd
|
|