got a couple of knives in from a friend to sharpen/repair.....they're in rough shape....here's a sample:
So I have a couple of questions...
1) last time I worked on a broken tip, everyone said to work from the spine down. How does one do that w/o creating a bevel on the spine? Grind the knife against the stone perpendicular to the stone? Would this be a good task for the steel flattening plate (#150)?
2) What's the best way to get those massive chips out? Something similar to the spine? (grind it perpendicularly on the flattening plate)
Any other thoughts? (I don't know the details of the abuse that led to this...)
I can't quite make out the brand....here's the best photo I could get of the maker's mark:
A chipped shun, who would've guessed.
It's a Shun, most likely vg-10. Just put tip of the spine down on a diamond plate and start pushing and pulling away and towards yourself until the spine reaches the edge or is about 1mm away. Then just start on a low grit stone and sharpen as usual until the chips are mostly gone. Move up to a 1k stone and just sharpen as regular up to 5k then strop.
You can even take a magic marker and draw on the knife the new curve down to the edge as a template to follow. You kind of have to start back a bit to keep the tip natural looking.
For both spine and edge I would use automotive sandpaper, grit P120, 90 degree with the spine. With the edge, I would suggest an edge trailing motion under some 80 degree.
the problem with fixing the tip by grinding down the spine is are you not going to completely change the look of the knife with a very triangular tip? Or is that just something you have to accept if you break off a tip?
You gotta blend it in, which means grinding quite far back from the tip as well
Originally Posted by vicv
My knives don't look like that and I've broken many a tip. You just have to start back far enough to make it blend naturally. In this particular case I would start about halfway back in the first image shown.
Originally Posted by vicv
That's what I thought. I did it once on a cheap knife with a belt grinder before. It worked and fast but looked funny afterwards. As far as the chips though I also used my grinder before perpendicular then thinned the edge back out. Worked quite well and put actual edge on with stones. That was easy. Fixing a tip takes a lot more skill.
Here's a little bit better idea of what needs removal. Still this is by no means exact but a basic guideline.
It is a good bit of removal still but keeps the profile basically the same.
Thanks guys...I'll think on it and give it a go next weekend....will be interesting to use the diamond plate in this way.