Sorry for the vague subject heading.

I'm wondering if someone here can give me an idea as to improve on my grinding results.

I'm at the point where I can grind most any shape, bevel, etc with fair success. My big passion has been double-hollow-ground daggers and fighters, and flat ground bowies.

I get the sharp center lines I want, and I can get the blades finished out like I want to, but I think it's taking waaaaaay too long.

I read somewhere that most guys doing hand-rubbed finished like mine go from the grinder to 400 grit paper.

I'm finding that I need to start around 150 to get all of the scratches out. Which makes it even more time consuming to ensure I keep sharp grind lines.

On stainless I grind it 60 then 120 then off to Paul....upon return it's usually 60 or 120, then 240, 320 or 400, 600, trizacts.... Why in the heck am I still left with scratch marks????

On the rare occasion I mirror polish, they seem to buff right out.... This is happening on my hollow and flat grinds.

I've tried pushing really hard (harder to control), I've pushed with medium pressure, and I've used very very light passes...all with this same result.

I finish ground a recurve dagger last night. I took it down with a 50, a brand new 240, a new 400, a new 600, and then an A16. I've had to go to 150 to get some of the cross scratches out.

Suggestions??? And yes I'm getting good contact to the wheel, I don't have wavy grinds.

Help??? Please? Thanks :)

Nick

After heat treating you want to avoid coarse grits entirely, nothing lower than 240 grit. Put a scratch in un hardened steel and it comes out easily but put a scratch in hardened steel and you have the devils own time getting it out.

Nick, If you'll go to this link you'll find out everything I know about polishing.

pub42.ezboard.com/fcustom...D=23.topic (http://pub42.ezboard.com/fcustomknifedirectoryforumfrm5.showMessage?topicID =23.topic)

I just "polished" an S 60V blade yesterday (All day long....) and then hand sanded it. I know better, now, than to heat treat before polishing!!

Anyway, I usually pretty much ploish the blade, stopping short of buffing, then sand it, with whatever grit I like; usually 600 X or finer.

My belting stages are:
Grind after heat treat with 50X (Which I used prior oto heat treat, also.)
Go over it with a new 400X, removing all 50X scratches
Go over that with a 400 X Cork belt
Then finish with a 600 X Cork belt
Then buff with SS306 RCH compound for 2-5 min., depending on how large the blade is, as related in the link above.
Have fun!

Thanks for the replies.

Thanks for the heads up on the link Steve. I think one problem for me might relate back to that thread Ricardo started on wheel durometer.

I really appreciate the help. It's really frustrating to be trying to make daggers that have that "cut-yourself on it" centerline where the bevels meet and realize you still have scratches.

I sure wish I could come be a fly on the wall of your shop Steve. I'm going to give that 50x to 400x a shot and see what happens.

Thanks again!!!
Nick

I use Steve's method of going from a 50 grit to a 400 grit. It is an excellent technique. There is no missing any scratches due to the belts being too close in grit size.

There isn't anything to be gained, in my mind, by going through 4-5 different grit sizes, before your reach 400x. Like Bob says, it's easier to remove a 50x scratch with a 400x belt because the 50x scratch is more easily seen while working with the 400 x belt.

But.........everyone had to do it the way it workd for him, that's understandable. Ya gotta feel comfortable with your techniques.

I started progressing from 60 grit to 220 grit for another reason, but I stuck with it because I like the overall results much better. When I used an 120 grit belt in between, I found that I was removing too much material prior to establishing good plunge cuts with a flexible belt. What I found is that I was wasting my time and money on the 120 grit belts because a sharp 3M 707E belt (what I use) works faster in the long run anyway. I wish someone made a good ceramic 400 grit belt (let me know if someone does). The 400 grit belts I've been using are great for cleanup, but don't seem to make the transition from 60 grit very well, at least not for me. This is what has been working for my flat grinds as I only recently began experimenting with hollow grinding on my new machine. In many aspects grinding is grinding, but I've noticed the techniques are quite different (I may be going about it wrong :) ), and I'll probably be experimenting for a while.

Brett

Hey, what works for you works for you. We are all always experimenting. That's what is so great about the Forums. We can hear of a different way of soing things, try it and either use it, or go back to our old ways, which may be better for us. At least we can see what works for someone else and use it if it's appropriate. Keep sharing your ideas and techniques. Thanks!

Thanks for all the help guys. The bottom line is practice, but it sure is nice to be able to come in here and ask for advice from so many people.

Brett, a collector that bought a dagger from me came by the house the other week, he had bought a knife from you...GREAT work. Your style is very similar to mine, and he said you were about my age too (he thought).

Thanks!
Nick

Some great information here. Another little trick that works for me is that I spray the blade with a thin coat of the of Steel Blue DYKEM spray layout fluid each time I move to a finer grit belt. The coating will stay in any scratch or low spot and will be very visible, letting me see any scratches left in the blade from the previous belt. When you are finished with your grinding any coating still on the blade is easily washed off with acetone.
Mike

Thanks for the tip, Mike. Sounds like it'd work.

Nick,

I talked quite a bit with Murray during the PKA show and he showed me numerous knives, including that fine dagger of yours. Did he tell you that he initially passed over my table because I didn't have prices on the cards next to the knives? One of the many things I learned from him.
I think we are about the same age. I'm 28.
I've noticed that our styles have a good bit in common, as well as our finishes.

Brett

The layout fluid trick is neat. I'm going to use it for a while...

Funny, I use the stuff "blue dinkum" on motor heads to see how far I've cut the ports out

Is that different than "Dykem Steel Blue" or the same thing? Paint on or spray?

The trick of coloring your scratces is a good one. I don't know if it will work on stainless, but what I do on carbon steel is give the blade about a 5 to 10 second dip in 3/1 ferric chloride between grits. Will color the bottom of the scratches dark grey. Seems to me that my dykem would sand off before I got completely through the scratch. With acid the scratch is pretty visible till it's gone. The etch is too light to affect the finish on the blade itself. Anyway ya'll can try it and it might work for you. be careful mike

Probably wouldn't work on heat treated SS. However, lots of guys polish before heat teat and it might etch enough at that point to work.
Thanks.

It's the same stuff, sorry brain cramp. www.dykem.com/Products/Ma...youtfl.htm (http://www.dykem.com/Products/MarkingSystems/LayoutFluids/layoutfl.htm)
it comes in different colors and it can be spray or paint I think they make markers now too. I think 3m makes a similar product as well. Most tool companies will have it MSC, Travers etc.

That marker would come in handy now and then, also, to cover a slip-up or a miss-scribed line, in laying out a knife.

They do make them, look around at the link I left, just be careful not to get a permanent metal marker!

Interesting. They have a heck of a lot of products there. I'm going to locate one of those markers in blue.