Need belt recommendation for hollow grinding above 220 grit?

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REK Knives

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I see some very nice hollow grinds on customs I get in from time to time, very clean. I can get good hollow grinds up through 220 using ceramic belts and they look nice and clean, but if I go above 220 I have to switch to something like the gator trizacts which, because of their thickness, they have some give to them and end up causing convexing right behind the edge and then near the grind line area instead of a full clean hollow grind all the way through.

Not needing to go real high, maybe just 400 or 600 grit.

Wondering if you guys have any recommendations... Thanks for any and all input!
 
Josh, You may want to try Norax X65 and X45 belts after 220 grit to refine your hollow grind. If you are not going for a high polish then try a 400 or 600 cork belt from Hermes at Tru Grit Abrasives. I always keep these belts handy and they are useful. Larry

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I think you'll really like cork belts :thumbup: They also last forever and a half! ;) You should pick up a couple cork belts as well as some Norax belts as Larry suggested. You could also try the "non-gator" trizact belts, as they are much thinner.

~Paul
My YT Channel Lsubslimed
... (It's been a few years since my last upload)
 
I'm with Larry, on this one. When I was doing a lot of hollow grinding, I really loved the finish I got with Norton X series belts. 3m Micron are great, too, but they don't last long. That's not a problem if you did your previous grit progression properly, and only becomes a problem when you have deep scratches that weren't worked out ahead of time.


LARRYZ10 said:
Josh, You may want to try Norax X65 and X45 belts after 220 grit to refine your hollow grind. If you are not going for a high polish then try a 400 or 600 cork belt from Hermes at Tru Grit Abrasives. I always keep these belts handy and they are useful. Larry

vUcbKh2m.jpg
Click to expand...
 
Alright so I tried the x65 after my 120 on 2 knives now... For some reason I keep getting variation/waviness toward the tip. It was hard to photograph, but here it is. This isn't the only part (grind to flat) but it also happens along the spine in the grind itself near the tip. When I switched back to a ceramic 220 no issues and it was nice and clean. Here is a pic of the issue on a Swamprat Jackmandu, and the final result after the ceramic.

I think I am going to try the micron belts next, they may be the ticket... the trizacts and I'm sure the cork will give the effect I am trying to shy away from - i.e. a hollow grind with convexing going on at both near the edge and near the grind transition to the flat.

i-tTfcXvQ-X2.jpg

IMG_20160610_200155-X2.jpg
 
I would suggest trying some of the higher grit klingspor j-flex belts. They are nice and thin belts so you won't have to worry about the "convexing" effect, and they leave nice finish as well, although I have only gone up to 400 with them, I haven't tried the higher grits... yet. But I still say they are most definitely worth a try! Of course they won't last as long, but they aren't as expensive either. :thumbup:

Beautiful clean grinds as always man! :)

~Paul
My YT Channel Lsubslimed
... (It's been a few years since my last upload)
 
Is it possible your problem is due to inconsistant pressure on the blade as you go across? I often find my now weaker arms and fingers can give some odd results.
Frank
 
Frank Niro said:
Is it possible your problem is due to inconsistant pressure on the blade as you go across? I often find my now weaker arms and fingers can give some odd results.
Frank
Click to expand...

Yes frank, inconsistency on my part could always be an issue :) but the problem seems to disappear when I switch to a different belt for some reason. Maybe because it cuts faster and therefore hides my inconsistency? Dunno...
 
I think you should embrace the Trizact Gators. The great thing about them is that the structured abrasive is the same thickness regardless of grit. That keeps your overall grinding radius consistent as you work through. I rough grind with a Blaze 50 and then go to a Gator A160, then A65 and A30. The A30 is about a 600 grit finish. If I'm going to hand finish the blade, I will then use a cork belt but, for a nice clean "as ground" finish the A30 is it!

Bob
 
RangerBobTX said:
I think you should embrace the Trizact Gators. The great thing about them is that the structured abrasive is the same thickness regardless of grit. That keeps your overall grinding radius consistent as you work through. I rough grind with a Blaze 50 and then go to a Gator A160, then A65 and A30. The A30 is about a 600 grit finish. If I'm going to hand finish the blade, I will then use a cork belt but, for a nice clean "as ground" finish the A30 is it!

Bob
Click to expand...

Bob, I think you may have nailed it... I have always used a really flat belt (like a Norton r823 or similar) up through 220 grit and THEN tried to switch to the trizacts which causes convexing in the two areas mentioned above because the trizacts are so thick. I think if I started at a lower grit w/ them, like A160 that would START with forming the hollow grind to the trizacts and the progression would be easy and clean at that point. Thanks for pointing this out!!
 
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