Question on progression of grits

G

glarmore

Joined
Oct 7, 2006
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When I grind, I tend to do everything at 36 grit. Afterwards, I move to 120, 400, and then hand sanding.

This can leave quite a bit of hand sanding. What does everybody else do. The finish I go for is hand rubbed.

Thanks,

Glen
 
Well, here is what I use. 60 ceramic, the rest are all Norzon or Trisact and are 180, 100, 75, 45, 30, 16, and 5. BUT, I do all my grinding after heat treat and make only folders. Frank
 
If you don't like to hand sand as much, get a finer finishing belt. Just know that those really fine belts wear out pretty quickly if you try to remove big scratches with them.
 
I start at 60 for large blades and 80 for folders and then 120, 220, 320 then hand sand typically starting with 220 or 320. 36 just seems to leave too many scratches for me and it only save a couple minutes of grinding. I did use 36 on some Axes since I had alot to remove.
 
I only make fixed blades so I start at 50 or 60 then go to 120, then Trizact 300 and 160.
Heat treat, then Trizact 160,65 and 45 then go to hand sand.
 
I use a 60 grit for 1/4" stock or an 80 grit for 5/32 and thinner,then 120,220,400,and to hanks sanding. 36 grit will leave some scratches that are hard to get out.
Stan
 
I tried starting with 36 to rough in my grinds tonight. I had picked up some 36 grit Blaze from Tracy, and boy do they take off metal! From the 36, I went to 60 Blaze, then 120 Blaze, and I knocked down the scratches with a 600 grit equivalent Trizact before heat treat.

After heat treat, I'll clean things up with a Trizact 120 equivalent and then go to 400 or 600 before sanding out.

Your hand sanding may be taking forever because of the deep scratches left from your 36 grit belt. I dont' know if you're getting them all out with your 120 before progressing to the 400. I imagine you're probably just hiding them with a finer scratch pattern, and they don't show up until you start sanding. Try an intermediate between the 36 and the 120 to remove more material before the higher grits.

--nathan
 
I'm no expert, but I've used 36 before in this order: 36, 60, 220, 400, 600 with a good machine finish as the result. I make folders mostly and usually just start with a 60 grit and go up from there instead, the 36 just takes too much off too quick on a small blade with my grinder.
~JW
 
I will tell you that 36 grit works REALLY fast on a forged to shape blade with bevels and tapers already forged in as well. :D I seriously made maybe 10 passes per side to true up my bevels and remove all forging scale and marks before moving on to 60 to finish my bevels up to the spine at the plunge. All those makers who have in the past suggested that a few extra minutes at the anvil save lots of time at the grinder were absolutely correct (not that I doubted ;) ).

--nathan
 
The problem is 36 grit grooves left behind when you jump to 120 grit. That would be the same as going from 100 grit to 400 grit in one step ( actually worse). Put a 60/80 grit step in the and you will see a lot of improvement. Also, it will do you no favor to move on to the next grit until all the previous grit marks are gone.
 
:thumbup:Thanks for the input. It looks like I have at least two problems causing me to take a long time hand sanding. First is jumping from 36 right to 120 grit. I think that I am just hiding the deep scratches. I will add a grit in between. The second is that I am heat treating after just 36 and 120 grit. This not only leaves me with hidden, deep 36 grit scratches, but they are hardened as well.

Thanks,

Glen Larmore
 
glarmore said:
:thumbup:Thanks for the input. It looks like I have at least two problems causing me to take a long time hand sanding. First is jumping from 36 right to 120 grit. I think that I am just hiding the deep scratches. I will add a grit in between. The second is that I am heat treating after just 36 and 120 grit. This not only leaves me with hidden, deep 36 grit scratches, but they are hardened as well.

Thanks,

Glen Larmore
Click to expand...

I think you just answered your own question! I would take the scraches down by at least two grit progessions, then heat treat, if that is how you want to do the process, but the 36 - 120 is leaving to many scratches for HT at that point! :)
 
Could be my imagination but I've found that the 40grit blaze eats steel nearly as fast as a 36 but without leaving the pesky deep scratches that show up after finer grits. I do grind a few passes on an 80 then to 220.

-Josh
 
Time to buy more belts. Thanks for the info everybody. I was going from 50/60 to 120. I'll add some 36 and 80 to the mix. All this hand sanding is killing my wrist(broken a long time ago while skating).
 
Guys

Since no one specified which grit grading system you are referring to, I'll just include this link to Klingspor technical section and their chart of the different grit systems.

http://www.klingspor.com/gritgradingsystems.htm

NOTE, if you jump from 400grit on the CAMI scale to P600 on the P-grading system you just went to a coarser abrasive.
Inquiring minds want to know!
Jim A.
 
This is what I'm using now:

40, 80 & 120 grit 3M 977 ceramics --> 220 gators --> A65 Trizacts

From this point, if flat ground, I'll go straight to hand sanding. If I'm hollow grinding, I'll often jump into A45, A30 and even A16 Trizacts.

These may change... I'm thinking about getting a batch of 50-grit Blazes from Tracy as he has a quantity discount that makes them comparable in cost with the 977's that I get from Pops. I also may try the Gators at 120-grit just for fun and pick up some Norax belts for the finer grits... just for comparison.

Erin
 
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