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Low grit & vertical vs horizontal


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My usual finish on a blade it 400 grit and then some polishing on the buffing wheel, occasionally I'll go to 800 grit before buffing.

Jason Knight mentioned in a video that he does a 220grit finish that looks better than most, and that got me thinking.

 

The last hunting knife I finished I took a big chance on my grinding skills and did the final finish on the bevels on the wheel and sanded the flats.  It looked better than my usual finish, and the reactions of others proved it.
Also finished a cleaver in O1, a gift for my cousin, so I decided no way am I spending days sanding it, so it got a vertical finish using a Scotchbrite fine belt.

Same story, much lower grit finish, but the final product looked good, arguably better than 1 of 4 and 2 of 4 that were sanded to a horizontal 400grit finish.

I stuffed up the Scotchbrite belt in the process which is quite an expensive mistake, but I'm getting more first opportunity I can.

Interested in hearing opinions.....

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I think the finish of a blade is mostly a matter of taste. You decide where you stop. I have also seen gorgeous crisp edges belt grinder finishes. Some makers are insanely skilled on the 2x72...

 

However, I'd be curious to see corrosion resistance tests done on carbon steels comparing lower grit+Scotch Brite vs higher grits. 

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For a while, I was using the Scotchbrite belts on any hollow ground blade I made. It was the only way I could figure out how to finish them. Then I moved to Trizac A45 belts, as I was using them to set the plunge lines and figured I would just use it on the whole blade (flat and hollow grinds). 

 

Ultimately, I think Joel is correct, it's a matter of taste. With the horizontal finish, it is critical that your last sanding passes are uniform and parallel or it doesn't look right. I have done the final vertical finish on flat grinds using a disc sander with a rubber pad from 220 up to 600 grit and the look can be fine. I still do a variety of finishing techniques and grits, depending on how I feel, what the blade is, or just how much effort I think needs to go into any particular blade.  I now keep 2x72 belts up to 600 grit on hand. Do I use them on every knife? Not even close, but sometimes I take the bevels to 400 on the belt. It really depends on conditions.

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a higher polish is a bit more resistant to rust but if you leave a 1000 grit finished blade out with a 200-400 grit blade in the rain they will both get rusty. deeper scratches will hold moisture and gunk, gunk will attract moisture and if your blade is oiled the moisture can still wick through the gunk and start rusting the blade. fun fact: a blade with too much oil will get covered in dust which will wick moisture to the blade, this is how a blade can rust if it has been sitting in a drawer untouched for some time. blades dont need much oil if they are wiped down after each use to remove debris and moisture.

 

i have been doing 400 grit trizact finishes, i try to keep all the sanding marks going the same direction just like hand sanding and remember to check for deep scratches because they are harder to see when you are finishing a blade with a belt grinder. sometimes i do some handsanding afterwards, usually starting with 220 grit sandpaper after 400 grit trizact.

 

"soft" belts (i mean any thick belt, scotchbrite, tricazt...) might make your bevels a little less flat which you can see in the light reflection of a blade.

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  • 2 weeks later...

Thanks for the replies, I have 4 trizacts, 2 x 1" belts and 2 x 2" belts in the medium and fine.....can't remember the numbers.

They were my secret with the hunting knife I mentioned, can't do the same with the other belts I have.

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