Surface Conditioning Belts?

Sgt_Bobbo

Sgt_Bobbo

Joined
May 21, 2012
Messages
344
I have a couple of new surface conditioning belts that are course and ultra fine and I have a question about how to use them. I hand sanded to 120 grit then used the course belt then the ultra fine belt. The issue is that the blade looks incredible dull and even though I am using the belts vertically (from spine to edge) I am also getting horizontal scratches in my blade. What am I doing wrong? Do they need to be broken in or loaded with compound?

Thanks for the help.
 
I can tonight. I already stopped using them on the current knife I am making and went back to a hand sanded 120 grit finish.
 
If you see horizontal scratches after vertical buffing, they are old scratches that you haven't sanded away. The last sanding needs to be finer than 120 grit if you don't want to see scratches. I use 220, done on the belt grinder. If doing it by hand, it is done in the same direction that the belt will run, or it will likely show the lines you see. Surface conditioning belts are great for a machine finish, but won't cover up bad or incomplete sanding.

Also, I use one or the other, but not both belts. Once you have used the coarse belt, the fine will only polish down the coarser lines and make them muddy. I use a medium ( maroon) for most all blades.
 
I really appreciate the feedback. I will had sand to a 220 grit belt in the same direction I will use the ultra fine belt. I dont have the skill to go to 220 grit on the grinder yet, I get uneven lines.
 
So you have a tan belt and a grey belt? You may want to go up to 320 for the grey belt.
 
No. Blue is fine.

Tan - coarse
Maroon - medium
Blue - fine
Grey - super fine

220 > blue belt should work fine.
 
Good plan. If the ultra fine doesn't do what you want ( I find it looks a bit "washed out" and uneven), follow with the coarser belt. I have coarse,medium, and fine (brown, maroon, and blue)
 
Has anyone tried coarse? Its seams like that might be perfect for removing scratches. I don't know who sells them either. I have some for my 5" grinder so I guess I could give it a try.

The coarse ones are great for light grinding on aluminum since they don't clog. They remove material way faster than you would think.
 
I have a coarse belt. It cleans up a 120 grit surface pretty nicely. I mostly use it for knocking light rust off stuff, since everything in my shop rusts unless it's at the bottom of my quench tank.

But, what I've been doing with it lately is when I get an oil quench knife rough ground, and ready for heat treat, going over every surface with the brown belt, so there's a nice uniform finish and no sharp corners. More as piece of mind than anything. Then again when it comes out of the quench so it's nice and clean to put into the temper oven.
 
I tried it again last night and decided to keep all of my hand sanding length wise (from tip to handle) for ease. I sanded up to 220 grit then threw on the blue belt and ran it the same way. Worked like a charm and looks great. Thanks everyone.
 
Ive been hand sanding my flats the length of the knife up to 400g, and the bevels on the grinder (perpendicular to flats) up to 220 or 400.. after I get the bevels the way I like, I hit the bevels with a blue fine conditioning belt until its a nice even finish, this makes scratches on the flats obviously 90 degrees to my hand sand finish. Then I will do a quick hand sand on the flats lengthwise again being careful not to hit the bevels, otherwise I start over haha. I like the perpendicular grind lines even though its a pain.



This one below had a quick buff to it also but hand sand lines are still present

 
I use a fine scotchbrite loaded with black compound after progression: 60, 120, Trizact- a160, a100, a65, a30. On plungless kitchen knives i do the final vertical finish on a large wheel, being super careful not to stop anywhere during the pass. The passes are LIGHT.

IMG_20180823_141554765.jpg IMG_20180823_141803298_HDR.jpg
 
Maineiac1 said:
Ive been hand sanding my flats the length of the knife up to 400g, and the bevels on the grinder (perpendicular to flats) up to 220 or 400.. after I get the bevels the way I like, I hit the bevels with a blue fine conditioning belt until its a nice even finish, this makes scratches on the flats obviously 90 degrees to my hand sand finish. Then I will do a quick hand sand on the flats lengthwise again being careful not to hit the bevels, otherwise I start over haha. I like the perpendicular grind lines even though its a pain.



This one below had a quick buff to it also but hand sand lines are still present

Click to expand...

Do you use a jig to grind your edge bevels? Reasion I ask is the edge bevel grind lines are running vertical and do not sweep with the edge.
 
JTknives said:
Do you use a jig to grind your edge bevels? Reasion I ask is the edge bevel grind lines are running vertical and do not sweep with the edge.
Click to expand...
No jig, all freehand. Yes I’ve noticed that with a couple I’ve done like the bottom picture. I’ve been able to fix that since. Too one actually micrometers right on the full bevel length. I’ve found when I scribed my lines I wasn’t scribing them right so they were tapered a little
 
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