Help With Polishing

[BePrepared]

I am trying to learn how to put a decent looking finish on my blades

I have a Craftsman 2/3 hp 4x36 belt/disc sander with 200,400, 600, 800, and cork belts

i have managed to get a finish that doesn't look absolutely horrible, but it's not uniform, and i can't seem to get anything resembling a real polish

I'd like some pointers. Should i sand dry, with water, or with oil? is there a technique that's more effective?

 

[lonepine]

I'm trying to learn also. I've seen the most improvement in my own work when I go to 1000, 1500, and 2000 grit papaer and wet sand (in the kitchen sink). I had to get these higher grit papers from an automotive supply place.

I'm pretty sure I'm not removing all the sand marks from the previous paper and I'm left with areas that aren't as nice as others. I've also seen a big improvement since I started wearing a magnifying headpiece. I can see better where the problems are that way.

- Paul Meske

 

[Daniel Fairly Knives]

2 things...

Draw File - if the grind lines aren't super flat and clean you will have a hard time finishing the knife. Try draw filing with a fine file then hand sanding from 180 or 220 grit on up to 600 or so, removing scratches from the previous grit along the way. Back your sandpaper with something rigid like a radiused piece of hardened steel. I'm not too sure about your particular grinder but you may have to file in your plunges with a round or half round file. You can clean them up with a dowel and then your sanding block.

Practice - Grind tons of knives, every good maker has a big box of rejects. Try making 5 of the same knife and make each one better than the next.

I hope this helps!

 

[Stacy E. Apelt - Bladesmith]

Daniel has pretty well summed it up.

If it isn't dead flat when rough it will show horribly when polished smooth.

Start with a flat surface.
Grind as flat as you can to 400 grit, then take the blade to a granite surface plate with 220 grit sand paper taped to it. Spray the paper with a mist of dish soap and water. Work the blade on the paper, and you will see the high and low spots. When they are all gone, switch to 400 grit paper. When that is good, switch to normal hand sanding of the blade with a flat sanding block backing the paper. Go up the grits from 400 to 2000 ,or higher. At this point it should look gleaming and shiny. You can hand buff this with a soft cloth and metal polish, or quit at the sanded finish.
Power buffing a blade to get a mirror polish is a dangerous task, and I won't go into it here.