finish grit sanding on your flat ground knives?

C

curtis K

Joined
Oct 15, 2009
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79
Gentlemen,
How do you do your finish grit sanding (220, 400, 600, 800, etc.) on your flat ground knives? I have tried leather backing, graphite, cork/rubber, hard plastic, and have had moderate results. I usually resort to a pad sander but this tends to wash grind lines a bit.
 
I use poundo board from Tandy attached to a piece of mircata. It has just enough give and works great on the higher grit papers.
 
Goldsmithy said:
http://www.youtube.com/watch?feature=player_detailpage&v=YDVVprFLZEU

This shows a great way to make a sanding stick. Gives you tight corners, and flat, supported flats. ....Teddy
Click to expand...

That's a lot of work

I belt sand to a clean 400 grit then hand sand with 400, 600, 1000, 1500, 2000. But lately I've started doing this: hand sand to 400 grit, etch, then hand sand with 1000 grit. It gives it a neat looking satin finish.

I have several sanding sticks but mainly use a 6" piece of 1/2" micarta that is super flat. I cut the paper into strips wide enough for the blade and hold the paper down with my thumbs as I sand. If I really want to hog of the steel (220, 320, etc.) then I'll cut the paper into strips and spray it with adhesive and glue it to a 12" piece of mild steel that I can really bare down on.
 
Old file that I surface ground the teeth off of. I bet I'll never have to replace it. If the grind
is good to about 400 grit there ain't much time sanding.
Ken.
 
Any block of flat and hard wood makes a good sanding block. 2X2X6" works well.

It isn't the block that makes the finish come out good, it is the amount of time you spend on the sanding, and the sanding technique. Sanding techniques and lubricants is a topic that has been discussed many times.
 
kc custom said:
Old file that I surface ground the teeth off of. I bet I'll never have to replace it.
Click to expand...

Same here. I have three in different widths/thicknesses.

Maybe it's just me, but I think most people make this way too complicated :)
 
I agree with everyone, I typically use a micarta block and some shaped micarta pieces to get into the hard spots. The way I found to miminmize the sanding time

BTY as a consultant I should be charging you for this advice.

IS...........make sure you do a really good job through the 400 grit, if there are some scratches left, it is a lot of work to remove the past 400. I find after 400 its goes pretty quick
or a quick as sanding time can be, but you really got to get some good light and some magnification to make sure after 400 you got the job done, obviously changing the angle between grits.
I plan for the 400 to be the length of the blade that way it is 90 degrees to the scratches left by the belts.
 
I've taken to finishing flat grinds lengthwise on a platen. While it is common knowledge that I sell platens here, you can utilize this technique with any platen to get a head start on your hand sanding or eliminate it completely.

There are aspects my process that apply to grinding against a platen regardless of lengthwise or conventional. Of particular note is the belt I'm using and what I've done to it.

This is a 320 grit belt finish that is as clean as a hand rubbed finish:

http://i566.photobucket.com/albums/ss107/Nathan_the_Machinist/062113/3_zpsf309616d.jpg~original

This is from a post elsewhere where I describe my process. There is some hard earned knowledge here:

Nathan the Machinist said:
snip

For the final finish pass I like to double up two belts so it has a bit of give. This will give you the smoothest most even finish. A clean 120 grit grind doesn't look rough and a clean 320 grit looks slick as hell.

I like the yellow Klingspor 312 J flex belts. Other belts I've tried tend to gouge and gall when a bit of grit pulls free. It goes without saying, use fresh belts.

In order to run two belts at the same time you're going to need to stretch a belt. Take a new belt and put it on the grinder under high tension and run it and get it soaking wet. Once it runs a little while it will stretch so you'll need to stop and pull your attachment out and run the tension up again. At this point it is stretched. You'll want to go ahead and rub the grit off the belt splice at this point to prevent splice bump from showing up in your finish. I use an old file. You can then take another belt like it that hasn't been stretched to run inside of it and they'll run together that way.

snip
Click to expand...
 
Here's a photo of what I use.
9332701820_75fae08ab2.jpg

My hand sanding fixture was modeled off one that Nick Wheeler developed. I have a matching piece of plexi-glass on top that can be adjusted with set-screws to support the tip of the blade. My primary sanding sticks are pieces of aluminum angle. I find that the angle gives me a good place to "pinch" the sandpaper strip to keep it tight. Base (large-grit) sanding is done with the angle sanding fixture alone in order to keep all of the lines crisp. My finish sanding stick is the same, but has some thin cork material attached.


bladsmth said:
It isn't the block that makes the finish come out good, it is the amount of time you spend on the sanding, and the sanding technique.
Click to expand...

This is worth a second read. :thumbup:


It may have already been mentioned... but it pays to keep your sanding area relatively clean. I like to wipe everything down with fresh paper towel between grits... even washing my hands. It's no fun to have a stray piece of old grit screw up your finish.

Erin
 
I use a sheet of glass, cloth backed sandpaper to 1200grit and then micromesh sheet. I wet the paper down by rolling it up and placing in a pint glass full of water. Then I slap the wet sheet to the glass to stick it.
 
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