Thread: Progression

I was wondering the progression between sandpaper, tumbler, and micromesh (i have 3m micron papers):



150 - 220 - 330 - 600 - 1000 - 1500 - 2000 - 3000 - tumbler walnut - 30 micron - 15 - 9 - tumbler corn - 3 - 2 - 1 ?

Also I have gotten to the 1000 grit sandpaper and the surface seems to have scratches but that 1000 won't take out. I am not sure how I missed them since I spent lots of time at each grit. I put the blade in the tuumbler with walnut and rubbing compound and flitz for 2 days and it is a mittor finish but with these background scratches. Do I need to go back to 150 or lower?

I have 5 blades I have restored from rusty pitted mess and am pretty close to done with these scratches being the last bastion.

They all need scales and frankly I am tired already from the sanding, anyone out there want to scale them for me?

Before/After, the 5th is still in the tumbler:

You improved to soon in your progression.
If you go from 150 to 220 you have to sand with 220 until all the 150 grit scratches are gone and you're left with the 220 scratches.
If you go horizontal with 120 and vertical with 220 you will see when you can progress.

Hope this helped

I am starting to think the scratches are from the 80 - 120 dremel flap wheel used to get the pits and rust out. It is very difficult for me to sand vertical across the blade but I understand what you are saying. Maybe I need to put the sandpaper on a rubber tube or something, my fingers are shot.

Honestly the 150 took the piss out of me. I probably did push through 220 too fast but I spent about 15 minutes on each grit after 150.

I agree the problem probably arises in the middle of the succession, rather than at the fine end. Most processes become a lot more trouble if you sand other than along the length of the blade. But with the flap wheel you could make it identical by using it at a recognisable oblique angle.

Personally I consider them a bit too aggressive, and prone to go for edges. I much prefer pieces of cork tile or rubber sheet on one of their arbors, to which you superglue a disc of fine abrasive paper. I also hacksawed a piece from an annealed wood rasp, and silver soldered it at an oblique angle to a short steel rod with a file handle on the other. At that stage it was for smoothing the bottom of the action recess in a gunstock, but I then glued some fine paper to a cork tile, and I can cut small pieces with an old pair of scissors, impale them on my rasp push-stick, and discard them as they clog.

Wow guys, at 9 microns steel starts to squeek and it is scary how beautiful it becomes. By 1 micron I am not sure even flitz can improve it or perhaps even make it worse. The only data missing here is the best order of progression to optimize the process. Please if anyone can put my progression into proper order I would appreciate it.

Originally Posted by Caledonian

I agree the problem probably arises in the middle of the succession, rather than at the fine end. Most processes become a lot more trouble if you sand other than along the length of the blade. But with the flap wheel you could make it identical by using it at a recognisable oblique angle.

Personally I consider them a bit too aggressive, and prone to go for edges. I much prefer pieces of cork tile or rubber sheet on one of their arbors, to which you superglue a disc of fine abrasive paper. I also hacksawed a piece from an annealed wood rasp, and silver soldered it at an oblique angle to a short steel rod with a file handle on the other. At that stage it was for smoothing the bottom of the action recess in a gunstock, but I then glued some fine paper to a cork tile, and I can cut small pieces with an old pair of scissors, impale them on my rasp push-stick, and discard them as they clog.

I agree I think there could be a custom made 'perfect' accessory for even a dremel that would be around a 3 inch diameter wheel of rubber which you can superglue fine sandpaper to and a slightly longer shaft then typical dremel accessories so you have room around it to work. I have a feeling anyone producing this attachment could sell it by the thousand. Maybe even it comes with 100 pre-cut strips of all the grits from 200 down to 1 micron.

I have found goind across instead of with the length causes larger scratches hard to remove as a result of shaving slightly the sand paper off the edge and then depositing the grains on the blade face which instantly put deeper scratches in. Very hard to remove going along the length.

Originally Posted by groovyd

I agree I think there could be a custom made 'perfect' accessory for even a dremel that would be around a 3 inch diameter wheel of rubber which you can superglue fine sandpaper to and a slightly longer shaft then typical dremel accessories so you have room around it to work. I have a feeling anyone producing this attachment could sell it by the thousand. Maybe even it comes with 100 pre-cut strips of all the grits from 200 down to 1 micron.

I have found goind across instead of with the length causes larger scratches hard to remove as a result of shaving slightly the sand paper off the edge and then depositing the grains on the blade face which instantly put deeper scratches in. Very hard to remove going along the length.

A disc anywhere that diameter would impose MUCH greater centrifugal force, at Dremel speeds, than a smaller one, with considerable risk of extreme vibration and disintegration. That is dangerous, not just a little but very.

Long ago I chucked a piece of spring tempered piano wire in a Dremel, and it immediately bent at right angles right at the chuck, which you could hardly do with your fingers, setting up a really frightening vibration. I dread to think where it might have gone if it had broken off. i think a 1in. disc is pretty safe, but although I use burrs without goggles or glasses, I wouldn't do that with any sanding or cutting disc.

I also doubt the usefulness of a Dremel-speed disc of finer than about 400 grit, since it isn't practical to use it wet. Maybe with a flexible shaft tool you could. Still, the rotary direction of any scratches are enough, if they show through finer polishing, to tip you off to what stage it happened at.

I am pretty certain the dremel caused the scratches. Problem is the grits available are too low. I have some chinese flap wheels up to 400 but they don't expand and are pretty much junk. Even simply a line of quality flap wheels with grits up to 1k where hand sanding becomes trivial would be great. Perhaps even 400 is enough if it is a good quality unigrit paper. They sell synthetic wool wheels which are actually pretty decent but they are expensive. I have done wet sanding on the dremel and it works fine. You wet the blade not the attachment.

Clearly any attachment for a dremel needs to be well balanced and made strong to prevent flying apart. You could easily come up with one of larger diameter that is spoked or just using a very light plastic or fiberglass wheel. I built a 6 foot aircraft propeller that was balanced so i am not too worried about the technical aspects of speed and balance. Clearly using a dremel you should be wearing eye protection. Mine is mounted on a vise which is rock solid like a proper grinder.

A really awesome accessory would be a planetary gear attachment that gears down the rpm by 10 and increases the torque by 10.