so here is something i have been dealing with. i will finish sand a belt all the way up to almost a 2,000 grit finish. i will leave it alone, come back to it, inspect it. rinse repeat. just to make sure i didn't miss any spots.
then i go to hand sand it and out of no where after a short time sanding what seems to appear are things as deep as a 36g scratch from belts.
i took my time running up a whole variety of belts and grits.
and its not like its hiding in the plunge. but right in the center of the blade where a blind man could find it. its happened a few times to me this past month.
there is no way i missed a scratch that big.
am i doing something wrong? (clearly)
i try to take my hand sandings up to 400-600g
thanks guys!
Hello Zach. Yep it happens. What grit do you start hand sanding with? My process is to finish grind to 400, sharpen and test, then start hand rubbing at 220. You will be able to see any bad scratches very easily especially if it is a two inch mark. Just wondering if your marks are appearing about two inches from your plunge area? If so it is the two inchitis. When you are trying to get the plunge area defined and good you can inadvertently push too hard on the side of the platen away from the plunge and cause a two incher. Hard to get out and hard to see if your grind marks all go the same direction. I usually go back one grit with the grinder and grind on a slight diagonal to the previous marks. It will show up a two inch mark plain as day and allow to really tell when you get it out.
Brion
Brion Tomberlin
Anvil Top Custom Knives
ABS Mastersmith
Zach
In addition to Master Smith Brion Tomberlin's advice, you will find a lot of advice on the Topic of the Month for May 2013 at, Click: Blade Finishing.
Dan Cassidy
Journeyman Smith
Send an email to Dan
i take all the way up to a5 belt, then i inspect the piece. normally i don't go to hand sanding right away. i want to let it sit and go back to it with fresh eyes to see if i missed anything. then i start with 220 and work up. sometimes i've just gone straight in with 400.
this last time the scratch was about 1" from the plunge.
what really gets me is it was a 36g scratch.
Zach;
Something that might help: after each grit on the grinder; give the blade a quick etch.
This will color all the blade, even the bottoms of the scratches.
Makes the scratch really stand out when you go to the next grit.
Hand sand that one area where the scratch is to a 400 or so. Etch that spot. If the "scratch" is still there; it is in the steel; not on it.
Different problem.
Mike
Mike Williams
Master Smith
|quoted:
Zach;
Something that might help: after each grit on the grinder; give the blade a quick etch.
This will color all the blade, even the bottoms of the scratches.
Makes the scratch really stand out when you go to the next grit.
Hand sand that one area where the scratch is to a 400 or so. Etch that spot. If the "scratch" is still there; it is in the steel; not on it.
Different problem.
Mike
Brilliant!
i shall do this next batch!
Zach,
I'm don't understand the idea behind using belts to 2000 grit, then hand sanding to 4-600, but the first thing I would do is stop using 36 grit belts on steel. The second would be to make sure there are no stray 36 grit chunks contaminating any other belts/buffs etc... 36 grit is great for roughing handle material. Dan
Zach,
How is your sanding on this blade going?
As Mike alluded to, the scratches may not be on your steel, it may be in the steel. It could be alloy banding. There is a thread on alloy banding here.
|quoted:
Zach,
How is your sanding on this blade going?
As Mike alluded to, the scratches may not be on your steel, it may be in the steel. It could be alloy banding. There is a thread on alloy banding here.
i haven't had the opportunity to get to any more hand sanding as of yet. i have some knives that i need to go back and do some touch ups before i soak them in acid.
hopefully next week i will be able to make 1 or 2 more damascus knives for a little gun and knife show i'm going to. i will try to report back. i have a wicked crazy schedule these next 2ish weeks.
thanks for checking in on me.
also when it comes to my steel, everything i use is from aldo. if that means anything.
