Any tips for keeping lines crisp when hand sanding?

JG Custom Metal Works

JG Custom Metal Works

Joined
Nov 27, 2013
Messages
1,626
Let me start off by saying a couple things.

I've watched Nick Wheeler's hand sanding videos multiple times.

I use a hard backing for my sandpaper holder. It's a piece of 1084 ground flat. 90 degrees on one side and radiused on the other for getting up into different types of plunges. I don't double the sandpaper over itself when wrapping it around the bar. I just lay the grit side of sand paper face down on a bench, place the bar in the middle/on top of it, pull the top and bottom parts of the sandpaper strip tight around the bar, and pinch/hold them together on the backside of the bar. Then sand. I try real hard to not leave any slack that could mush around and hit the blade surface where I don't want.

I've been doing this for a while now and am not a new knife maker. I'm far from a master bladesmith though. I've just found other ways to get around this issue. Do belt finishes, flat grinds, or hand sand a particular area and then come back after with the surface grinder and make a couple passes on the flats that are next to the area that was hand sanded(where the sandpaper had kissed it a few times).

The main instances in which this happens is NOT on full flat grind knives. Full flat ground knives are easy. I can hand sand the entire bevel lengthwise no problem. It's when I have multiple areas with opposing grind directions. For instance a knife that has a primary bevel ground on the machine and then the flats surface ground. Hand sanding the primary bevel lengthwise really isn't an option unless I come back with the surface grinder and hit the flats again.

I guess another way of asking this question is, how are you vertically hand sanding your bevels without hitting the flats? Do you just hand sand the bevel and then come back and hit the flats afterwards?

I'm starting to see the appeal of those industrial tumblers for finishing. urgh...
 
I will be watching this for answers, too. I have been using birch plywood as a backer, and knew it was not hard enough. I definitely lose detail. I was going to make a metal backer literally today, but after reading this, may wait to see what people say. Although, I guess a steel backer has to be better than my plywood.
 
When hand sanding, I don't touch the flats until I am all done sanding the bevels. It seems easier to me to keep the sanding block dead flat coming off the tang/ricasso then onto the flat on the blade. Alternately, I will hand sand the bevels and then use a welding magnet to hold it and sand the flats on the belt grinder. I prefer the contrast of the belt finish/ hand finish between the bevels and flats. That's how i do it anyway.
 
I quit holding sandpaper on my blocks when doing this because of washing out lines. No matter how hard I would try I'd always end up with some slack at some point. So now I either CA glue or use feathering cement on my blocks and it's become much easier to maintain those lines. CA glue works better, more work to change paper as I'm scraping the block clean again with a razor. Feathering cement makes for quick changes but actually seems to pad the paper a bit with defeats the purpose of using a rigid flat block, so I've basically compromised to using CA glue on my steel faced blocks, which are easy to clean with a razor, and feathering cement on my leather/soft face blocks.

I also agree with Kevin that finishing flats last makes it easiest, whether you're surface grinding them or hand sanding them.
 
I do the same as you do initially JG with the surface ground piece of 1084. I hate to go back to the surface grinder afterwards. Sometimes I'll use spray adhesive on the back of sandpaper on a granite slab. Spray it down good with windex and carefully do straight pulls on the flats. I tried the Gough block, I didn't like it personally.
 
A granite plate with sandpaper helps a lot. I find even 3/8" thick hardened sanding blocks flex with pressure. As I get close to final proportions, lighter pressure helps, and I have sanding blocks reinforced with angle or t profiles to address this. It's theses details that separate a dood knife from a great knife. I'm gluing the paper to the blocks now too. I'm using a spray adhesive too.

My next large abrasive order will be adhesive backed.
 
I use a small piece of granite (1.5" x 5") as a hand sanding block with a piece of sand paper pulled taut over it when I need to do detailing where I can't use a surface plate. Gluing the paper to it works too but changing grits is a bit more of a hassle.
 
kdogmcg said:
i have a bunch of corian I wonder if that would make good sanding blocks? Sorry if that's hijacking.
Click to expand...

I have a piece waiting to be cut up into sanding blocks myself. I think it will work great.
 
I have a drawer full of Gesswein EDM stones in my toolbox at work. They're a pain to keep clean in my opinion. If you have an ultrasonic cleaner that seems to work ok. But even with a fluid they load up fast. They are quite hard and hold their shape well though.
 
I like my flats to have the same finish as the blade. I want it to look like one flowing finish from tang to tip. I also glue the sand paper onto my sanding sticks. My sticks are hardened D2 with one side square and one slightly rounded. When I do the flats I turn the sanding stick on an angle so the stick has more contact and surface area with the flat. If you run the stick perpendicular to the blade you have very little flat area to keep you square. By turning it allmost 90° I keep some part of the stick on the tang at all times. This keeps the rest of the stick square and flat. That being said most knives I make are full flat ground so I like my plunge cut to come up and arc into nothingness and disappear and run along the spine. Let's see if I have an example.

This is a 220gr finish on the tang and edge bevels. I love a nice crisp edge at the plunge cut and then smoothly disappear as it arcs into the spine. This is Damascus so I'm not going crazy with the hand sanding, only up to 400 grit or so.
Photo%20Oct%2018%2C%2010%2032%2017.jpg
 
JTknives said:
I like my flats to have the same finish as the blade. I want it to look like one flowing finish from tang to tip. I also glue the sand paper onto my sanding sticks. My sticks are hardened D2 with one side square and one slightly rounded. When I do the flats I turn the sanding stick on an angle so the stick has more contact and surface area with the flat. If you run the stick perpendicular to the blade you have very little flat area to keep you square. By turning it allmost 90° I keep some part of the stick on the tang at all times. This keeps the rest of the stick square and flat. That being said most knives I make are full flat ground so I like my plunge cut to come up and arc into nothingness and disappear and run along the spine. Let's see if I have an example.

This is a 220gr finish on the tang and edge bevels. I love a nice crisp edge at the plunge cut and then smoothly disappear as it arcs into the spine. This is Damascus so I'm not going crazy with the hand sanding, only up to 400 grit or so.
Photo%20Oct%2018%2C%2010%2032%2017.jpg
Click to expand...

Yeah, like I was saying, full flat grind knives are easy to do because you don't have any flats alongside the main bevel to worry about. The flats, like you said, can just be blended into the main bevel. It's the saber grind knives I'm worried about mainly.

I see some guys that have some amazing hand sanding skills. Bona for instance does a lengthwise scratch pattern that arcs with the belly of the blade. I'll see if I can find a picture.
 
JG Custom Metal Works said:
Yeah, like I was saying, full flat grind knives are easy to do because you don't have any flats alongside the main bevel to worry about. The flats, like you said, can just be blended into the main bevel. It's the saber grind knives I'm worried about mainly.

I see some guys that have some amazing hand sanding skills. Bona for instance does a lengthwise scratch pattern that arcs with the belly of the blade. I'll see if I can find a picture.
Click to expand...

+10 on Bona's finishing.
 
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