Asking for polishing/hand-sanding advice!

[Blumbo]

Hi all!

I was hoping to get some help since I’ve been running into a wall with some of my polishing projects! I find I’m currently just using a soft balsa wood base and handsanding with my fingers on a small square of sandpaper, but I find that my fingers get really sore after a few hours and it kinda worsens my carpal tunnel. I feel like this makes me more impatient so I spend less time than I need on lower grits so sometimes I don’t get all the scratches out of the core steel especially, which is really frustrating. Are there any good suggestions for implements that would allow me to put good pressure onto the sandpaper/blade in a more ergonomic way without using my fingers directly on the sandpaper that yall would recommend?

 

[HSC /// Knives]

A few hours... that's a long time

What kind of steel is the knife and what Abrasives are you using specifically? Brand and grit

 

[Blumbo]

Recently I’ve been polishing up some Tanaka B1/AS - using 3M sandpaper, 100/150/220/320/400/600/800

 

[HSC /// Knives]

Recently I’ve been polishing up some Tanaka B1/AS - using 3M sandpaper, 100/150/220/320/400/600/800

Which 3M specifically ?
Abrasives can vary significantly

 

[HSC /// Knives]

Recently I’ve been polishing up some Tanaka B1/AS - using 3M sandpaper, 100/150/220/320/400/600/800

You probably need more pressure
I used an old file with leather backing

 

[Blumbo]

Which 3M specifically ?
Abrasives can vary significantly

Just whatever I can find at Home Depot lol

 

[Blumbo]

You probably need more pressure
I used an old file with leather backing

How do you get the sandpaper to stick to the file? Thanks for all your time!!

 

[HSC /// Knives]

View attachment 314379

Just whatever I can find at Home Depot lol

And there's your problem
Try indasa rhynowet redline or 3M black ice

 

[HSC /// Knives]

How do you get the sandpaper to stick to the file? Thanks for all your time!!

I have psa (adhesive) backed sandpaper
But i also non psa Abrasives and you don't need it to stick. It will stay on the leather with your hand pressure

 

[KasumiJLA]

I can help you here since I often polish honyaki blades with sandpaper. There are two phases when I use sandpaper: hard backing and soft backing.

Hard backing
Just like @HSC /// Knives I use something super hard to put the sandpaper underneath. I have a large wooden bar with about 1/2 inch surface area that is in contact with the blade. This bar is long enough that I can really put a lot of weight on it so I can work faster. When it stops cutting, I expose new abrasive and continue. Don't waste your time trying to cut steel when it cuts halfway.

Soft backing
For soft backing I start using this technique with 1k grain. After using hard backing to make everything homogeneous, I then use my fingers as soft backing to define the scratch pattern. It obviously cuts much slower but the purpose is to reduce the depth of the scratches and refine the work before continuing with my diamond pastes.

Grit progression

using 3M sandpaper, 100/150/220/320/400/600/800

I think you create a lot more work for yourself with such tight progression. Personally I always have the same pattern: 220-320-400-600-1k. The gap between 220 and 320 is in my opinion the most important because that's really where the scratches are the deepest. One of my rules is if it took me 20 minutes with the 220 paper, then it should take me at least 30 minutes for the same effort with the 320 paper. This way I make sure that I have erased the previous grain size. The more I increase the finishing grain, the more time is increased to make sure it's clean and uniform.

The right brand
Obviously the quality of the sandpaper you use will largely influence the time required to polish. I personally use Rhynowet, I wouldn't change for anything else. 3M for auto can do the job but if you can try to get some Rhynowet I highly recommend it! Avoid at all costs anything on Amazon that has really low prices. Not mixing brands also helps to get something precise because 600 grit from 3M is not the same as 600 from Rhynowet. The same applies to whetstone.

Have fun!

 

[MSicardCutlery]

Try indasa rhynowet redline or 3M black ice

This.
Especially Rhynowet. It's something of a staple among knifemakers, and with good reason. Also, fwiw, my own progression is usually to double the previous grit number. 320->600->1200->2k. From 2k up things get difficult with monosteel, but soft-clad san-mai should still be pretty easy.

Are you using a lubricant? Some people use windex, personally I use WD40. The oil makes for a smoother finish, but the windex probably cuts faster.

 

[MSicardCutlery]

This.
Especially Rhynowet. It's something of a staple among knifemakers, and with good reason. Also, fwiw, my own progression is usually to double the previous grit number. 320->600->1200->2k. From 2k up things get difficult with monosteel, but soft-clad san-mai should still be pretty easy.

Are you using a lubricant? Some people use windex, personally I use WD40. The oil makes for a smoother finish, but the windex probably cuts faster.

Also, regarding time.

If the 220 grit belt finish is even, I can create a 320 grit hand finish in less than 10 minutes per side. It usually isn't perfect though so it's typically more like 15 minutes. Going up to 600 grit takes about the same amount of time. The jump to 1200 grit takes about 50% longer. I suspect because the smaller grits load and break down that much faster. Mind you, this is my day job, so I've got a ton of incentive and practice at working quickly.

 

[Blumbo]

Thanks all for your time/experience!! Lots for me to work on here! I’ve just been using water in a spray bottle as a lubricant, but I’d give windex a try if it were significantly faster!

 

[HSC /// Knives]

Thanks all for your time/experience!! Lots for me to work on here! I’ve just been using water in a spray bottle as a lubricant, but I’d give windex a try if it were significantly faster!

Personally, I don't think the lubricant is going to make a significant difference, but it's different for everybody and everyone has their own method

The change and sandpaper will make huge difference. That and the pressure of a hard backing.

 

[harken]

I will add, that from my humble, VERY limited experience using sandpaper to adjust my knives and learning to polish w/o going into the JNAT rabbit hole, using WD40 as a lubricant does add some limited rust resistance to knives, though that may be due to the smoothness MSC mentioned.

 

[Rangen]

FWIW, Black Ice appears to be a Norton product, not 3M. I had never heard of it before, but will check it out at some point.

 

[Blumbo]

Out of curiosity is there a difference between the abrasives used in rhynowet and rhynostick?

 

[HSC /// Knives]

FWIW, Black Ice appears to be a Norton product, not 3M. I had never heard of it before, but will check it out at some point.

Correct, my mistake. Yes it's Norton.
It's a good product and close to rhynowet but I think the rhynowet is a little better

 

[refcast]

So per @HSC /// Knives saying how much better the rynowet sandpaper is, and knife making forums say it is, I bought some. Indasa rhyno redline is much much better than the 3m stuff at home Depot (I used the rhynogrip roll one with adhesive back). There's a couple different variations of it . . . Sheets rolls etc. It lasts longer, can withstand more pressure, doesn't disintegrate, feels sharper, can cut into hard steel readily. Feels like a nice file. I tried the 150 grit, have a 320 grit I need to try too. The adhesive back is mildly sticky . . . Not ultra sticky so might need another adhesive if mounted to a block for thinning

 

[refcast]

Mounted it on wood, added water, worked for 15-20 minutes, eventually leveling out at like the speed of a 3000 grit stone. Tends to hide low spots but great thinning feel and even edge -- very crisp edge, easy deburr, fast to form a burr. 150 grit rhynogrip, 2 3/4 inch wide I think. Speed is similar to a glass shapton 500 I think or a little faster. Cutting feels is different because the abrasive is raised over the surface . . . In my opinion a better cutting feel than stones. Highly recommended. Its like $35 for a giant roll . . . Depends on the grit. I want to try a lower grit too. Pic of 150 grit before use

https://indasa-direct.com/collectio...ynostick-redline-psa-sanding-rolls-960-series