Hand sanding

I've got a quick question about hand-sanding blades. I've just started using this technique, and I keep having problems with scratchs appearing when I get to the 400-600 grit hand sanding. I just got Wayne Goddard's video on cable damascus, and he mentions that most scratchs that show up during finishing are from the 60-grit belt. To prevent this I marked my blades with a marking pen after 60-grit, then used a 100-grit belt and a magnifying glass to remove all the ink marks. But I'm still getting scratchs. I haven't been using the marking pen on up through the belt grits - should I do that?

I use light to look for scratches. If you go from 60 grit to 100 grit, you should be able to hold the blade at an angle under a light and see any scratches. One problem a lot of people have is seeing scratches and then they continue to work towards finer grits. You will not be able to get a 60 grit scratch out with a 600 grit belt. Stay at the 100 grit level until you are certain there are no scratches. If you happen to find one during the 400-600 grit phase, go back to 100 grit and finish the job before proceeding. You will save yourself a lot of headaches.

I don't use markers except for flat hand sanding. A good eye is a lot better than the marker trick. Just don't talk yourself into believing there is no 60 grit scratch. I did that in the beginning, I would see a scratch and tell myself that it will go away witht the rest of the polishing, then I would finish the knife and it would be really obvious then. So I would have to go all the way back to 100 grit and do it over. That was a lot of wasted energy and time.

If you are working on flat surfaces, one thing that will help identify scratches tremendously is to change the direction you are sanding 45 degrees with each progressive grit. In good light, you will know when all the scratches from the previous grit are gone.

This is infinitely more difficult to do if you are working on a hollow-ground surface.

Question, what are you using to back your sand paper with? If it is just sand paper wrapped around a file, or peice of wood, or something else hard, that will scratch the metal thru the sand paper, maybe try leather glued to a peice of wood? Creates a pad for the sand paper..... dunno what your technique is, so you might already be doing this.... let us know how it works out...


Ben

Ben,

I use a half-round hardwood block for backing my paper. I radiused the sharp edges to match my plunges. I've never had any problem with the wood scratching the steel. I do use leather, but only for the final finish. It 'softens' the finish.

Brett

contaminated or a bad batch of sandpaper. I keep mine in sealed tupperware containers.

All these are good tips.

Also, use different light sources to locate that last scratch before moving on. I use incandescent, halide, florescent, and sunlight in search for that elusive last scratch. Hold the blade at different angles when checking.

Hey guys,
Thanks for all the responses. For those of you that asked, I use a piece of leather glued to a wooden block. Haven't had any problems with it scratching. Does anybody use one of those magnifying visors like fly-tiers use? That's something else Wayne Goddard had on his video, but I'm thinking that with good light it could be avoided. Thanks!

Josh

P.S. to Terry: I really liked the tutorials on your web site. I'm got two knives that I'm going to use the solder-free guard method on - I can't solder very well at all!

One thing you may want to keep in mind is to change or clean you paper more often that you think you need to. Any little piece of metal or A/O that attaches itself to your sand paper can cause this in finer grits, and they only thing you can do is go back to a lower grit to remove it.

Been there done that.

Mike

Josh,
I often use an Opti-Visor like you were talking about. For me me it's a necessity in some cases. I don't see as well as I used to.

For a while I was using them during the entire hand-rub operation, but I believe that was making my vision even worse. Now I just put them on for that final look on the piece before moving to the next finer grit.

By the way, I'm glad you liked the tutorials. Thanks for the kind words.

One step up from the marker trick. I coat my blades with Dyechem layout fluid in between each grit. It penetrates into every little nook and cranny. If you still see blue, keep sanding. Showed this to Trace Rinaldi when he visited my shop for a day. He was laughing at first, but by the end of the day he was asking me where to buy it from.

Also, it will show any micro fracture in a heartbeat. Great for checking blades after heat treating.