How to.. Shiny as a mirror?

T

twoblink

Joined
Apr 26, 2001
Messages
30
I'm quite curious how knife makers get the knives polished so shiny..

Do you all use like a polishing stone, or some sort of sand belt?

I'm also curious how long it takes to get a nice mirror-like shine..

Thanks!
 
To polish a blade you usually finish it with a cloth or felt wheel on a motor. It's called a buffer. The wheel is coated with an abrasive paste called tripoli, that comes in small blocks of waxy substance. The heat of the attrition against the wheel melts the wax and makes the abrasive stick to the wheel.
The buffer can polish a blade to mirror shine. Is also a very dangerous piece of equipment. Wire or pieces of cloth can snag in the blade, rip it from your hands and throw it with incredible force. For this reason you must always use the buffer with the wheel turning down, and the blade positioned so that if it snags, it is thrown away from you.
Another method is hand polishing. Longer, but safer.

The other crytical factor in getting a mirror surface is the type of steel you are polishing. Powder stainless steels are those that get the best polish. Standard carbon steel won't get such a mirror polish and is best left at a 600-800 grit satin finish, possibly lengthwise.
 
I have an angle grinder, can I just bought a felt head for it, and get some buffing compound?

About how long are we looking at; like 5 minutes or half an hour or longer with a buffer??
 
It depends upon the finish on your blade before you start polishing. If there are grind/sanding lines present, then you may need to start by hand sanding with coarse sandpaper to remove the deeper scratchs. Then progress to finer and finer sandpaper until you start seeing a shine on the steel. . . . Then you would move to buffing the blade.

The whole process may take several hours or more.

An angle grinder would work in a pinch, but you may want several different polishing buffs to be used with varying grits of tripoli. Just make sure that you keep safety as your utmost concern. If you snag your blade with an angle grinder, you will be in for a big surprise.

Mike L.
 
so if angle grinders are not the generally accepted item, what is.. belt sander, with a cloth belt??

any pics of equipment you can link me to?
 
An angle grinder would be VERY DANGEROUS to try to buff with. Don't even think about it!
Use your belt sander to the finest grit you have, then switch to hand sanding . Hand sand to 2000 grit, then hand polish with tripoli followed by hand polishing with rouge.It may take as much as 8-10 hours on some blades, but a perfect finish is not something you can rush.
Stacy
 
twoblink said:
so if angle grinders are not the generally accepted item, what is.. belt sander, with a cloth belt??

any pics of equipment you can link me to?
Click to expand...

Something like this
Craftsman%206%20in%20belt%20sander.jpg


I have a small one like this 36" one
B00062NESM.01._SCLZZZZZZZ_V1101952564_.jpg
 
To polish my knives I hand polish them with wet and dry, stepping down the grit to 1800 w & d.
They come up to a mirror finish.
I have just purchased some Cork belts that I am going to try on my belt sander when they arrive.
 
A Buffer is one of most dangerous machines in a knife shop. And it can getaway from you in a instant. If you are new to knife making I would suggest visiting someone who has a shop and seeing the process. I use one in my shop and most serious knife makers do. I illustrated my setup on my site. There are different kinds of compound to use on a buffing wheel and each one is designed for a certain purpose.
 
I stone mine with EDM water stones to 900 grit then go to the Baldor Buffer starting with dark grey, then green chrome, then white and finally pink. PLEASE PLEASE PLEASE pay attention to what is being said about how dangerous buffing is. I have built a 1/2" plywood box around my buffer and attached my dust collector to it. The box will stop the throw short of hitting any equipment, walls or windows and the dust collector helps with the airborn partivles. WEAR A RESPIRATOR!!!!! I won't let anybody be in my shop while I am buffing to avoid distraction as well as liability.
 
I got a Grizzly belt grinder that has the buffer attached , and so I got to learn the sound a knife makes as it gets snagged by the buffer and bangs off the cement floor on my very first day of knife making.

I have never come close to hurting myself with the buffer, however I can see how a guy could.
I also question why will a knife always tend to land on it's point and get bent rather than on the tang?.
 
Stag & Steel said:
Allan...when you throw a knife...don't you want it to hit point first:)
Click to expand...

Yes, when you are tossing the blade at something nice and soft...
However when you are just about finished with a blade , and then while doing the last of the buffing have it snag for a split second, get ripped out of your hands, and sent straight down into the cement flooring, I question why it will always land point down?

It never just bangs on the tang ....
 
Just kidding you....I have broke the tip off a few, cut fingers, chipped handles and thumped myself so hard I was afraid to look and see what I did to myself. I have tore chunks out of a 12" buffing wheel big enough to have to throw the wheel away. Buffing is definitely not for the faint of heart!
 
I've finished to a mirror finish only twice and I had made those two upon request, since I am not a fan of mirror finished blades anyway. The first one was completed without a hitch. The second one went around the wheel and glanced off my side. Hurt like hell. I didn't complete that second one on the buffer, but finished it by hand instead. I won't mirror polish anymore on a buffer and will resist hand finishing one. I don't appreciate the look and making something that I personally don't appreciate is boring to me and not satisfying. I would rather make knives with other finishes for many more years, than be laid to rest with a mirror polished one that went through my innards!
 
Not that this is the only way to do it but I make up to six knives a week; all with a mirror finish. I start with 50 grit belts to tear off steel and than go to a 120 grit to refine the cut. Always making sure that I take all the 50 grit scratches off with the 120. Next comes the 220 grit making sure all the 120 grit scratches are removed (you can't take 50, 120 or 220 grit scratches off with buffing compound). The last belt I use is a well worn 400 grit, I have used 600 grit belts but they wear out too quickly. If the 400 grit is too aggresive, rub on a little buffing compound to plug up the grit. I try to get an almost polished blade with the 400 grit. from there I clamp the blade on my work bench and hand sand with a 400 grit wet/dry paper removing all the belt scratches and create new scratches the length of the blade. You want to buff across the scratches not with them: the buffing compound will polish the bottom of the scratches as easily as the top and you never get rid of them. Next the buffer. I start with green Acme compound from Pop Supply, then a white stainless and finish up with Fabuluster. Change wheels with each compound: don't mix them on the same wheel. Keep the blade cool in water or you will get an orange peel affect.

It has taken me years to get where I am today with my polishing: lots of trial and error and experimentation with different compounds. I feel that I have a way to go before I get a perfect polish without rounding off my grind lines. Maybe it is one of those things that I will never accomplish but I keep striving for improvement.

Has anyone told you yet to be careful with the buffer?
 
Thanks!! I really appreciate it..

I read on some guy's website, that buffing is ridiculously dangerous.. now I know why :eek:
 
Just a question, as i`ve never buffed a blade in my life.
Would it work if you clamped the blade onto a piece of wood? Or micarta? Or some kind of hard surface, so that the material overshoots the blade in all directions, and just polish a little bit at a time?
Sure, it`d hurt more to be hit with a piece of wood or micarta, when flung off the buffer. But atleast it won`t shred you to bits.
Would this work??
 
aarya...I do have a piece of pine that I screw thin blades like fillets to and buff from handle to tip. This keeps the flex and grab from happening.
 
You must log in or register to reply here.
Back
Top