Sunday, October 4, 2009

Stropping A Flat Ground Blade

There has been a ton of writings about the importance of keeping your carving knife sharp. What I am about to explain and show is how I learned to keep my knife sharp. My knife blades are ground flat. When the blade is ground flat, there is no bevel. When I get a new knife I make sure the blade is ground flat and that the knife maker makes it as sharp as possible. If I don't buy from the knife maker, I send the knife to one for a flat regrind and sharpening. This way I know I start out with a well shaped and sharp knife. From this point on it is my responsibility to maintain the blade as sharp as possible. This I do by stropping the blade about every 15 minutes of heavy use, and at the end of each carving session. I use a leather strop. On one side of the strop the leather is rough side out. This is the side that I rub stropping compound into. I think that most of the "harder" stropping compound will work. The other side of the strop is the smooth side of the leather. The leather on a strop should be thin and a bit hard. By this, I mean, you do not want a soft leather that will compress when you strop the knife blade. You should be able to keep your knife sharp by frequent and proper stropping. One of the best practices to follow is to never let your knife blade get really dull before stropping. And I never use a stone or anything other than my strop except if the blade somehow gets damaged. And in my humble opinion a really dull blade is damaged. And yes, while learning to keep my knife sharp I've damaged it a few times. Stropping: Start by placing your strop on a flat surface, with the rough side with the compound facing up. Place blade flat on the strop surface. Place your index finger onto the blade tip, holding the blade flat against the strop. Use your finger to put a little pressure on the blade tip, while holding the blade flat against the strop and push the blade to the right, keeping the same amount of pressure on the tip. Do this three or four times. Do not let the knife "run" off the end of the strop. Do not let the blade "roll" at the end of the strokes, lift it straight up. Do this same stropping of the same side of the blade, only move your finger holding the blade flat against the strop, down for each sequence of stropping. Keep moving your finger down the blade to strop the whole length of the blade. After the one side of the knife blade is completely stropped do the other side in the same manner. After both sides of the blade have been stropped on the leather with the compound, turn the strop over and complete the same sequence on the side of the strop with the smooth leather. A simple test to see if the blade is sharp is to lay the blade perpendicular (at right angle) to your thumb nail, and with hardly any pressure, pull it towards you over the nail. If the blade sides without catching (digging in) it's not sharp. Most of my whittling is done with my pocket knife. This means that my knife is always carried with me. There isn't a day that goes by when I am not tempted to use my knife for something other than whittling. Don't do it! The fastest way to dull and quite possibly damage the knife blade is to use it for anything other than whittling/carving good wood. The following are things that I have done in the past that have really dulled the blade, and in some cases damaged it as well: Cutting twine, rope, opening a cardboard box, sharpening a pencil, cleaning my fingernails, opening plastic get the idea. You don't have to remove a hubcap with your knife to damage it.


Marcia said...

I'm not sure what you mean by ground flat? I have flexcut knives... are they ground flat?

And what are you doing on the very last shot with your thumbnail? *confused*


Tom H said...

Thanks Marcia! You're a good editor. I added some clarification to the post. Flat ground means that there is no bevel to the blade. The blade on my thumb nail (at right angle to the nail) is a simple test to see if it is sharp. When you apply very little pressure and drag the blade down your thumb nail, and it catches, it's sharp. If it slides down without catching, it's not as sharp as it should be. Thanks again!

Gene said...

great info Tom .. good for all carvers to know


Marcia said...

I didnt mean to edit.. I just really didnt know. Is a bevel a bad thing? I'm still trying to learn knives, and trying to get sharper ones. :D

Umm.. I think I'll not do that to my thumb nail.. something tells me I might loose it.. *grin* I'm just not that brave I guess.

Thanks Tom.


Hal in Seattle said...

Since i'm to cheap to buy an Oar Carver like yours. i'm want to try and duplicate it with a Rough Rider. Some questions if i may, how long is it closed ? How long is the blade? and i think you said it locks , so it can 't close while your carving? Also did the blade come that way or was it altered by Rick? If you don't want to devulge the info. i understand.
Keep up the good work , between you & Thomp , Gene(Flatplane),Lynn(outwestwood carving) and Don (woodbeecarver)Theres some much to learn and so little time.


Tom H said...

Marcia, The "editor" reference was a compliment. I need editing!

Tom H said...

Hal, I'll try to post a photo of the Ore Carver, with the blade opened.

Anonymous said...

i really feel stupid, as i have seen your strop.
i made a strop out of a paint stirrerer, not sure about the spelling there, and glued leather on both sides,
the common paint stir wooden stick,
is that long enough?
and try to drag vlade accross the leather at least 20 to 25 time s , on both sides , is that good or is it overkill?
sam carnes

Tom H said...

Sam, If you're concerned about the length of the strop, all I can tell you is that Ol' Thomp's strop is about 6 feet long and he runs along with his knife blade held flat againt it when stropping. That way, he says he only has to run the blade once down the strop and then back on the other side of the blade.

Thomp said...

heck tom, sam,
i was thinking of glue'n a long belt on the porch hand rail and get my grand son to run my tools across them,

no Sammy for real i do have one hone 18" long, thinking it takes less time to hone that way, but you got to get your body positioned right to keep from rounding out the edge on the knife..

i backed it with a hardwood stick 3/8" thick,
on the backside i glued with low tack contact adhesive spray some 600 grit wet/dry so i didn't have so much stuff to pack to the porch

Robert Cahill said...

Marci, I am not an expert on knifes. I also have a flexcut and at the carving club they say it has a bevel. If my understanding is correct if you put a staight edge on the cutting edge of the blade to the top non cutting edge and there is a space then it has a bevel if not then it is a flat .

How long does that sandpaper last between changes/

Thomp said...

im known for using the wet/dry sandpaper longer than most, not frugal but lazyness causes that..

i dont follow all the rules even though sandpaper is the cheapest part of any job.. i use it till it dont cut the steel and becomes slick or so torn up i have to use my heat gun and scraper to remove all the sandpaper and adhesive lumps and replace it....

a bit of acetone may help get off the kumps of glue, but use low tact adhesive to keep the sandpaper in place...

ive only had the 600 grit paper 5 months and replaced it 2 times, but your mileage may vary, remember i make 10 or more knives a month...

the wet/dry lasts longer if its kept wet while using it, but when done re wet the paper and clean off all the Smuts, dross or filings ... and keep the grit clean and open...

Marcia... im still working on the flat ground explanation to show you the

carlyd said...

I'm a new carver and this article has helped me alot to strop my knife. Thanks and great blog. Will be looking forward to many more great hints and tips from you.