how to sharpen your woodworking tools with sandpaper - adhesive backed mylar film
In carpentry, few people will be as controversial as the best way to grind tools.
An excellent way to use Waterstones has been published on instructures: Why consider another way, why would you consider using a rough sheet on your precious woodcut and flat iron
The main reason is: cost.
The cost of a good Waterstone is $100 per Waterstone (
You should have several different grits). And sandpaper?
Less than $2 each.
However, this is not a fair comparison.
The stone will last for several years;
You have to buy a lot of sandpaper and replace it when it's worn out.
But the bottom line is that the sandpaper method is much cheaper.
The second reason: simple.
The method of sandpaper is simple.
The third reason: for most of us, if carefully operated, the sandpaper method will produce the sharpest cutting edge we have experienced.
You use sandpaper, but it's not what we usually use in a woodworking shop.
The condition of your tool and how good the edges you want will determine what sandpaper you need.
This photo shows what's in my store.
You don't need all of this, three is enough: 600, 1200 and 2000;
Or 800, 1500 and 2500.
Most of the time, you will find these in the auto shop and some hardware stores.
Really exquisite sandpaper is available in car paint and body shop.
It's all black "wet" or "dry" paper.
If you want to go further, buy one or two sheets of 2500, but anything over 2000 is hard to find.
Finally, I used a honing grinding compound, which I got from Li Gu hardware, where there is also a wide variety of fine sand grain sharpening grinding paper.
This note assumes that the shape of the blade slope is quite good and does not require grinding on the power grinder.
Hang out the sand paper on the cast steel frame of my table saw.
This one works, but the blade will tear it up soon if the paper is not tight.
The better thing is to buy sandpaper yourself.
But these are hard to find.
A good, practical solution is to stick the tape to a 3/4 mid-fiber board as shown in the figure.
You can use a thin coating of spray glue or wood glue.
Then, place another mid-fiber board on the sandpaper and clip the "sandwich" into the vise to flatten the paper and make sure it attaches smoothly.
Make a few of these various frosted blocks and throw them away when worn out.
This is about 50 cents.
The block in the photo is 3 1/2 "x 12 ".
Smooth the back first.
This process is sometimes overlooked but important.
The cutting edge of the blade is where the two surfaces meet and both must be sharp.
On the back, the key is 1/2 or less of the tip.
The initial sand depends on the condition on the back of the blade.
If it is scratched, rusted or uneven, start with 400 of the sand, and then start with 800, work at the tip until sand or higher in 2000.
In this photo, the "abrasive plate" is a medium-fiber plate that is glued to the surface with sandpaper.
Place the blade in the guide rail at the correct angle and polish the main inclined plane with beading. (
If you are not sure that you are honing at the right angle, see next).
Most blades have 25 degrees or 30 degrees angle.
Similar to back grinding, grits depends on the quality of the blade.
If the blade shape is not good, start with the lower sand.
According to the rule of thumb, you can double the number of sand for each continuous step.
So if you start with 400 sand, progress to 800, then 1500, then 2500.
In this photo, I used a 2500 sand grinder on the self-adhesive Mylar backing.
It's usually hard to know if you're honing at the right angle, especially after the beveled becomes shiny.
Here's a great way to "see" your progress.
In the first photo as described above, mark the bevel area with a felt pointed marker.
Then, after several tempering, look at the Beeline: the shiny area is where you take off the material.
If the shiny area is a thin strip of the tip, like in the second photo, you are exactly where you want to go next and hone the micro-beveled.
The final honing grinding stage is a micro-inclined plane, which is a slightly steep slope (
About two or three degrees)
At the tip.
This will be the sharpest and finest part of the blade.
The good part is
Sharp, this is the only part of the blade that needs to be re-polishedtouch.
Some honing grinding rails have an additional setting for this micro-angle.
Some craftsmen completed the final stage by hand.
I usually do this by placing a few square Fumika or some other sheet material under the wheel of the honing grinding guide.
Increasing the wheel will only make the angle steeper a few degrees.
In order to get the final polishing effect, the honed compound can be used with bare hands.
Scrape this compound onto a small piece of mid-fiber board and it goes on like a dark crayon.
Then polish the bevel, especially the tip.
This will be obvious when you hold the blade, and when you increase the angle, it will start to go deep into the fiber board.
So, you need to keep the blade at a certain angle to polish it before it starts to go deep into the mid-fiber board.
Good luck and hope it works for you.