Introduction: Make a Card Scraper From Old Saw
I recently made a saw cabinet/shelf thing and I didn't have the space for this saw. It was fine because I don't like the way it cuts, was bent, and it was getting dull anyway.
So, I made it into a card scraper. A card scraper is used to scrape sort of like a hand plane. If used right I read it makes a finer, smoother surface than sanding.(no clue if it's true)
-I have never used or owned a card scraper so I have no idea if it is the right size or bevel or anything like that. I am open to comments on how it should be.
This build took about 45 minutes (actually 46:34:) It was quick, fun, learning experience, and will come in handy for current (and future) refinishing projects.
The video doesn't show all the steps and improvements so I recommend reading the instructable too.
- 1st-Acquire an old saw
- Dremel or rotary tool-I used this
-Angle grinder would also work
- Cut off wheel
- screw driver
- straight edge
- sand paper
- palm sander-could use disc sander or hand sand
- disc sander-could use a file
Step 1: Remove the Handle
This part is pretty straight forward. Take out the screws(called saw screws),using a screw driver, in the handle and pull out the nut on the other side(called a split nut)
Step 2: Layout the Scraper Outline
I made my scraper about 4.25" by 3.25" (10.795cm by 8.255)
I used a sharpie and ruler to lay out a rectangle, trying to keep everything square:)
To keep the blade as flat as possible the cutting edge will be the back of the saw.
Step 3: Cut It Out
Make sure to clamp the blade down when cutting
I chucked up a cutoff wheel in my rotary tool and just followed the lines drawn. At this point it doesn't matter if its straight because we'll fix this later with the file and sander.
Always where a dust mask/respirator, eye protection, and hearing protection when using a rotary tool, unless you want to die a early, painful death. Just kidding, but it will affect your health.
Step 4: Clean Up the Edges and Add a Bevel
I took it to my disc sander to make the edges flat. (you could use a file or sandpaper) After flattening the sides it was time to establish the cutting edge.
To do that I used my ruler and picked the flatter of the two sides. Then I tilted my table 35 degrees and sanded the cutting edge leaving a point in the middle.
I didn't go super indepth on bevel sanding because there are plenty of other ibles on it.
Step 5: Test It Out
Turns out 35 degrees wasn't the way to do it. All it did was make dust. A card scraper is supposed to make small shavings similar to a plane.
I adjusted my table tilt to about 45 degrees and ground to the center on both sides again.
Another quick test proved that I did something right (sort of:) the second test made small actual shavings.
(keep reading, it changes again)
Step 6: Round the Top Corners-Optional
Not all card scrapers have rounded top corners (maybe none do?) but I add some to mine.
I drew a curved edge just inside the two top corners using a small roll of tape as a guide. Then I sanded to that line using a disc sander.-could use a file
I'm working on patenting this method and calling it insta-corner-round
Step 7: Sand the Surface
I wanted the surface to be shiny and look a little more like metal.
I took a palm sander with 80 grit sand paper to the surface and it shined up nicely. I stopped at 80 grit cause i'm sure it will get scratched anyway.
Step 8: Last Words-I Did It Wrong
Turns out a card scraper doesn't have a bevel at all. The cutting edge is actually created by the 90 degree edge being rolled over with a file or screw driver.
This isn't in the video because that was published before I learned this:)
How to do that
-Sand/grind the cutting edge flat at 90 degrees
-Take a screw driver/file and draw it across one side of the 90 degree edge causing it to roll.(this makes a burr which is sharp and cuts when drawn across a surface)
-Do the same to the other side.
-test it out, hold it more parallel to the surface(takes practice)
Now you have an actually card scraper.
Step 9: Finished
I used it again for a longer period of time to take the finish off of some chair rails and it works fairly well. It is tricky to sand in these rails and scraping them is actually faster, in about 2 passes it removes the varnish and stain. The rounded top edges make it comfortable to hold.
I am very happy with the result(once it was fixed) and it went much faster and worked out better than expected. After the edge was fixed it made much bigger shavings.-like a plane
This is an entry in the One Hour Challenge
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