Introduction: Jig for Sanding Small Parts
A sanding block can make the process of sanding a whole lot easier, but what about sanding small objects that are too small for a sanding block? Rather then trying to move the sand paper over the object, it's sometimes easier to move the object against a piece of sandpaper. One problem with this though, is the sheet of sand paper tends to move around, so you need to use one hand to hold the work piece and one hand to keep the sandpaper from moving.
I needed a better way to sand the 24 different blocks that made up the blocks and marbles toy I've been working on. I'd recently been reading about bench hooks and though maybe I could adapt one to my problem.
A bench hook is a simple jig made with a flat piece of wood and two cleats, one on the bottom and one on the top. The bottom cleat is held against the edge of your workbench or in a bench vise while the upper cleat it used to provide a stop for your work piece whether you're sawing, planing, or performing some other operation.
Fashioned after a bench hook, the sanding hook, as I'm calling it, has the same bottom cleat as a bench hook, but instead of another cleat on top, it has two hold downs for keeping a sheet of sand paper stationary.
Step 1: Materials
Here is a list of materials I used in constructing the sanding hook
- 1/2" Baltic Birch plywood (at least 10" by 19")
- 2x4 lumber (at least 10" long)
- Four 1-1/4" Construction screws
- Four 1-1/2", 10-24 round head machine screws
- Four 10-24 wing nuts
Your material list will vary depending on the size of sanding hook you want to make. I sized mine to fit a regular 9"x11"sheet of sand paper, so I made it 10" wide by 14-1/2" long. To reproduce the sanding hook I built, this means you'll need a piece of plywood at least 19" long by 10" wide and a 2x4 at least 10" long.
Step 2: Tools
Here are the minimum required tools to complete the project:
- Tape measure
- Counter-sinking bit
- 1/4" drill bit
- 5/32" drill bit
- 3/8" drill bit (preferably one that leaves a flat bottomed hole)
Instead of the hand drill, I actually used a drill press to drill many of the holes. To cut the plywood to size and rip the 2x4 into a 2x2, I used a table saw. To cut the 2x2 to length, I used a miter saw, but you could just as easily use a circular saw for all these operations.
Step 3: Cut the Plywood Cleats
Setup your saw to cut a 10" wide strip from the piece of plywood. If you are using a table saw this involves setting the fence 10" away from the blade. If you're using a circular saw you could clamp a straight piece of wood or other material to help you make a straight cut.
Cut a 10" strip from your plywood that's at least 19" long. This is the raw stock for your base and two upper cleats that hold the sandpaper.
Next setup the fence or cutting guide to cut the 2" wide cleat from the piece you just cut. Then cut the first cleat and repeat the cut to make the second cleat.
Step 4: Layout Pieces and Mark for Length
To judge how long you need to make the base, lay a sheet of sand paper on the remaining 10" wide strip of plywood. Then lay the two cleats on top of the sand paper. I figured that if the cleats overlapped the sand paper by about 1/4", that would provide enough friction to keep it in place, but not cover too much usable sand paper. So that means that you'll want to cut the base to 14-1/2" long.
Once you're satisfied with your layout, mark the base for length, setup you fence, and make the cut.
Step 5: Drill Holes for the Plywood Cleats and Base
I drilled two 1/4" through-holes in the cleats and each side of the base for the hold down bolts. I roughly located the holes on the center line of the long axis of the cleats (1" away from the edge) and 2" away from both sides.
Although you could layout the holes and use a hand drill, I used my drill press with the fence and stop blocks to setup the first hole. Then it was just a matter of lining up the edges to drill each hole -- no measuring or layout required for the holes to align perfectly.
Step 6: Drill Counter Bores
I recessed the heads of the bolts so the lower cleat sits flush and the base sits flat on a workbench. I used a 3/8" Forstner bit to drill /18" deep counter-bores.
Step 7: Test the Sand Paper Holder
At this point I wanted to test the jig to see if the holes all aligned properly and if it actually held the sandpaper stationary, so I attached the plywood cleats to the base with the 10-24 bolts and the wing nuts. I slipped a piece of sandpaper under the cleats and tightened the wing nuts.
I test sanded some small parts and the sandpaper stayed in place
Step 8: Cut the Bottom Cleat
Now that I was confident the jig would work, I needed to make the bottom cleat that holds the jig in place. If you don't already have a 2x2, setup your saw to make a 1-1/2" wide cut and rip the 2x2 from the 2x4.
Next you need to cut the 2x2 to length. You could just assume it should 10" to match the base, since it isn't critical that the cleat be perfectly flush, but I like to make things neat so I marked the cleat by matching it to the base.
Step 9: Drill and Counter-Sink Holes for the Bottom Cleat
To attach the bottom cleat, I used 1-1/4" construction screws. You could just set the base on top of the cleat and drive the screws in, but I find that it's hard to get pieces to come together tight if you thread the screw through both the top and bottom pieces. Plus, unless you drive the screws far enough into the plywood, the sandpaper holding cleat wouldn't sit flush.
So I drilled four pilot holes spaced somewhat equally within the outline of the bottom cleat with a 5/32" drill bit. You only want to drill through the base. Then I counter sunk the holes so the screw heads would sit below the surface with a counter-sink bit.
Step 10: Fasten Bottom Cleat
Now all that's left to do is screw the bottom cleat on. Make sure that you put the two bolts in the place first, otherwise you'll be taking the cleat off again.
You can drill pilot holes for the wood screws if you wish, especially if you plan on tightening the screws with a screwdriver, If you do be sure to use a size that's smaller than the screw threads.
Step 11: Final Assembly and Thoughts
All that's left is to put the plywood cleat back into place and start using the sanding hook.
You might want to epoxy the bolts in place. Otherwise they might spin while you're tightening the wing nuts. I found that it was just as easy to hold the bolt by the threads while tightening the wing nuts. I'm able to apply more than enough pressure to hold the sandpaper in place.
Depending on the wing nuts you choose you may want to place a washer underneath them so they don't dig into the wood.