Palm sander fixture for scale slabs
While working on my first restoration, I hit a small stumbling block - the 1/8" thick slab of scale material I ordered was actually somewhere around 3/16" to 1/4" thick. Rather than trying to sand the slab down by hand, I made the following fixture -- for under $12 -- in order to be able to take advantage of the time and energy saving benefits of a palm sander.
- One 1/2" thick, flat piece of hardwood with its length and width sized to be 1" wider than the size scale slabs you like to work with. For example, I don't plan on making scales longer than 6" and wider than 1 1/2" from the base of their arc to the top of their arc. I went with hardwood for two reasons: 1) durability against use and repetitive screwing/unscrewing, 2) it's important the piece be flat. I don't have of milling a piece of wood to ensure it's flat. So I did the next best and easiest thing - I went to Home Depot, grabbed a 4" wide by 1/2" length of red oak from the aisle with wooden flooring stairwell materials, and had them cut me an 8" piece. Unlike all the rough cut lumber, the pieces in this section are pre-milled to be flat. (Cost: ~$1)
- One piece of 1/2" x 36" x 1/8" steel bar stock from Home Depot (~$3)
- One 1/4" carbide drill bit. You'll be drilling steel with this so it MUST be carbide. (~$2)
- One 1/8" carbide drill bit. Again, you'll be drilling steel with this so it MUST be carbide. (~$3)
- One packet of #8-1/2 flat head wood screws (8 screws total needed). (~$2)
- Cut the bar stock into 4 pieces: 2 that are the same width as you piece of wood, and 2 that are the same length as the wood MINUS 1". SEE PICTURES BELOW
- Using the 1/8" bit, drill two evenly spaced holes in both short pieces of bar stock, two evenly spaced holes in one long piece of the bar stock, and 4 evenly spaced holes in the other long piece of bar stock. NOTE: To drill the steel A) use a hammer and nail to tap indents where you plan to drill so the bit has something to bite into and won't 'dance' across the surface, B) put a drop or two of oil - camellia, motor, WD-40, whatever - on the indent to provide a little lubrication and cooling. C) drill on LOW speed (the lower the better), the bit will cut MUCH more quickly and effectively at low speed whereas high speed can heat up the bit, degrade, and dull it
- Use the 1/4" bit to countersink all of the 1/8" holes you just drilled. Be careful - it goes quick and if you're not carefull it can go all the way through and ruin the hole (i.e. you'll notice one of my long pieces have 5 holes instead of 4). SEE PICTURES BELOW
- Arrange the bar stock pieces on you piece of wood as shown below. Mark the holes on the wood. FOR THE 4-HOLED PIECE OF BAR - only mark TWO holes on the wood.
- Use the 1/8" bit to drill the marked screw holes in the wood
- Screw the bar stock pieces to the wood
The reason for 4 holes in piece of bar stock: If you want to work on a wider slab in the future, unscrew the two screws holding down the 4-holed bar, slide it out to the desired spot. Mark and drill holes in the wood for the TWO bar holes that WERE NOT used in the last postion. By staggering the holes from one position to another (e.g. zig-zagging between sets), you can set positions for many small, incremental width changes without each new set of holes overlapping/widening the previous set of holes.
That's it. Rubber cement you slab into the fixture. Let the cement set. Then pull out your palm sander and go to work thinning down you slabs to 1/8 of an inch thick.
While this is not so exact as to assure a perfect, even, absolute 1/8" thickness on a slab, it'll get well withing the ballpark.