DIY: Map Board and Sifter

One thing I really enjoy is a good DIY project, especially if I’m making geology tools. It’s often much cheaper to use homemade tools, and there’s a sense of pride in knowing that the sifter you’re pulling fossils out of mud with is something you poured time and sweat into making. Aside from rock hammers, shovels, and other rockhounding necessities, there are some tools that many people don’t think about that can make your time in the field a lot easier. So here, I’ll show you an easy to make a couple of those.

MAP BOARD

Before I went to field camp in Nevada this past summer, I was given a long list of supplies I needed for collecting data and making maps. One of these items was a map board. The benefit of making a map board versus using a clip board is that you can have a lot more room to work with. Maps can be big! And a clip board just won’t suffice when dealing with large areas of land on a 1:12,000 scale map. Another benefit is that there is no ferrous material in the map board, meaning a compass won’t be influenced by any magnetism (a problem I’ve encountered many times when orienteering with a basic clip board). So here’s how to make a very basic but effective map board. I usually make 12″ x 18″ boards, but these instructions will show you how to make an 18″ x 24″ board.

Supplies:
  • 18″ x 24″ polycarbonate (plexiglass) sheet ~ $6
  • Duct tape ~ $2
  • Glass cutter ~ $2
  • Ruler

 

Step 1: Find a flat surface. Lay down newspaper if you wish to keep the polycarbonate sheet from getting scratched and to protect the floor/table from the glass cutter.

Step 2: Lay down the polycarbonate sheet and draw/scratch a line down the middle. I line a ruler up in the middle as a straight edge, and then run the glass cutter along the side of the ruler to make a line. This line is where the hinge of the board will be, so try to get it as close to the middle as possible. Also, be sure to make the line perpendicular to the long axis of the sheet. Hamburger, not hot dog!

Polycarbonate sheet with guide line

Polycarbonate sheet with guide line

Step 3: Continue to run the glass cutter along this line until a deep groove is made. Keep cutting along this line until you’ve cut about 1/2 or 3/4 of the way through the sheet.

Step 4: Align this groove with the edge of the table. Once you have this groove along the square edge of a table, put pressure on both sides of the line. Don’t try to force it, but keep giving even pressure until the glass breaks along the groove you made. If it doesn’t break easily, cut the groove a little deeper and try again.

Line the polycarbonate sheet up with the edge of a table and put pressure on both sides...

Line the polycarbonate sheet up with the edge of a table and put pressure on both sides…

... until it breaks.

… until it breaks.

Step 5 (OPTIONAL): Sand the edges of the sheets. While not necessary, I like to have nice smooth surfaces on my tools. Be warned though that sandpaper will scratch the sheet.

Step 6: Place the two halves adjacent to each other and tape them together with duct tape. On the front side, I touch the boards together, getting them as close as possible and then run tape along the middle. For the reverse side, I will collapse the map board (like closing a book) then run tape along the spine. This ensures that the hinge will open and close properly and won’t have to be forced when closing it.

Place the two halves next to each other and get the duct tape ready.

Place the two halves next to each other and get the duct tape ready.

Tape both sides of the board along the hinge.

Tape both sides of the board along the hinge.

Step 7: Get outside and enjoy your map board! Print out a topographic map of a state park, grab a compass, and test your orienteering skills; find a geologic map and use the map board to mark your finds; or go sit on a hillside and paint scenery. The map board has many great uses.

If only I could get to Venus so I could use this map...

Finished map board.

TIP: Home Depot and many other hardware stores sell an 18″ x 24″ plexiglass sheet. This can either make an 18″ x 24″ map board by cutting the sheet in half or two 12″ x 18″ map boards by cutting the sheet into quadrants. The latter is a nice size because when collapsed, it can fit easily into a backpack.


GRAVEL SIFTER

One of the most useful tools I’ve used is a gravel sifter. While most think of gravel sifters as yard and gardening tools, I’ve found a few more uses for them. Depending on the size of the chicken wire or mesh you use, the sifter is perfect for collecting rocks and fossils in sand/mud. I’ve used this sifter to collect vertebrate fossils in the Peace River, FL, shark teeth at Venice Beach, and shark teeth in northern Mississippi.

Supplies:
  • 2x4x8 wood ~ $4
  • 3/4″ poultry net staples ~ $3.50
  • 1/4″ chicken wire ~$5
  • 2 1/2″ wood screws ~ $2.40
  • Miter saw
  • Power drill
  • Ruler/measuring tape
  • Wire cutters
Sifter supplies.

Sifter supplies.


Step 1: Cut the 2×4 into four 2′ sections. Use the miter saw to cut the board into four equal sections. It’s important to make sure they are all the same length or else the frame won’t be symmetrical.

Four equal 2x4 sections.

Four equal-length 2×4 sections.

Step 2 (OPTIONAL): Sand down the wood. Again, this isn’t necessary, but I like to do a thorough job and also like to not risk splinters (ouch).

Step 3: Screw the four 2′ sections of board into a rectangle. Once the four pieces are in position, secure them with the 2 1/2″ screws into a rectangle-shaped frame. Since there won’t be any direct loading on the frame, the way you screw it together isn’t critical, as long as it makes a “squarish” shape.

2x4 Frame

2×4 Frame

Step 4: Cut out a section of chicken wire to cover the frame. Use wire cutters to cut the chicken wire into the same size/shape as the frame. If the wire goes over the edges a little bit, that’s okay.

Step 5: Secure the chicken wire onto the frame with poultry net staples. I place one staple every three or four inches just to be secure, but you can use less. And in the spirit of geology, I always use a rock hammer to hammer down the staples.

Poultry net staples.

Poultry net staples.

Stapling the chicken wire with poultry net staples.

Securing the chicken wire with poultry net staples.

Step 6: Hammer down the loose edges of the chicken wire. This step helps prevent getting poked. The loose ends on the chicken wire can be sharp, but they can be hammered into the wood frames so you don’t cut or poke yourself. Safety first!

Gravel sifter.

Gravel sifter.

Step 7: Get sifting! Find a creek or river bottom and sift through the sediments. You never know what you might find.

TIP: These instructions show how to make a 2’x2′ sifter. For younger rock hunters, try making a 1’x1′ frame.


 

Special thanks Gruncle Woodruff for giving me inspiration for the fossil sifter. Couldn’t have done it without you, Gruncle!

Tim

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