Here's my Tech article for the Baileigh Bailout contest. At first I was going to do a post on metal shaping/ making a gas tank, but I figured I should mix it up a bit an do something off the wall that everyone can do at home with little money and still have great results. Besides if I just happen to win I'll be doing quite a bit more posts using my new Baileigh Industrial tool! So without further adieu... This tech post will go through all of the steps to cast car club plaques from scratch, however the general rules of sand casting can be applied to any sort of casting project that you might have. Step 1 Making the wooden buck that you will use to make the sand cast. I generally do all the wood work by hand. For plaques specifically I actually use different layers of wood. I start with a base in the rough shape of the final piece, and then add on. For this plaque (which is acutally for our clubs bike plaques), I used 1/4 inch bass wood, which you can find at any local hobby store that sells remote controlled airplane kits. I use bass wood instead of balsa because it is more dense and less pourous which will be a big deal later when you coat the wood with varnish, but it is also easier to work with than hardwoods and can be cut with an exacto knife. I generally buy couple pieces of flat 1/4 inch, and a couple stringers (thin strips). Take your drawing of the plaque and trace the letters on to the wood with a piece of carbon paper one at a time (this is because you have to bevel the cutouts). I genreally use a few different tools to cut out the letters, a knife, small scroll saw blade, small hack saw blade, finger nail file, small jewlers files, and some smooth grit sand paper. You want your end product to have between a 1 degree to 3 degree bevel from top to bottom of the letter (this is so the sand holds its form). The more intricate the piece the more degree I put on the cutouts. once the pieces are cut out (hours of work). Take them and glue them to the base. take the stringers and cut them to fit around the outside of the piece so that they make a border around the letters (this will give the plaques the look of being routed instead of cut out by hand. Once every piece fits the way you want it to glue the pieces to the base, for this I use super glue becasue its quick and thin, you don't want any excess coing out the sides because it will ruin the clean look of the piece(and possibly the mold). Bevel the sides of the outer edges the same way you did the letters. Once done you can glue the whole piece to a stiff board, so that it won't warp. Step 2 Use a thick varnish that dries slowly and put coat after coat onto the piece, do this with a nice brush so that you don't get streak marks in the final product. You will want to have a nice thick smooth coating on the piece so that it fills in the grain, as well as builds up anywhere the letters meet the base. You want to have whats called a valley between horisontal and vertical pieces. This is a sloping transition instead of a hard edge. Once that is done coat the area on the board around the plaque, so that sand won't stick later. After it is completely dry lightly sant the tops of the letters with 320/400 grit and a block so that they are all the same plane, and smooth. Here is the final product: Step 3 This step could be skipped if you are a daring and adventurous individual that doesn't care too much about wasting time... I learned the hard way one time loosing a buck when it caught fire (sand was too hot). So now I always make a silicone mold of the original just in case, its quick to do, and though a little pricey worth every penny considering it takes up to 40 hours to make the original.... Make a thing aluminum (or whatever isn't porous) outer ring. You want the ring to sit away from the buck at least a half inch. and Make sure the ring sits above the buck at least a 1/4 inch. This way the silicone doesn't loose shape. Duct tape the ring to the wood base really well so that it creats a liquid tight seal (nothing worse than watching $30 worth of silicone run onto the floor). Mix your silicone together in a disposable container, do this well but not vigorously so that you can keep the bubbles to a minimum. once it is thoroughly mixed poke a whole in the bottom edge of the container, set it on a table, and let the silicone run into the ring that you made. Let it run into one corner only and flow to the other, this is the best way to eliminate bubbles, and air pockets without having a vacuum chamber. Once the mold has set up you can remove the outer ring ( but retain this so that the mold will hold its shape. You can then remove the silicone from the buck (but do this carefully so that it doesn't tear). Now you are ready to pour a plastic copy of the original buck. I do these for two reasons, one is to make sure the mold looks good, and two, to make multiples if I plan on casting more than one at once. Step 4 It is finally time to start setting up for the sand casting. Most hobby casting store or web sites sell casting kits like the one I have here. These are very good for small items but for really large stuff you need more professional equipment. One of the most important parts of the sand casting process it what is called the Cope and Drag. It is two halfs that have centering pins to align them up with each other once the buck it removed. The one pictured here is a small flask style used in jewlry making. It is a little too small for the plaque that I am doing so I made my one revised version out of flat stock. I left the centering pins off of mine because I'm only concerned with picking up the detail of one of the sides. I then cut the corners once it was bent in a rectangle and tappered them out then wleded it back up which helps the sand stay in form once it is pressed. More to come!