This Instructable will cover two ways to form the objects being made. The pictures are from a variety of trial and error projects and won't match up but the steps are the same. Recently I got a solder suck (like a little turkey baster) after several months of desoldering old electronics for their components I have a bag full of little solder bits. I also ended up with a bunch of stumpy crayons and candles. But what to do with this old stuff.
The solution was to melt both down and make them into the shapes I wanted.
The two methods are using a knife to shape the wax and them making a mold of it or using a lathe to shape the wax and then molding that.
This project deals with molten metal and wax, along with plaster of paris (follow safety instructions on box) and most solder contains some lead so wash your hands frequently. Please be careful as all of the above can damage you, I am not responsible if you hurt yourself. (the knob was made from lead free solder)
Step 1: Materials (knife Method)
Materials (the main ones )
Wax (old candles,crayons,or you can buy it in a candle making kit)
A knife (small)
Carving tools (optional)
solder (recycled or bought)
A couple of aluminum cans or another container that can be used for mixing the plaster
a stove and pot
a fire pit
some scrap metal (old dvd player) or a crucible
pliers (needle nose)
Plaster of paris (hardware store or art supply) varies on amount depending on the size of mold/object your making
hot glue gun
pin (or paperclip or thin pointy carving tool)
wood (for fire)
dust masks (for plaster of paris)
some sort of coating for the final project (paint, polyurethane, or something)
release agent (vasaline, oil, soot)
image editing software (any with measurements/rulers)
a 3d editing software (not strictly needed but if you want to make a custom object it's necessary)
It's a long list but most are common tools or can be scavenged
Extra materials for lathe method
another smaller piece of scrap metal
tin snips (scissors that will cut the scrap metal)
sharpie (or permanent marker)
Allan key(s) for lathe
small file (recommended)
other helpful but not necessary items:
A glove that resists heat
large tongs for fire pit
a vibrating motor(or table to set the wax)
Step 2: Get Blueprints
There are a couple of ways of doing this but you will need
for the carving method a top side and front view of your desired object scaled to the size that you need it
for the lathe method you just need the side view
To get three views you can either do a quick internet search to find the images or you can follow my method of making your own 3d designs and printing there blueprints. First make your object (try and be only as complicated as your real world modeling skills are with a knife) and then set your views to top,front and side. Then take a screen shot (print screen on windows) and paste it into your image editing software that is set to the size of paper your printing on (8.5 x 11 in) and scale the images to the right size by comparing it to a line drawn of the correct length. Then print off your image(s)
Step 3: Make Wax Block
I had allot of trouble with getting mine free of air and water bubbles, however I think a vibrating motor will help alleviate these problems.
First melt the wax in an aluminum can emerged in boiling water. Then take the cardboard tube and hot glue one end to a piece of scrap wood so that it is water tight. When the wax is completely melted pour it into the tube (attach vibrating motor now to avoid sinkage/bubbles). If your using the hand carved method you can just remove the can and agitate it while it dries. To remove the can simply cut it off or unwind/tear it off (careful its sharp) this can also be done with the cardboard tube but a better way is to emerse the tube in water until it is soggy enough to easily come of the wax without sticking.
If the lathe method is being used cut the wax so that one end is triangular (so it will fit in the chuck nicer)
Step 4: Carve Wax
for the hand carved method cut the block to approximate size and then place the paper image ontop and pock holes along the major features so that it leaves an outline on the wax. Next following these guides carve the wax to the desired shape.
for the lathe method trace the outline of the piece onto the smaller piece of scrap metal and cut along it with the tin snips so that a 2d version of your object is cut out. Now I advise sharpening this new custom cutting tool with the file but its probably jagged enough to cut on it's own. Next secure this blade into the tool mount and the piece of wax in the chuck (tightly) and move the custom blade slowly into the wax until eventually the object you want is completely finished.
Step 5: Prepare Mold
Once the object(wax) is complete make a mold out of plaster of paris by following the mixing instructions on the back of the box while also following the safety instructions. Coat the wax with the release agent so that it will not stick to the mold, For two part (multiple use)mold only submerge the object half way into the plaster. If your object is symmetrical (lathe turned) then the mold can most likely be used multiple times just ensure that once the plaster sets your piece can be removed. If its hand carved chances are it won't come out of the mold as easily and will likely be a one use mold, however it means you can skip a step and almost completely cover the object with plaster(leave a opening to pour the metal into/wax out of). For two piece molds once the bottom half has set cover the plaster with the realses agent and then rpour over top of the object completly covering it. When both haves are dried remove the outer casing and separate the mold this sometimes need a little poke all the way from the outside of the mold right into the wax to release the vacume, or a thin layer of plaster all the way around may be needed to be cut through.
Step 6: Prepare the Crucible
If you already have a crucible (something to melt the solder in ) then obviously you can skip this step. I made mine by hammering the DVD casing into a tube like shape and then checking water tightness in the sink. My first attempts at making a crucible failed don't use copper pipe or an aluminum flashlight body.
Step 7: Casting the Metal
make a fire (be safe about it) and place the crucible with solder in it into the fire until it is melted, then pour the molten metal into the mold. If the object is complicated and has fine detail it is a good idea to heat the mold up (in the fire) before pouring the metal. If you had a one time mold first heat the mold until the wax drips out then pour in metal. Then brake off the mold. Or separate the mold and remove new metal object (depending what type of mold you have).
Step 8: Finishing Touches
sometimes there will be extra plaster stuck to the object or a ring of solder around the were the mold halfs touch these can be removed by knife or soldering iron. If you are using recycled solder it is a good idea to coat the metal with something to prevent the lead that is in it from coming in contact with your skin.