Sprues are those (red wax tube) things that attach to your wax patterns in Ceramic Shell and Investment lost wax casting molds. To hold those sprues to your patterns the conventional method is wax welding the two different types of wax together by basically fusing the parts, cooling them completely, and smoothing the ensuing wax mess. We switched to a sprue glue that is commercially produced but tired of the $8 per puck price tag. The glue is great because it is twice as fast and doesn't wreck your pattern. So, we figured out how to make it, and here are some recipes.
Montana Sprue Glue:
3 pts. Pine Resin or Gum Rosin in crystal form
1 pt. Beeswax (we use the dirty stuff from the local honey producer)
.1-.5 pt. Vaseline to make softer or stickier
.1-.5 pt. Candle wax to make harder or less sticky
As resin/rosins vary in tackiness, that is the component I would vary if your batch isn't sticky enough.
I slow heat a crock pot or wax melter to 170 degrees F, no warmer.
Put in Resin and Beeswax.
Add last two ingredients as needed.
Scoop out a sample to cool completely.
Check how it handles, heats, melts and fuses, cool workpiece, and test tensile strength, adjust.
Safety:
Always ventilate your workspace and locally ventilate your wax melting pot.
Always wear splash resistant goggles when working with hot liquids.
Rubber gloves aren't much use here, but cheap leather farm gloves are okay.
Never allow wax pot to get above 195 degrees F.
Stir with metal utensil, gently and slowly.
Never work wax with sandals or any open toed shoes.
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