Pouring and Working Wax p. 5
Pouring and Working Wax p. 5
Pouring a wax may seem to not involve much, but in actuality it can be very involved. I preheat all molds in a converted refrigerator (plans and instructions in “making your equipment” section) so my molds are at a constant temperature, year around, whether poured in the cold of winter or the heat of summer.
Mold Heater: I have an adjustable thermostat set at around 100 deg F, hooked to a hot plate for heat inside a used refrigerator. There is also a small squirrel cage fan that runs continuously to keep the heated air at a constant temperature through out the molds in the refrigerator. The molds go int the refrigerator for a a good number of hours (varies with size) to make sure all of the molds are of an even temperature through out the load then removed one at a time to pour wax into them.
Wax Tank(s): Right now I have a broaster/roaster table-top unit I bought at a second-hand store. This unit plugs into a wall outlet and has a thermostat temperature control that I use for the bulk of the wax. I also have a thermostat controlled “crock-pot” type unit for the initial 1 or 2 coats of wax that have more hardener mixed into the blend (hardener is somewhat expensive so I just have the first coat or 2 make of the harder wax, then use a softer mix to build up the “wax”.
Wax Blends: I use 2 different wax blends for making a casting wax. I keep each wax mix in it’s own temperature controlled container and have pouring containers in each pot. I have the harder wax in a 1.5 gallon “infinite” adjustable (not a low-medium-high type thermostat but one with a dial and degrees) crock pot and the softer blend, for the 2nd and 3rd layers, in an electric, table top, “roaster oven” (see pictures 1 & 2 below).
The first coat of wax is a “harder blend”, more PX20 and it is held at a higher temperature (near 220 deg F) so it doesn’t “freeze” as fast, making “freeze lines” on the wax surface and is more liquid, thus filling in the detail in the mold much better.
I use REMET’s Premier Bronze wax for the bulk of the blend, and mix in REMET’s PX20 hardener, mixing in more of the PX20 for wax molds to be made/worked in the summer (hotter temperatures harder wax) and use less of the PX20 in the winter. The amount of PX20 runs around 15 to 30 %, the amount is really up to you, depending on your preferences. PX20 can make the wax VERY brittle at higher percentages (great for sharp, fine details and a very hard wax), while straight Premier Bronze wax is just WAY TOO SOFT by itself, so mix to your liking. I make the outer layer (the first layer) of the wax with the harder wax mix, then “build up” the interior with a somewhat softer blend of Premier Bronze and PX20. Again the hardness is really up to you to decide, it just depends on what you like to work with.
Body Protection: When pouring hot wax, use protective gloves (rubber), face mask and an apron, to keep from getting burned by the hot wax splashes, especially when pouring the higher temperature, first layer wax. When pouring the wax into the warmed molds, especially on the first coat, be careful to not make bubbles in the wax as you pour,,, let the wax run down the inside wall of the molds and pour in the wax as fast as you safely can.
Pour Hole Plug: I make a tapered, RTV covered, foam filled plug to cover the fill hole in the molds so I can roll the mold to any direction without getting the hot wax on my clothes or myself (see the plugs, picture 3). Once you get the molten wax into the mold, plug it, hold in the plug and roll the mold to wet all surfaces. The first coat should be “rolled” for at least 30 seconds to a minute, but these times will need to be figured out by you, using your equipment, wax blends and temperatures, so the 30 seconds is really just a starting point. Let the first coat cool a few minutes, but not too long as it is really a thin coat, then pour in the second coat of the softer, lower temperature wax blend and keep this layer rolling around in the mold for 1/2 to 1 minute, again figure out your times with your setup. With my setup, I let this 2nd coat cool for a good number of minutes to an hour or more before pouring in the 3rd coat. The 3rd coat is again the softer, cooler wax blend, and done like the 2nd coat. For my setup, this is all I need to do as the wax is now close to 3/32” or 1/4” thick. If yours is too thin, pour in a 4th coat after the 3rd coat has cooled. Be sure that the 2nd and additional coats are kept in the mold and the mold constantly rolled and rotated for a good deal of time. If the wax coming out of your first attempts is too thin, look at wax temperatures, time you keep the wax in the molds for each coat and be aware of the ambient temperature as higher temps will slow wax/mold cooling after each wax application.
Wax Tools can vary from purchased tools, modified dental tools, knives, sharpened/formed sticks, home made tools of wood, metal or plastic, patching wax (purchased or homemade), some sort of hot tools(s) and on and on. Also some clean chunks of foam rubber are good to lay the wax on. I feel you need good lighting and either REAL GOOD eyesight or magnification assistance. Just what tools you find suit your needs will come with working on wax for a while. Try things, most anything you think might do what you are after, you just never know what will do the trick.