Flow lines on injected wax models

WAX INJECTION AND WAX TEXTURING

Wax injection can be a black art. What works for one may not work for others. Wax too hot can cause problems or solve problems. Mold temperature can be a problem.

I have created many buckles for which I made rubber molds. Normally I do not have problems in the waxes I inject.

I use Rio’s Pink Buckle wax. I inject from my pressurized wax injector at a pressure of around 12 psi and a temperature a little less that 160 degrees. My wax pot is pressurized by a built in pump. I clamp the mold in a clamping device. That seems to work for me.

I do not inject wax into a warm mold. If the wax is warm from a previous injection the design is not sharp. The edges are rounded and not sharp. Either a hot mold or too hot wax caused this problem. I find the best wax I get is from the first injection of the day.

The faster the wax flows inth the mols the better.

I think the lines you describe are chill lines caused by the wax flow stopping for an instant then flowing again. This could easily be caused by inconsistent pressure on the injector pump.

This is the back on one of my Bolas. It is around three inches long, 2 mm thick with engraving that is 1 mm deep.

If I have a problem getting wax into the bottom of the mold I spray the surface with silicone spray and put talc in the cut edges of the mold. If all that does not work I place 18 gage wires in the mold from the inside bottom of the mold to the outside. This provides large vent holes.

One solution to the flat back of the mold being not perfect is to texture it. One texture can be created by using a small wax burr in a cable driven hand piece. Tap the burr into the wax so that the burr just cuts a shallow cut. The texture can be varied by using different sizes of burrs. Note there are burrs sold by Rio that are specifically designed to cut waxes.