The Ultimate Guide to Casting X-One Castable Resin

In this article, I will outline my step-by-step personal procedure for achieving high-quality casting results with 3D printer resin

 

Washing Procedure

 

For X-One wax resin, I recommend a first wash step in alcohol from 5 to10 minutes (3 minutes if using an ultrasonic cleaner). After the first wash, always dry the models with compressed air and then spray them again with alcohol. This step ensures the removal of any residue of unpolymerized resin, which may still be present on the surface of the piece. It is essential to pay attention to this phase, especially to the blowing, to remove any trace of resin from the details and cavities.

After cleaning, when I'm not in a hurry, I let the 3d printed models rest on the table for about two or three hours. If I have to cast immediately, I always prefer to do a 5-minute UV cure to have the pieces as dry as possible.

Each resin has its post-printing preparation cycle to which must be adhered specifically. In the case of X-One and all BlueCast castable resins, this process is short and simpler than competitors.

 

Assemble the Casting Tree with 3d Castable Resins

 

It is always good practice to lightly sand the points where the injection channels will be placed. After sanding, I apply a drop of wax, which I then heat and spread with the wax heater. Only at this point I can proceed with the welding of the wax sticks, obtaining clean and very resistant joints, difficult to pull apart. On how to correctly position the pieces on the tree we will talk in another article, mentioning the principles of metallurgy.

 

How to Properly Prepare the Investment

 

Once the tree is prepared, I always blow it with compressed air to remove any dirt and impurities and I proceed to the preparation of the investment. Although I use an automatic mixer like Saint Louis model, I always prefer to manually measure both water and powder with a scale, because the mixers may not always be precise. In the case of investments such as Plasticast or Optima Prestige, my water/gypsum ratio is 36:100. If I use a manual mixer like an electric kitchen whisk, I slightly modify the ratio to 37:100 to have a more liquid mixture.

After preparing water and powder in two separate containers, I check the functionality of all the elements (vacuum pump, valves, whisks, etc.). There is nothing more frustrating than having to throw away all the work due to a technical problem and not having checked in advance.

I then pour the water first into the mixer bell and gradually add the investment. Immediately after, I mix manually with a silicone spatula to remove any lumps or deposits from the bottom of the container. This operation never lasts more than one or two minutes.

Once the manual mixing is finished, I insert the bell loaded with the premixed investment into the mixer and start the vacuum mixing for a maximum of 2-3 minutes. I use the variable speed whisks to obtain a more homogeneous compound. Once ready, I pour the compound into the flask opening the drop valve, always under vacuum. Only after filling the flask, I activate the vibration and detach the mixer motor, so that the vibration is more effective. The maximum vacuum vibration time I use is 2-3 minutes.

 

If I use a manual mixer, I always proceed with the separate preparation of the elements, adding the powder to the water and never the other way around. Before starting the manual mixing with a whisk, I perform a vacuum degassing cycle to eliminate the formation of foam or air bubbles. During mixing, which lasts a maximum of 2-3 minutes, I always use the lowest speed available to avoid incorporating too much air into the investment and accelerating its hardening. Never prepare quantities of investment less than 400/500 grams with manual mixers.

 

In both cases, the cycle should never last more than 7 minutes and it is essential to always use fresh distilled water, stored in the refrigerator or in a cool place. Hot water accelerates the hardening process of the gypsum, compromising the final result of the casting. I advise against ever using tap water, which may contain chemicals or impurities that can alter the chemical properties of the gypsum and compromise the performance of the investment.

If I have to prepare more flasks, I proceed for each of them from the beginning, never preparing the investment for more trees at once.

Once the investment is finished, I proceed to clean all the equipment, but above all to store the investment in its original packaging and store it in a dry place. Humidity damages it, making it unusable. Remember that investments also have an expiration date.

 

I then let the flask rest undisturbed for at least two hours, three in winter. Chemistry and metallurgy are not art, but science. Jewelry and metalworking are an art, but not the casting. In 10 years I have seen colleagues knead the investment by hand without any measuring instruments, hearing them say: "For the past 30 years, you could have achieved better and more precise results simply by measuring and following the manufacturer's recommended procedures.”.

 

My Best Burnout Cycle for Resin Casting

 

In my case, I use perforated flasks because I work with closed vacuum systems. Any type of flask is fine, as long as it complies with the equipment used. I have seen perforated flasks used without a flange externally to the vacuum chamber.

The burnout cycle I use for 3d resins is always the same for years, positioning the flask with the cone facing downwards:

 * 0-150°C

 * 150°C – 3 hours

 * 150-700°C

 * 700°C – 3 hours

 * Ramp: 8°C/min.

CELSIUS DEGREES

 

Using a ventilated oven, I don't need to turn the flask upside down during burnout. In the case of static ovens, I recommend turning it upside down with the cone facing upwards for the last hour at maximum temperature.

Once the burnout is finished, I let the flask cool down to an indicative temperature of 580°C, which is never absolute. This temperature varies depending on the alloy used, the geometry of the models and the casting system. The metal temperature is also variable and does not depend at all on whether resin or wax is used. I always invite everyone to refer to the technical data sheets of the alloy supplier and the instructions of their casting machines.

After the metal casting is finished, before immersing the flask in water, I always let it rest for a MINIMUM of 15 minutes, to avoid surface defects or breakage of the pieces due to excessively strong thermal shocks.