Injection molding material SHERA Cast

SHERACAST - Molding paste for model casting

Destination
For chrome alloys using slow convection heating or rapid firing.

Technical data
Working hours - 4-6 minutes
Operating temperature (important!) 20 - 23 ° C (powder and liquid)
SHERA labels all of its products. We recommend that you do not use it in combination with products from another manufacturer, as this negatively affects the quality of the casting.

Mixed Proportions
Silicone duplication:
100 g model of powder: 21 ml of liquid
flask: 400 g of powder: 84 ml of liquid
Gel Duplication:
model: 100g powder: 19-20ml liquid
             400g powder: 76-80ml liquid
Flask: 100g powder: 21ml liquid
             400g powder: 84ml liquid

Temperature
When mixing powder with liquid, room temperature is required.
(Ideally maintained indoors at 23 ° C).
Training
Treat the model in a circle with a dry trimmer so that the base becomes conical. The base of the model should have a minimum thickness of 2 cm in the thinnest place.

Do not use silicone flasks and wax blanks with a stress relieving agent. Under no circumstances should you use a flask with petroleum jelly.

Estimated data for expansion control
For model:
approx. 70-80% SHERALIQUID: 30-20% de-ionized water, depending on the type of work and shrinkage of the metal used.
For flask:
50% SHERALIQUID: 50% de-ionized water

Mixing
- Pour water into the mixing flask.
-add powder
- mix vigorously for 15 seconds
- mix under vacuum for 45 seconds; speed approx. 250 rpm. (revs will reduce expansion more)
- Leave the mixture under vacuum for the next 15 seconds without mixing.
Use mixing flasks and spatulas only for investment material. Never use them for gypsum. Mixing flasks must be absolutely clean and free from residual investment material. Clean scratched mixing flasks with sandpaper.

Vibrating table processing
Fill the flask at the lowest vibration. Stop the vibration as soon as the flask is full. To prepare the flask, treat the surface opposite the gate.

Gel Duplication
If the duplicate form is chilled in cold water, the duplicate material must accept room temperature and be dried before filling it with the investment material. After approx. 30 minutes, remove the model. Dry in the muffle for 25 minutes at 160-180 ° C and lower it for 2 seconds in the SHERAPOR-L hardener. Place the model in the muffle for the next 5 minutes.
When using high-speed firing, we do not recommend gel duplication.

Silicone duplication
After 20 minutes, remove the model from the mold and dry in an oven or muffle at 140 ° C for at least 5 minutes.
Apply SHERAMODELLHAFTGRUND for better grip on the wax.

Heating and casting
a) conventional heating process
When using the process of conventional heating, an increase in the established expansion is observed. Therefore, the liquid concentration can be reduced to 5-10%, depending on the type of work and the alloy used.

Exposure stages are not an absolute necessity; if the flask should warm up:
1. stage at 290 ° C, heating level 3 ° C / per minute; heating for 20 minutes;
2. stage at 590 ° C, heating level 6 ° C / per minute; heating for 20 minutes;
3. final temperature approx. 850 ° C (no need for a higher temperature); heating level 8 ° C / min; warming up for 40 minutes.
If vacuum / pressure casting is used, the final temperature should be increased to approximately 50 ° C.
(If the furnace is full, then a full warm-up at the final temperature will last 20 minutes longer).

b) High-speed firing
For high-speed casting, we recommend silicone coating, if possible, rather than gel.
As a phosphate-containing material, the package is hygroscopic and it is better to use it in bags for high-speed firing. Material in large packages is only suitable if stored properly, in which it cannot absorb water (storage in a container with a tight-fitting lid). If the material has absorbed water, breaks and chips may form.
Treat the surface opposite the sprue.
Set time: 20 minutes from the start of the mixing process.
Place the flask in the oven at 800 ° C and continue heating, if necessary, to the final temperature, taking into account the metal used (max. 850 - 900 ° C). Heating at final temperature for 40 minutes.
Caution: Place the flask with sprue face down on the ceramic base plate.
Do not open the oven while the flasks are warming up!
Make sure there is enough space in the oven when using high-speed firing.
The warm-up time is increased by 10 minutes with each new additional flask.

Cleaning
The flask can be gently cooled under running water after about 30 minutes after casting.
Other technical information

The material contains quartz. If dust forms during mixing, wear a face mask or respirator to avoid health problems.
Always leave unused mixing flasks filled with water.
Avoid any contact of phosphate-containing materials with gypsum-containing materials, tools and containers.
Fill the mixing flasks with water if you are not using them. Do not clean the flasks for mixing with detergents, this may cause slow setting of the investment material or it will remain soft.