First post but MAN, this has been an INVALUABLE resource. Ohhhhh, the amount of learning and investment to learning this industry. Im all in! From lab equipment, to drivers, and beyond. So, I thought Id pay a little bit of it back. Theres been many posts about hydrocolloid. One thing that I love about is how replaceable it is. One thing I hate about it is how EXPENSIVE it can be. 6kg of Egger is over $200 and Krystalloid is a bit better but not as forgiving and the dreve lacks tinsel strength upon impression removal. Ive gone through countless hours figuring this out and gave up no less than 5 times. Until, I read the Krystalloid MSDS. While this doesnt give the recipe, upon further reading on the effects Agar reacting with ethylene glycol, I had another starting point. I finally recreated, in my opinion, an improved Krystalloid. This is still reversable. All the items can be purchased from Amazon or from a chemistry supply house. One thing is imperative to have, and that is a reliable food/ gram scale.
this is the recipe for a 500g batch.
125g - propylene gycol
125g- ethylene glycol
15g - vegetable glycerine
5g - Agar Agar Powder (NOT THE FLAKES)
1g - Borax (not essential but seems to help with mold strength)
230g - filtered water
1) mix all the liquids together at room temperature.
2) add the Agar Agar. Using a whisk, stir in the Agar to the mixture. Let soak in solution for minimum of ten minutes. I like to use a stand-up mixer during the entirety of the soak time. HOWEVER, BE CAREFUL! ETHYLENE GLYCOL IS WHAT MAKES ANTI-FREEZE AND SHOULD NOT EVER BE INGESTED. Clean-up well with dish soap and water. I wash everything 3 times. Lol.
3) pour solution into a small cooking pot. Set the cooking temperature to LOW or 1. Allow to come to temperature. Stirring often.
4) increase cooking temperature to MEDIUM. Monitor temperature very closely with an infrared thermometer. Solution should NEVER come to a boil. Continue stirring as often as possible. The agar is not into solution YET. The mixture should be very cloudy when you stir.
5) This process can take up to 20-30 minutes, if not longer. Once you are able to stir the mixture and the cloudiness doesnt reappear then the agar has been absorbed into solution. Leave on stable heat (90-95°C) for an additional 15 minutes.
6. Pour i to separate container and allow to cool at room temperature. You will notice that it will stay rather thinly viscous even at lower temperature. Once it is at about room temperature, place into the refrigerator for one hour. Then you are ready to GO!
FOR REHEATING:
1) Cut/ chop the solidfied agar into small squares. The finer the chop the easier it will melt. Place into a small glass bowl that is microwave safe.
2) heat in the microwave for 2 minutes at 10-20% power. Monitor through the window during the melting process.
3) once complete, stirr the colloid slowly for 30 seconds to evenly dosperse the hotter and cooler liquids in the mixture. Allow the rest a total of 90 seconds while stirring. Repeat steps 2-3 until mixture is completely liquified and there are no lumps.
Optional: after the melting process is complete, I dont stir the solution. My microwave has a “warm and hold” setting. I press the warm and hold button and allow it to warm/ equalize for 5-10 minutes, depending on the amount of colloid. Also, if you go TOO long a film/skin will form on the top of the colloid (kinda like queso). You can easily remove it with a large spoon.
4) let cool to 115F and then slowly pour with the stream no wider than a pencil and the container as close to the investment form as possible.
this recipe is a little thinner than most (almost Dreve fotogel viscosity but WAY thinner than the nicefit). Small bubbles will NORMALLY escape no problem. I use a chemistry plastic disposable pipette to remove large bubbles.
