Budget Solution: Glycerine VS Saline Water, A One Year Test.
With a large resin tank, you will have 14L to fill up the tank. Investing a tank full of resins could be expensive...so we looked for other solution, found these two options and did a long time experiment on both since the day we decided to build a large printer.We will talk about the pros and cons of both method, and why we recommend Glycerine as the best solution.
On Glycerine: Left - Mango Cast, Mid-Espresso, Right-New resin in testing.
Result: Distinctive layers. Won't mix with resin when stirring. Settle back slowly after time.
Why resin floats?
Resin has a lighter density(~1.02 - 1.15g/cm³) than both saline water(~ 1.2 g/cm³) and glycerine(1.26 g/cm³).
Method 1: Saline Water (Not so recommend)
Pros: Easy to get, just mixing table salt with water til saturated.
Print quality: Great
Cons: After 1-2 week, water starts to dry out, you will get lots of salt crystal after every print. The longer time used, dry out more, too many salt left on panel every time.
Solution: add water/replace regularly to keep salt saturation level.
Method 2: Glycerine (Recommend) Pros: Cheap to buy, we get it around USD$50 for 25KG in Hong Kong.
Print Quality: Great
Cons: Occasionally a spot if the resin layer is too thin.
Solution: Keep the resin at 1cm- 2cm thick. The spot could also be sand away.
As resin itself has some separate of its pigment, from time to time a separated yellowish layer could be seen. It's more obvious for Espresso (Black) resin, the resin becomes bit greenish instead of dark black color. Its normal. We would recommend to stir the resin every time before print.
In both method this layer tends to mix down a bit with the glycerine/saline water. Just stir it thoroughly and it won't affect the print quality.
After collecting back the resin, please do not put back with unused resin. It is recommend to store with 2 times more glycerine/saline water as the base in the container.
Keep it in cool place, avoid direct lighting.