I found it was prone to breaking as I removed the thicker supports -yes, true. It it is problematic. Now I tend to group those supports as a bunch together and technically use them as sprue base and do not remove them, just break the base layer off and it is ready to be used in the jewelry tree(not sure the english equivalent. Frequently it work but requires additional work at the end.

I also run a wax mill, a Roland JWX-30 4-axis Wax Milling Machine - I do not have them at my disposal as well as rubber molding staff so I have to make this option work somehow

Platinum investment - If you don't like working with it, then don't. - That was a good advice thank you, never thought about that. Just joking. I definitely dont as it requires more effort than the regular investment but for now was the only way I got more or less reliable surface. As I do not want to do additional investments into specialised technology for working with this kind of investment I still want to try make the Plasticast work. By the way I tried to dilute this investment a bit also and seems that Formula also works the best thiker rather than diluted. One clear advantage of phosphate based investments is the possibility for rapid burnout.

It should turn to a pinkish-white color when it's properly cured. - By the way I tried mixing the green and cast materials, added a bit green in it. It basically behaves as cast in terms of curing but was a bit sturdier. Also you do not have to use up the curing lamp resource, direct sunlight does the same trick. Just leave them under direct light for half a day or a day.

FTX Green, expansion starts at around 800F (426C) - thank you for this data. It definitely starts smell plasticky around 300C. The only thing I havent tried is to increase the process of climbing the temperature from 150C to 500C to 3-4 hours hoping that the degrading and oxidising of plastics will happen slowly, fully burn the ash and will ruin less the surface during the burnout. It seems that the rapid burnout ruins the walls inside the mold with regular investments and lives small trash pieces inside. When metal filles in the mold the trash pieces ruin the surface leaving dents in it. For example Sample 1.jpgSample 2.jpgSample 3.jpg

But if you're working within a strict budget, like I was - yes, that is true also. The investment should be justified. The thing is I do not have materials and instruments for rubber molding so I have to buy them as well if I will go that way and for the moment I am trying to avoild it. Actually I wrote to their support asking the questions but have no answer so far. I have a feeling that their advirtisement for a "castable" material was a bit too optimistic.