well the title says it all ! but i think its very cool since not many people are advertising that method !! i can see some use in it when it comes to tools and many other things !
Good job, looks very nice. You can also make plaster molds and do lost PLA casting by burning or melting out the PLA from the molds and filling them back up with molten metals. If you're going to do that, don't forget to vibrate the plaster before it sets to eliminate air bubbles.
Wouldn't TPU make a better mold? It's flexible, so it probably would be re-usable.
You misunderstand. The point of lost PLA casting is to make a positive in PLA then form a mold around it. You then place the mold into an oven and burn out the PLA leaving a cavity in the mold that you later fill with metal.
That video was about printing the mold directly in PETG and it recommended against using PLA for the mold. My point was that if you're going to print a mold for epoxy casting, TPU would probably be better.
As an analogy to the ancient technique of lost wax casting, lost PLA casting strikes me as dicey. I'm skeptical that you would ever get all of the PLA out of the mold by burning (judging by how hard it can be to clean a nozzle), and if you make a mold that separates into parts, you could simply pull out the PLA part without burning it.
If you're going to go that route and want a reusable mold, might as well do it with silicone.
Gotta start somewhere. It can be done but you have to bake it for quite a while.
If the object requires a breakable mold because the mold can't reasonably be made in parts, with lost wax at least the sculptor could be confident that the wax would drain out, and what wouldn't drain would vaporize or float to the top as metal was poured in. PLA is way more viscous and doesn't vaporize, it wouldn't necessarily drain out, and if I baked it, wouldn't I end up with bits of charcoal inside?
This video explains it pretty well.
That was a captivating video. Thanks.
Way beyond what I can do living in an apartment though. :)
XD At least I know you won't be burning your place down today.