I carve them from lightweight insulating bricks, they do last 3-6 pours. I bought box of them for furnace which newer happened, so now i use them, then they are ok. Alumina with some binder, good till 1100 C, but cracks quite fast if thin walled. Will cut some small, but thick tiles from them and make a box from sheet metal to last. You suggestion on pouring cup size ? I think - is it possible to make it big enough to take all metal and make it once pour only ? I do bury them at 2/3 of height. Did some run-outs they do fell "funny". But my pouring flip-flops was ok. And i always make sand 1- 2 cm lower than bucket to have a place for runned out metal. Absolutely. Before using pouring cup and finding proper cover for foam - i think of going die cast way from laminated laser cut sheets. Green sand casting with lost foam caused too much tools wear due to embed sand.
Have you seen this thread? http://forums.thehomefoundry.org/index.php?threads/reuasbale-offset-pouring-basin.688/ Best, Kelly
Yes, you are. Loved it after inventor/solidwork stuff - which are over complicated for hobby use. I think, i will make a longer video with walkthrough from simple part drawing to finished casting. And it makes some movent too. Gif is heavy, save it.
Any sections that see the pressurized air should be a good porosity test for your castings. We used to make sterling engines with very low operating temperatures and the working fluid was Helium........castings would have now chance to contain it. Best, Kelly
Mine will be more of medium temperature. I could go till 700-800 celsium, but it needs at least 310 ss steel which is unobtanium in small quantities. And good old 304 is ok up to 550-600 max. But whole tubes for hx cost me only 8 euros. Flanges are reusable if needed. And all sliding surfaces (piston rings and cylinders) are sourced from china oil free compressors. Ptfe lip seal.. Any more data on your low temperature ones ?
They ranged from small devices (.25-1.5 watt heat load) that were about the size of small soft drink can to multiple kw units. They operated down to about 75 Kelvin. The small ones were used for cooling infrared sensors (focal plane arrays) on heat seeking missiles, defensive countermeasures, night vision equipment, etc, and the large ones for liquefying air and storing the resulting O2 and N2. -Military stuff. Best, Kelly
I think, i do found a possible way to test coating thickness if you can see a text it is not to thick:
