The riser is a greater mass then the spew, its supposed to solidify last so that the casting has somewhere to pull molten metal from while it is solidifying to minimize shrinkage =)
Very nice!! I have just discovered casting at home. So If my questions come off as way to newbish thats why lol. But the purpose of the riser is so thats where the shrinkage will occur instead of the part itself? Also, wouldnt the sprew take care of that? Thank you!!!
The riser is not only a reservoir for extra molten metal, it also helps in visualising how much metal you still need to add and most importantly, directional solidification. You don't want your metal to solidify from both sides because then you get a weak and mushy centre. So when the molten metal fills up the riser, metal starts solidifying from the runner side (your main metal, that is the metal filling up the mould). The metal filling up the riser is the extra unnecessary metal which prevents solidification of the metal in the mould on its side. So the solidification takes place from the runner's side to the riser's side and in that direction only.
Your work is very clean and obviously well practiced. I liked the overhead camera angle when you were pouring the iron. Thanks for sharing.
The riser is a greater mass then the spew, its supposed to solidify last so that the casting has somewhere to pull molten metal from while it is solidifying to minimize shrinkage =)
Thanks
very nice and simple. so easy to understand😇
Very nice!! I have just discovered casting at home. So If my questions come off as way to newbish thats why lol. But the purpose of the riser is so thats where the shrinkage will occur instead of the part itself? Also, wouldnt the sprew take care of that? Thank you!!!
The riser is not only a reservoir for extra molten metal, it also helps in visualising how much metal you still need to add and most importantly, directional solidification. You don't want your metal to solidify from both sides because then you get a weak and mushy centre. So when the molten metal fills up the riser, metal starts solidifying from the runner side (your main metal, that is the metal filling up the mould). The metal filling up the riser is the extra unnecessary metal which prevents solidification of the metal in the mould on its side. So the solidification takes place from the runner's side to the riser's side and in that direction only.
What is your sand formula?
Thank you!
Thank you...
isnt it more effective by using your hands insted of the stick?
Best vedio
See my video How to make cast iron molding sand.