I'm totally obsessed with YouTube videos of small manufacturing in Pakistan. One of the things I've noticed is that when they're making their own sand, it sure looks like they're using drain oil for binder. Is that even possible?
His two videos are interesting from a minimal equipment standpoint and the use of super-small flasks. ** Is anyone here regularly using molasses-bonded sand? ** Part of my learning curve was sand. If I were to do it all over with today's knowledge, I'd start with 50# of Petrobond and then work towards green sand. Instead, I started with 3$US/50# (23kg) home improvement store general purpose sand which mean screening and drying and winnowing and throwing quite a bit out along with trying to find the right bentonite clays to make green sand. Results were fair and things improved once I got my first batch of Petrobond. Not that homemade green sand is impossible, there is just one less variable in the process using 'known good' sand...I spent more on a cute little Harbor Freight concrete mixer to mull sand than I did on my original furnace kit and extra crucible. Eventually I found a 7$/50# home improvement store sand that is clean and dry and intended as paint texture that is 60-mesh works and well for lost foam and an industrial supply store (specialty store for abrasive blasting) that sells everything clean/dry including a 130-mesh sand for 12$/50# that is zero waste and zero labor to prep for green sand. My next scheme is to mix a bag of that into K-Bond.
I watched the video, the man explains it clearly, but I consider this sand as too coarse which compromises fine details. And even with a low temperature alloy like aluminum, it gets black like the Petrobond sand. So I prefer the DIY greensand made from ordinary silica sand, bentonite and water.
What always fascinates me about that type of sand, is the way it flows, completely different from any type of clay bonded sand.
Not sure how much he has used it, but IIRC Stevan posted about messing around with some molasses bonded sand a while ago after seeing some of the same videos. Jeff
This is interesting. I wonder if the sand can be reused after mulling, maybe in an air tight container?
The cement and synthetic oil sand seemed problematic when splitting the molds, like it did not know where to stick and where to part.
Maybe the oil doesn't let the cement bond, just holds it in the oil mix so there's really not much cohesion. If a fine sand and cement very dry grout using water or something that would let the cement desolve and bind it might work better. Of course you again have sand, or maybe some other substance so the surface finish would probably suffer some Don't know, I'm kinda new at this, just thinking out loud.
My Grandfather was in foundries, he told me that at one time molasses was used as a binder. I worked in a brass foundry making plaques and we skin dried the face of the mold. That is we sprayed sugar water on the face then dried it with a soft flame. Made a slick finish.
That sugar would turn to carbon as soon as the hot metal hits it and would be easier to apply than graphite.
I worked in an aluminum petrobond shop in north Georgia, Glenncast. Very large aluminum castings. We used spent motor oil.
