I use sodium sillicate for a sand binder, but some guys use molassis. What are you trying to make? <iframe width="420" height="315" src="//www.youtube.com/embed/CbLBiCdgRi4" frameborder="0" allowfullscreen></iframe>
Thanks for link... Just want to know how make a sand core (water circuit) for casting an alu flat head, and to delete the sand into it after casting...
For casting that you would want the sodium sillicate for sure, its a much stronger binder for the sand. Once the metal is poured the heat brakes down the binder a bit so the core can be knocked apart and shook out. Ive been considering casting a flat head as well, but for the time and trouble it may just be cheaper to buy a set. That is unless you are making one that isnt available, maybe for a banger??
http://www.alloyavenue.com/vb/forum.php Join up with us over here, Im DavidF on the forum over there. Theres lots of good guys willing to help out.
Where do you want to start? First, you have selected the material (aluminum), next you need to design what you want. Make sure to add the appropriate shrink value to the casting so you get the size you want after casting. Next, make patterns and core boxes. The pattern is for the head, the core box is for the water circuit. Assure that there are supports (registers) for the core to hold it in place securely when placed inside the mold. The youtube video above shows what you can make, but it has plenty of mistakes and safety issues. That is fine, it is just back yard casting. Aluminum is easier to cast in the back yard than iron, it needs about half the heat to melt. you may be better off making the tooling yourself and taking it to a local foundry to have cast, they usually make one off stuff pretty cheap. Starting with the core is backwards unless you have the tooling already.
Just for fun, I took Sculpture 101 in college because the Art department had a good foundry program. I just wanted to get some background on the processes... I've never cast anything in earnest. Perhaps there is a similar program near you? Gary