Charles, I pour bronze on occasion at 1950f, and started doing so on concrete. I later read this was not recommended, but I have never had the concrete pop. The conditions I was in was on old concrete in the middle of summer in a dry climate, which may have had something to do with it. On the other hand, I have never seen a commercial investment foundry that didn't pour over cement, and that included ferrous alloys closer to 3000F. All I can say is draw your own conclusions. By my experiences, I sure don't know. Regards, Doug Charles & Dorothy Brumbelow wrote: >First - > >All "the books" say one should not set up to melt and pour aluminum or other >high melting temperature metals on a concrete floor, because when (not if) >there is a spill the moisture within the concrete will turn to steam with >explosive force, sending shrapnel flying. > >A sand working area is recommended. > >What happens if the sand is damp and molten metal is spilled on it? > >Second - > >When the mold ready for pouring is being moved from the bench where it was >rammed up to the place where the metal will be poured, should it be carried >on and later set on top of a board to keep the rammed sand from falling out >or getting collapsed by irregularities in the sand floor? This would be a >board such as is used when the cope or drag is being flipped for pattern >removal. > >Thanks, Charles > >MODEL ENGINEERING DISCUSSION LIST. > >To UNSUBSCRIBE from this list, send a blank email to, >modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line. > > > > -- Doug Edwards Stueart@xxxxxxxxx Building a 70 ton Willamette in 1.6" http://www.rad45.org/Supplies.htm Building a 80 ton Climax in 1.6" MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.