Could you tell me how to go about casting this item in green sand using alliminum. I have no experience with casting. Please be patient. Greg
Welcome. There are several methods, and folks here have their preferences, ie: lost wax, lost foam, green sand mold, bound sand mold, etc. I can speak to my preferences only, which are either a green sand or sodium silicate (SS) bound sand mold. If you don't mind the new cast part being slightly smaller, you can use that part as a pattern. Assuming a green sand approach (green sand = sand mixed with clay and a little water), you buy or make some green sand, make two boxes (cope and drag) typically from wood, wax the pattern (floor wax will do it), press the sand around the part in one of the wood boxes, turn the box over and clean the sand from around 1/2 the part, then fill the second box with sand. A video is worth a thousand words so I will post one (or two) below. I have been trying to get a buddy of mine into casting for a while, and its like I told him, first you build a foundry, then you........ And he said "Yes, but I can also teach a snake to tap dance, once I get the shoes on him".
I have used this method, but with sodium silicate bound sand instead of green sand. These are not my videos.
Welcome to the forum. Some questions for you: What is the part and what does it do? How many of them do you want to make? Does it need to be an exact replica (PatJ's question) Do you presently have a furnace or any foundry equipment? Best, Kelly
Appears to have been die cast. You may be able to add a cheek for that one undercut I'm seeing. Hard to say though without having the part in hand to see the relief angles. Could be a perfect time for lost foam casting. What is this part anyways??
I have tried to cast this item as one but when I extract the item the sand breakers away near the 2 small lugs and I do not know what to do about the recession the under side. Could you giv me a sketch as how to go about the process. Thank you Greg
The part comes off the caravan awning. I require 2 . Not a exact replica I have a oil furnace and Ihave made my casting boxes.
Look into making them out of foam and doing lost foam casting I think it will be your best chance for a quick success. The other way would require you to fill the center of the part leaving core prints extending beyond the part, then making up a core box to make the core (sand filler block) It is difficult for me to explain this way of doing things with out you understanding the terminology
How do you make a core and what material do you to make it out of. How do you suspend the cor in the sand mold.
Here's one way cores are made out of sand. In this video the core is rammed up in a "core box" and bonded with sodium silicate hardened by CO2. Tere are also some old school recipes for cores hardened by baking that use molasses water or boiled linseed oil as binders: The second video linked in post #2 shows how sand cores are suspended in the mold by way of "core prints" that are built into the pattern. I agree that lost foam casting would probably be an easier way to reproduce this part though; you wouldn't need to make any cores at all if you did it that way... That said, I'm sure we could walk you through it if you decide to go with greensand and cores. If you've gone out of your way to build and/or acquire all the stuff for sand casting, you'll be wanting to figure out cores at some point... Jeff
I'm struggling a bit with the pictures and the undercuts as to whether there is a part position such that it could be made with a two piece mold and no cores. Even if so, it would require a complex parting line, or has been suggested the addition of a cheek of some sort to your flasks. If it could be drawn in a two piece mold you could just free mold and cope down to such a parting line for only two pieces. If that is a die cast part, it probably has less draft than you'd prefer for sand casting. A reasonable facsimile of that part could fairly easily be made using lost foam. In that case, any parting line complexity and coring would become moot points. However you would need to be comfortable fabricating the foam patterns. It would be a reasonable approach for just two pieces. I have quite a few threads in the lost foam sub forum on machining/working foam and the lost foam method of casting. There is the more obvious solution; if it doesn't need to be aesthetically correct, it could be weldment fabricated from cut steel plate. Casting is a great skill but not always the most practical solution for every problem. Best, Kelly
Me too... Thinking its split in the middle with the flange ears to the top and bottom... as pictured in photo 3
there is no irregular parting at all the first picture is rammed exactly as seen in the drag, the cope is then rammed , flip, then lift off the drag, open mold remove the part from the cope. a good coat of sandable primer on the part, and cast in Zamak rather then aluminum, the shrinkage issue is covered. QED V/r HT1
For that, looks to me like you'd need some kind of follower in the cavity and extending beyond the finger like features. If the part sat flat on the flange, per picture 3, it looks like there would be back draft on the trailing edges under those finger like projections. Best, Kelly
One word...... WAX! You guys KNEW that was coming. Is this thing outta production with no spares available? How's your carving skills?
