Found Dreaming

Hi guys long time no see been busy with my other hobby, building a hot rod. To that end I want to copy the piece bellow and would like some advice on where I should make the parting line. I'm going to make a silicone mold then a wax impression then a plaster cast before pouring in ali to start with.

Keep posting your progress. I will be interested in your methods and especially your problems and how you solve them.

Do I know you from the Metal Meet forum?

Richard

Why go through all that BS? That's a perfect example of using green sand to cast that into. You have green sand, right? If not, let me educate you on how to create some and how to do that so simple it will astound you. That's a perfect example of sand casting 101.

I have done some casting but please explain I'm all ears.
Rasper I was on the BYMC forum

I agree with F.C. I could mold that up in just a few min, The has perfect draft it parts at the edge all the way around, the center to me looks like a perfect pour area. Keep us posted!

Assuming you have a flask capable of handling that pour, ... and, enough sand to pack both halves of the flask (also ensure you have at least three inches all around the pattern within the flask)... I would rub your original down with powdered graphite till the entire thing shines like it's polished. Set the free floating original (upright position) on a pattern board within your inverted flask and pack it well with sand till the drag is full. Skim off the excess to level the base of the drag, then flip the flask/pattern board/sand/original (carefully) over (all as one). Remove the loose pattern board. At this point you take a spoon and begin to carve away sand exposing all areas of the original except for areas that are undercut. The idea here is to expose only that which a direct pull of sand will not damage the sand from release of the original. Once you expose all the relief (beveled) areas (leaving all undercuts packed with sand around the original), dust your packed/carved out drag with parting compound then install your cope. Before packing your cope you need to mark the cope sides with indications where you intend to punch your vents, riser and sprue where they will not interfere with the cast/pattern itself. Pack the cope, punch your sprue, riser and vents, auger out your sprue to form a pour cup, blow the debris away, lift your cope and set on its side. If your cope has any tears, now is the opportunity to use a baby spoon and repack those areas (gently) with your sand. Once satisfied with how your cope drew release from the original (and/or repaired) you then pull your original carefully from the drag. The original looks to be iron, therefore, a couple speaker magnets will work nicely to lift it without requiring you to gouge edges of your sand impression to acquire finger holds. Again, if the drag, now, has tears you patch those gently as well. Once satisfied all looks acceptable carefully carve in your gating to connect to risers, vents and sprue you punched. Gently blow out residual loose sand, then install your waiting cope onto the drag. From there place a sufficient weight onto the combined flask to ensure it don't lift when the mold is poured Then pour the mold... that simple!

When you place your original onto that pattern board you should be able to see what is an undercut and what isn't. Think gradual slope of packed sand away from where the leading edge of an undercut begins (5 degrees minimum slope, more if you can manage it in the flask you have). The surface of your sand mold face will be uneaven with the parting line between cope and drag following the contours of the sand you carved away from the original.

If this isn't clear enough i suppose i could sketch an example to illustrate the process.

Ok... here's something that might help... this pic illustrates having packed the sand cope with a free floading original exhaust flange inside, which I then flipped, removed the pattern board then carved away the sand to expose the parting line I drew with a sharpie felt pen on the original.

Here is a picture which shows how the cope released from the drag. From here all that's left is to connect the gate and riser to the original pattern itself then remove the original, blow out the mold gently, then apply the cope to the drag, weight it then pour. What you have in those wings would be a walk in the park.

thank you Thats what I thought you meant. The reason i considered doing it the other way was to leave me with a permanent mold for making future pieces. also my sand is not black like yours its more of an ochre colour.

My sand is black (or dark) due to years of use. The more you cast the darker your sand will become with carbon fines. That's a GOOD THING!!