Foundry/Green Sand

[STGRule]

I am interested in trying to cast some very small (6"-8") lead sturgeon shapes to test an underwater camera. I'm thinking if I had some foundry sand I could use one of the sturgeon I carved as the form for the sand. My thinking is the sand would be less likely to ruin my carved sturgeon than say, plaster or something. I understand that the sand has to be pounded over the form so I may just carve another one that won't make me cry if it gets ruined (yes, I can cry over ruined art when it takes that long to carve). My questions are: Will this work with lead? Where can I find foundry/green sand? Has anybody ever casted with foundry sand and lead? Any tips? How about coloring them (is there a way to cast in color?)

[ 11-12-2003, 05:51 PM: Message edited by: STGRule ]

[jocose]

stg theres a foundry in northwest portland called esco, they are a customer of the engineering company i work for, ill try to get your answers tomorrow, friday at the latest.. joco

Holy bad dreams Batman! I spent nearly 15 years in a foundry...specifically making sand molds and cores :shocked:
You can find foundry sand at LaGrande Industrial Supply in Portland. There are also some custom sand mold makers.

[STGRule]

I just need to do this as cheap as possible plus I've never done this before so now I want to. :grin:

[thecougdad]

The trick here is to remove your art work from the sand, without destroying the cavity. A split pattern mounted on a plywood backer with holes aligned to your cope and drag, top and bottom of your flask. I would use Petro-bond sand, no muling required, good details but pour it outside as the lead will burn the oil that bonds the sand and smokes a lot. Make your pattern by gluing paper between two pieces of wood, that way you can split the half's to mount on the plywood.Hope this helps.

[STGRule]

I don't need a cope and drag. I just need one of them. Don't know which is the top and which is the bottom. I just need the top half to set on the river bottom in different water conditions. I need it to have the upper body shape, dorsal fin and the top half of the heterocercal tail. It needs to look sturgeon-like from the top so I think I can do it with just half of the mold.

I don't know what a flask is. I don't know what Petro-bond sand is. I don't know what muling is. I do however know that melted lead is poison and needs to be done outside and with a respirator (I'm old and mortal).

[ 11-12-2003, 08:57 PM: Message edited by: STGRule ]

[thecougdad]

Your sand will be dry, muling is adding moisture to bind it together.( Petro-Bond uses oil as the binder.) Too much water and you will have some explosive safety issues. Take it to someone that knows what they are doing! Sorry I was just trying to help.

[STGRule]

Not a problem, I need all the help I can get (no comments please). I just would like to do it myself so I need it to be low-tech. I understand the danger of the fumes and of moisture in the sand. Is the Petro-bond easier to use than the foundry/green sand? I understand (just from reading) that the Petro-sand just needs a very small amount of oil to work? I have no idea how to use the foundry/green sand either. I just guessed that you packed the material around a form, removed the form, very carefully poured melted lead, and waited until the whole mess cooled (maybe a day or so?) and then un-molded it. I have no idea what it would look like after and if it is possible to color it. I only said I don't know what those terms meant so you would explain them to me.

[thecougdad]

Green foundry sand contains silica, wear a mask if you chose to use it. Like I said earlier I would buy a bag of Petro-Bond sand, it will be ready to use. Build a rectangular box without a top or bottom out of 3/4" plywood. Place the box on another sheet of plywood. Ram (Pound )the sand into the box good and tight, up to the top. Use cornstarch powder on your pattern as a parting compound. Force your pattern into the sand, and remove. Pour the molten lead and let it cool. About an hour should do.

[Snapset]

I have done some lead pouring in the past with homemade molds. What I used was Bread pans and Plaster of Paris. For a release agent I used Vaseline on the wood original (It was a fish shaped piece of black walnut and I used it for downrigger weights.)

Whether or not it damages your art piece depends on the type of wood and the finish it has. If it has a plastic finish (Polyurethane) it should work just fine.

A rubbed wax finish should come out just fine also. My method was to pour the bread pan half full, press the original in half way, put a heavy book over the top and shims underneath to prevent floating, then let that set up. I then removed the original put a thin layer of Vaseline over the top, poured the top half of plaster and let it cure also.
Then I removed the original and baked the 2 halves for a few hours at 200 degrees. I ground a sprue hole with a dremel,and I was ready to go. It only held up for a dozen or so weights, but it was a fun project nevertheless.

[AuntyM]

Have you thought about using latex? I have made some candle molds out of latex molding material sold by Pourette Manufacturing They also have molding clays.

If you call and ask for Jeff (Gutz) would probably be able to explain the process.

[STGRule]

Sounds like the Petro-bond is the way to go. Have any idea where I can get it in the Portland area?

Aunty, I need them to be heavy enough to stay on the bottom so I need to use lead. I don't think the latex would stand up to it. I think molten lead is hotter than molten wax. But I'll check it out.

[ 11-13-2003, 10:07 AM: Message edited by: STGRule ]

[kamloops]

The green slag sand comes out of the Glenbrook Nickle Smelter in Riddle Oregon. It's sold under the trademark of Green Diamond Abrasives.
This product is marketed to the Construction, Industrial and Industrial sandblasting.
La Grand Industrial or other Industrial Supply Houses.

Seattle/Puget Sound has it's own version of sand.
It's called Kleen Blast, it is a Copper Slag and is black in color.

[Gun Rod Bow]

STG, you have mail.

Kamloops, although that is Green and it's sand it's not Green Sand as in Green Sand Casting.

I think the mold and plaster idea is the closest bet.

[jocose]

stg my friends at esco foundry recommended lagrand industrial too. they use green sand castings in there number 1 plant but its mixed in huge bulk quantities on there site.. i was hoping to snag a 100 pound sack for you but failed.. sorry.. good luck joco

[kamloops]

G R B,

www.greendiamondsand.com/products

STG
Good Luck