What are you guys using for molds. I have a ton of lead that I removed from the restoration of Gene WInfields Shop Truck. I would like to make a model or a plaque or someting out of it. I need ideas. Any help would be great. Link to the restoration thread. Check it out.
Years ago when I was a plumbers apprentice (we used lead and "oakum" for drain pipe joints), I used sand with a little motor oil to make it kinda stick. This was just for grins, single cavity, stick something in the sand, remove it and pour. Crude but fun.
How about a small desk paperweight with the WINFIELD logo and a brief discription as to where the metal came from ...... " Made from body lead used in the original Gene Winfield 1935 shop truck " I would be interested in something like this. Carey
You can buy buckets of sand from foundry suppliers, mail order or locally. Get a chemically bonded sand and follow the mix ratios for professional results right out of the box. Still need the pattern though. Lead might even be low temp enough for something like a plaster mold even.
YOUR collection !!!!.......I was thinking about MY collection !!!!....HA !! HA !! I seem to remember that there is a rubber type product that low temp. melting point metal can be cast in. ....mould it around the original pattern...then let cure ....then pour metal in....comes out exactly as the original... Carey
Make sure that if you use sand that is tempered with water , that you let the mold dry out for a couple days....if not, the lead can explode when it is poured in...ask me how I know !!!! Carey
Have not tried lead but, Smoothon.com make lots of good mold making materials. I like that I can cast plastic and low temp Metals with their Silicone Rubber. This pic is a little part for a 1939 Packard dash I was working on.. I got other photos here... They are Kind of Big though http://woodgraining.com/cgi-bin/photos/pro/emAlbum.cgi?c=show_thumbs;p=PLASTIC
Another pic the red stuff is the high temp stuff, but its not as tough as the blue stuff. Both seem to work fine for the metal i was pouring. Jdee
A plaque would be a nice idea, or you can make a shifter knob out of it. It will probably be to soft, but it would be a cool project for sure...
Ok i have a question ,what was used to replace the lead . is this a correct restoration and or are you using new lead just curious.c
jdee is speaking of leadfree pewter.. and silicone rtv rubber.. I buy the same stuff from a supplier for use with the high school students.. you might also consider "lost FOAM" method of casting.. make your model outta pink insulation foam.. and bury it in sand. pour molten metal in and burn out the foam leaving the "part"
sawzall don't give me any ideas I'm kind of done with casting the metal parts now. I sure know how to make a mess UV cured plastics is my newest project, sure worked nice on the 39 Packard Speedo Lenses.. Kind of cool that you can use a clear mold rubber and fill it with UV cure Resin and zap it with a light and have a done part is 5 secs. Mold making can be a fun thing for sure.. Jdee
Lead is likely too low temp for lost foam and would end up with a pinholed mess from the combustion gas. One of the keys to lost foam success is having enough heat in the melt to combust the foam completely and instantly Consider making yourself a thumb sized pouring basin in the bottom of the mold with a short runner to the part. The basin will catch some impurities in the melt, but also wherever you pour is at high risk for surface erosion, and since the basin will be removed you don't care about it's surface finish. Slice the very bottom off since that's where impurities will settle, and remelt the basin slug in the next batch. I dunno about lead but many metals are improved by additions of virgin alloy. The fact your lead has been heavily heat worked may affect it's flow characteristics a little bit, plus the additions would stretch the batch. good luck with your cool project!
I was thinking about this same thing the last few days. My thoughts have been more about how to make a cool mold. My father in law bought one of the Sears computer wood milling printer /milling thingy a few years ago. With the software, you could make 3D patterns on the screen and the printer / milling thingy would carve the pattern out of wood. I figured if you could reverse the image, you had the perfect mold maker for sand casting. If my memory serves me correctly, you could use true type fonts in patterns. here is the machine: http://www.sears.com/shc/s/p_10153_12605_00921754000P
That is just what I've made, I've used mostly birch and pine. And some Bondo, but that is a secret. And a shame. Made some valve covers few years back, you'll find my post about it from Tech Archive. I made shapes and everything by sanding etc, that is quite slow... but here was post some half year ago from guy who drew new top for 97's on some computer-program, then took it to 3D printer and got it cast. That is what they do nowadays, it's faster and more accurate. And creates less sweat!
If your going to use wood as a pattern try a simple coat fo shellac or some other type of sealer. Use a parting powder like talc or similar before you cover the mold with sand. I did this with my students 25 years ago. Be sure to get the lead hot enough to flow. Its melting temp is not very high. Have fun!
This is a good point. Melted and hot enough to flow are 2 different things and is a common first timer mistake. The foundry term is superheat and is typically 200-300 degrees over melt pt on aluminum or steel. If your pattern has any amount of detail it's better to err on the hot side. Since lead is lower temp you might be able to scale it down, but probably not by much. If your old lead has nasties in it, use a piece of coat hanger type wire as a slag rod. Roll the tip of it across the top of the melt pool and try to gather a glob. Rolling action is the key to successful "slagging" Good luck!
To further get rid of the nasties once the lead is molten, add some wax. About an inch or so from an old 1" diameter candle works well. If you want to be a purist, then use paraffin. You can even get it a Wallyworld in the canning section. Usually around the appliance section. The wax will smoke and may catch fire, but just let it burn till it stops if it does, then skim the nasties from the sides and bottom of the pot. Works when I clean lead for bullets, so ought to work to make other castings as well. Make sure there's no water anywhere near the molten lead it will EXPLODE and burn the living **** out of you and that ****s forever... Be careful and be sure to show us how things turn out. VonDad
Heard about this, moisture will create somekind of explosion... but will it happen with all materials when cast? I'm thinking about br*** now.
Everybody has been giving great ideas. Here are two more (maybe not that great) First is you can pour directly into a metal mold. So if you can directly machine your mold in aluminum, cast iron, you should be able to pour into it. Second you could use a lost wax technique. Make a model in wax, add runners and sprues etc. Coat the wax with a ceramic. Fire the ceramic (the wax melts out... and is "lost"). Then pour the molten metal into the mold. Break the ceramic and you have your part. You may be able to find a foundry that caters to bronze artists to make the ceramic mold for you. Good Luck. Have Fun. Be Safe!
Make sure your molds are DRY! Think about it- when your molten whatever hits the water in the mold, it turns the water into steam... very powerful stuff that powered locomotives for years. The only place for that steam to escape is back up the pouring hole, the overflow holes, or to simply cause the mold to explode.
Water expands greatly (approx 1600 times) when it turns to steam, so that applies to any metal that melts above 210F. Splashing liquid metal around is dangerous. Search for "Petrobond", if you want to do sand casting.
...and here it is, explained so simply that even I can understand! Did not think it far enough (water=steam), ofcourse it goes that way! Dumb me! Why, oh why... Don't know who made this, but he made his own metal lathe using casting techniques http://www.backyardmetalcasting.com/lathe1.html Not bad, huh?
Sort of but not really. Wet molds will spit and sputter a little bit back out the pouring hole, but that's why you wear pouring gear. Generally molds are permeable enough and the metal enters slow enough that the steam can escape in a controlled and less explosive fashion thru the mold. Plus there's vents and molds are quite sturdy. You can actually turn a garden hose onto the top of molten metal, you'll make a cloud of hot steam, which is dangerous, but no explosion. However, if you put metal on top of water, like spilling onto a wet floor or into a wet pit then you get a steam explosion and the leading edge of the steam is the liquid metal. Uber-dangerous. Another reason for the safety gear. Many of these accidents happen when pouring off unused metal into wet containers If you use chemical bonded sand with cope & drag construction, then you may get a solid pop when pouring. It's fairly common for binder fumes to ignite internally as the cavity fills. Liquid metal is some cool ****.
The Jalopy Journal
