casting ash trays?

[ramsies11]

my friend and i were over at my girlfriends house and her dad told us that his dad was an artillery man in WWII so his dad always sent home a massive amount of howitzer shells. what he said his father did was he cut off the bottom of it about 5inches down so he had a good deep bowl and he took a round file and made the spots for the cigarettes. my friend and i have already bought a 20$ howitzer shelll and made a very very cool ashtray out of it.

being the kid that thinks he can make a buck off of anything, i was wondering how i would go about making a mould of the shell-ashtray and be able to mass produce them out of aluminum and use a nontoxic brass paint on them. ill sell them as a novelty and tell people they arent made from real howitzer shells.

if someone knows how to make the mould where i can keep the stamped writing on the bottom and the depression on the firing cap on there itd be wonderful.

i planned on making and selling these for about 15 bucks each.ive got enough scrap piles at my farm that i can find a good load of old scrap aluminum.

[Steve Sells]

dont bother casting in Al then coating it, cast in bronze or brass.

[ramsies11]

right now i dont have the proper equipment to cast brass or bronze. i still need a good respirator and a graphite crucible.

[dan_m]

I'd make a silicone rubber mold of the shell, then cast waxes and pour them in metal. I'd go with bronze as well, but if you do use scrap aluminum know that it will come out better if you melt down cast pieces (car wheels, bicycle cranks, etc) instead of extruded ones (like tubing). PlatSil 71-20 from Polytek is a good silicone to start out with if you've never done it before. You would need to get a cheap pottery kiln to burn out the wax. You could also sand cast it using the original shell as a pattern, but you'd still need some stuff you don't have yet and in my experience it's not nearly as forgiving of a process.

[Fe-Wood]

Smooth-on makes good rubber mold products. Latex is also good and cheeper. Casting is an art and science. Mold making is the same. Read up on it, a lot. If memory serves me right, you may be in for a 3 part mold witch can be tricky. Bando, Plaster of Paris and Fiberglass all make good mother molds. Depending on the quality of the rubber used for the mold, you can make a 100 or 1000's without mold degrade. You might consider making the mold and casting wax parts then mounted them to the sprues and have them cast.

[ramsies11]

dan, how would i go about making said mould? im a little confused on where exactly i would pour in my aluminum and how exctly to get the shell out. and i have alot of old aluminum cookware and such hidden away in junk piles. i think all the easy to take aluminum tubing has already been stolen. and do i have to have some sort of kiln for the hardening or could i use an oven or even the propane forge/ foundry?

fe-wood, i saw the bondo and plaster mould on a casting video on youtube where these two russian children made brass from scratch. that was one of my original thoughts on the mould but i didnt know how to make it.

[dan_m]

You need a kiln (not an oven or forge) if you are using the investment casting/lost wax process. Green sand molds don't need to be heated. I wrote a post that is pinned at the top of the foundry & casting section, you should read through it if this is something you're interested in pursuing. There is a lot of basic info on the process and equipment, and at the end there is a list of good reference books on both investment and sand casting. I would highly suggest picking up a few books on the subject before you try this, it's quite a bit more involved than it might seem, and very hazardous.

[ramsies11]

i was afraid i was getting a little in over my head. if i can find a set of cheap stamps for stamping metal, i will cheat on the back of it. but ive no idea how toproperly make a green sand cast of the basic cup shape i want.

[ThomasPowers]

First thing I thought was: you could probably make them for only a bit more than you could sell them for. Loose a bit on every sale and then make it up on volume!

I took a brass casting course at a local college's arts dept as an "out of hours course" taught me the basics and safety needed to work with the stuff.

I strongly suggest people getting hands on training first as there are some subtle gotchas that can ruin your day (or your life). I've talked with several people who told me that taking a class was too expensive for them; but then found that one ER visit cost them more than a dozen classes---not even including downtime, scars and pain!