I'm thinking of trying a POP lost wax casting by covering the mold after burn out with a POP shell to capture the details then compacting in a flask using adobe clay. I think I've read something similar but I'm new to this, just wondering if it's possible. I'll prepare the adobe like green sand but maybe not need to have as fine a mix texture due to the POP shell. I'll be using brass. I'm in NM, adobe clay is easily obtainable. Thanks for any thoughts, John ,,,
Why would you do that instead of just using proper investment? These guys are in YOUR BACKYARD! https://www.riogrande.com/searchres...sort=relevancy&layout=card&numberOfResults=36 Want predictable results, use tried and true materials and practices. You can try anything you want and who knows, you might succeed. I usually have way too many hours in a piece to cheap out and get mediocre results. I just won't do it anymore.
Why would I do that ? For one reason I simply can't afford to buy that costly stuff, old phart on fixed income. I'm new to this casting game, something to do to keep me off the street corners and outa bars. Just a hobby, anyway I figger if the ancients could cast thousands of years ago without the modern stuff maybe I could too. Never know, I might just stumble onto something that works as well and cheap as dirt . As far as hours "invested" I have more time than anything else. Thanks, John ,,,,,
The old masters understood how to use PoP. It was a careful mixture of Pop, grog (old casting material) sand, dung and straw. What you don't know YET is plaster of paris while may seem dry is not. This creates problems when hot metal comes in contact with it. Often times it can have explosive results. This is why you will not find guys here to tell you to mix something with plaster of paris and go cast metal. Many of us have tried (including me) and have failed miserably. We actually have one guy here that when he was actively casting bronze art stuff, made giant investments. I'm talking BIG blocks of plaster of paris. From there, he would have to heat these heavy blocks for days on end super slow to drive out the moisture. Even then, problems can happen. I suggest cutting your expenses somewhere else for a short time and buy the correct material. When I started, I cringed at the cost of ceramic shell, the shipping and a couple hundred pounds of silicas. All I did was waste a year of my life searching for a cheaper option. I'll never get that time back. We had an old fart here a couple of years ago go through the exact same thing. He farted around too long and never cast a thing. All the while I was leaning on him to just pay the man. Failures happen no matter what you do, but it's easier to help you troubleshoot when we don't have to consider some home brew or mystery metal. You can reinvent the wheel later. IF you really wanna work like the ancients, visit this youtube channel. He rolls old school and is a super nice guy. https://www.youtube.com/c/ArchaeometallurgieDe this might also help you.
I have (only once) successfully done an aluminum casting in PoP/sand investment, a PoP mold needs to be thoroughly heated to at least 350°F just prior to casting to avoid the problems Jason was referring too. While that's easy enough to do, the PoP so treated becomes quite fragile and easy to damage, I believe commercial gypsum based investment plasters have additives that help to maintain the structural integrity of the heated mold. Commercial investment plaster is well worth the fairly modest additional expense, especially if you have a local source.
Everyone here knows I'm one of the cheapest bastards on earth, if I can save a buck I certainly will! That's why I've spent the last 2 years gearing up my capabilities in the garage. I'm too cheap to pay someone else to mess up crap I can screw up just the same! Most of the time, I get better results!
