Casting a Mould
Casting a Mould
(OP)
So the part that I am trying to make is a dry cast concrete corbel.
That is my ultimate goal. I'm choosing dry cast concrete because once you are set up you can make parts continuosly and basically at your own speed. This as opposed to wet cast where one would have to cycle in and out of a set of moulds.
Ok so that's the part, now I need a mould.
A Aluminum mould would be bad ass as a 4 piece block mould.
Possibly three pieces but due to some undercutting I'm thinking four.
So now how to get the mould? Do I contract a foundry?
We have one very nearby. OOOOORRRRR do i build a furnace and make my own. (I tried plastic already and that was a failure due to material degrade issues)
So? any thoughts?
That is my ultimate goal. I'm choosing dry cast concrete because once you are set up you can make parts continuosly and basically at your own speed. This as opposed to wet cast where one would have to cycle in and out of a set of moulds.
Ok so that's the part, now I need a mould.
A Aluminum mould would be bad ass as a 4 piece block mould.
Possibly three pieces but due to some undercutting I'm thinking four.
So now how to get the mould? Do I contract a foundry?
We have one very nearby. OOOOORRRRR do i build a furnace and make my own. (I tried plastic already and that was a failure due to material degrade issues)
So? any thoughts?





RE: Casting a Mould
OR
Really thick aluminum plate, with cavities by CNC milling.
Mike Halloran
Pembroke Pines, FL, USA
RE: Casting a Mould
I have done sone research and a cheap home made foundry with charcoal fits the bill and is almost free to make so I think I am going to go for it and cast my own
RE: Casting a Mould
If you are making a mold at home I assume you plan to use an existing version of the corbel as a form for a sandcasting mold? Or the corbel itself coated with a ceramic spray as the casting surface for the aluminum mold (I don't know how well concrete withstands a quick burst of heat from 1100*F metal)? Sounds like an interesting backyard project, best of luck.
Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations
RE: Casting a Mould
RE: Casting a Mould
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Casting a Mould
RE: Casting a Mould
Dry cast concrete is sort of a misnomer. It is moist sand and cement mixture and not trulu dry. The mould is of course open on one side and after it is packed with this mixture the aluminum mould is unbolted and the part is released not unlike a sandcastle.
After the concrete cures (sometimes in a steamroom) the process is complete. The moulds are not hot or anything and at the point where you are casting parts there is no danger save for smashing your fingers as you tamp down the sand and cement mixture.
As for cnc, that's for all you guys that just happen to have a $200,000.00 machine in there garage. I have a router and a hammer.
OK, I've got more than that but I'm trying to make a point.
Expanding on that for a minute and slightly off the subject I've notice that a few of you blokes totally live up to the tagline of smart questions for smart people who are even smarter than you or however that goes. I mean some of you dudes are just ridiculously smart. My point is that I am not generally thought of by people who know me as fitting that description and if I am intruding into your world of really really smart people just let me know. I'm not trying to pose as one of yas, but even the really stupid answers on this forum are light years ahead of most of the other sites. I'm hoping to learn something from you guys and so far so good. As long as wikipedia holds out and doesn't crash I'm good. Just wanted to hang out for a while with someone smarter than myself. Hope you guys don't mind. I'll try not to dumb down the site too much.
RE: Casting a Mould
I am somewhat of an expert on wetcasting but have never cast a dry cast part in my life. I don't like to read fiction books and I don't make silly artsy things so when I ran into this problem of how to turn out hundreds? of these corbells for my house at a dirt cheap price I thought of this method and I am very excited to try this. Rubber moulds dont work well unfortunately because the are flexible and my plastic moulds just sucked because apparently I am just too impatient to let the paint dry on the mother part. I have been thinking about making a blast furnace for a while now so I finally came up with a reason so I'm going to go ahead and do it.
And finally, what is the advantage of zinc over aluminum and assuming I chose zink, where would I source this. I don't need specifics, I mean I can google that but would I go to scrap metal or a supplier or what? Scrap aluminum is everywhere. Unless the advantage is great, and I don't know so I'm asking, whouldn't it be a better choice? I am going at this furnace thing with the intent of building a perfectly fine furnace for no money except one bag of cement. I think I have everything else and of higher quality than I've seen online.
And thanks again for the responses. Can't promise to take every suggestion but I do promise to think about what you are suggesting and I appreciate the time you spend giving advice. It is generous to offer it and it is appreciated.
RE: Casting a Mould
RE: Casting a Mould
RE: Casting a Mould
RE: Casting a Mould
Mike Halloran
Pembroke Pines, FL, USA
RE: Casting a Mould
RE: Casting a Mould
Look at spats.
B.E.
http://ww
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Casting a Mould
RE: Casting a Mould
Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations
RE: Casting a Mould
As stated earlier I have a phobia about that so thanks for feeding the monster Bwahaha
RE: Casting a Mould
So I just learned something
hope anyone reading this did also.
Think I will let this thread die a natural death and move on
gd luk