Thread: Melbourne Foundry Suppliers

Originally Posted by garym

I would but the dog absolutely loathes company in the evenings.

OTOH the idea of turning an $8 bag of kitty litter into a $5.00 bag of bentonite by ruining a $120.00 blender, DOES seem attractive...

Hmm... the economics would seem a bit dodgy put that way. I must be channelling the Gingery Brothers where you can't do anything the easy way

Originally Posted by garym

i would but the dog absolutely loathes company in the evenings.

Otoh the idea of turning an $8 bag of kitty litter into a $5.00 bag of bentonite by ruining a $120.00 blender, does seem attractive...

lmao. Do yourself a favour, don't think about the cost until you're halfway through doing it

Bentonite is "drillers clay" used to make seal between the bore hole and the bore casing ,thats one of its common uses .
If you know any drillers they may be able to tell you where to get it.

Kev.

There's always a 'Health Food' shop that'll sell you bentonite clay (it's a natural detox mineral, doncha' know) - only $20 for 500 grams. At that price, the cat sure does have a spoiled bum!

Hi Gary,

I wouldn't bother with kitty litter or animal feed supplements, it's not suitable for making green sand unless you grind it, and even then i'm not sure it will be any good.

I bought some stockfeed bentonite, and ended up giving it to the rellies to use for kitty litter, it's much cheaper than the supermarket kitty litter..

If you only plan on doing a few castings every so often then I would recommend you get some petrobond, it's expensive, but worth every penny in terms of quality of casting and it's mostly re-usable.

To make your own green sand, efficiently really needs a muller, so the two paths to get started in casting are as follows...

1. Buy some petrobond and start casting..

or

2. Get FOUNDRY grade bentonite, some good sand, build a muller, learn how to make good quality green sand.... and so on.....

Of course, if you are going to be casting a lot, like a production foundry, then the economics of green sand will win hands down.

Regards
Ray

Originally Posted by RayG

Of course, if you are going to be casting a lot, like a production foundry, then the economics of green sand will win hands down.

Regards
Ray

What are the economics of green sand?, I was under the impression that resin bonded sand worked out better and thats why foundries use it in preference to green sand?. Sure with resin it's easier to throw away the used sand than reuse but because there's no requirement for frames like green sand, so it's easier to make many as many moulds as you have the sand for. The moulds are mechanically strong and handle easy as they don't break with a knock.

I've had this discussion with the professional foundry guy I learn from, he said he wouldn't go back to green sand if you paid him.

Originally Posted by Graziano

What are the economics of green sand?, I was under the impression that resin bonded sand worked out better and thats why foundries use it in preference to green sand?. Sure with resin it's easier to throw away the used sand than reuse but because there's no requirement for frames like green sand, so it's easier to make many as many moulds as you have the sand for. The moulds are mechanically strong and handle easy as they don't break with a knock.

I've had this discussion with the professional foundry guy I learn from, he said he wouldn't go back to green sand if you paid him.

5 bucks per kilo for petrobond, versus 75 cents per kilo.

Edit: That's not really the whole story, resin bonded sand is yet another step up in equipment requirements, not even sure it's really appropriate for a home foundry unless (as I keep saying) you are planning to do a lot of casting. As far as green sand goes, I don't think it's in the same league as the later technologies, I can understand why your foundry guy wouldn't want to go back. But we are talking about small backyard foundries, not commercial operations, and green sand is cheap and produces acceptable results IF you mull it properly and get the moisture content right.

My point is quite simple, for a small backyard foundry, forget green sand and buy a bucket of petrobond.

Regards
Ray

I agree with Ray, just get Petrobond. I bought a bucket of it a year or so ago and at the rate im using it hobby casting i'll still have it 5 years from now. Its awesome stuff.

One thing that counts against using the urethane three component resins is that the cross linker additive ages rapidly so you don't get much shelf life. The only reason I use it in preference to other methods is I can get it as I need it in small quantities without buying 50 odd litres of the stuff. That said it's great to stuff to use.

Slightly off topic for a moment, but since you guys seem to have played with metal casting a bit - how much of a smell is created when you're melting down a bunch of aluminium or cast iron (if anyone has something hot enough for iron)? I wouldn't mind having a play sometime, but I have a suspicion that molten aluminium might create enough stink for the neighbours to object....

Originally Posted by Jekyll and Hyde

Slightly off topic for a moment, but since you guys seem to have played with metal casting a bit - how much of a smell is created when you're melting down a bunch of aluminium or cast iron (if anyone has something hot enough for iron)? I wouldn't mind having a play sometime, but I have a suspicion that molten aluminium might create enough stink for the neighbours to object....

Hi Jekyll and Hyde,

No problems with smells from casting. Never really noticed any objectionable smell from molten Aluminium. We get on pretty well with the neighbors anyway. They are more likely to come and see what's going on than complain.

Regards
Ray

The only offensive smell youll get is if your using one of those waste oil burners that are described around the place. They reek badly, and could easily offend you neighbors/street.

Brendan

The rocket engine roar of a gas burner is likely to attract attention, especially if you manipulate the gas valve to get the furnace to light with a spectacular boom. Resin bonded sand does stink as the liquid metal chars it and there's white smoke as well. I don't know about the other casting methods but I'd imagine there's smoke at least.

Originally Posted by Graziano

The rocket engine roar of a gas burner is likely to attract attention, especially if you manipulate the gas valve to get the furnace to light with a spectacular boom. Resin bonded sand does stink as the liquid metal chars it and there's white smoke as well. I don't know about the other casting methods but I'd imagine there's smoke at least.

I think I'd get away with the noise of the burner, I've indoctrinated them all pretty well on the usual noises (grinders, hammers, compressor etc), but smoke could be a problem... How much smoke are we talking, and is it a prolonged sort of thing, or only for a few seconds?

Originally Posted by Jekyll and Hyde

I think I'd get away with the noise of the burner, I've indoctrinated them all pretty well on the usual noises (grinders, hammers, compressor etc), but smoke could be a problem... How much smoke are we talking, and is it a prolonged sort of thing, or only for a few seconds?

It's about the smoke level of a backyard leaf fire and rather acrid stink for about 30 seconds minimum, you want good ventilation. I have no idea about green sand or petrobond but I'd imagine the smoke level is bad.