Mortar usually is not sufficiently strong if used in gaps or
thicknesses more than what is average for a mortar joint.usually 3/8
inch or less. It simply does not have the strength, may resist the
heat ok, but it lacks strength

Why would you want to put a mix of mortar in your greensand. Would the
stuff not get hard and clumped up permanently when the stuff gets
dried, which it will do on its own chemical reaction no matter how
well you seal it. Once any mortar or cement as such has water added,
its a process you can't stop.

Greensand is only bentonite and sand and appropriate percentage of
water. Really no need to add anything else.

Persoanlly I wuld look around for some castable or even ramable
refractory, its pretty cheap to buy, and then you'll have something.
While all these various homebrews may work, as in resisiting heat etc,
they do very little of anything good when compared to commercially
available refractories.




On 14 Jul 2003 17:53:19 -0700, (Mustafa Al-Shawaf)
wrote:

x-Hi group.
x-
x-So I want to build the Gingery Charcoal Foundry. I have been looking
x-around for fire clay, and I finally found a place that said they carry
x-the stuff. So I paid for it, and when I went to pick it up, I found
x-out that what they sold me is fireplace mortar. Will this stuff work
x-to line the furnace? It says that it will withstand up to 2200 F
x-which seems okay. Also, do you guys think that I can use this in the
x-green sand mix?
x-
x-Mustafa

--
Visit my website:
http://www.frugalmachinist.com
Contents: foundry and general metal working and lots of related projects.
Regards
Roy aka Chipmaker // Foxeye
Opinions are strictly those of my wife....I have had no input whatsoever.
Remove capital A from chipmAkr for correct email address

The mortar I've bought for gas forge use is rated for 3000 F. I'd take
the mortar back.

Steve Smith

Mustafa Al-Shawaf wrote:

Hi group.

So I want to build the Gingery Charcoal Foundry. I have been looking
around for fire clay, and I finally found a place that said they carry
the stuff. So I paid for it, and when I went to pick it up, I found
out that what they sold me is fireplace mortar. Will this stuff work
to line the furnace? It says that it will withstand up to 2200 F
which seems okay. Also, do you guys think that I can use this in the
green sand mix?

Mustafa

Hello, Al!

Locate your nearest potter's supply house, and ask if they have clay in dry,
powdered form. If they do, you are in business. If they do not, buy some clay
anyway, dry it out in the oven, put it on a breadboard, and break it up with a
wooden mallet. Make sure to use a mask though, or you will end up with a sore
throat. Good luck!

Michael

Michael Mandaville

Subject: Fireplace Mortar vs. Fire Clay
From: (Mustafa Al-Shawaf)
Date: 7/14/2003 7:53 PM Central Daylight Time
Message-id:

Hi group.

So I want to build the Gingery Charcoal Foundry. I have been looking
around for fire clay, and I finally found a place that said they carry
the stuff. So I paid for it, and when I went to pick it up, I found
out that what they sold me is fireplace mortar. Will this stuff work
to line the furnace? It says that it will withstand up to 2200 F
which seems okay. Also, do you guys think that I can use this in the
green sand mix?

Mustafa

On Mon, 14 Jul 2003 21:16:02 -0600, Steve Smith
wrote:

The mortar I've bought for gas forge use is rated for 3000 F. I'd take
the mortar back.

I'd say! They sold you the wrong stuff or didn't understand what you
were doing. I think I got the 3200°F material. I used the high
density cement which is less insulative but much stronger and will
last longer. The next furnace I make I'll probably only use this
stuff in the bottom and use the less dense, more insulating, material
for the walls and lid. The way it is now it will last for years and
years but it takes a lot of heat to get going and take forever to cool
back down, plus a lot of heat to keep it at temperature.

John

Please note that my return address is wrong due to the amount of junk email I get.
So please respond to this message through the newsgroup.

On Tue, 15 Jul 2003 10:57:22 -0400, "C.W. THomas"
wrote:

snip
x-For casting sand, I would reccomend bentonite(cat litter) and sharp silica
x-sand(play sand) throw a little bit of wood flour(dusty byproduct of sanding
x-wood) about 1 cup per 50 lbs of sand mix or you might try graphite (it's
x-purpose is to create a reducing atmosphere in the mold when the molten metal
x-is poured into it).

snip
x-
x-
x-C.W. Thomas
x-
x-
snip


Of all the foundries and casting books I have read, I have yet to read
or hear that woodflour or other additives are for making a reducing
atmosphere. From what I gather it aids in bonding sand grains and
improving surface texture. For the most part, keeping a greensand
simple makes for a better product. he more thats added the more you
have to try and juggle around when it need rejuvinating. Adding wood
flour and such often causes greensand to mold up and get pretty nasty.
I have seen and used sea coal and on occassoin graphite, but it was in
conjunction with a cast iron pour, but it results using the stuff was
ot any better than doing it without, but there are some applications
that do require additon of additives.
--
Visit my website:
http://www.frugalmachinist.com
Contents: foundry and general metal working and lots of related projects.
Regards
Roy aka Chipmaker // Foxeye
Opinions are strictly those of my wife....I have had no input whatsoever.
Remove capital A from chipmAkr for correct email address

A regular one from a home furnace ...


"MikeM" wrote in message
om...
"C.W. THomas" wrote in message
...
Hi;

No you wouldn't want to use fireplace morter in the greensand mix unless
you
only want to use it once. I built an oil fired furnace which I've melted
5-7
lbs of cast iron and all manner of aluminum and brass for the last 5
years.
I used firebrick and regular portland mortar. The bottom has about 2
inches
of loose sand so I can clean up dross and molten spills. The thing is
made
from on old water heater. the only problem is the top occasionally sheds
bits of fire brick and morter. But it still works fine after 5 years...

Have fun.


Cheers;


C.W. Thomas







Sounds interesting, what kind of oil burner are you using?
Mike.