make sand or clay for castings

[ruben]

hello

Good afternoons
I wanted to make casting mold sand that is like petrobond, red in color, and oil-bonded

a question (I don't know if it's a stupid question)
If I change the bentonite clay for natural red clay the color will change like the petrobond

thank you

 

[Fidlstyks]

hello

Good afternoons
I wanted to make casting mold sand that is like petrobond, red in color, and oil-bonded

a question (I don't know if it's a stupid question)
If I change the bentonite clay for natural red clay the color will change like the petrobond

thank you

Red Petro Bond is sold on eBay and Amazon as Jewelry Sand. Red sand is also sculpture sand. I buy coffee can size containers at a Jewelry Supply in Dm Ia. I think $15 for a gallon size. I cast brass builder plates in it.

If feels soft and pliable while spongy to handle.
The other red sand we had was Albany sand. I think from Albany NY.
It was a fine grain sand we used with aluminum with a clay percentage just right for water base molding.
Petrobond mix is also discussed in the other thread. The clay has a differnet flake form that works with oil.
I would look for a local Sculpture Foundry. They may have bulk size at, $15 per pound on line, it would prove costly.

 

[wce4]

hello

Good afternoons
I wanted to make casting mold sand that is like petrobond, red in color, and oil-bonded

a question (I don't know if it's a stupid question)
If I change the bentonite clay for natural red clay the color will change like the petrobond

thank you

Why are you asking the same question that you post in Engine from Castings? Did you not see the response from SmithDoor and myself about how to make petrobond sand ?

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[GreenTwin]

Response was posted here:

https://www.homemodelenginemachinist.com/threads/make-sand-for-castings.36889/

.

 

[Fidlstyks]

Why are you asking the same question that you post in Engine from Castings? Did you not see the response from SmithDoor and myself about how to make petrobond sand ?

​

Looks like from the post dates he posted both the same day.
I found some of the answers in the other thread not quite as I understnd it.
The Red Petro Bond sand is Jewlers Sand.
It does not turn from red to black, but may get darker with burning. All my black Petro Bond does not start red anyway.
I use 93% Walmart Isopropyl alchohol for a catalyst. But it is designed with propylene carbonate as wce4 stated, but that is expensive.
The clays can be both be red for Petrobond, or Albany sand, but as I understand, cannot be exchanged.
Petrobond clay is special. The smallest form is as flakes and are different.
Oil in regular Bentonite repells oil.