Casting video

[Commander_Chaos]

At 1:25 they appear to be painting the mould with something. Anyone know what it is?

https://youtu.be/6kcUJeg4Ifk

[lynnl]

I suspect it's a mold release spray. Something like this: https://www.amazon.com/Castin-Craft-.../dp/B008GUYMNW

(...maybe a more industrial-like version.)

[wierdscience]

Refractory coating, it stops metal penetration into the sand and makes for a better surface finish.

https://ha-international.com/pdf/Ref...OverviewV1.pdf

https://www.refcotec.com/products/refractory-coatings

[lynnl]

I thought the 1:25 meant a minute and 25 seconds. I quickly realized you meant 1 hr & 25 min, so I skipped ahead to that point, and didn't see the process of ramming up the mold.
When they were breaking out the casting, that mold sure looked far more substantial than just rammed sand. Did they add something, e.g waterglass to it to make it harder?
I know waterglass is used in making cores, with some gas (maybe CO2) shot through to harden it.

[Texasbowhunter]

Educational
Thanks for sharing
Paul

[camdigger]

At 1:25 they appear to be painting the mould with something. Anyone know what it is?

https://youtu.be/6kcUJeg4Ifk

I suspect that the sand is a CO2 cured product. Note at 32:30 and 1:14:00, they are injecting a gas, presumably to activate the sand binder. The spray at 1:25:00 is a type of refractory wash to prevent sand erosion and to improve surface finish.

There is no practical need for mold release in a one time use sand mold.

[Commander_Chaos]

I suspect that the sand is a CO2 cured product. Note at 32:30 and 1:14:00, they are injecting a gas, presumably to activate the sand binder. The spray at 1:25:00 is a type of refractory wash to prevent sand erosion and to improve surface finish.

There is no practical need for mold release in a one time use sand mold.

I'm almost ashamed to say that I've watched the whole thing more than on once, LOL. They were definitely hardening the mould as well as the cores with CO2. They hardened the sand in two stages, one with a long wand to get into the deep areas and once with a cup to get the accessable surfaces. It looked like they were using hardenable sand in place of facing sand and then ramming regular sand in behind it.



I'm going to go out on a limb and say they had done this before