Release agent question

Home enthusiasts discuss their Foundry & Casting work.

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GlennW
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Re: Release agent question

Post by GlennW »

I use release agents from Miller-Stephenson.

It may be worth a phone call, as they have them for many applications.

https://miller-stephenson.com/chemicals ... se-agents/
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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Harold_V
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Re: Release agent question

Post by Harold_V »

Are you doing foundry work now, Glenn? (I'm curious about your use of release agents)

H
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jscarmozza
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Re: Release agent question

Post by jscarmozza »

Thanks for the new supply source Glenn, I'll keep that. Right now the silicone appears to be working fine, I think my sodium silicate solution is way past it's shelf life at over 3 years old. After my last post I made two more simple cores, one using the 5% by weight ratio and the other a richer mix, both crumbled like the wheel core so the binder must be the problem.
John
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GlennW
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Re: Release agent question

Post by GlennW »

Harold_V wrote: Wed Dec 09, 2020 2:46 amAre you doing foundry work now, Glenn? (I'm curious about your use of release agents)
I haven't delved into the foundry world as of yet. I use release agents with structural epoxies occasionally.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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Harold_V
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Re: Release agent question

Post by Harold_V »

GlennW wrote: Wed Dec 09, 2020 9:12 pm
Harold_V wrote: Wed Dec 09, 2020 2:46 amAre you doing foundry work now, Glenn? (I'm curious about your use of release agents)
I haven't delved into the foundry world as of yet.
It's a strange and fascinating world, and has always held my attention, although I never had a desire to work in a foundry. I hope to acquire the necessary skills to cast on a hobby basis, though.
I use release agents with structural epoxies occasionally.
That's in keeping with what I imagined, as I don't recall you ever talking about foundry work.
Thanks!

H
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GlennW
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Re: Release agent question

Post by GlennW »

I remember doing foundry work in High School making some aluminum castings in metal shop class, but that's about it. Couldn't even imagine that sort of thing going on in today's world.

I don't think I could deal with another "hobby" right now! I've got 10,000 square feet of things to do and there is only two of us doing it.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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Harold_V
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Re: Release agent question

Post by Harold_V »

GlennW wrote: Thu Dec 10, 2020 8:46 pm I remember doing foundry work in High School making some aluminum castings in metal shop class, but that's about it. Couldn't even imagine that sort of thing going on in today's world.
You got that right!
A lot of the equipment I have is due to our government deciding that we, as a nation, were above working with our hands, so they decided to abandon the industrial arts programs in pretty much all schools. After all, doesn't everyone want a formal education (with due respect to those who have one)? As a result, all of the shops in the Jordan School District closed, with the equipment auctioned off. Good for me, as I ended up with some outstanding buys, a power riddle, foundry bench, pyrometer, about a dozen crucibles, some still unused, crucible shanks, and a large number of flasks, both aluminum and steel, of various sizes, and lots of other things needed for a small foundry. Not so good for us as a nation, however, because now there's almost nowhere a kid can learn anything that might lead to a cut or a bruise.
I don't think I could deal with another "hobby" right now! I've got 10,000 square feet of things to do and there is only two of us doing it.
Good to hear you're staying busy, my friend.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
jcbrock
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Re: Release agent question

Post by jcbrock »

Hope this isn't too far afield of the thread origin, but one place to find foundry intro is the art world. My son has been taking classes at the Chicago Fire Arts Center in Minneapolis https://cafac.wildapricot.org/classes/metalcasting/. Another arts organization in SE Minn has an annual iron casting workshop. I'd think there has to be something similar here in the PNW, although I admittedly haven't done any research.
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NP317
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Re: Release agent question

Post by NP317 »

jcbrock wrote: Fri Dec 11, 2020 7:40 pm Hope this isn't too far afield of the thread origin, but one place to find foundry intro is the art world. My son has been taking classes at the Chicago Fire Arts Center in Minneapolis https://cafac.wildapricot.org/classes/metalcasting/. Another arts organization in SE Minn has an annual iron casting workshop. I'd think there has to be something similar here in the PNW, although I admittedly haven't done any research.
University of Washington in Seattle had a serious fire arts department and facilities, when I left in 2009.
A look at their online webpages should provide more information.
Two pics attached of the iron castings done there by one of my graduate students. He also designed and cast a large steam beam engine that ran on air, operating a 12" diameter knitting machine making large knit tubes that stretched through a local museum for many months. Incredible work.
RussN
1 ROSETTE BOBBIN.jpg[/attachment ][attachment=0]4 FIVE YEAR PLAN.jpg
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jscarmozza
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Re: Release agent question

Post by jscarmozza »

After going through a half dozen different core recipes, I went back to my simple oil sand mix. I was getting very frustrated with my lack of success and would have given up if it wasn't that one time one part of the core would come out and the next time another part would come out, so I figured sooner or later the whole thing has to come out...and did. What I found out was that I was packing the mold too tight! Pounding the oil sand mix into the mold was the problem, light packing was the answer. Oil sand has almost no green strength until it's baked, so I figured packing it tight would help it stay together, it didn't. Light packing and gentle handling of the green cores was the trick. As far as the release agent, I used baking flour to dust the core box before filling. I got 12 nice cores for my Heisler wheels.
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Harold_V
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Re: Release agent question

Post by Harold_V »

Well done!
In regards to hard packing, seems to me a light packing would be desirable, so the core breaths freely. Likely to break out better after pouring, too.

I can't help but wonder about the use of flour for parting. It tends to get sticky, which would be opposite the desired result. Not having done any of this, what are your thoughts on using parting that is used in ramming sand molds? Seems to me it might work a little better.

Of what metal will your wheels be cast?

H
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jscarmozza
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Re: Release agent question

Post by jscarmozza »

Hi Harold, I'm going to make brass wheels and add steel tires, I experimented with this technique and it seemed to work pretty well.
At first I tried silicone spray as a release agent with the sodium silicate core, it released fine but my sodium silicate was no longer any good. Then I tried a variety of core mixes using sand, flour, molasses, water, oil to no avail, with these core mixes I tried the silicone spray again, graphite, talc and flour as release agents, nothing worked. I had done this before with a different wheel pattern and after a similar string of failures I got it, the question was now what did I do? So I went back to an old post on this site and a conversation with Big Dave on the matter which brought me back to my basic oil sand core mix and baking flour release agent technique. Once I got the packing procedure correct I was good to go. Before I started I washed out the mold with alcohol to get all the residuals out of it and let it dry over night, but from then on I just dusted it with flour before each filling. Weather permitting I'm planning to pour next week, my pours are now weather dependent as I have to move stuff out of the garage to make room, the pantograph took up my pouring floor space:)
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