That’s just Chinese borosilicate glass.
Do not use any borosilicate whatsoever above 250C. If you go above that stress will build up and is essentially garbage unless you anneal it again.
There are special circumstances when you can slightly bend the rules above but you need to know a lot about glass, and preferably a polarizer to do so safely
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On a side note, I just tried melting some 3mm boro from my local headshop(a basic tube for glasswork, trying to do my own basic stuff, so really cool you do that. would love to check out your work) with a propane torch, and I HARDLY got it hot enough after many minutes of direct blue flame tip to even get it pliable… I never did get it hot enough to blow a bubble into the bottom to give it some bouncy, since it straight sinks in distilled H20 lol. I did manage to get the bottom sealed at least XD (was trying to make my own hydrometer)
That’s great info, thanks mate!
I wonder how they get away with false advertising like that?
Seems lotsa people could or would be or maybe are getting hurt?
That is like. Lawsuit city, lol.
You need some oxygen too. We use propane and oxygen.
Quartz is amazing. You can get it red hot and drop it in water and it’s perfectly fine.
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I agree. I love me some quartz. And yes, after researching it seemed I’d need at least oxy/p to be more successful in my endeavor. I can’t afford that so just bought some 1mm boro hoping I could maybe at least pull that off with just propane.
That really confirms it, thank you. Sure you would have got a laugh out of watching me do this. I will try to take a pic of my embarrassment and send it later XD
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There’s also the issue of the stir bar degrading
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That has been stressing me out too. haven’t looked into super high temp bars. But I think I’ve seen people distill sulfuric acid with just the normal old bars?
You’ll need glass encapsulated stir bars. Samarian cobalt will work.
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One has to imagine it can be done without said magical aide…else one has to ask how the alchemists got their vitriol.
Presumably you’ve seen this?
Certainly the next trick the above is used for is to distill said vitriol sans stir bar…
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Yes. I have seen basically every video on homemade heating mantle making XD I WAS shooting for a hybrid between the one you posted and another with a pid and stirrer. Before I caved and got a premade 2l mantle and some stove rope ;p
But I do get the point you’re driving for. Thanks as always cyclo =D
If you use the correct mantle, setup and vacuum system you can drive that temp of sulfuric acid right around 300c under vacuum. Your earlier estimation is in open atmosphere essentially. Under vacuum that number decreases alot.
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I’m only able to pull a soft open loop vacuum using a medical skin care device I found at a goodwill on sale for 7 dollars… Lol.
I wish I had a heavy duty vacuum setup… life would be so much easier.
Really SUCKS not having vacuum. Ohh. get it? SUCKS? XP
Also can’t afford expensive vac grease, but do have Teflon ptfe tape but don’t think that would hold up at those temps.