Sciencemadness Discussion Board

Steel/Glass Interface

DFliyerz - 9-6-2015 at 12:23

I'm planning to try a distillation that involves molten sodium hydroxide, which would obviously destroy a glass RBF. What's a good way to get an interface between ground glass and stainless steel, or does a company make stainless steel RBFs?

aga - 9-6-2015 at 13:00

This was a surprising find :-

http://catalog.hsmartin.com/viewitems/round-bottom-stainless...

blogfast25 - 9-6-2015 at 13:01

Your best bet might be like a female (steel) / male (glass) ground glass type of joint. Not easy, I know. But a permanent, bonded glass/steel joint would be very hard due to different thermal expansion coefficients, I think. Or a ball joint type of link...

Can you elaborate on your actual purpose?


[Edited on 9-6-2015 by blogfast25]

BromicAcid - 9-6-2015 at 13:05

For my attempts at CS<sub>2</sub> I took a female 24/40 joint and inserted it into a reducing adapter for a steel pipe. I used fireplace cement which is mostly silicates (and bonds well to glass) to fill in the gap around the glass between the steel and then 'fired' it in my oven. When it was done I screwed it on top of lengths of pipe whenever I needed a connection to my glassware. If you don't have a female 24/40 joint give it time, something will break eventually.

sulfurcondenser3.jpg - 59kB

smaerd - 9-6-2015 at 13:13

I can also vouch for fireplace putty.cement. It does what it's supposed to do, withstand high temperatures and create a seal. I have no idea how it would handle at molten NaOH temperatures but a small scale test could be done and its very cheap.

blogfast25 - 9-6-2015 at 13:46

Quote: Originally posted by smaerd  
I can also vouch for fireplace putty.cement.


How do you apply it?

Funkerman23 - 9-6-2015 at 14:19

No kidding! I figure they won't sell to us amateurs but it couldn't hurt to ask. Those wound be very handy to have...
Quote: Originally posted by aga  
This was a surprising find :-

http://catalog.hsmartin.com/viewitems/round-bottom-stainless...

smaerd - 9-6-2015 at 14:35

blogfast25 - it's just a gummy solid. When I used it I was destructively distilling sodium benzoate in a coffee can. I just gooped it around the interface liberally. Didn't read the instructions I don't think there is a setting time or anything.

Zombie - 9-6-2015 at 17:09

There are a lot of 1400^f ceramic epoxies as well. They will remain flexible enough to tolerate differing expansions.

Just google High temp Epoxy. I use them very often in engine porting, and they hold.

blogfast25 - 9-6-2015 at 18:12

Zomb, if it survives the savagery a Nooow Yank Hillbilly undoubtedly puts his death by speeding on wheels machines through, it'll probably be good enough for my humble causes! :D:D:D

Zombie - 9-6-2015 at 19:15

Very likely indeed sir.

DFliyerz - 10-6-2015 at 12:39

I think I'll definitely take this approach, especially considering that I have a three-way adapter with the bottom male part broken off. Boy, am I glad that I saved that now!