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-   -   Joining polycarbonate /Perspex panels to make a case? (https://www.vintage-radio.net/forum/showthread.php?t=141696)

Al (astral highway) 28th Nov 2017 2:47 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
Quote:

I heard that chloroform was a good solvent for chemically welding perspex...!
8-o

emeritus 28th Nov 2017 6:15 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
I have a 57ml ( = 2 fl.oz) bottle of "Plastic Weld" cement that I got from a stand at a model railway exhibition a year or so ago. It consists of Dichloromethane (Methylene Chloride), and Perspex is one of the plastics that it is stated to be suitable for welding. I have only used it on Polystyrene.

Skywave 28th Nov 2017 7:01 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
Quote:

Originally Posted by Richard_FM (Post 995053)
I heard that chloroform was a good solvent for chemically welding perspex, though very hard to obtain & use!

"Very hard to obtain". Indeed: there are excellent reasons for that! :devil:

Al.

Richard_FM 28th Nov 2017 7:25 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
It was mentioned in Cyril Freezer's book of 1001 Model Railway Tips.

Even when it was written it mentioned you had to sign the poisons register to obtain it.

It can be potentially deadly even in the right hands!

mark_in_manc 28th Nov 2017 8:23 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
You've reminded me there's a bottle at work, originally for that purpose. It's probably been there 30 years. My boss didn't know what was in it, and gave it a sniff...

[Off topic - of a similar vintage we also had several brown 1 litre laboratory bottles of Gallenkamp's finest 'Oil, Olive B.P.'. These were surplus, and I've been topping up the wife's flashy 'extra-virgin' bottle when her back has been turned for the last year or so. She doesn't seem to have noticed we have Italy's answer to the magic porridge pot.]

ColinTheAmpMan1 1st Dec 2017 8:08 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
A few points here. A bottle of chloroform that is 30 years old could have degraded and/or evaporated during that time. Chloroform is usually stabilised with ethanol or amylene these days to prevent degradation. If your boss was daft enough to take a sniff of something in the bottle without knowing what it was, he is a fool, to say the least. Was there nothing on a label to inform him?

With regard to the poisons register, I don't think there has been such a thing for some time. There again, in my day-job before I retired, I was in a research group at Imperial College, London and we used quite a lot of chloroform - there again we were in an academic environment and educated people.

If I were you, Marc, I wouldn't use that Gallenkamp olive oil for anything culinary. Again, after 30 years it has a good chance of having degraded by oxidisation or polymerisation. The "BP" designation means that it was meant for pharmaceutical purposes anyway. "BP" is "British Pharmacopia" and indicates that.

On principle, I wouldn't take anything out of a workshop or laboratory and use it for a culinary purpose. How do you know that it isn't impure? That might mess up any experiments that you might use it for, but consuming it might do a lot more damage.
Colin.

RojDW48 2nd Dec 2017 3:50 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
Quote:

Originally Posted by Richard_FM (Post 995053)
I heard that chloroform was a good solvent for chemically welding perspex, though very hard to obtain & use!

Quite right - it is known as Chloroform welding. Believe it or not I used to teach the technique to children (!) as part of their D&T course when I was a teacher in secondary school - carefully of course, and in a fume cupboard in a science lab. It works very well and is invisibly neat, but the surfaces have to mate perfectly - it won't 'fill' at all.

I am fairly sure it won't work with Polycarbonate.

G6Tanuki 3rd Dec 2017 4:31 pm

Re: Joining polycarbonate /Perspex panels to make a case?
 
Quote:

Originally Posted by ColinTheAmpMan1 (Post 996025)
On principle, I wouldn't take anything out of a workshop or laboratory and use it for a culinary purpose. How do you know that it isn't impure? That might mess up any experiments that you might use it for, but consuming it might do a lot more damage.
Colin.

This is wise indeed: though I do have fond memories of working in an undergrad biochemistry-lab and being amused at the supervisors quaffing their coffee from 250-millilitre beakers and stirring in ANALAR reagent-grade sucrose because they were too mean to buy their own sugar!


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