Gluing perspex.
 

Anybody had success with gluing perspex ,I am thinking of making a lid for my Technics turntable.Thank.s Mick.

Re: Gluing perspex.
 

Talk to the Perspex suppliers - there is a special adhesive for it.

Re: Gluing perspex.
 

It used to be called Tensol, when ICI made it. The action is at least partly a solvent one, so it dissolves the acrylic which then resets, leaving a weld rather than a glue joint. If done carefully enough (joint surfaces machined cleanly, no air bubbles trapped in the joint) you can get a completely invisible joint this way.

With experience it's possible to achieve the same effect using pure chemical solvents. I seem to recall that dichloromethane works. I worked for a while in a chemistry lab where the graduate students built really professional looking perspex boxes to cover their laser equipment. But they had easy access to solvents, the experience of colleagues who would help them and, most of all, the knowledge needed to keep themselves safe. I'd hesitate to recommend this approach to anyone who didn't have these things.

Cheers,

GJ

Re: Gluing perspex.
 

You can still get 'Tensol 12' for gluing perspex, but be sitting down when you see the price :

http://modelshop.co.uk/Shop/Adhesive...-500ml/ITM5062

For 'just' dichloromethane, see :

http://modelshop.co.uk/Shop/Adhesive...-500ml/ITM5061

There are doubtless other suppliers, this one is convenient for me as I can pick the stuff up rather than having to hang about for a parcel to come.

Re: Gluing perspex.
 

it would appear cyanacrolate ( superglue ) can also be used, although it tends to bloom on clear plastic surfaces

https://en.wikipedia.org/wiki/Poly(m...g,_and_joining

Re: Gluing perspex.
 

:idea:
I haven't tried this for a long time, so I stand to be corrected, but I do believe that if you take chips of Perspex and dissolve them in acetone, you get an effective Perspex adhesive.

Al.

Re: Gluing perspex.
 

I've chloroform is a good solvent for chemically welding it together, but understandably hard to obtain.

Re: Gluing perspex.
 

Tensol 12 is perfect for Perspex, and with care, the joints will be invisible.


Be aware that this chemical is dangerous. Work outside, or in a GOOD airflow, otherwise you will be overcome by it vey quickly.


Kevin

Re: Gluing perspex.
 

In the days when I was an analytical chemist, we used chloroform to make perspex pieces of equipment. Scheduled poison nowadays I expect.

Re: Gluing perspex.
 

I remember reading in a book on rail modelling that you will have to sign the poisons register when buying some, I'm not sure if even that is allowed these days.

Re: Gluing perspex.
 

“Plastic Weld” works well. It’s readily available from model shops but is very runny, needing close fitting joints to “wick” in. I think it is dichloromethane.

Re: Gluing perspex.
 

Many years ago I glued a piece of flat perspex to a cylinder of it and I seem to remember using modeller's glue - the stuff that people use to assemble model airplanes etc.
Another adhesive that may be worth trying is PVC solvent - the stuff used by plumbers for joining waste pipe and elbows etc together.
Try some on a scrap piece of perspex first.

Re: Gluing perspex.
 

Tensol 12 as previously mentioned is designed specifically for this job and is the one to use. Getting a nice clean transparent join is not easy to achieve especially if you don't do this sort of thing every day. I found myself in exactly this situation a couple of years ago when I wanted a perspex lid for my own turntable. After much thought and several attempts at cutting the perspex cleanly and accurately (jigs, routers, super sharp cutters etc.) it became obvious that I wasn't going to get a decent result without using a lot of time and Perspex!
I found a superb company in Bootle Liverpool who make Perspex fabrications all the time and do display cases for shops, museums and the like. They have also made many turntable lids for people over the years and to be honest the cost was less than my buying the perspex and the Tensol 12 but, more importantly they did an unbelievable job.

I'm sure there will be a similar outfit in your area but if you want to check out the folks I used here's the details:

http://epsliverpool.co.uk/

Really helpful friendly people.

Cheers,
Steve.

Re: Gluing perspex.
 

These are the same substance - methyl ethyl ketone (MEK). They may well dissolve perspex but I think the chlorinated solvents work better.

One thing to bear in mind is that extruded acrylic sheet usually comes with significant stress in its surface layers as a result of the way it's made. A consequence of this is that solvents with a high vapour presure can very easily cause localised crazing of the surfaces. Acetone is dreadful for this. I've seen very expensive laser safety goggles, made of custom acrylic, destroyed simply by someone opening an acetone bottle nearby and leaving the top off. Since MEK is another ketone I think using it might be risky. If you have a large temperature-controlled box then you can anneal the surface stress out of perspex. But there is then a risk of the sheet deforming during the annealing process (voice of experience speaking here).

I would certainly second Steve's recommendation that you talk to a specialist fabricator. They can be surprisingly cheap, especially if you want a 'standard' size (don't forget to check how far any counterweight at the back of the tonearm moves) and they will almost certainly be cheaper than you teaching yourself how to do it.

Cheers,

GJ