Thread: Gluing Perspex

Thinking about this and AS IT APPLIES TO LUCITE OR PLEXIGLASS. (Upper case for emphasis) I have glued Lucite using Super Glue or Cyanoacrylate. This was back when Cyanoacrylate was only sold commercially as 'Eastman 910'. The big thing is that the two surfaces must be in perfect contact. Much like when you are using chloroform as the glue.

The Cyanoacrylate is incredibly water proof. One evening after dinner SWMBO and I were spinning Melamine dinner plates on the dinette table while drinking beer. (Don't go there!) One of the plates rolled off the dinette table and split in half. I brought some Eastman 910 home from work and glued the Melamine plate back together. We used that plate for another 5 years or so and even ran the plate through the dish washer on a regular basis.

True Perspex is polycarbonate if you are using acrylic then just use clear wet area silicone

Originally Posted by China

True Perspex is polycarbonate if you are using acrylic then just use clear wet area silicone

I think you should check your facts, old mate. The trade name Perspex was first registered by ICI in 1950 although the material itself was developed in 1934. It is described as polymerised methyl methacrylate i.e. "acrylic".

Linear polycarbonate was developed by Bayer in 1953 and trade named Merlon and later Makrolon.

Thanks for the silicone tip.

mick

Originally Posted by China

True Perspex is polycarbonate if you are using acrylic then just use clear wet area silicone

Just clearing up a few terms here folks.

Perspex is a "trade name" for poly-methyl-meth-acrylat (PMMA), with a formula of (C₅O₂H₈)_{n ,} other trade names for PMMA are Lucite and Plexiglass.
Most plastic shops will also call this acrylic.

There are various forms of Polycarbonate (PC) but the main one is a polymer of C₁₆O₅H₁₈- note the different C-O-H ratios to PMMA
"Acrylic" is a generic term that applies to any material made from acrylic resins, it includes Paints, fabrics, and plastic sheet goods like PMMA and PC.

The main differences between PMMA and PC is that PC has a higher impact resistance, is less brittle and can be formed into 90º bends at room temperature. 2
Regular PMMA is cheaper and has a higher scratch resistance than regular PC.
PC safety glasses and MC helmet visors undergo a special treatment to make them more scratch resistant.

The photo shows a TS guard I made using PC sheet folded at room temperature attached to a thick piece of PMMA (Perspex)
The PC is slightly yellow because it is around 34 years old and came out of the first clean laboratory I built at work.
That lab was was demolished in 2002 and the most of the insides of that lab ended up in a skip and I managed to rescue some pieces of the PC.

G'Day Mick, I used to buy polycarbonate and the tube of glue to join it for use in the pharmaceutical industry from Dotmar Engineered Plastics...
Dotmar - Australia's Leader in Engineering Plastics | Acrylic, Polyurethane, Polycarbonate, PVC, HDPE and More
If all else fails, maybe a phone call on Monday to them.
Cheers, Peter

Information was given to me by a plastic wholesaler years ago I have never had any reason to substantiate it thanks for putting me right

If you flame treat an edge it will not glue, DAMHIKT.

Chris,
Is there a reason flamed edges won't glue? I never tried to glue a flamed edge but I find your caution exceptionally interesting and I will certainly avoid trying to glue flamed edges.

Originally Posted by rrich

Chris,
Is there a reason flamed edges won't glue? I never tried to glue a flamed edge but I find your caution exceptionally interesting and I will certainly avoid trying to glue flamed edges.

My question would be - why wuuld you want to flame an edge which you are going to glue?

Originally Posted by rrich

Chris,
Is there a reason flamed edges won't glue? I never tried to glue a flamed edge but I find your caution exceptionally interesting and I will certainly avoid trying to glue flamed edges.

TBH I have no idea as it was something I found out by accident because from memory I was not specifically looking for it after I built a dust shroud and it appeared to glue OK using acetone and the parent material then fell apart when it was used.

Doug, the reason I did it was that I had tried flame polishing and had no problems at all doing it using a small Oxy tip so I happily did it all because it looks so good and appealed to my OCD! Pat Warner who used to build the most beautiful jigs, art really, for routers and who unfortunately passed away late last year was a genius with this stuff and I always wished I could have had a chat with him and learned his techniques.

Originally Posted by Chris Parks

If you flame treat an edge it will not glue, DAMHIKT.

Flame treatment produces a very thin layer of decomposed polymer that contaminates the joint and hence won't bond as effectively as untreated polymer.
If that layer is sanded or scraped off it will then bond like unheated polymer.
The same applies to some other polymers and heated bending and welding.
I never tested whether a hot air gun was better than a flame but I suspect it would be the same.

Selleys produce an All Plastics glue which I have found to be effective on all plastics I have tried - including polycarbonate.