Thread: Gluing Perspex

We used to use perspex shavings dissolved in acetone. It was a looong time ago and I can't remember whether the joint was clear or not.

Thanks Tony. I can't see any reason why it shouldn't be clear. I'll give it a try.

mick

I found this YouTube interesting when we were looking at using Perspex at work
https://youtu.be/hT6Ow_cBTps

There was also a good video showing the smoothing of the edges with a flame

I think the tech officer used Acrifix but i’m not sure which one and I’m not back to work for a few weeks.

Also, Weld-on 3 is also available in Australia and it works by capillary action so may give a clear joint?

We use chloroform at work and when OHS required us to stop using it we switched to acrylic cement.
I recommend using a hot air gun with a fine nozzle rather than a flame as it provides for a bit more leeway between a clear and a charred finish.
As usual practice several times before doing it on the real pieces

Try the local chemist (drug store) for the chloroform. If you're nice and honest about the use they may sell it to you.

I just had a horrible thought. What if I want to "weld" Lucite (Plexiglass) with chloroform? You guys in OZ are usually following the US in terms of environmental requirements. I probably couldn't find any chloroform anywhere in the country regardless of quantity.

Originally Posted by rrich

Try the local chemist (drug store) for the chloroform. If you're nice and honest about the use they may sell it to you.

I seriously doubt it. They probably don't even have it in their store and any they have, they would account for every last millilitre.

You cannot even purchase raw alcohol in Australia without a licence and have to keep strict records of dates, username, volumes, what it was used for.
At Uni we used it for special cleaning of electronic parts and had to sign off for any quantities we used. Once I accidentally left the top off a large bottle of alcohol and about 25 ml was lost due to evaporation and I got rapped over the knuckles for this. Today I believe they use IPA.

Originally Posted by Glider

The horizontal piece is 47 x 600 & the vertical is 500 x 600.

Mick what about getting a 547 x 600 piece with a 90° bend in it? This may make for less of a dirt trap in the corner (curved as opposed to sharp 90°). Acrylic suppliers use a gas torch to heat and soften and then bend, and are usually quite skilled at it, in my experience.

I'm assuming that the bend showing out is concave rather than convex.

Originally Posted by FenceFurniture

Mick what about getting a 547 x 600 piece with a 90° bend in it? This may make for less of a dirt trap in the corner (curved as opposed to sharp 90°). Acrylic suppliers use a gas torch to heat and soften and then bend, and are usually quite skilled at it, in my experience.

Unless you are really skilled this will put a bow in both pieces. If that is not a problem then no worries.

As usually practice everything first.

Yes, I am suggesting getting it done by a pro.

Originally Posted by BobL

Once I accidentally left the top off a large bottle of alcohol and about 25 ml was lost due to evaporation and I got rapped over the knuckles for this.

Nice one Bob

I used to do a lot of this work. Bending is easy and probably the best option imo. You use a heating element alongside two cooling elements to create a localised heated area. Then you simply fold the piece between two hard points set the appropriate distance apart on a flat base. It is important to hold it down while it cools to avoid bowing. You can't just fold it like a piece of paper. Gluing the jointed edge surfaces together (use a jointer), can be a bit of hit and miss by pros and amateurs alike. It is extremely easy to create a bubbled mess of a joint using acrylic cement. Sometimes you can fix it with a syringe loaded with thin cement, but sometimes the initial bond blocks the path needed for the thin cement to fill the bubbled cavitys.

Originally Posted by Kuffy

I used to do a lot of this work. Bending is easy and probably the best option imo. You use a heating element alongside two cooling elements to create a localised heated area.

At work we had a custom bender made using a 1.2 m long element mounted in an adjustable gap between two lengths of 30 x 30 mm Al square tubing that had water going through it and the perspex was held firmly clamped to the cooling tubes. I found that heating the perspex from one side left the other side too hard and by the time the other side was hot enough to bend the sheet bubbles had started appearing on the heated side. We tried flipping sheets over and alternately heating each side - this was OK for small pieces but harder for larger sheets. I finally worked out that heating the non-element heated side with a hot air gun with a fine nozzle delivered enough heat for it to bend. HD clamping was needed otherwise there was always a small bow in the bend In fact I don't recall getting any bend longer than about 250 mm dead flat..

Originally Posted by rrich

You guys in OZ are usually following the US in terms of environmental requirements.

Considering the latest policy changes, I certainly hope not.

mick

Originally Posted by FenceFurniture

Mick what about getting a 547 x 600 piece with a 90° bend in it? This may make for less of a dirt trap in the corner (curved as opposed to sharp 90°). Acrylic suppliers use a gas torch to heat and soften and then bend, and are usually quite skilled at it, in my experience.

I'm assuming that the bend showing out is concave rather than convex.

Good point about a radiused corner Brett, but it'll go into the dishwasher on a 50C eco cycle. Anne wants to keep the Perspex screen as unobtrusive as possible. The splashback and bench is marble with a 90 degree intersection. She's design and operations whereas I'm only logistics and a downstream consumer.

I'm going to try Tony's acetone suggestion and see how I go, especially as it'll evaporate very quickly.

It's somewhat ironic that chloroform is strictly controlled but I could probably obtain other chlorinated hydrocarbons like tri and perchlorethylene and possibly even carbon tet. without difficulty despite their nasty toxicity.

mick