Welding Plastic

[ebee]

Hello,
I hasve some clear perspex type tube about 75mm dia.
I want to cut it and join it to form a "U" that will be watertight (don`t ask why). Any ideas!

Thanks

 

[Diyisfun]

Chloroform, is a solvent for PERSPEX, as long as it is perspex.

When I worked in developement, we often made mock ups using perspex.

You will need a syrinx also.

You can get them from a dispensing chemist.

You may have problems being supplied with the items, if you are a company a piece of headed paper with your request may work for you. It did for us.

Super glue will also work..

or look here
http://www.google.com/search?q='per...ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7GGLJ_en

 

[ebee]

Thanks for the reply.
When I say Perspex I mean clear plastic, I might have a problem getting Chloroform (well I hope so anyway). Super glue sounds worth trying.

 

[Burnerman]

You really need to identify which plastic you are trying to glue, but acrylics respond well to Tensol Cement, available from K&M Wholesale, Sheffield, or local plastic suppliers. Cheers John

 

[dextrous]

Hello,
I hasve some clear perspex type tube about 75mm dia.
I want to cut it and join it to form a "U" that will be watertight (don`t ask why). Any ideas!

You can buy the thing you're trying to manufacture quite discretely you know

 

[Deleted member 105431]

solvent cement from a plumbers merchant.

 

[ColJack]

what kind of radius are we talking about in the "U bend"?

and for what?

you might be able to get a glass U bend made if you ask the right people...

 

[JohnD]

you can soften Perspex enough to bend it, with heat. I have an idea it is just above 100C but you can look it up. A domestic cooking oven will do iit.

You will have a problem preventing the tube from collapsing when you bend it. I suppose fill it up inside with something.

I have only bent flat 10mm perspex sheet, to make screens for a m/bike.

You can protect it with paper to prevent it sticking to whatever you are heating or holding it with

 

[mattylad]

Funny, I'm sure that I replied to this thread a couple of days ago?

 

[JohnD]

Funny, I'm sure that I replied to this thread a couple of days ago?

Have you ever experienced Déjà vu?

 

[JohnD]

Funny, I'm sure that I replied to this thread a couple of days ago?

Have you ever experienced Déjà vu?

 

[ebee]

Thanks for the replies.
Yes I wanted to make a U (or an N really) and as I have a straight piece I thought the simplest way might be two cuts at 45 degrees then turn around and and fix together.

I did say don`t ask why .

Well it`s for flying fish.

Two tanks filled with water and connected by a loop filled with water going up then accross then down. As the fish were swimming thru this tube they would be above the water level of the two tanks , therefore "flying fish"

 

[Diyisfun]

As already said, Perspex is easy to bend, you can use a heat blower or put it in the oven.
If you make a wooden tool /former make certain that the edges are not sharp.
Over bend it by a few degrees & it will return a few degrees

 

[regsmyth]

I'd have thought that trying to bend 75mm dia tube without some really good setup of formers etc would not be possible, or at the very best would have a very uneven and unnattractive surface shape.
I think you're best using straight cuts as you suggest. If the tube is PVC, then solvent weld from a plumbers merchant would be ideal. It also does ABS I believe, and possibly acrylic, so make sure you know what it is you're using.
But I think a butt weld won't be strong enough, and that the join would need "sleeving" for strengthening, which would also hide the mess that the join would look like.
See if you can buy anything, or use flexi pvc tube instead. This will be thick walled, and you still have to work out how to fix it at each end. Big jubilee clip I guess.
All the best.

 

[wotan]

Ebee wrote: Two tanks filled with water and connected by a loop filled with water going up then accross then down. As the fish were swimming thru this tube they would be above the water level of the two tanks , therefore "flying fish". .Would they not be 'Syphon assisted fish' in the true sense flying means in free air.

Wotan