I've had a go at it - I'm as incompetant at welding plastic as I am welding
steel. But it's no harder than welding steel if you have the right gear,
and the right filler rods, and someone who knows what they are doing show
you the method and the tricks. Isn't that how you get to weld steel too?
The big difference is that with plastic welding you are forcing a partly
melted filler rod into a heated and partly melted joint, which is quite
different from either arc or oxy welding.

And just like welding steel, if you have a lot to do it's worth buying the
right gear, getting someone to show you how to do it, and practising until
the results are OK. If it's a one-off job find someone who already knows
how to do it, and has the right gear.
David

"John" wrote in message
...
I've been planning to try some welded plastic fabrication, but I
haven't gotten around to it yet.

It's kind of like oxy-acetylene, using a "torch" and plastic filler
rods. The torch uses electric heat and compressed air to melt the
plastic at the joint and the compatible filler rod is introduced and
melted in.

this is the torch, from a well known US plastics vendor:

http://www.usplastic.com/catalog/pro...Super+Welde r

rods are available in many materials, including LDPE, HDPE, and PP

http://www.usplastic.com/catalog/pro...ne+Welding+Rod


Here is the same idea, from a noted seller of low cost, imported
tools;
http://www.harborfreight.com/cpi/cta...emnumber=41592
Notice the 1:10 price ratio.

I've tried the same concept using a propane torch, it works, but it
also introduces carbon into the joint, which probably doesn't do it
any good.

If anybody is experienced with this equipment and/or has hints on
technique, I'm all ears.

Best, John


On Mon, 1 Sep 2003 09:05:21 -0400 (EDT), (Ron
Thornton) wrote:

There is no reliable way to repair PE with glue, epoxy or otherwise.
The only way to repair it that will last is to melt it together. A
soldering iron may work on thin pieces but to get adequate penetration
in the kind of thickness I think we are talking here, you need more
heat. A heat gun with a funnel output or a plastic welding gun
(preferred) is needed.

Ron

"Brian D" wrote in message news:Igy5b.349237$uu5.69452@sccrnsc04...
I know the poly welders at work are a special breed. I was suggesting
taking it to a shop to have fixed. Polyethylene is a bear to do anything
with because nothing glues to it very well. Can't speak about the 'torch
it' first technique, which means I can't say it works or not. Sounds
interesting if it needs to be a DYI job, or an adhesive caulk, maybe with a
patch? Either way, I was talking about having a shop do the welding...

Brian


"Ron Thornton" wrote in message
...
Ultra sound is another way to heat the plastic. Not very practical for
the DIYer.

Ron


I think I'd give up on trying to weld the plastic yourself. PE needs
to be welded under inert gas.

-Kevin