building a plastic welder.

[savarin]

I didnt know where to post this so thought I would try here.
I have some plastic (HDPE) welding to do but not really enough to warrant buying a piece of equipment for $160+ that wont be used much.
I have a hot air gun (cheap, like me) and though that I could make a new nozzle for it to concentrate the air stream but have a fear this would constrict the flow so much the gun would overheat and blow the temperature fuse.
I thought that maybe if I cut a triangular shaped hole in the wide part of the nozzle before the restricted tip and cover it with a slide I could regulate the flow rate by using this as a by-pass valve thus keeping the original air flow through the gun hopefully preventing overheating of the element.
I have welded PE donkeys years ago so the actual process doesnt hold much mystique but wonder if the above would actually work in practice.
Thanks

 

[Sharky]

Here's a possibility:

http://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-96464.html

On sale for $49.99, I have one but have only used it a couple of times.... it did the job pretty well.

 

[ray hampton]

can this welder be use on PVC tubing and sheets of plexiglass , I thinking about using plexiglass to craft boxes to hold small tools

 

[Harvey Melvin Richards]

can this welder be use on PVC tubing and sheets of plexiglass , I thinking about using plexiglass to craft boxes to hold small tools

You can thermo weld PVC, but standard schedule 40 pipe is a little thin for someone with no experience. I don't think you can thermo weld plexi, although it can be solvent welded. If you need translucent, you can get PVC sheets that are translucent.

For small boxes, the best plastic would be ABS sheets and solvent welding. It makes a very strong joint.

 

[savarin]

Here's a possibility:

http://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-96464.html

On sale for $49.99, I have one but have only used it a couple of times.... it did the job pretty well.

Hmm, havnt seen that design here, guess I had better look harder. I hesitate to buy from the US as sometimes the shipping costs really boost
the price.

 

[savarin]

In for a penny in for a pound. I decided that as it was such a simple exercise to make the nozzle and test it I should give it a go.
Heres the nozzle with the bypass slider


on the cheap hot air paint stripper gun


This is the first test attempting to weld a strip of the plastic bottle to its base.
It stuck but did not actually fuse and pulled of quite easily.



For the second attempt I abraded the strip and the base where I was attempting to weld it.
A resounding success, totally fused and impossible to pull off. The black marks are from the pliers I used to pull the strip off.


Next test is to see if it cuts out or blows the thermal fuse after a period of time. I'm keeping my fingers crossed.
The job I want this for is to weld two blue plastic barrel halves into a trough.
The sections that are to be welded are relatively thick sections so will be a good test.

 

[savarin]

to continue,
it worked really well --- for 2 inches, a strong weld that wouldnt break apart.
BUT
the gun burnt out completely:angry:
back to the drawing board