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Repair Burnt Out HF Plastic Welder?

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vtsteam:
Here's a pic of all the pieces in the torch. This one is considerably simpler and more compact than more recent offerings in hot air plastic welders. New ones seem to have a built-in fan, Understandable because of the mistake/burn-out problem. But I prefer this simpler and more compact welder.

Its only need is a compressed air source. The actual air requirements are very low, and this unit came with an auxiliary 15 psi regulator (1 bar) for adjustment. If I recall correctly the actual welding pressure was around 2 psi, with the router controller turned down substantially for lower heat. Out of the box it was way too hot for clean welds.

awemawson:
I have a Leister Triac Heat Gun that I bought at a boot fair at least 20 years ago  and it's still working. I first came across them when we had some industrial flooring laid at work and the contractor was welding the vinyl sheets together and it worked superbly.

Just a 'hair drier on steroids' - various diameter nozzles - variable speed air blower - quite controllable. Loads of used ones on ebay at very modest prices so not worth making one and messing with hand held mains devices in my view.

I also have a Chinese 'hot air gun' that is perfectly capable of melting plastics (including itself!) that I use for heat shrink tubing amongst other things.

Mending yours Steve: if you can isolate the broken coil and short it out and feed the rest with 6/7th of it's rated voltage (103 volts in your case) from a transformer you should be good to go.

vtsteam:
Andrew, since I use a speed controller with it, anyway would it still require a transformer?

awemawson:
Well that depends on all sorts of things Steve !

Dropping the volts means that you know that you're not going to expend too much power in it and melt things unintentionally. Your speed controller may achieve to same end if it's range is suitable

John Rudd:
The speed controller could be modified to prevent too high a voltage being applied….

Usually these things are just a phase angle triggered thyristor circuit, so by adding a value to the charging resistor will effect the output voltage at max output….you can try by using a filament bulb as a load and measuring the max voltage developed across it….

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