Homebrew PCBs

markuszingg wrote:
> --- In Homebrew_PCBs@yahoogroups.com, Adam Seychell 
> <adam_seychell@y...> wrote:
> 
>>This weekend I played around with my hot air welder again, trying 
>>to get better  practice. I bought three types or welding rod, and 
>>small and large triangle type and a 3 mm round, each type comes 
>>in 50 rods per pack. I found triangle is the best. For 4.5mm 
>>sheet I use the larger triangle, for 3 mm sheet I use the small 
>>triangle rods. Practice on lots of scrap pieces and then try and 
>>break the weld when cooled. A *really* good weld will not break 
>>at the weld, but rather the sheet its self will break. The trick 
>>is to get the right temperature setting and nozzle distance from 
>>the work piece. There is a fine line between burning the plastic 
>>and not heating it enough to properly fuse. If the temperature is 
>>too low then it takes too long to melt the plastic and so too 
>>much heat transfers to the bulk of the material, which makes 
>>everything deform and then you cannot push hard of the rod. If 
>>the heat is too hot then it very easy to burns the plastic which 
>>contaminates it with carbon and produces a weak weld.
>>
>>Adam
> 
> 
> Hi Adam
> 
> The trick that I use is the hot air welding gun itself. It's 
> temperature is automatically controlled and it is having a digital 
> display showing the temperature which also can be used to set the 
> temperature requested. It then takes the gun probably 10 seconds or 
> so to reach a new temeparature level and it then stays there. This 
> really helps a lot in getting consistent good results.
> 
> Markus
> 
> 
> 

Do you have brand name / model number for the hot air welder 
you are using ? I have a Leister Tirac S
http://www.leister.com/english/html/inhalt/6_1_3.html
It does not have digital temperature readout.